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library(tidyverse)
library(patchwork)
library(seacarb)
library(marelac)
library(metR)
library(scico)
library(lubridate)
library(zoo)
library(tibbletime)
library(sp)
library(kableExtra)
library(LakeMetabolizer)
library(rgdal)
library(ggnewscale)

1 Scope of this script

  • Analyse field data recorded on board SV Tina V
  • derive a best guess estimate for net community production (NCP)

2 Sensor data

2.1 Data preparation

Profile data are prepared by:

  • Ignoring those made on June 16 (pCO2 sensor not in operation)
  • Removing HydroC Flush and Zeroing periods
  • Selecting only continuous downcast periods
  • Gridding profiles to 1m depth intervals
  • removing grids with pCO2 < 0 µatm (presumably RT correction artifact after zeroing)
  • Discarding profiles with 20 or more observation missing within upper 25m
  • assigning mean date_time_ID value to all profiles belonging to one cruise
  • discarding “coastal” station P01, P13, P14
  • Restricting profiles to upper 25m

Please note that:

  • The label ID represents the start date of the cruise (“YYMMDD”), not the exact mean sampling date
tm <-
  read_csv(
    here::here(
      "data/intermediate/_merged_data_files/response_time",
      "tm_RT_all.csv"
    ),
    col_types = cols(
      ID = col_character(),
      pCO2_analog = col_double(),
      pCO2_corr = col_double(),
      Zero = col_character(),
      Flush = col_character(),
      mixing = col_character(),
      Zero_counter = col_integer(),
      deployment = col_integer(),
      lon = col_double(),
      lat = col_double(),
      pCO2 = col_double()
    )
  )


# Filter relevant rows and columns
tm_profiles <- tm %>%
  filter(type == "P",
         Flush == "0",
         Zero == "0",
         !ID %in% parameters$dates_out,
         !(station %in% c("PX1", "PX2"))) %>%
  select(date_time,
         ID,
         station,
         lat,
         lon,
         dep,
         sal,
         tem,
         pCO2_corr,
         pCO2,
         duration)

#calculate mean location of stations
stations <- tm_profiles %>% 
  group_by(station) %>% 
  summarise(lat = mean(lat),
            lon = mean(lon)) %>% 
  ungroup() %>% 
  mutate(station = str_sub(station, 2, 3))


# Assign meta information
tm_profiles <- tm_profiles %>% 
  group_by(ID, station) %>% 
  mutate(duration = as.numeric(date_time - min(date_time))) %>%
  arrange(date_time) %>% 
  ungroup()

meta <- read_csv(here::here("data/input/TinaV/Sensor",
                            "Sensor_meta.csv"),
                 col_types = cols(ID = col_character()))

meta <- meta %>% 
    filter(!ID %in% parameters$dates_out)

tm_profiles <- full_join(tm_profiles, meta)
rm(meta)


# creating descriptive variables
tm_profiles <- tm_profiles %>% 
  mutate(phase = "standby",
         phase = if_else(duration >= start & duration < down & !is.na(down) & !is.na(start),
                         "down", phase),
         phase = if_else(duration >= down  & duration < lift & !is.na(lift) & !is.na(down ),
                         "low",  phase),
         phase = if_else(duration >= lift  & duration < up   & !is.na(up  ) & !is.na(lift  ),
                         "mid",  phase),
         phase = if_else(duration >= up    & duration < end  & !is.na(end ) & !is.na(up   ),
                         "up",   phase))

tm_profiles <- tm_profiles %>% 
  select(-c(start, down, lift, up, end, comment, p_type, duration))


# select downcast profiles only
tm_profiles <- tm_profiles %>% 
  filter(phase %in% parameters$phases_in)

# grid observation to 1m depth intervals
tm_profiles <- tm_profiles %>%
  mutate(dep_grid = as.numeric(as.character(cut(
    dep, seq(0, 40, 1), seq(0.5, 39.5, 1)
  )))) %>%
  group_by(ID, station, dep_grid, phase) %>%
  summarise_all("mean", na.rm = TRUE) %>%
  ungroup() %>%
  select(-dep, dep = dep_grid)

# Remove zero pCO2 data
tm_profiles <- tm_profiles %>%
  filter(pCO2 >= 0)


# subset complete profiles of stations not included in analysis
profiles_stations_out <- tm_profiles %>% 
  filter(station %in% c("P14", "P13", "P01"))

profiles_stations_out_in <- profiles_stations_out %>% 
  filter(dep < parameters$max_dep_gap,
         phase == "down") %>% 
  group_by(ID, station) %>% 
  summarise(nr_na = parameters$max_dep_gap/parameters$dep_grid - n()) %>% 
  mutate(select = if_else(nr_na < parameters$max_gap,
                          "in", "out")) %>% 
  select(-nr_na) %>% 
  ungroup()

tm_profiles_stations_out <- full_join(profiles_stations_out_in, profiles_stations_out)
rm(profiles_stations_out, profiles_stations_out_in)


# subset complete profiles of stations included in analysis
tm_profiles <- tm_profiles %>% 
  filter(!(station %in% c("P14", "P13", "P01")))

profiles_in <- tm_profiles %>% 
  filter(dep < parameters$max_dep_gap,
         phase == "down") %>% 
  group_by(ID, station) %>% 
  summarise(nr_na = parameters$max_dep_gap/parameters$dep_grid - n()) %>% 
  mutate(select = if_else(nr_na < parameters$max_gap,
                          "in", "out")) %>% 
  select(-nr_na) %>% 
  ungroup()

tm_profiles <- full_join(tm_profiles, profiles_in)

tm_profiles <- tm_profiles %>% 
  mutate(select = if_else(is.na(select) | select == "out",
                                "out",
                                "in"))
rm(profiles_in)

2.2 pCO2 profile overview

tm_profiles %>%
  arrange(date_time) %>%
  ggplot(aes(pCO2, dep, col = select, linetype = phase)) +
  geom_hline(yintercept = 25) +
  geom_path() +
  scale_y_reverse() +
  scale_x_continuous(breaks = c(0, 600), labels = c(0, 600)) +
  scale_color_brewer(palette = "Set1", direction = -1) +
  coord_cartesian(xlim = c(0, 600)) +
  facet_grid(ID ~ station)
Overview pCO~2~ profiles at stations (P02-P12) and cruise dates (ID). y-axis restricted to displayed range.

Overview pCO2 profiles at stations (P02-P12) and cruise dates (ID). y-axis restricted to displayed range.

tm_profiles %>% 
  group_by(select) %>% 
  summarise(nr = n_distinct(ID, station)) %>% 
  ungroup()
# A tibble: 2 x 2
  select    nr
  <chr>  <int>
1 in        78
2 out        8

2.3 Subset

tm_profiles <- tm_profiles %>%
  filter(select == "in",
         phase == "down") %>%
  select(-c(select, phase)) %>% 
  filter(dep < parameters$max_dep)

2.4 Cruise dates

# assign mean date_time stamp
cruise_dates <- tm_profiles %>% 
  group_by(ID) %>% 
  summarise(date_time_ID = mean(date_time),
            date_ID = format(as.Date(date_time_ID), "%b %d")) %>% 
  ungroup()

# join profiles and mean date
tm_profiles <- inner_join(cruise_dates, tm_profiles)

cruise_dates %>% 
    write_csv(here::here("data/intermediate/_summarized_data_files",
                       "cruise_date.csv"))

2.5 Station map

2.5.1 Load SOOP Finnmaid data

# read file
fm <-
  read_csv(here::here("data/intermediate/_summarized_data_files",
                      "fm.csv"))

# filter data inside map
fm <- fm %>%
  filter(
    lat <= parameters$map_lat_hi,
    lat >= parameters$map_lat_lo,
    lon >= parameters$map_lon_lo
  )

# tag data inside study area to be analyzed
fm <- fm %>%
  mutate(
    Area = point.in.polygon(
      point.x = lon,
      point.y = lat,
      pol.x = parameters$fm_box_lon,
      pol.y = parameters$fm_box_lat
    ),
    Area = as.character(Area),
    Area = if_else(Area == "1", "utilized", "sampled")
  )

# write tagged data to be analyzed in NCP reconstruction
fm %>%
  filter(Area == "utilized") %>%
  select(-Area) %>%
  write_csv(here::here(
    "data/intermediate/_summarized_data_files",
    "fm_bloomsail.csv"
  ))

2.5.2 Load MODIS satellite image

# handling of the satellite image was inspired by this website:
# https://shekeine.github.io/visualization/2014/09/27/sfcc_rgb_in_R
# https://www.neonscience.org/resources/learning-hub/tutorials/dc-multiband-rasters-r

# read raster file manually downloaded from:
# https://worldview.earthdata.nasa.gov/

EGS  <-
  raster::stack(here::here("data/input/Maps",
                   "MODIS_2018_07_26_EGS.tiff"))

# convert to tibble
EGS <- raster::as.data.frame(EGS, xy = T)
EGS <- as_tibble(EGS)

# rename coordinates and subset region
EGS <- EGS %>%
  rename(lat = y,
         lon = x) %>% 
  filter(lat >= 56.4, lat <= 58.3)

# stretch histograms of each band and convert to RGB color
EGS <- EGS %>%
  mutate(
    MODIS_2018_07_26_EGS.1_s = MODIS_2018_07_26_EGS.1 * 2.5,
    MODIS_2018_07_26_EGS.2_s = MODIS_2018_07_26_EGS.2 * 2.5,
    MODIS_2018_07_26_EGS.3_s = MODIS_2018_07_26_EGS.3 * 2.5
  ) %>%
  mutate(
    MODIS_2018_07_26_EGS.1_s =
      if_else(MODIS_2018_07_26_EGS.1_s > 255,
              255,
              MODIS_2018_07_26_EGS.1_s),
    MODIS_2018_07_26_EGS.2_s =
      if_else(MODIS_2018_07_26_EGS.2_s > 255,
              255,
              MODIS_2018_07_26_EGS.2_s),
    MODIS_2018_07_26_EGS.3_s =
      if_else(MODIS_2018_07_26_EGS.3_s > 255,
              255,
              MODIS_2018_07_26_EGS.3_s)) %>%
      mutate(
        RGB = rgb(
          MODIS_2018_07_26_EGS.1_s,
          MODIS_2018_07_26_EGS.2_s,
          MODIS_2018_07_26_EGS.3_s,
          maxColorValue = 255
        )
      )

# select relevant columns
EGS <- EGS %>%
  select(-c(
    MODIS_2018_07_26_EGS.1,
    MODIS_2018_07_26_EGS.2,
    MODIS_2018_07_26_EGS.3
  )) %>% 
  select(-c(
    MODIS_2018_07_26_EGS.1_s,
    MODIS_2018_07_26_EGS.2_s,
    MODIS_2018_07_26_EGS.3_s
  ))

# plot map
EGS <- EGS %>% 
  rename(long = lon)

p_MODIS <-
  ggplot(data = EGS,
         aes(long, lat, fill = RGB)) +
  coord_quickmap(expand = 0) +
  geom_raster() +
  scale_fill_identity() +
  annotate(
    "rect",
    ymax = parameters$map_lat_hi,
    ymin = parameters$map_lat_lo,
    xmax = parameters$map_lon_hi,
    xmin = parameters$map_lon_lo,
    fill = NA,
    color = "orangered",
    size = 1.5
  ) +
  scale_x_continuous(breaks = seq(10, 30, 1)) +
  labs(x = "Longitude (°E)", y = "Latitude (°N)") +
  ggsn::scalebar(
    EGS,
    transform = TRUE,
    model = "WGS84",
    dist_unit = "nm",
    dist = 25,
    location = "bottomleft",
    anchor = c(x = 15.75, y = 56.6),
    st.dist = 0.05,
    st.size = geom_text_size
  )

2.5.3 Load bathymetric map

# read file
map <-
  read_csv(here::here("data/input/Maps", "Bathymetry_Gotland_east_small.csv"))

# filter region for plot
map <- map %>%
  filter(
    lat < parameters$map_lat_hi,
    lat > parameters$map_lat_lo,
    lon < parameters$map_lon_hi,
    lon > parameters$map_lon_lo
  )

# adjust resolution
map_low_res <- map %>%
  mutate(
    lat = cut(
      lat,
      breaks = seq(57, 58, 0.01),
      labels = seq(57.005, 57.995, 0.01)
    ),
    lon = cut(
      lon,
      breaks = seq(18, 22, 0.01),
      labels = seq(18.005, 21.995, 0.01)
    )
  ) %>%
  group_by(lat, lon) %>%
  summarise_all(mean, na.rm = TRUE) %>%
  ungroup() %>%
  mutate(lat = as.numeric(as.character(lat)),
         lon = as.numeric(as.character(lon)))

# downsize track data for plot
tm_track <- tm %>%
  arrange(date_time) %>%
  slice(which(row_number() %% 10 == 1))


# plot map
p_map <-
  ggplot() +
  geom_contour_fill(
    data = map_low_res,
    aes(x = lon, y = lat, z = -elev),
    na.fill = TRUE,
    breaks = seq(0, 300, 30)
  ) +
  geom_raster(data = map %>% filter(is.na(elev)),
              aes(lon, lat),
              fill = "darkgrey") +
  geom_path(data = tm_track, aes(lon, lat, group = ID, col = "Data\nused")) +
  scale_color_manual(values = c("orangered"),
                     name = "") +
  new_scale_color() +
  geom_path(data = tm_track, aes(lon, lat, group = ID, col = "sampled")) +
  geom_path(data = fm, aes(lon, lat, group = ID, col = Area)) +
  geom_label(
    data = stations %>% filter(!(station %in% c("14", "13", "01"))),
    aes(lon, lat, label = station, col = "utilized"),
    size = geom_text_size
  ) +
  geom_label(
    data = stations %>% filter(station %in% c("14", "13", "01")),
    aes(lon, lat, label = station, col = "sampled_station"),
    size = geom_text_size
  ) +
  geom_point(aes(parameters$herrvik_lon, parameters$herrvik_lat)) +
  geom_text(
    aes(parameters$herrvik_lon, parameters$herrvik_lat, label = "Herrvik"),
    nudge_x = -0.05,
    nudge_y = -0.01,
    size = geom_text_size
  ) +
  geom_point(aes(parameters$ostergarn_lon, parameters$ostergarn_lat)) +
  geom_text(
    aes(parameters$ostergarn_lon, parameters$ostergarn_lat,
        label = "Östergarnsholm\nFlux tower"),
    nudge_x = -0.07,
    nudge_y = 0.03,
    size = geom_text_size
  ) +
  geom_text(aes(19.26, 57.57, label = "SOOP Finnmaid"),
            col = "white",
            size = geom_text_size) +
  geom_text(aes(19.54, 57.29, label = "SV Tina V"),
            col = "white",
            size = geom_text_size) +
  coord_quickmap(
    expand = 0,
    ylim = c(parameters$map_lat_lo + 0.01, parameters$map_lat_hi - 0.01)
  ) +
  scale_x_continuous(breaks = seq(10, 30, 0.1)) +
  labs(x = "Longitude (°E)", y = "Latitude (°N)") +
  scale_fill_gradient(
    low = "lightsteelblue1",
    high = "dodgerblue4",
    name = "Depth (m)\n",
    breaks = seq(30, 150, 30),
    limits = c(0, 180),
    guide = "colorstrip"
  ) +
  guides(
    fill = guide_colorsteps(
      barheight = unit(4.5, "cm"),
      show.limits = TRUE,
      frame.colour = "black",
      ticks = TRUE,
      ticks.colour = "black"
    )
  ) +
  scale_color_manual(values = c("white", "darkgrey", "orangered"),
                     guide = FALSE)

p_MODIS + p_map +
  plot_layout(ncol = 1) +
  plot_annotation(tag_levels = 'a')
Location of stations sampled between the east coast of Gotland and Gotland deep.

Location of stations sampled between the east coast of Gotland and Gotland deep.

ggsave(
  here::here("output/Plots/Figures_publication/article",
             "Fig_1.pdf"),
  width = 175,
  height = 200,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here("output/Plots/Figures_publication/article",
             "Fig_1.png"),
  width = 160,
  height = 170,
  dpi = 300,
  units = "mm"
)

rm(map, map_low_res,
   fm, tm_track)

rm(tm)

2.6 Data coverage

# calculate mean samppling dates per station
cover <- tm_profiles %>%
  group_by(ID, station) %>%
  summarise(date = mean(date_time),
            date_time_ID = mean(date_time_ID)) %>%
  ungroup() %>%
  mutate(station = str_sub(station, 2, 3))

# create coverage plot
cover %>%
  ggplot(aes(date, station, fill = ID)) +
  geom_vline(aes(xintercept = date_time_ID, col = ID)) +
  geom_point(shape = 21) +
  scale_fill_viridis_d(labels = cruise_dates$date_ID,
                       name = "Mean\ncruise date") +
  scale_color_viridis_d(labels = cruise_dates$date_ID,
                        name = "Mean\ncruise date") +
  scale_x_datetime(date_breaks = "week",
                   date_labels = "%b %d") +
  labs(y = "Station") +
  theme(axis.title.x = element_blank())
Spatio-temporal data coverage, indicated as station visits over time.

Spatio-temporal data coverage, indicated as station visits over time.

ggsave(
  here::here(
    "output/Plots/Figures_publication/article",
    "Fig_2.pdf"
  ),
  width = 100,
  height = 65,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/article",
    "Fig_2.png"
  ),
  width = 100,
  height = 65,
  dpi = 300,
  units = "mm"
)

rm(cover)

3 Bottle CT and AT

At stations P07 and P10 discrete samples for lab measurmentm of CT and AT were collected. Please note that - in contrast to the pCO2 profiles - samples were taken on June 16, but removed here for harmonization of results.

# read files
tb <-
  read_csv(
    here::here("data/intermediate/_summarized_data_files", "tb.csv"),
    col_types = cols(ID = col_character())
  )

# select stations, harmonize depth range and date ID
tb <- tb %>%
  filter(station %in% c("P07", "P10"),
         dep <= parameters$max_dep) %>%
  mutate(ID = if_else(ID == "180722", "180723", ID))

# join with mean cruise dates
tb <- inner_join(tb, cruise_dates)

3.1 Mean AT

In order to derive CT from measured pCO2 profiles, the alkalinity mean + sd in the upper 25m and both stations was calculated as:

# AT mean calculation
AT_mean <- tb %>% 
  filter(dep <= parameters$max_dep) %>% 
  summarise(AT = mean(AT, na.rm = TRUE)) %>%
  pull()

AT_mean
[1] 1719.706
# AT SD calculation
AT_sd <- tb %>% 
  filter(dep <= parameters$max_dep) %>% 
  summarise(AT = sd(AT, na.rm = TRUE)) %>%
  pull()

AT_sd
[1] 26.95771

3.2 Mean Salinity

Likewise, the mean salinity amounts to:

# Sal mean calculation
sal_mean <- tb %>% 
  filter(dep <= parameters$max_dep) %>% 
  summarise(sal = mean(sal, na.rm = TRUE)) %>%
  pull()

sal_mean
[1] 6.908356
tb_fix <- bind_cols(start = min(tm_profiles$date_time), 
          end = max(tm_profiles$date_time),
          AT = AT_mean,
          AT_sd = AT_sd,
          sal = sal_mean)

tb_fix %>% 
  write_csv(here::here("data/intermediate/_summarized_data_files", "tb_fix.csv"))

3.3 CT* calculation

The alkalinity-normalized CT, CT*, was calculated.

# calculate CT*, referred to as CT_star in the code
tb <- tb %>% 
  mutate(CT_star = CT/AT * AT_mean)

3.4 Vertical profiles

3.4.1 Stations

tb_long <- tb %>%
  pivot_longer(c(sal:AT, CT_star), names_to = "var", values_to = "value")

tb_long %>%
  ggplot(aes(value, dep)) +
  geom_path(aes(col = ID)) +
  geom_point(aes(fill = ID), shape = 21) +
  scale_y_reverse() +
  scale_fill_viridis_d(labels = cruise_dates$date_ID) +
  scale_color_viridis_d(labels = cruise_dates$date_ID) +
  facet_grid(station ~ var, scales = "free_x") +
  theme(legend.position = "bottom",
        legend.title = element_blank())
Discrete sample profiles for individual stations

Discrete sample profiles for individual stations

3.4.2 Mean

# grid data into 5 m intervals
# because some samples were not taken at exact 5m depth intervals
# and calculate cruise mean value within each depth interval
tb_long_mean <- tb_long %>%
  mutate(dep_grid = as.numeric(as.character(cut(
    dep,
    breaks = seq(-2.5, 30, 5),
    labels = seq(0, 25, 5)
  )))) %>%
  group_by(ID, date_time_ID, date_ID, dep_grid, var) %>%
  summarise(value = mean(value, na.rm = TRUE)) %>%
  ungroup()

p_AT <- tb_long_mean %>%
  filter(dep_grid < parameters$max_dep, var == "AT") %>%
  ggplot(aes(value, dep_grid)) +
  annotate(
    "rect",
    xmin = AT_mean - AT_sd,
    xmax = AT_mean + AT_sd,
    ymin = -Inf,
    ymax = Inf,
    alpha = 0.3
  ) +
  geom_vline(data = tb_fix, aes(xintercept = AT), linetype = 2) +
  geom_path(aes(col = ID)) +
  geom_point(aes(fill = ID), shape = 21) +
  scale_y_reverse(sec.axis = dup_axis()) +
  labs(x = expression(A[T] ~ (µmol ~ kg ^ {
    -1
  })),
  y = "Depth (m)") +
  scale_fill_viridis_d(guide = FALSE) +
  scale_color_viridis_d(guide = FALSE) +
  theme(axis.text.y.right = element_blank(),
        axis.title.y.right = element_blank())

p_CT <- tb_long_mean %>%
  filter(dep_grid < parameters$max_dep, var == "CT") %>%
  ggplot(aes(value, dep_grid)) +
  geom_path(aes(col = ID)) +
  geom_point(aes(fill = ID), shape = 21) +
  scale_y_reverse(sec.axis = dup_axis()) +
  labs(x = expression(C[T] ~ (µmol ~ kg ^ {
    -1
  })),
  y = "Depth (m)") +
  scale_fill_viridis_d(guide = FALSE) +
  scale_color_viridis_d(guide = FALSE) +
  theme(axis.text.y = element_blank(),
        axis.title.y = element_blank())

p_CT_star <- tb_long_mean %>%
  filter(dep_grid < parameters$max_dep, var == "CT_star") %>%
  ggplot(aes(value, dep_grid)) +
  geom_path(aes(col = ID)) +
  geom_point(aes(fill = ID), shape = 21) +
  scale_y_reverse(sec.axis = dup_axis()) +
  labs(x = expression(paste(C[T], "*", ~ (µmol ~ kg ^ {-1}))),
       y = "Depth (m)") +
  scale_fill_viridis_d(labels = cruise_dates$date_ID,
                        name = "Mean\ncruise date") +
  scale_color_viridis_d(labels = cruise_dates$date_ID,
                        name = "Mean\ncruise date") +
  theme(
    axis.text.y = element_blank(),
    axis.title.y = element_blank()
  )

p_AT + p_CT + p_CT_star +
  plot_annotation(tag_levels = 'a')
Discrete sample profiles as the mean of individual stations

Discrete sample profiles as the mean of individual stations

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_B1.pdf"
  ),
  width = 150,
  height = 80,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_B1.png"
  ),
  width = 150,
  height = 80,
  dpi = 300,
  units = "mm"
)

rm(tb_long_mean, p_AT, p_CT, p_CT_star, tb_fix)

3.5 Surface time series

# surface time series per station
tb_surface <- tb_long %>%
  filter(dep < parameters$surface_dep) %>%
  group_by(ID, date_time_ID, var, station) %>%
  summarise(value = mean(value, na.rm = TRUE)) %>%
  ungroup()

# mean surface time series across stations
tb_surface_station_mean <- tb_long %>%
  filter(dep < parameters$surface_dep) %>%
  group_by(ID, date_time_ID, var) %>%
  summarise(value_mean = mean(value, na.rm = TRUE),
            value_sd = sd(value, na.rm = TRUE)) %>%
  ungroup()

# create time series plot
tb_long %>%
  filter(dep <= 10) %>%
  ggplot() +
  geom_line(data = tb_surface, aes(date_time_ID, value, col = "Individual")) +
  geom_line(data = tb_surface_station_mean, aes(date_time_ID, value_mean, col =
                                                  "Both (mean)")) +
  geom_point(aes(date_time_ID, value, fill = dep), shape = 21) +
  scale_fill_scico(palette = "oslo",
                   direction = -1,
                   name = "Depth (m)") +
  scale_color_brewer(palette = "Set1", name = "Station surface mean") +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  facet_grid(var ~ station, scales = "free_y") +
  labs(x = "Mean transect date")
Time series of bottle data. Shown are raw data at water depth <= 10m, as well as mean values of samples collected at water depths < 6m (usually collected at 0 and 5 m).

Time series of bottle data. Shown are raw data at water depth <= 10m, as well as mean values of samples collected at water depths < 6m (usually collected at 0 and 5 m).

rm(tb_long, tb_surface, tb)

Note:

  • CT* drop and temporal patterns agree well with those found in the CT* time series derived from pCO2 measurements (below).

4 CT* calculation from pCO2

Alkalinity normalized CT (CT*) profiles were calculated from sensor pCO2 and T profiles, and constant mean salinity and mean alkalinity values. Note that the impact of fixed vs. measured salinity has only a negligible impact on CT profiles.

# calculate CT_star
tm_profiles <- tm_profiles %>%
  mutate(
    CT_star = carb(
      24,
      var1 = pCO2,
      var2 = AT_mean * 1e-6,
      S = sal_mean,
      T = tem,
      P = dep / 10,
      k1k2 = "m10",
      kf = "dg",
      ks = "d",
      gas = "insitu"
    )[, 16] * 1e6
  )

# write CT_star profiles file
tm_profiles %>%
  write_csv(
    here::here(
      "data/intermediate/_merged_data_files/CT_dynamics",
      "tm_profiles.csv"
    )
  )

# calculate CT_star test profiles for higher mean alkalinity 
tm_profiles <- tm_profiles %>%
  mutate(
    CT_star_test = carb(
      24,
      var1 = pCO2,
      var2 = (AT_mean + 2*AT_sd) * 1e-6,
      S = sal_mean,
      T = tem,
      P = dep / 10,
      k1k2 = "m10",
      kf = "dg",
      ks = "d",
      gas = "insitu"
    )[, 16] * 1e6
  )

5 Profile plots

5.1 All individual profiles

# arrange by date (oldest first)
tm_profiles <-  tm_profiles %>%
  arrange(date_time_ID)

# create temperature profiles plots
p_tem <-
  tm_profiles %>%
  ggplot(aes(tem, dep, col = ID, group = interaction(station, ID))) +
  geom_path() +
  scale_y_reverse(expand = c(0, 0)) +
  labs(x = "Temperature (\u00B0C)",
       y = "Depth (m)") +
  scale_color_viridis_d(guide = FALSE)


# create pCO2 profiles plots
p_pCO2 <-
  tm_profiles %>%
  ggplot(aes(pCO2, dep, col = ID, group = interaction(station, ID))) +
  geom_path() +
  scale_y_reverse(expand = c(0, 0)) +
  labs(x = expression(italic(p)*CO[2] ~ (µatm))) +
  scale_color_viridis_d(guide = FALSE) +
  theme(
    axis.text.y = element_blank(),
    axis.title.y = element_blank(),
    axis.ticks.y = element_blank()
  )

# create CT* profiles plots
p_CT_star <-
  tm_profiles %>%
  ggplot(aes(CT_star, dep, col = ID, group = interaction(station, ID))) +
  geom_path() +
  scale_y_reverse(expand = c(0, 0)) +
  labs(x = expression(paste(C[T], "*", ~ (µmol ~ kg ^ {-1})))) +
  scale_color_viridis_d(labels = cruise_dates$date_ID,
                        name = "Mean\ncruise date") +
  theme(
    axis.text.y = element_blank(),
    axis.ticks.y = element_blank(),
    axis.title.y = element_blank()
  )


# Combine and safe plots to file
p_tem + p_pCO2 + p_CT_star +
  plot_annotation(tag_levels = 'a')
Individual vertical profiles per cruise day and station.

Individual vertical profiles per cruise day and station.

ggsave(
  here::here(
    "output/Plots/Figures_publication/article",
    "Fig_3.pdf"
  ),
  width = 150,
  height = 80,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/article",
    "Fig_3.png"
  ),
  width = 150,
  height = 80,
  dpi = 300,
  units = "mm"
)

rm(p_tem, p_pCO2, p_CT_star)

5.2 Mean profiles

Mean vertical profiles were calculated for each cruise day (ID).

tm_profiles_ID_mean <- tm_profiles %>%
  select(-c(station, lat, lon, pCO2_corr, date_time)) %>%
  group_by(ID, date_time_ID, dep) %>%
  summarise_all(list(mean), na.rm = TRUE) %>%
  ungroup()

tm_profiles_ID_sd <- tm_profiles %>%
  select(-c(station, lat, lon, pCO2_corr, date_time)) %>%
  group_by(ID, date_time_ID, dep) %>%
  summarise_all(list(sd), na.rm = TRUE) %>%
  ungroup()

tm_profiles_ID_sd_long <- tm_profiles_ID_sd %>%
  pivot_longer(sal:CT_star_test, names_to = "var", values_to = "sd")

tm_profiles_ID_mean_long <- tm_profiles_ID_mean %>%
  pivot_longer(sal:CT_star_test, names_to = "var", values_to = "value")

tm_profiles_ID_long_test <-
  inner_join(tm_profiles_ID_mean_long, tm_profiles_ID_sd_long)

tm_profiles_ID_long <- tm_profiles_ID_long_test %>% 
  filter(var != "CT_star_test")

tm_profiles_ID_mean_test <- tm_profiles_ID_mean

tm_profiles_ID_mean_test <- tm_profiles_ID_mean_test %>% 
  mutate(CT_star_delta = CT_star - CT_star_test)

tm_profiles_ID_mean <- tm_profiles_ID_mean %>%
  select(-CT_star_test)

tm_profiles_ID_mean %>%
  write_csv(here::here("data/intermediate/_merged_data_files/CT_dynamics", "tm_profiles_ID.csv"))

rm(
  tm_profiles_ID_sd_long,
  tm_profiles_ID_sd,
  tm_profiles_ID_mean_long
)
tm_profiles_ID_long %>%
  ggplot(aes(value, dep, col = ID)) +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  scale_color_viridis_d() +
  facet_wrap( ~ var, scales = "free_x")
Mean vertical profiles per cruise day across all stations.

Mean vertical profiles per cruise day across all stations.

5.3 CT* sensitivity to mean AT

tm_profiles_ID_mean_test %>%
  ggplot(aes(CT_star_delta - mean(CT_star_delta), dep, col = ID)) +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  scale_color_viridis_d()
Offset between C~T~* calculate from mean A~T~ and  mean A~T~ + 2 SD of A~T~, displayed as mean vertical profiles per cruise day across all stations.

Offset between CT* calculate from mean AT and mean AT + 2 SD of AT, displayed as mean vertical profiles per cruise day across all stations.

5.4 All individual profiles per cruise day

profiles_min_max <- tm_profiles %>%
  group_by(dep) %>%
  summarise(max_CT = max(CT_star),
            min_CT = min(CT_star),
            max_tem = max(tem),
            min_tem = min(tem)) %>%
  ungroup()

p_CT <-
  tm_profiles %>%
  ggplot() +
  geom_ribbon(data = profiles_min_max,
              aes(xmin = min_CT,
                  xmax = max_CT,
                  y = dep),
              alpha = 0.2) +
   geom_path(aes(CT_star, dep, col = station)) +
  scale_y_reverse() +
  facet_grid(ID ~ .) +
  labs(x = expression(paste(C[T], "*", ~ (µmol ~ kg ^ {-1}))),
  y = "Depth (m)") +
  theme(strip.background = element_blank(),
        strip.text = element_blank(),
        legend.position = "none")

cruise_labels <- c(
  `180705` = cruise_dates$date_ID[1],
  `180709` = cruise_dates$date_ID[2],
  `180718` = cruise_dates$date_ID[3],
  `180723` = cruise_dates$date_ID[4],
  `180730` = cruise_dates$date_ID[5],
  `180802` = cruise_dates$date_ID[6],
  `180806` = cruise_dates$date_ID[7],
  `180815` = cruise_dates$date_ID[8]
)

p_tem <-
  tm_profiles %>%
  ggplot() +
  geom_ribbon(data = profiles_min_max,
              aes(xmin = min_tem,
                  xmax = max_tem,
                  y = dep,
                  fill = "Min/Max"),
              alpha = 0.2) +
  geom_path(aes(tem, dep, col = station)) +
  scale_y_reverse() +
  scale_fill_manual(values = "black", name = "") +
  scale_color_discrete(name = "Station") +
  guides(color = guide_legend(order = 1)) +
  facet_grid(ID ~ .,
             labeller = labeller(ID = cruise_labels)) +
  labs(x = "Temperature (\u00B0C)",
       y = "Depth (m)") +
  theme(axis.title.y = element_blank(),
        axis.text.y = element_blank())

p_CT | p_tem
Mean vertical profiles per cruise day across all stations plotted indivdually. Ribbons indicate the standard deviation observed across all profiles at each depth and transect.

Mean vertical profiles per cruise day across all stations plotted indivdually. Ribbons indicate the standard deviation observed across all profiles at each depth and transect.

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_C3.pdf"
  ),
  width = 120,
  height = 180,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_C3.png"
  ),
  width = 120,
  height = 180,
  dpi = 300,
  units = "mm"
)

rm(p_CT_star, p_tem, cruise_labels, profiles_min_max)

Important notes:

  • the standard deviation of CT in the upper 10m increases on June 30.

CT, pCO2, S, and T profiles were plotted individually pdf here and grouped by ID pdf here. The later gives an idea of the differences between stations at one point in time.

# tm_profiles_highres <- tm_profiles_highres %>% 
#   filter(phase == "down")

pdf(file=here::here("output/Plots/CT_dynamics",
    "tm_profiles_pCO2_tem_sal_CT.pdf"), onefile = TRUE, width = 9, height = 5)

for(i_ID in unique(tm_profiles$ID)){
  for(i_station in unique(tm_profiles$station)){

    if (nrow(tm_profiles %>% filter(ID == i_ID, station == i_station)) > 0){
      
      # i_ID      <-      unique(tm_profiles$ID)[1]
      # i_station <- unique(tm_profiles$station)[1]

      p_pCO2 <- 
        tm_profiles %>%
        arrange(date_time) %>% 
        filter(ID == i_ID,
               station == i_station) %>%
        ggplot(aes(pCO2, dep, col="grid_RT"))+
        geom_point(aes(pCO2_corr, dep, col="grid"))+
        geom_point()+
        geom_path()+
        scale_y_reverse()+
        scale_color_brewer(palette = "Set1")+
        labs(y="Depth [m]", x="pCO2 [µatm]", title = str_c(i_ID," | ",i_station))+
        coord_cartesian(xlim = c(0,200), ylim = c(30,0))+
        theme_bw()+
        theme(legend.position = "left")
      
      p_tem <- 
        tm_profiles %>%
        arrange(date_time) %>% 
        filter(ID == i_ID,
               station == i_station) %>%
        ggplot(aes(tem, dep))+
        geom_point()+
        geom_path()+
        scale_y_reverse()+
        labs(y="Depth [m]", x="Tem [°C]")+
        coord_cartesian(xlim = c(14,26), ylim = c(30,0))+
        theme_bw()
      
      p_sal <- 
        tm_profiles %>%
        arrange(date_time) %>% 
        filter(ID == i_ID,
               station == i_station) %>%
        ggplot(aes(sal, dep))+
        geom_point()+
        geom_path()+
        scale_y_reverse()+
        labs(y="Depth [m]", x="Tem [°C]")+
        coord_cartesian(xlim = c(6.5,7.5), ylim = c(30,0))+
        theme_bw()
      
      p_CT_star <- 
        tm_profiles %>%
        arrange(date_time) %>% 
        filter(ID == i_ID,
               station == i_station) %>%
        ggplot(aes(CT_star, dep))+
        geom_point()+
        geom_path()+
        scale_y_reverse()+
        labs(y="Depth [m]", x="CT_star* [µmol/kg]")+
        coord_cartesian(xlim = c(1400,1700), ylim = c(30,0))+
        theme_bw()
      

      print(
            p_pCO2 + p_tem + p_sal + p_CT_star
            )
      
      rm(p_pCO2, p_sal, p_tem, p_CT_star)

      
    }
  }
}

dev.off()

rm(i_ID, i_station)
tm_profiles_long <- tm_profiles %>%
  select(-c(lat, lon, pCO2_corr)) %>% 
  pivot_longer(sal:CT_star, values_to = "value", names_to = "var")


pdf(file=here::here("output/Plots/CT_dynamics",
    "tm_profiles_ID_pCO2_tem_sal_CT.pdf"), onefile = TRUE, width = 9, height = 5)

for(i_ID in unique(tm_profiles$ID)){

  #i_ID <- unique(tm_profiles$ID)[1]
  
  sub_tm_profiles_long <- tm_profiles_long %>% 
        arrange(date_time) %>% 
        filter(ID == i_ID)
 
  print(
  
  sub_tm_profiles_long %>% 
    ggplot()+
    geom_path(data = tm_profiles_long,
              aes(value, dep, group=interaction(station, ID)), col="grey")+
    geom_path(aes(value, dep, col=station))+
    scale_y_reverse()+
    labs(y="Depth [m]", title = str_c("ID: ", i_ID))+
    theme_bw()+
    facet_wrap(~var, scales = "free_x")
   
  )  
  rm(sub_tm_profiles_long)
}

dev.off()

rm(i_ID, tm_profiles_long)

5.5 Incremental changes

Changes of seawater vars at each depth are calculated from one cruise day to the next and divided by the number of days inbetween.

tm_profiles_ID_long <- tm_profiles_ID_long %>%
  group_by(var, dep) %>%
  arrange(date_time_ID) %>%
  mutate(
    date_time_ID_diff = as.numeric(date_time_ID - lag(date_time_ID)),
    date_time_ID_ref  = date_time_ID - (date_time_ID - lag(date_time_ID)) /
      2,
    value_diff = value     - lag(value, default = first(value)),
    value_diff_daily = value_diff / date_time_ID_diff,
    value_cum = cumsum(value_diff)
  ) %>%
  ungroup()
tm_profiles_ID_long %>%
  arrange(dep) %>%
  ggplot(aes(value_diff_daily, dep, col = ID)) +
  geom_vline(xintercept = 0) +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  scale_color_viridis_d() +
  facet_wrap( ~ var, scales = "free_x") +
  labs(x = "Change of value inbetween cruises per day")

5.6 Cumulative changes

Cumulative changes of seawater vars were calculated at each depth relative to the first cruise day on July 5.

tm_profiles_ID_long %>%
  arrange(dep) %>%
  ggplot(aes(value_cum, dep, col = ID)) +
  geom_vline(xintercept = 0) +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  scale_color_viridis_d() +
  facet_wrap( ~ var, scales = "free_x") +
  labs(x = "Cumulative change of value")

Important notes:

  • Salinity in the upper 10m decreases by >0.1 on June 30, and returns to average conditions already on Aug 02.

Cumulative positive and negative changes of seawater vars were calculated separately at each depth relative to the first cruise day on July 5.

tm_profiles_ID_long <- tm_profiles_ID_long %>%
  mutate(sign = if_else(value_diff < 0, "neg", "pos")) %>%
  group_by(var, dep, sign) %>%
  arrange(date_time_ID) %>%
  mutate(value_cum_sign = cumsum(value_diff)) %>%
  ungroup()
tm_profiles_ID_long %>%
  arrange(dep) %>%
  ggplot(aes(value_cum_sign, dep, col = ID)) +
  geom_vline(xintercept = 0) +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  scale_color_viridis_d() +
  scale_fill_viridis_d() +
  facet_wrap( ~ interaction(sign, var), scales = "free_x", ncol = 4) +
  labs(x = "Cumulative directional change of value")

6 Time series plots

6.1 Depth intervals

Mean seawater parameters were calculated for 5m depth intervals.

tm_profiles_ID_long_grid <- tm_profiles_ID_long %>%
  mutate(dep = cut(dep, seq(0, 30, 5))) %>%
  group_by(ID, date_time_ID, dep, var)  %>%
  summarise_all(list(mean), na.rm = TRUE) %>% 
  ungroup()

tm_profiles_ID_long_grid %>%
  ggplot(aes(date_time_ID, value, col = as.factor(dep))) +
  geom_path() +
  geom_point() +
  scale_color_viridis_d(name = "Depth (m)") +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  facet_wrap( ~ var, scales = "free_y", ncol = 1) +
  theme(axis.title.x = element_blank())

tm_profiles_ID_long_grid %>%
  mutate(value = round(value, 1),
         date_ID = as.Date(date_time_ID)) %>%
  select(date_ID, dep, var, value) %>%
  pivot_wider(values_from = value, names_from = var) %>%
  kable() %>%
  add_header_above() %>%
  kable_styling(full_width = FALSE) %>% 
  scroll_box(height = "400px")
date_ID dep CT_star pCO2 sal tem
2018-07-06 (0,5] 1528.4 98.3 6.9 15.4
2018-07-06 (5,10] 1541.9 106.0 6.9 14.7
2018-07-06 (10,15] 1562.9 123.3 6.9 14.1
2018-07-06 (15,20] 1575.0 136.5 7.0 13.9
2018-07-06 (20,25] 1589.1 153.5 7.0 13.7
2018-07-10 (0,5] 1500.3 86.1 6.9 17.0
2018-07-10 (5,10] 1517.0 93.4 6.9 15.9
2018-07-10 (10,15] 1561.0 124.6 6.9 14.4
2018-07-10 (15,20] 1584.4 148.5 6.9 14.0
2018-07-10 (20,25] 1596.1 163.8 7.0 13.5
2018-07-19 (0,5] 1466.8 79.1 6.9 20.5
2018-07-19 (5,10] 1479.3 81.5 7.0 19.0
2018-07-19 (10,15] 1553.9 124.4 7.0 15.5
2018-07-19 (15,20] 1586.9 155.0 7.1 14.4
2018-07-19 (20,25] 1597.8 168.3 7.2 13.9
2018-07-24 (0,5] 1439.9 69.0 7.0 21.5
2018-07-24 (5,10] 1453.4 73.2 7.0 20.7
2018-07-24 (10,15] 1565.5 141.8 7.0 15.8
2018-07-24 (15,20] 1609.3 190.8 7.1 14.3
2018-07-24 (20,25] 1618.7 206.1 7.1 13.6
2018-07-31 (0,5] 1474.7 100.3 6.8 24.3
2018-07-31 (5,10] 1484.4 99.2 6.8 22.3
2018-07-31 (10,15] 1582.6 165.6 6.9 16.0
2018-07-31 (15,20] 1626.7 226.6 7.0 14.0
2018-07-31 (20,25] 1645.5 277.0 7.1 13.0
2018-08-03 (0,5] 1458.2 91.1 6.9 24.9
2018-08-03 (5,10] 1471.5 93.4 6.9 23.2
2018-08-03 (10,15] 1590.1 177.3 6.9 15.9
2018-08-03 (15,20] 1634.9 246.1 6.9 13.9
2018-08-03 (20,25] 1651.5 290.6 7.0 12.8
2018-08-07 (0,5] 1473.1 92.1 6.9 23.0
2018-08-07 (5,10] 1483.4 98.6 6.9 22.5
2018-08-07 (10,15] 1605.2 200.1 6.9 15.5
2018-08-07 (15,20] 1638.8 257.3 7.0 14.0
2018-08-07 (20,25] 1650.7 291.8 7.1 12.8
2018-08-16 (0,5] 1555.9 140.6 7.0 18.6
2018-08-16 (5,10] 1561.3 146.8 7.0 18.5
2018-08-16 (10,15] 1581.8 173.5 7.0 17.7
2018-08-16 (15,20] 1638.9 276.9 7.0 14.8
2018-08-16 (20,25] 1679.2 404.0 7.1 11.6
rm(tm_profiles_ID_long_grid)

6.2 CT* sensitivity to mean AT

Mean seawater CT were calculated for 5m depth intervals based on two AT values.

tm_profiles_ID_long_grid <- tm_profiles_ID_long_test %>%
  mutate(dep = cut(dep, seq(0, 30, 5))) %>%
  group_by(ID, date_time_ID, dep, var)  %>%
  summarise_all(list(mean), na.rm = TRUE)

tm_profiles_ID_long_grid %>%
  filter(var %in% c("CT_star", "CT_star_test")) %>% 
  ggplot(aes(date_time_ID, value, col = as.factor(dep))) +
  geom_path() +
  geom_point() +
  scale_color_viridis_d(name = "Depth (m)") +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  facet_wrap( ~ var, scales = "free_y", ncol = 1) +
  theme(axis.title.x = element_blank())

rm(tm_profiles_ID_long_grid)

Calculate CT* changes for range of AT errors

CT_star_sens <- tm_profiles %>%
  filter(dep < parameters$surface_dep,
         date_ID %in% c("Jul 06", "Jul 24")) %>%
  select(date_ID, tem, pCO2) %>%
  group_by(date_ID) %>%
  summarise_all(mean, na.rm = TRUE) %>%
  ungroup()

CT_star_sens <- expand_grid(CT_star_sens, factor = seq(-3, 3, 0.2))

CT_star_sens <- CT_star_sens %>%
  mutate(AT = (AT_mean + factor * AT_sd) * 1e-6)

CT_star_sens <- CT_star_sens %>%
  mutate(
    CT_star = carb(
      24,
      var1 = pCO2,
      var2 = AT,
      S = sal_mean,
      T = tem,
      k1k2 = "m10",
      kf = "dg",
      ks = "d",
      gas = "insitu"
    )[, 16] * 1e6
  )

CT_star_sens <- CT_star_sens %>%
  mutate(AT = AT * 1e6) %>%
  select(date_ID, factor, AT, CT_star) %>%
  pivot_wider(names_from = "date_ID",
              values_from = c("CT_star"))

CT_star_sens <- CT_star_sens %>%
  mutate(CT_star_delta = `Jul 24` - `Jul 06`) %>%
  select(factor, AT, CT_star_delta)

CT_star_delta_mean <- CT_star_sens %>%
  filter(factor == 0) %>%
  pull(CT_star_delta)

CT_star_sens <- CT_star_sens %>%
  mutate(CT_star_delta_offset = CT_star_delta - CT_star_delta_mean,
         CT_star_delta_offset_rel = CT_star_delta / CT_star_delta_mean *100,
         AT_offset = AT - AT_mean)

CT_star_delta_sd <- CT_star_sens %>%
  filter(factor == 1) %>% 
  pull(CT_star_delta_offset)


CT_star_sens %>%
  ggplot(aes(AT_offset, CT_star_delta_offset)) +
  annotate(
    "rect",
    xmin = -AT_sd,
    xmax = +AT_sd,
    ymin = -Inf,
    ymax = Inf,
    alpha = 0.3
  ) +
  annotate(
    "rect",
    xmin = -Inf,
    xmax = Inf,
    ymin = -CT_star_delta_sd,
    ymax = +CT_star_delta_sd,
    alpha = 0.3
  ) +
  geom_vline(xintercept = 0, linetype = 2) +
  geom_hline(yintercept = 0, linetype = 2) +
  geom_line(col="red") +
  scale_y_continuous(
    expression(paste(
      "Absolute bias ", Delta ~ C[T], "*",  ~ (µmol ~ kg ^ {
        -1
      })
    )),
    sec.axis = sec_axis(
      ~ . / CT_star_delta_mean * 100,
      name = expression(paste("Relative bias ", Delta ~ C[T], "* (%)")),
      breaks = seq(-10, 10, 1)
    )
  ) +
  scale_x_continuous(expression(paste("Absolute bias ", A[T]  ~ (µmol ~ kg ^ {
    -1
  }))),
  sec.axis = sec_axis(~ . / AT_mean * 100,
                      name = expression(paste(
                        "Relative bias ", A[T], " (%)")),
      breaks = seq(-10, 10, 1)))

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_C1.pdf"
  ),
  width = 83,
  height = 60,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_C1.png"
  ),
  width = 83,
  height = 60,
  dpi = 300,
  units = "mm"
)

7 Hovmoeller plots

7.1 Absolute values

bin_CT_star <- 30

p_CT_star_hov <- tm_profiles_ID_long %>%
  filter(var == "CT_star") %>%
  ggplot() +
  geom_contour_fill(aes(x = date_time_ID, y = dep, z = value),
                    breaks = MakeBreaks(bin_CT_star),
                    col = "black") +
  geom_point(
    aes(x = date_time_ID, y = c(24.5)),
    size = 3,
    shape = 24,
    fill = "white"
  ) +
  scale_fill_scico(
    breaks = MakeBreaks(bin_CT_star),
    guide = "colorstrip",
    name = "CT_star (µmol/kg)",
    palette = "davos",
    direction = -1
  ) +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  labs(y = "Depth (m)") +
  coord_cartesian(expand = 0) +
  theme(axis.title.x = element_blank())

bin_Tem <- 2

p_tem_hov <- tm_profiles_ID_long %>%
  filter(var == "tem") %>%
  ggplot() +
  geom_contour_fill(aes(x = date_time_ID, y = dep, z = value),
                    breaks = MakeBreaks(bin_Tem),
                    col = "black") +
  geom_point(
    aes(x = date_time_ID, y = c(24.5)),
    size = 3,
    shape = 24,
    fill = "white"
  ) +
  scale_fill_viridis_c(
    breaks = MakeBreaks(bin_Tem),
    guide = "colorstrip",
    name = "Tem (°C)",
    option = "inferno"
  ) +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  labs(y = "Depth (m)") +
  coord_cartesian(expand = 0) +
  theme(axis.title.x = element_blank())

p_CT_star_hov / p_tem_hov
Hovmoeller plotm of absolute changes in C~T~ and temperature.

Hovmoeller plotm of absolute changes in CT and temperature.

rm(p_CT_star_hov, bin_CT_star, p_tem_hov, bin_Tem)
bin_CT_star <- 30

p_CT_star_hov <- tm_profiles_ID_long %>%
  filter(var == "CT_star") %>%
  ggplot() +
  geom_contour_fill(aes(x = date_time_ID, y = dep, z = value),
                    breaks = MakeBreaks(bin_CT_star),
                    col = "black",
                    size = 0.1) +
  geom_vline(aes(xintercept = date_time_ID),
             col = "white",
             linetype = "1f") +
  scale_fill_scico(
    breaks = MakeBreaks(bin_CT_star),
    guide = "colorstrip",
    name = expression(paste(C[T],"*")~(µmol ~ kg ^ {-1})~" "),
    palette = "davos",
    direction = -1
  ) +
  guides(fill = guide_colorsteps(barheight = unit(3, "mm"),
                                 barwidth = unit(65, "mm"),
                                 frame.colour = "black",
                                 ticks = TRUE,
                                 ticks.colour = "black")) +
  scale_y_reverse(sec.axis = dup_axis()) +
  scale_x_datetime(breaks = "week",
                   date_labels = "%b %d") +
  labs(y = "Depth (m)") +
  coord_cartesian(expand = 0) +
  theme(
    axis.title.x = element_blank(),
    axis.title.y.right = element_blank(),
    axis.text.y.right = element_blank(),
    legend.position = "bottom",
    legend.margin = margin(0, 0, 0, 0),
    legend.box.margin = margin(0, 0, 0, 0)
  )

bin_Tem <- 2

p_tem_hov <- tm_profiles_ID_long %>%
  filter(var == "tem") %>%
  ggplot() +
  geom_contour_fill(aes(x = date_time_ID, y = dep, z = value),
                    breaks = MakeBreaks(bin_Tem),
                    col = "black",
                    size = 0.1) +
  geom_vline(aes(xintercept = date_time_ID),
             col = "white",
             linetype = "1f") +
  scale_fill_viridis_c(
    breaks = MakeBreaks(bin_Tem),
    guide = "colorstrip",
    name = expression(Temperature~("\u00B0" * C)),
    option = "inferno"
  ) +
  guides(fill = guide_colorsteps(barheight = unit(3, "mm"),
                                 barwidth = unit(55, "mm"),
                                 frame.colour = "black",
                                 ticks = TRUE,
                                 ticks.colour = "black")) +
  scale_y_reverse(sec.axis = dup_axis()) +
  scale_x_datetime(breaks = "week",
                   date_labels = "%b %d") +
  labs(y = "Depth (m)") +
  coord_cartesian(expand = 0) +
  theme(
    axis.title.x = element_blank(),
    axis.title.y.right = element_blank(),
    axis.text.y.right = element_blank(),
    legend.position = "top",
    legend.margin = margin(0, 0, 0, 0),
    legend.box.margin = margin(0, 0, 0, 0)
  )



p_CT_star_ID_cum <-
  tm_profiles_ID_long %>%
  filter(var == "CT_star") %>%
  ggplot(aes(value_cum, dep, col = ID, fill = ID)) +
  geom_hline(yintercept = 12, col = "red") +
  geom_path() +
  geom_point(shape = 21, col = "black") +
  scale_y_reverse(expand = c(0, 0),
                  position = "right",
                  sec.axis = dup_axis()) +
  labs(x = expression(paste(C[T],"*", ~ cum. ~ changes ~ (µmol ~ kg ^ {
    -1
  }))),
  y = "Depth (m)") +
  scale_color_viridis_d(labels = cruise_dates$date_ID, guide = FALSE) +
  scale_fill_viridis_d(labels = cruise_dates$date_ID, guide = FALSE) +
  theme(axis.title.y.left = element_blank(),
        axis.text.y.left = element_blank())



p_tem_ID_cum <-
  tm_profiles_ID_long %>%
  filter(var == "tem") %>%
  ggplot(aes(value_cum, dep, col = ID, fill = ID)) +
  geom_hline(yintercept = 12, col = "red") +
  geom_path() +
  geom_point(shape = 21, col = "black") +
  scale_y_reverse(expand = c(0, 0),
                  position = "right",
                  sec.axis = dup_axis()) +
  labs(x = "Temperature cum. changes (\u00B0C)",
       y = "Depth (m)") +
  scale_color_viridis_d(labels = cruise_dates$date_ID) +
  scale_fill_viridis_d(labels = cruise_dates$date_ID) +
  theme(
    legend.position = "top",
    axis.title.y.left = element_blank(),
    axis.text.y.left = element_blank(),
    legend.title = element_blank(),
    legend.key.size = unit(4, "mm"),
    legend.key.width = unit(4,"mm") 
  )

((p_tem_hov | p_tem_ID_cum ) + plot_layout(tag_level = 'new', widths = c(2.3, 1))) / 
((p_CT_star_hov | p_CT_star_ID_cum ) + plot_layout(tag_level = 'new', widths = c(2.3, 1))) +
  plot_annotation(tag_levels = c('a', '1'))

ggsave(
  here::here(
    "output/Plots/Figures_publication/article",
    "Fig_4.pdf"
  ),
  width = 175,
  height = 150,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/article",
    "Fig_4.png"
  ),
  width = 175,
  height = 140,
  dpi = 300,
  units = "mm"
)

rm(p_CT_star_hov, bin_CT_star, p_tem_hov, bin_Tem, p_CT_star_ID_cum, p_tem_ID_cum)

7.2 Incremental changes

bin_CT_star <- 2.5

CT_star_hov <- tm_profiles_ID_long %>%
  filter(var == "CT_star") %>%
  ggplot() +
  geom_contour_fill(
    aes(x = date_time_ID_ref, y = dep, z = value_diff_daily),
    breaks = MakeBreaks(bin_CT_star),
    col = "black"
  ) +
  geom_point(
    aes(x = date_time_ID, y = c(24.5)),
    size = 3,
    shape = 24,
    fill = "white"
  ) +
  scale_fill_divergent(breaks = MakeBreaks(bin_CT_star),
                       guide = "colorstrip",
                       name = "CT_star (µmol/kg)") +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  theme_bw() +
  labs(y = "Depth (m)") +
  coord_cartesian(expand = 0) +
  theme(axis.title.x = element_blank(),
        axis.text.x = element_blank())

bin_Tem <- 0.1

Tem_hov <- tm_profiles_ID_long %>%
  filter(var == "tem") %>%
  ggplot() +
  geom_contour_fill(
    aes(x = date_time_ID_ref, y = dep, z = value_diff_daily),
    breaks = MakeBreaks(bin_Tem),
    col = "black"
  ) +
  geom_point(
    aes(x = date_time_ID, y = c(24.5)),
    size = 3,
    shape = 24,
    fill = "white"
  ) +
  scale_fill_divergent(breaks = MakeBreaks(bin_Tem),
                       guide = "colorstrip",
                       name = "Tem (°C)") +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  theme_bw() +
  labs(x = "", y = "Depth (m)") +
  coord_cartesian(expand = 0)

CT_star_hov / Tem_hov
Hovmoeller plotm of daily changes in C~T~ and temperature. Note that calculated  value of change (in contrast to absolute and cumulative values) are referred to the mean dates inbetween cruise, and are not extrapolated to the full observational period.

Hovmoeller plotm of daily changes in CT and temperature. Note that calculated value of change (in contrast to absolute and cumulative values) are referred to the mean dates inbetween cruise, and are not extrapolated to the full observational period.

rm(CT_star_hov, bin_CT_star, Tem_hov, bin_Tem)

7.3 Cumulative changes

bin_CT_star <- 20

CT_star_hov <- tm_profiles_ID_long %>%
  filter(var == "CT_star") %>%
  ggplot() +
  geom_contour_fill(
    aes(x = date_time_ID, y = dep, z = value_cum),
    breaks = MakeBreaks(bin_CT_star),
    col = "black"
  ) +
  geom_point(
    aes(x = date_time_ID, y = c(24.5)),
    size = 3,
    shape = 24,
    fill = "white"
  ) +
  scale_fill_divergent(breaks = MakeBreaks(bin_CT_star),
                       guide = "colorstrip",
                       name = "CT_star (µmol/kg)") +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  theme_bw() +
  labs(y = "Depth (m)") +
  coord_cartesian(expand = 0) +
  theme(axis.title.x = element_blank(),
        axis.text.x = element_blank())

bin_Tem <- 2

Tem_hov <- tm_profiles_ID_long %>%
  filter(var == "tem") %>%
  ggplot() +
  geom_contour_fill(
    aes(x = date_time_ID, y = dep, z = value_cum),
    breaks = MakeBreaks(bin_Tem),
    col = "black"
  ) +
  geom_point(
    aes(x = date_time_ID, y = c(24.5)),
    size = 3,
    shape = 24,
    fill = "white"
  ) +
  scale_fill_divergent(breaks = MakeBreaks(bin_Tem),
                       guide = "colorstrip",
                       name = "Tem (°C)") +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  theme_bw() +
  labs(x = "", y = "Depth (m)") +
  coord_cartesian(expand = 0)

CT_star_hov / Tem_hov
Hovmoeller plotm of cumulative changes in C~T~ and temperature.

Hovmoeller plotm of cumulative changes in CT and temperature.

rm(CT_star_hov, bin_CT_star, Tem_hov, bin_Tem)

8 Depth-integration CT

A critical first step for the determination of net community production (NCP) is the integration of observed changes in nCT over depth. Two approaches were tested:

  • Integration of changes in nCT over a predefined, fixed water depth
  • Integration of changes in nCT over a mixed layer depth (MLD)

Both aproaches deliver depth-integrated, incremental changes of CT inbetween cruise dates. Those were summed up to derive a trajectory of cummulative integrated nCT changes.

8.1 Fixed depths approach

Incremental and cumulative nCT changes inbetween cruise dates were integrated across the water colums down to predefined depth limits. This was done separately for observed positive/negative changes in CT, as well as for the total observed changes.

Predefined integration depth levels in metres are: 9, 10, 11, 12, 13

8.1.1 Calculate inCT

iCT_star_grid_sign <- tm_profiles_ID_long %>% 
  select(ID, date_time_ID, date_time_ID_ref) %>% 
  unique() %>% 
  expand_grid(sign = c("pos", "neg"))

iCT_star_grid_total <- tm_profiles_ID_long %>% 
  select(ID, date_time_ID, date_time_ID_ref) %>% 
  unique() %>% 
  expand_grid(sign = c("total"))

for (i_dep in parameters$fixed_integration_depths) {

iCT_star_sign_temp <- tm_profiles_ID_long %>% 
  filter(var == "CT_star", dep < i_dep) %>% 
  mutate(sign = if_else(ID == "180705" & dep == 0.5, "neg", sign)) %>% 
  group_by(ID, date_time_ID, date_time_ID_ref, sign) %>% 
  summarise(CT_star_i_diff = sum(value_diff)/1000) %>% 
  ungroup()

iCT_star_sign_temp <- iCT_star_sign_temp %>% 
  group_by(sign) %>%
  arrange(date_time_ID) %>% 
  mutate(CT_star_i_cum = cumsum(CT_star_i_diff)) %>% 
  ungroup()

iCT_star_sign_temp <- full_join(iCT_star_sign_temp, iCT_star_grid_sign) %>% 
  arrange(sign, date_time_ID) %>% 
  fill(CT_star_i_cum)


iCT_star_total_temp <- tm_profiles_ID_long %>% 
  filter(var == "CT_star", dep < i_dep) %>% 
  group_by(ID, date_time_ID, date_time_ID_ref) %>% 
  summarise(CT_star_i_diff = sum(value_diff)/1000) %>% 
  ungroup()

iCT_star_total_temp <- iCT_star_total_temp %>% 
  arrange(date_time_ID) %>% 
  mutate(CT_star_i_cum = cumsum(CT_star_i_diff)) %>% 
  ungroup() %>% 
  mutate(sign = "total")

iCT_star_total_temp <- full_join(iCT_star_total_temp, iCT_star_grid_total) %>% 
  arrange(sign, date_time_ID) %>% 
  fill(CT_star_i_cum)

iCT_star_temp <- bind_rows(iCT_star_sign_temp, iCT_star_total_temp) %>% 
    mutate(i_dep = i_dep)


if (exists("iCT_star")) {
  iCT_star <- bind_rows(iCT_star, iCT_star_temp)
  } else {iCT_star <- iCT_star_temp}

rm(iCT_star_temp, iCT_star_sign_temp, iCT_star_total_temp)

}

rm(iCT_star_grid_sign, iCT_star_grid_total)

iCT_star <- iCT_star %>% 
  mutate(i_dep = as.factor(i_dep))

iCT_star_fixed_dep <- iCT_star
rm(iCT_star, i_dep)

8.1.2 Time series

iCT_star_fixed_dep %>%
  ggplot() +
  geom_point(data = cruise_dates, aes(date_time_ID, 0), shape = 21) +
  geom_col(
    aes(date_time_ID_ref, CT_star_i_diff, fill = i_dep),
    position = "dodge",
    alpha = 0.3
  ) +
  geom_line(aes(date_time_ID, CT_star_i_cum, col = i_dep)) +
  scale_color_viridis_d(name = "Depth limit (m)") +
  scale_fill_viridis_d(name = "Depth limit (m)") +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  labs(y = "iCT_star (mol/m2)", x = "") +
  facet_grid(sign ~ ., scales = "free_y", space = "free_y") +
  theme_bw()

8.2 MLD approach

As an alternative to fixed depth levels, vertical integration as low as the mixed layer depth was tested.

8.2.1 Density calculation

Seawater density Rho was determined from S, T, and p according to TEOS-10.

tm_profiles <- tm_profiles %>%
  mutate(rho = swSigma(
    salinity = sal,
    temperature = tem,
    pressure = dep / 10
  ))

8.2.2 Density profiles

tm_profiles_ID_mean_hydro <- tm_profiles %>%
  select(-c(station, lat, lon, pCO2_corr, pCO2, CT_star, date_time)) %>%
  group_by(ID, date_time_ID, date_ID, dep) %>%
  summarise_all(list(mean), na.rm = TRUE) %>%
  ungroup()

tm_profiles_ID_sd_hydro <- tm_profiles %>%
  select(-c(station, lat, lon, pCO2_corr, pCO2, CT_star, date_time)) %>%
  group_by(ID, date_time_ID, date_ID, dep) %>%
  summarise_all(list(sd), na.rm = TRUE) %>%
  ungroup()

tm_profiles_ID_sd_hydro_long <- tm_profiles_ID_sd_hydro %>%
  pivot_longer(sal:rho, names_to = "var", values_to = "sd")

tm_profiles_ID_mean_hydro_long <- tm_profiles_ID_mean_hydro %>%
  pivot_longer(sal:rho, names_to = "var", values_to = "value")

tm_profiles_ID_hydro_long <-
  inner_join(tm_profiles_ID_mean_hydro_long,
             tm_profiles_ID_sd_hydro_long)
tm_profiles_ID_hydro <- tm_profiles_ID_mean_hydro

rm(
  tm_profiles_ID_mean_hydro_long,
  tm_profiles_ID_mean_hydro,
  tm_profiles_ID_sd_hydro_long,
  tm_profiles_ID_sd_hydro
)
tm_profiles_ID_hydro_long %>%
  ggplot(aes(value, dep, col = ID)) +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  scale_color_viridis_d() +
  facet_wrap( ~ var, scales = "free_x")
Mean vertical profiles per cruise day across all stations.

Mean vertical profiles per cruise day across all stations.

8.2.3 MLD calculation

Mixed layer depth (MLD) was determined based on the difference between density at the surface and at depth, for a range of density criteria

tm_profiles_ID_hydro <- expand_grid(tm_profiles_ID_hydro, rho_lim = c(0.1,0.2,0.5))

MLD <- tm_profiles_ID_hydro  %>% 
  arrange(dep) %>% 
  group_by(ID, date_time_ID, rho_lim) %>% 
  mutate(d_rho = rho - first(rho)) %>% 
  filter(d_rho > rho_lim) %>% 
  summarise(MLD = min(dep)) %>% 
  ungroup()

8.2.4 Daily density profiles

tm_profiles_ID_hydro <-
  full_join(tm_profiles_ID_hydro, MLD)

tm_profiles_ID_hydro %>%
  arrange(dep) %>%
  ggplot(aes(rho, dep)) +
  geom_hline(aes(yintercept = MLD, col = as.factor(rho_lim))) +
  geom_path() +
  scale_y_reverse() +
  scale_color_brewer(palette = "Set1", name = "Rho limit") +
  facet_wrap( ~ ID) +
  theme_bw()
Mean density profiles and MLD per cruise dates (ID).

Mean density profiles and MLD per cruise dates (ID).

8.2.5 MLD timeseries

MLD %>%
  ggplot(aes(date_time_ID, MLD, col = as.factor(rho_lim))) +
  geom_hline(yintercept = 0) +
  geom_point() +
  geom_path() +
  scale_color_brewer(palette = "Set1", name = "Rho limit") +
  scale_y_reverse() +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  labs(x = "")

8.2.6 iCT_star calculation

iCT_star <- tm_profiles_ID_long %>% 
  filter(var == "CT_star")

iCT_star <- full_join(iCT_star, MLD)

iCT_star <- iCT_star %>% 
  filter(dep <= MLD)

iCT_star <- iCT_star %>% 
  group_by(ID, date_time_ID, date_time_ID_ref, rho_lim) %>% 
  summarise(CT_star_i_diff = sum(value_diff)/1000) %>% 
  ungroup()

iCT_star <- iCT_star %>% 
  group_by(rho_lim) %>% 
  arrange(date_time_ID) %>% 
  mutate(CT_star_i_cum = cumsum(CT_star_i_diff)) %>% 
  ungroup()

iCT_star <- iCT_star %>% 
  mutate(rho_lim = as.factor(rho_lim))

iCT_star_MLD <- iCT_star

rm(iCT_star, MLD, tm_profiles_ID_hydro, tm_profiles_ID_hydro_long)

8.2.7 Time series

iCT_star_MLD %>%
  ggplot() +
  geom_point(data = cruise_dates, aes(date_time_ID, 0), shape = 21) +
  geom_col(
    aes(date_time_ID_ref, CT_star_i_diff, fill = rho_lim),
    position = "dodge",
    alpha = 0.3
  ) +
  geom_line(aes(date_time_ID, CT_star_i_cum, col = rho_lim)) +
  scale_color_viridis_d(name = "Rho limit") +
  scale_fill_viridis_d(name = "Rho limit") +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  labs(y = "iCT_star [mol/m2]", x = "") +
  theme_bw()

8.3 Comparison of approaches

In the following, all cummulative iCT trajectories are displayed. Highlighted are those obtained for the fixed depth approach with 10 m limit, and the MLD approach with a high density threshold of 0.5 kg/m3.

iCT_star <- full_join(iCT_star_fixed_dep, iCT_star_MLD)

iCT_star <- iCT_star %>%
  mutate(group = paste(
    as.character(sign),
    as.character(i_dep),
    as.character(rho_lim)
  ))

iCT_star %>%
  arrange(date_time_ID) %>%
  ggplot() +
  geom_hline(yintercept = 0) +
  geom_point(data = cruise_dates, aes(date_time_ID, 0), shape = 21) +
  geom_line(aes(date_time_ID, CT_star_i_cum,
                group = group), col = "grey") +
  geom_line(
    data = iCT_star_fixed_dep %>% filter(i_dep == 12, sign == "total"),
    aes(date_time_ID, CT_star_i_cum, col = "12m - total")
  ) +
  geom_line(data = iCT_star_MLD %>% filter(rho_lim == 0.1),
            aes(date_time_ID, CT_star_i_cum, col = "MLD - 0.1")) +
  scale_color_brewer(palette = "Set1", name = "") +
  scale_x_datetime(breaks = "week", date_labels = "%d %b") +
  labs(y = "iCT_star [mol/m2]", x = "")

rm(iCT_star, iCT_star_MLD)

9 NCP determination

In order to derive an estimate of the net community production NCP (which is equivalent to the formed organic matter that can be exported from the investigated surface layer), two steps are required:

  • decision about the most appropiate iCT trajectory

  • correction of quantifyable CO2 fluxes in and out of the investigated water volume during the period of interest, this includes:

    • Air-sea CO2 fluxes
    • CO2 fluxes due to vertical mixing
    • CO2 fluxes due to lateral transport of water masses (not corrected here)

9.1 Best iCT estimate

To determine the optimum depth for the nCT integration we investigated the vertical distribution of cumulative temperature and nCT changes on the peak of the productivity signal on June 23:

tm_profiles_ID_long_180723 <- tm_profiles_ID_long %>%
  filter(ID == 180723,
         var == "CT_star")

p_tm_profiles_ID_long <- tm_profiles_ID_long_180723 %>%
  arrange(dep) %>%
  ggplot(aes(value_cum, dep)) +
  geom_vline(xintercept = 0) +
  geom_hline(yintercept = 12, col = "red") +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  labs(x = "Cumulative change of CT_star on July 23 (180723)") +
  theme(legend.position = "left")

tm_profiles_ID_long_180723_dep <- tm_profiles_ID_long_180723 %>%
  select(dep, value_cum) %>%
  filter(value_cum < 0) %>%
  arrange(dep) %>%
  mutate(
    value_cum_i = sum(value_cum),
    value_cum_dep = cumsum(value_cum),
    value_cum_i_rel = value_cum_dep / value_cum_i * 100
  )

p_tm_profiles_ID_long_rel <- tm_profiles_ID_long_180723_dep %>%
  ggplot(aes(value_cum_i_rel, dep)) +
  geom_hline(yintercept = 12, col = "red") +
  geom_vline(xintercept = 90) +
  geom_point() +
  geom_line() +
  scale_y_reverse(limits = c(25, 0)) +
  scale_x_continuous(breaks = seq(0, 100, 10)) +
  labs(y = "Depth (m)", x = "Relative contribution on July 23") +
  theme_bw()

p_tm_profiles_ID_long + p_tm_profiles_ID_long_rel

rm(
  tm_profiles_ID_long_180723,
  tm_profiles_ID_long_180723_dep,
  p_tm_profiles_ID_long,
  p_tm_profiles_ID_long_rel
)
tm_profiles_ID_long_180723 <- tm_profiles_ID_long %>%
  filter(ID == 180723,
         var == "tem")

p_tm_profiles_ID_long <- tm_profiles_ID_long_180723 %>%
  arrange(dep) %>%
  ggplot(aes(value_cum, dep)) +
  geom_vline(xintercept = 0) +
  geom_hline(yintercept = 12, col = "red") +
  geom_point() +
  geom_path() +
  scale_y_reverse() +
  labs(x = "Cumulative change of Temp on July 23") +
  theme(legend.position = "left")

tm_profiles_ID_long_180723_dep <- tm_profiles_ID_long_180723 %>%
  select(dep, value_cum) %>%
  filter(value_cum > 0) %>%
  arrange(dep) %>%
  mutate(
    value_cum_i = sum(value_cum),
    value_cum_dep = cumsum(value_cum),
    value_cum_i_rel = value_cum_dep / value_cum_i * 100
  )

p_tm_profiles_ID_long_rel <- tm_profiles_ID_long_180723_dep %>%
  ggplot(aes(value_cum_i_rel, dep)) +
  geom_hline(yintercept = 12, col = "red") +
  geom_vline(xintercept = 90) +
  geom_point() +
  geom_line() +
  scale_y_reverse(limits = c(25, 0)) +
  scale_x_continuous(breaks = seq(0, 100, 10)) +
  labs(y = "Depth (m)", x = "Relative contribution on July 23") +
  theme_bw()

p_tm_profiles_ID_long + p_tm_profiles_ID_long_rel

rm(
  tm_profiles_ID_long_180723,
  tm_profiles_ID_long_180723_dep,
  p_tm_profiles_ID_long,
  p_tm_profiles_ID_long_rel
)

The cummulative iCT trajectory determined by integration of CT to a fixed water depth of 12 m was used for NCP calculation for the following reasons:

  • During the first productivity pulse that lasted until July 23:

    • no negative nCT changes were detected below that depth
    • cumulative nCT switch sign at that depth
    • 95% of the cumulative warming signal appears across that depth
  • MLD were too shallow to cover all observed negative CT changes

9.2 Air-Sea CO2 flux

9.2.1 Surface water data

The cruise mean pCO2 recorded in profiling-mode (stations only) and depths < 6m was used for gas exchange calculations.

tm_profiles_surface_long <- tm_profiles %>%
  filter(dep < parameters$surface_dep) %>%
  select(date_time = date_time_ID, ID, tem, pCO2 = pCO2, CT_star) %>%
  pivot_longer(tem:CT_star, values_to = "value", names_to = "var")

tm_profiles_surface_long_ID <- tm_profiles_surface_long %>%
  group_by(ID, date_time, var) %>%
  summarise_all(list( ~ mean(.), ~ sd(.), ~ min(.), ~ max(.))) %>%
  ungroup()

rm(tm_profiles_surface_long)

p_pCO2_surf <- tm_profiles_surface_long_ID %>%
  filter(var == "pCO2") %>%
  ggplot(aes(x = date_time)) +
  geom_ribbon(aes(ymin = mean - sd, ymax = mean + sd,
                  fill = "\u00B1 SD"), alpha = 0.2) +
  geom_path(aes(y = mean)) +
  geom_point(aes(y = mean)) +
  scale_color_manual(name = "", values = "black", guide = FALSE) +
  scale_fill_manual(name = "", values = "black", guide = FALSE) +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop(italic(p)*CO[2], (mu * atm)))) +
  theme(axis.title.x = element_blank(),
        axis.text.x = element_blank(),
    legend.title = element_blank(),
    plot.margin = margin(0, 0, 0, 0, "cm"))

p_tem_surf <- tm_profiles_surface_long_ID %>%
  filter(var == "tem") %>%
  ggplot(aes(x = date_time)) +
  geom_ribbon(aes(
    ymin = mean - sd,
    ymax = mean + sd,
    fill = "Mean \u00B1 SD"
  ),
  alpha = 0.2) +
  geom_path(aes(y = mean, col = "Mean \u00B1 SD")) +
  geom_point(aes(y = mean, col = "Mean \u00B1 SD")) +
  scale_color_manual(name = "Sensor data", values = "black") +
  scale_fill_manual(name = "Sensor data", values = "black") +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop("SST", "(\u00B0C)"))) +
  theme(
    axis.title.x = element_blank(),
    axis.text.x = element_blank(),
    legend.key.height = unit(5, "mm"),
    legend.key.width = unit(5,"mm"),
    plot.margin = margin(0, 0, 0, 0, "cm")
  )


p_CT_star_surf <-
  tm_profiles_surface_long_ID %>%
  filter(var == "CT_star") %>%
  ggplot() +
  geom_ribbon(aes(
    x = date_time,
    ymin = mean - sd,
    ymax = mean + sd,
    fill = "\u00B1 SD"
  ),
  alpha = 0.2) +
  geom_path(aes(x = date_time, y = mean)) +
  geom_point(aes(x = date_time, y = mean)) +
  scale_color_manual(name = "", values = "black", guide = FALSE) +
  scale_fill_manual(name = "", values = "black", guide = FALSE) +
  new_scale_color() +
  geom_linerange(
    data = tb_surface_station_mean %>%
      filter(var == "CT_star"),
    aes(
      x = date_time_ID,
      ymin = value_mean - value_sd,
      ymax = value_mean + value_sd,
      color = "Mean \u00B1 SD"
    )
  ) +
  geom_point(
    data = tb_surface_station_mean %>%
      filter(var == "CT_star"),
    aes(x = date_time_ID,
        y = value_mean,
        color = "Mean \u00B1 SD")
  ) +
  scale_color_manual(name = "Bottle data", values = "red") +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop(paste(C[T], "*"),
                           (mu * mol ~ kg ^ {
                             -1
                           })))) +
  theme(
    axis.title.x = element_blank(),
    axis.text.x = element_blank(),
    legend.key.height = unit(5, "mm"),
    legend.key.width = unit(5,"mm"),
    plot.margin = margin(0, 0, 0, 0, "cm")
  )


p_pCO2_surf + p_tem_surf + p_CT_star_surf +
  plot_layout(ncol = 1)

start <- min(tm_profiles_surface_long_ID$date_time)
end   <- max(tm_profiles_surface_long_ID$date_time)

The regional variability of surface water parameters was:

tm_profiles_surface_long_ID %>%
  arrange(var) %>%
  kable() %>%
  add_header_above() %>%
  kable_styling(full_width = FALSE) %>%
  scroll_box(height = "400px")
ID date_time var mean sd min max
180705 2018-07-06 11:14:37 CT_star 1529.03664 8.2860670 1511.48597 1542.59277
180709 2018-07-10 08:45:37 CT_star 1500.62312 15.2681716 1471.06090 1520.34195
180718 2018-07-19 10:01:48 CT_star 1466.21102 11.7110194 1447.28435 1498.63202
180723 2018-07-24 07:58:29 CT_star 1439.88075 8.8623734 1415.45985 1455.43963
180730 2018-07-31 03:46:19 CT_star 1474.16535 25.0604599 1439.64329 1519.20430
180802 2018-08-03 05:15:01 CT_star 1458.26021 20.7150349 1433.97552 1508.09974
180806 2018-08-07 09:27:12 CT_star 1473.12374 13.3837746 1447.00957 1491.52908
180815 2018-08-16 00:06:57 CT_star 1556.12148 8.3924379 1540.81503 1570.11756
180705 2018-07-06 11:14:37 pCO2 98.46479 6.0783446 87.19708 110.10829
180709 2018-07-10 08:45:37 pCO2 86.08577 7.5655796 72.44860 95.54848
180718 2018-07-19 10:01:48 pCO2 78.58691 6.5048160 69.81332 101.52255
180723 2018-07-24 07:58:29 pCO2 68.89903 3.6761271 59.87298 75.31606
180730 2018-07-31 03:46:19 pCO2 99.47526 18.7269290 79.74149 134.65085
180802 2018-08-03 05:15:01 pCO2 91.10383 13.6139306 77.85520 126.69682
180806 2018-08-07 09:27:12 pCO2 92.07698 7.7401816 78.38500 103.82752
180815 2018-08-16 00:06:57 pCO2 140.86604 7.9253537 126.20428 154.87765
180705 2018-07-06 11:14:37 tem 15.33894 0.4452327 14.56363 16.25378
180709 2018-07-10 08:45:37 tem 16.98802 0.4766242 16.06309 17.89843
180718 2018-07-19 10:01:48 tem 20.39920 0.4276053 19.76884 21.24796
180723 2018-07-24 07:58:29 tem 21.42787 0.5128097 21.00967 22.95619
180730 2018-07-31 03:46:19 tem 24.24554 0.4607887 23.64305 25.31485
180802 2018-08-03 05:15:01 tem 24.86365 0.1595463 24.53541 25.17608
180806 2018-08-07 09:27:12 tem 22.96251 0.2082844 22.60425 23.35020
180815 2018-08-16 00:06:57 tem 18.62939 0.2737599 18.13858 19.01634

For the production pulse from July 6 - 24, this can be summarized as:

tm_profiles_surface_long_ID %>%
  filter(date_time < ymd("2018-07-26")) %>% 
  group_by(var) %>%
  summarise(SD_mean = mean(sd)) %>% 
  ungroup() %>% 
  kable() %>%
  add_header_above() %>%
  kable_styling(full_width = FALSE) %>%
  scroll_box(height = "400px")
var SD_mean
CT_star 11.031908
pCO2 5.956217
tem 0.465568

9.2.2 Wind and atm. pCO2

Metrological data were recorded on the flux tower located on Ostergarnsholm island.

og <-
  read_csv(here::here("data/intermediate/_summarized_data_files",
                      "og.csv"))

og <- og %>%
  filter(date_time > start,
         date_time < end)

rm(end, start)

9.2.3 Conversion to U10

Wind speed was determined at 12 and converted to 10 m above sea level, to be used for gas exchange calculation.

og <- og %>%
  mutate(wind = wind.scale.base(wnd = wind, wnd.z = 12))

Data sets for atmospheric and seawater observations were merged and interpolated to a common time stamp.

tm_profiles_surface_ID <- tm_profiles_surface_long_ID %>%
  filter(var %in% c("pCO2", "tem")) %>%
  select(date_time:mean) %>%
  pivot_wider(names_from = "var", values_from = "mean")

rm(tm_profiles_surface_long_ID)

tm_og <- full_join(og, tm_profiles_surface_ID) %>%
  arrange(date_time)

tm_og <- tm_og %>%
  mutate(
    pCO2 = approxfun(date_time, pCO2)(date_time),
    tem = approxfun(date_time, tem)(date_time),
    wind = approxfun(date_time, wind)(date_time)
  ) %>%
  filter(!is.na(pCO2_atm))

rm(tm_profiles_surface_ID, og)
p_pCO2_atm <- tm_og %>%
  ggplot(aes(x = date_time)) +
  geom_path(aes(y = pCO2_atm)) +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop(italic(p)*CO["2,atm"], (mu * atm)))) +
  theme(axis.title.x = element_blank(),
        axis.text.x = element_blank(),
    plot.margin = margin(0, 0, 0, 0, "cm"))

p_wind <- tm_og %>%
  ggplot(aes(x = date_time)) +
  geom_path(aes(y = wind)) +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop(U["10"], (m ~ s ^ {
    -1
  })))) +
  theme(
    axis.title.x = element_blank(),
    axis.text.x = element_blank(),
    legend.title = element_blank(),
    plot.margin = margin(0, 0, 0, 0, "cm")
  )

p_pCO2_atm + p_wind +
  plot_layout(ncol = 1) +
  plot_layout(guides = 'collect')

9.2.4 Air-sea fluxes

F = k * dCO2

with

dCO2 = K0 * dpCO2 and

k = coeff * U^2 * (660/Sc)^0.5

Unitm used here are:

  • dpCO2: µatm

  • K0: mol atm-1 kg-1

  • dCO2: µmol kg-1

  • wind speed U: m s-1

  • coeff for k calculation (eg 0.251 in W14): cm hr-1 (m s-1)-2

  • gas transfer velocities k: cm hr-1 (= 60 x 60 x 100 m s-1)

  • air sea CO2 flux F: mol m–2 d–1

  • conversion between the unit of k * dCO2 and F requires a factor of 10-5 * 24

Sc_W14 <- function(tem) {
  2116.8 - 136.25 * tem + 4.7353 * tem ^ 2 - 0.092307 * tem ^ 3 + 0.0007555 * tem ^
    4
}

# Sc_W14(20)

tm_og <- tm_og %>%
  mutate(
    dpCO2 = pCO2 - pCO2_atm,
    dCO2  = dpCO2 * K0(S = 6.92, T = tem),
    # W92 = gas_transfer(t = tem, u10 = wind, species = "CO2",
    #                      method = "Wanninkhof1")* 60^2 * 100,
    #k_SM18 = 0.24 * wind^2 * ((1943-119.6*tem + 3.488*tem^2 - 0.0417*tem^3) / 660)^(-0.5),
    k = 0.251 * wind ^ 2 * (Sc_W14(tem) / 660) ^ (-0.5)
  )
# pivot_longer(9:10, names_to = "k_para", values_to = "k_value")

# calculate flux F [mol m–2 d–1]

tm_og <- tm_og %>%
  mutate(flux = k * dCO2 * 1e-5 * 24)
#         flux_daily = rolling_mean(flux))

rm(Sc_W14)
p_flux_daily <- tm_og %>%
  ggplot(aes(x = date_time)) +
  geom_path(aes(y = flux)) +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop(F["daily"], (mol ~ m ^ {
    -2
  } ~ d ^ {
    -1
  })))) +
  theme(
    axis.title.x = element_blank(),
    axis.text.x = element_blank(),
    legend.title = element_blank(),
    plot.margin = margin(0, 0, 0, 0, "cm")
  )
# scale flux to time interval

tm_og <- tm_og %>%
  mutate(scale = 24 * 2) %>%
  mutate(flux_scale = flux / scale) %>%
  arrange(date_time) %>%
  mutate(flux_cum = cumsum(flux_scale)) %>%
  ungroup()


p_flux_cum <- tm_og %>%
  ggplot(aes(x = date_time)) +
  geom_path(aes(y = flux_cum)) +
  scale_fill_discrete(guide = FALSE) +
  scale_x_datetime(date_breaks = "week",
                   sec.axis = dup_axis()) +
  labs(y = expression(atop(F["cum"],
                           (mol ~ m ^ {
                             -2
                           })))) +
  theme(
    axis.title.x = element_blank(),
    axis.text.x = element_blank(),
    plot.margin = margin(0, 0, 0, 0, "cm")
  )

p_flux_daily + p_flux_cum +
  plot_layout(ncol = 1)

9.3 iCT correction

The cumulative integrated CT_star (iCT_star) time series obtained through integration across the upper 12m of the water column was used for further calculations of NCP.

Correction of iCT_star for air-sea CO2 fluxes will be based on estimates derived from observation with 30min measurement interval and calculation according to Wanninkhof (2014).

To derive an integrated NCP estimated, the observed change in iCT_star must be corrected for the air-sea flux of CO2. iCT_star was determined for the upper 12m of the water column. The MLD was always shallower 12m, except for the last cruise day. Therefore:

  • Cumulative air-sea fluxes can be added completely to iCT_star before Aug 7.
  • Between Aug 7 and the last cruise on Aug 15 it was assumed, that the CO2 flux was homogenously mixed down to the deepend thermocline at 17m. The flux correction applied to the upper 12m can therefore be scaled with a factor 12/17.

During the last cruise, deeper mixing up to 17m water depth was observed, resulting in increased iCT_star at 0-12 m and a decrease of iCT_star in 12-17m. The loss of CT_star in 12-17m can be assumed to be entirely cause by mixing with low-CT_star surface water. However, some of the observed CT_star loss is balanced through CT_star input attributable to the air-sea flux. Therefore, the observed loss, corrected for 5/17 of the air-sea-flux, was added to the integrated CT_star changes in 0-12m.

# extract CT data for fixed depth approach, depth limit 10m
NCP <- iCT_star_fixed_dep %>%
  filter(i_dep == parameters$i_dep_lim, sign == "total") %>%
  select(-c(sign, i_dep))

rm(iCT_star_fixed_dep)

NCP <- NCP %>%
  select(ID, date_time = date_time_ID, date_time_ID_ref, CT_star_i_diff, CT_star_i_cum)

# date of the second last cruise
date_180806 <- unique(NCP$date_time)[7]

9.3.1 Air-sea fluxes

# calculate cumulative air-sea fluxes affecting surface water column
tm_og_flux <- tm_og %>%
  mutate(
    flux_scale = if_else(
      date_time > date_180806,
      parameters$i_dep_lim / parameters$i_dep_mix_lim * flux_scale,
      flux_scale
    )
  ) %>%
  arrange(date_time) %>%
  mutate(flux_cum = cumsum(flux_scale)) %>%
  select(date_time, flux_cum)

# calculate cumulative air-sea fluxes affecting deepened mixed layer
tm_og_flux_dep <- tm_og %>%
  filter(date_time > date_180806) %>%
  mutate(
    flux_scale =
      (parameters$i_dep_mix_lim - parameters$i_dep_lim) / parameters$i_dep_mix_lim * flux_scale
  ) %>%
  arrange(date_time) %>%
  mutate(flux_cum = cumsum(flux_scale)) %>%
  select(date_time, flux_cum)

NCP_flux <- full_join(NCP, tm_og_flux) %>%
  arrange(date_time)

rm(tm_og_flux, NCP, tm_og)


# linear interpolation of cumulative changes to frequency of the flux estimates estimates
NCP_flux <- NCP_flux %>%
  mutate(
    CT_star_i_cum = approxfun(date_time, CT_star_i_cum)(date_time),
    flux_cum = approxfun(date_time, flux_cum)(date_time)
  ) %>%
  fill(flux_cum) %>%
  mutate(CT_star_i_flux_cum = CT_star_i_cum + flux_cum)


# calculate cumulative fluxes inbetween cruises
NCP_flux_diff <- NCP_flux %>%
  filter(!is.na(date_time_ID_ref)) %>%
  mutate(flux_diff = flux_cum - lag(flux_cum, default = 0)) %>%
  select(ID, date_time_ID_ref, observed = CT_star_i_diff, flux = flux_diff) %>%
  pivot_longer(cols = "observed":"flux",
               names_to = "var",
               values_to = "value_diff")

9.3.2 Vertical mixing

The aim is to approximate the CT entrainment flux between Aug 06 and 15. The relevant profiles are:

CT_mix <- tm_profiles_ID_long %>%
      filter(ID %in% c("180806"),
             var %in% c("CT_star"),
             dep < 17) %>% 
  summarise(mean(value)) %>% 
  pull()

CT_profile <- tm_profiles_ID_mean %>%
  filter(ID %in% c("180806"))

p_CT_star <- CT_profile %>% 
  ggplot() +
  geom_rect(
    data = CT_profile %>% filter(dep > 12, dep < 17),
    aes(
      xmax = CT_star,
      xmin = CT_mix,
      ymax = dep + 0.5,
      ymin = dep - 0.5
    ),
    alpha = 0.2
  ) +
  geom_hline(yintercept = c(12, 17)) +
  geom_segment(aes(x = CT_mix, xend = CT_mix,
              y = -Inf, yend = 17),
              linetype = 2) +
  annotate("text", label = as.character(expression(paste(C[T],"*")~mix)),
           parse = TRUE, x = 1580, y = 3,
           size = geom_text_size) +
  annotate("text", label = as.character(expression(paste(C[T],"*")~flux)),
           parse = TRUE, x = 1580, y = 14.5,
           size = geom_text_size) +
  geom_point(aes(CT_star, dep, fill = ID), shape = 21) +
  geom_path(aes(CT_star, dep, col = ID)) +
  scale_y_reverse() +
  scale_fill_viridis_d() +
  scale_color_viridis_d() +
    labs(y = "Depth (m)", x = expression(paste(C[T],"*", ~ (µmol ~ kg ^ {
    -1
  })))) +
  theme(
    legend.title = element_blank(),
    axis.text.y = element_blank(),
    axis.ticks.y = element_blank(),
    axis.title.y = element_blank(),
    legend.position = "none"
  )

tm_profiles_ID_long_temp <-
  left_join(tm_profiles_ID_long %>%
              filter(ID %in% c("180806", "180815"),
                     var %in% c("tem")) %>% 
              select(-date_ID),
            cruise_dates)


p_tem <- tm_profiles_ID_long_temp  %>%
  ggplot() +
  geom_hline(yintercept = c(12, 17)) +
  geom_path(aes(value, dep, col = date_ID)) +
  geom_point(aes(value, dep, fill = date_ID), shape = 21) +
  scale_y_reverse() +
  scale_color_viridis_d(name = "Mean\ncruise date") +
  scale_fill_viridis_d(name = "Mean\ncruise date") +
    labs(y = "Depth (m)", x = expression(paste(Temperature ~ "(\u00B0C)")))

p_tem + p_CT_star +
  plot_layout(guides = 'collect') +
  plot_annotation(tag_levels = 'a')

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_C2.pdf"
  ),
  width = 130,
  height = 110,
  dpi = 300,
  units = "mm"
)

ggsave(
  here::here(
    "output/Plots/Figures_publication/appendix",
    "Fig_C2.png"
  ),
  width = 130,
  height = 110,
  dpi = 300,
  units = "mm"
)


rm(p_tem, p_CT_star, CT_mix, CT_profile, tm_profiles_ID_long_temp)

The effect of mixing was derived from the mean concentration difference on Aug 06.

# calculate mixing with deep waters, corrected for air sea fluxes
CT_star_inventory_mean <- tm_profiles_ID_long %>%
  filter(ID == "180806",
         var == "CT_star",
         dep < parameters$i_dep_mix_lim) %>%
  summarise(CT_star_surface = sum(value) / parameters$i_dep_mix_lim) %>%
  pull()

CT_star_delta_mix <- tm_profiles_ID_long %>%
  filter(ID == "180806",
         var == "CT_star",
         dep < parameters$i_dep_mix_lim) %>%
  mutate(CT_star_delta_mix = CT_star_inventory_mean - value)

NCP_mix_deep <- CT_star_delta_mix %>%
  filter(dep < parameters$i_dep_mix_lim,
         dep > parameters$i_dep_lim) %>%
  summarise(value_diff = sum(CT_star_delta_mix) / 1000) %>%
  mutate(ID = "180815")

NCP_mix_shallow <- CT_star_delta_mix %>%
  filter(dep < parameters$i_dep_lim) %>%
  summarise(value_diff = sum(CT_star_delta_mix) / 1000) %>%
  mutate(ID = "180815")

rm(tm_og_flux_dep)

NCP_mix_deep_diff <- NCP_mix_deep %>%
  mutate(var = "mixing")

NCP_flux_mix_diff <-
  full_join(NCP_flux_diff, NCP_mix_deep_diff) %>% #
  arrange(ID) %>%
  fill(date_time_ID_ref)

NCP_mix_deep <- NCP_mix_deep %>%
  rename(mix_cum = value_diff) %>%
  select(ID, mix_cum)

NCP_flux_mix <-
  full_join(NCP_flux,
            NCP_mix_deep)

rm(NCP_mix_deep,
   NCP_mix_deep_diff,
   NCP_flux,
   NCP_flux_diff,
   date_180806)

NCP_flux_mix <- NCP_flux_mix %>%
  arrange(date_time) %>%
  fill(ID) %>%
  mutate(
    mix_cum = if_else(ID %in% c("180806", 180815), mix_cum, 0),
    mix_cum = na.approx(mix_cum),
    CT_star_i_flux_mix_cum = CT_star_i_flux_cum + mix_cum
  )

# reorder factors for plotting
NCP_flux_mix_diff <- NCP_flux_mix_diff %>%
  mutate(var = factor(var, c("observed", "flux", "mixing")))

NCP_flux_mix_long <- NCP_flux_mix %>%
  select(date_time, CT_star_i_cum, CT_star_i_flux_cum, CT_star_i_flux_mix_cum) %>%
  pivot_longer(CT_star_i_cum:CT_star_i_flux_mix_cum,
               values_to = "value",
               names_to = "var") %>%
  mutate(
    var = fct_recode(
      var,
      observed = "CT_star_i_cum",
      `flux corrected` = "CT_star_i_flux_cum",
      `flux + mixing\ncorrected (NCP)` = "CT_star_i_flux_mix_cum"
    )
  )


p_iCT_star <- NCP_flux_mix_long %>%
  arrange(date_time) %>%
  ggplot() +
  geom_col(
    data = NCP_flux_mix_diff,
    aes(date_time_ID_ref, value_diff, fill = var),
    position = position_dodge2(preserve = "single"),
    alpha = 0.5
  ) +
  geom_hline(yintercept = 0) +
  geom_point(data = cruise_dates, aes(date_time_ID, 0), shape = 21) +
  geom_line(aes(date_time, value, col = var)) +
  scale_x_datetime(date_breaks = "week",
                   date_labels = "%b %d",
                   sec.axis = dup_axis()) +
  scale_fill_brewer(palette = "Dark2", name = "Incremental changes") +
  scale_color_brewer(palette = "Dark2", name = "Cumulative changes") +
  labs(y = expression(atop(Integrated ~ paste(C[T],"*"), (mol ~ m ^ {
    -2
  })))) +
  guides(fill = guide_legend(order = 2)) +
  theme(
    axis.title.x = element_blank(),
    axis.text.x.top = element_blank(),
    legend.key.height = unit(5, "mm"),
    legend.key.width = unit(5,"mm"),
    plot.margin = margin(0, 0, 0, 0, "cm")
  )

p_iCT_star

NCP_flux_mix %>%
  write_csv(
    here::here(
      "data/intermediate/_merged_data_files/CT_dynamics",
      "tm_NCP_cum.csv"
    )
  )

NCP_flux_mix_diff %>%
  write_csv(
    here::here(
      "data/intermediate/_merged_data_files/CT_dynamics",
      "tm_NCP_inc.csv"
    )
  )

10 Open tasks / questions

  • clean and harmonize chunk labeling (label: plot, 1 plot per chunk, etc)

  • included removed stations in coverage plot

  • Significance of changes in AT for calculated CT_star changes

    • Calculate AT-S ratios, reconstruct AT profiles, calculate true CT_star profiles, normalize CT_star profiles to mean AT
  • demonstrate strong permanent thermocline at around 25 m

  • calculate oxygen demand for mineralization (4.68*1091.2 / (300e-6103) / 10^9)


sessionInfo()
R version 4.0.3 (2020-10-10)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)

Matrix products: default

locale:
[1] LC_COLLATE=English_Germany.1252  LC_CTYPE=English_Germany.1252   
[3] LC_MONETARY=English_Germany.1252 LC_NUMERIC=C                    
[5] LC_TIME=English_Germany.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] ggnewscale_0.4.5       rgdal_1.5-18           LakeMetabolizer_1.5.0 
 [4] rLakeAnalyzer_1.11.4.1 kableExtra_1.3.1       sp_1.4-4              
 [7] tibbletime_0.1.6       zoo_1.8-8              lubridate_1.7.9.2     
[10] scico_1.2.0            metR_0.9.0             marelac_2.1.10        
[13] shape_1.4.5            seacarb_3.2.14         oce_1.2-0             
[16] gsw_1.0-5              testthat_3.0.1         patchwork_1.1.1       
[19] forcats_0.5.0          stringr_1.4.0          dplyr_1.0.2           
[22] purrr_0.3.4            readr_1.4.0            tidyr_1.1.2           
[25] tibble_3.0.4           ggplot2_3.3.3          tidyverse_1.3.0       
[28] workflowr_1.6.2       

loaded via a namespace (and not attached):
 [1] colorspace_2.0-0    rjson_0.2.20        ellipsis_0.3.1     
 [4] class_7.3-17        rprojroot_2.0.2     fs_1.5.0           
 [7] rstudioapi_0.13     farver_2.0.3        ggsn_0.5.0         
[10] fansi_0.4.1         xml2_1.3.2          codetools_0.2-16   
[13] knitr_1.30          jsonlite_1.7.2      broom_0.7.3        
[16] dbplyr_2.0.0        png_0.1-7           compiler_4.0.3     
[19] httr_1.4.2          backports_1.2.1     assertthat_0.2.1   
[22] cli_2.2.0           later_1.1.0.1       htmltools_0.5.0    
[25] tools_4.0.3         ggmap_3.0.0         gtable_0.3.0       
[28] glue_1.4.2          Rcpp_1.0.5          cellranger_1.1.0   
[31] raster_3.4-5        vctrs_0.3.6         xfun_0.19          
[34] ps_1.5.0            rvest_0.3.6         lifecycle_0.2.0    
[37] scales_1.1.1        hms_0.5.3           promises_1.1.1     
[40] RColorBrewer_1.1-2  yaml_2.2.1          stringi_1.5.3      
[43] highr_0.8           maptools_1.0-2      e1071_1.7-4        
[46] checkmate_2.0.0     RgoogleMaps_1.4.5.3 rlang_0.4.10       
[49] pkgconfig_2.0.3     bitops_1.0-6        evaluate_0.14      
[52] lattice_0.20-41     sf_0.9-6            labeling_0.4.2     
[55] tidyselect_1.1.0    here_1.0.1          plyr_1.8.6         
[58] magrittr_2.0.1      R6_2.5.0            generics_0.1.0     
[61] DBI_1.1.0           pillar_1.4.7        haven_2.3.1        
[64] whisker_0.4         foreign_0.8-80      withr_2.3.0        
[67] units_0.6-7         modelr_0.1.8        crayon_1.3.4       
[70] KernSmooth_2.23-17  utf8_1.1.4          rmarkdown_2.6      
[73] jpeg_0.1-8.1        isoband_0.2.3       grid_4.0.3         
[76] readxl_1.3.1        data.table_1.13.6   git2r_0.27.1       
[79] reprex_0.3.0        digest_0.6.27       classInt_0.4-3     
[82] webshot_0.5.2       httpuv_1.5.4        munsell_0.5.0      
[85] viridisLite_0.3.0