Read data

This loads data from FluxDataKit.

df <- read_rds("~/data/FluxDataKit/rsofun_driver_data_clean.rds")

df_fr_pue <- df |> 
  filter(sitename == "FR-Pue") |> 
  select(forcing) |> 
  unnest(forcing)

Plot

GPP in years 2013 and 2014 is ominously low.

ggplot(data = df_fr_pue) +
  geom_line(
    aes(
      date,
      gpp
    ),
    colour = "black"
  ) +
  theme_classic() +
  theme(panel.grid.major.y = element_line()) +
  labs(
    x = 'Date',
    y = expression(paste("GPP (g C m"^-2, "s"^-1, ")"))
  )

Light use efficiency?

… or due to anomalously low MODIS FPAR?

Derive average light use efficiency per month.

df_lue <- df_fr_pue |> 
  filter(temp > 5) |> 
  mutate(yr = lubridate::year(date),
         mo = lubridate::month(date),
         apar = fapar * ppfd) |> 
  group_by(yr, mo) |> 
  summarise(gpp = mean(gpp),
            apar = mean(apar)) |> 
  mutate(lue = gpp/apar) |> 
  mutate(date = lubridate::ymd(
    paste0(
      as.character(yr),
      "-",
      as.character(mo),
      "-15"
    )
  ))
## `summarise()` has grouped output by 'yr'. You can override using the `.groups`
## argument.
ggplot(data = df_lue) +
  geom_vline(xintercept = seq(ymd('2000-01-01'),ymd('2015-01-01'), by = '1 year'), 
             color = "grey80") +
  geom_line(
    aes(
      date,
      lue
    ),
    colour = "black"
  ) +
  theme_classic() +
  theme(panel.grid.major.y = element_line()) +
  labs(
    x = 'Date',
    y = expression(paste("LUE (g C m mol"^-1,")"))
  )

More data for years 2021-2022 here. How to get data for years in between, such that we would have 2000-2022? Then, there is more data from release ICOS release 2023-1.