Derived fluxnet variables

Koen Hufkens

Source: vignettes/calc_daytime_vpd.Rmd

Daytime VPD

Daytime VPD is not provided in the daily FLUXNET2015 data files. Instead, we can derive it based on the half-hourly data, averaging half-hourly VPD of time steps where the shortwave incoming radiation "SW_IN_F" is greater than zero (i.e., during the day). To do this, we can set the getvars argment to list(vpd = "VPD_F_DAY") and additionally provide the directory where half-hourly files are located locally through the argument settings. We do this just for one year here (only year 2000 data is provided as external data in this package).

settings_fluxnet <- list(dir_hh = paste0(path.package("ingestr"), "/extdata/"), getswc = FALSE)

df_fluxnet <- ingest_bysite(
  sitename = "FR-Pue",
  source = "fluxnet",
  getvars = list(vpd  = "VPD_F_DAY"),
  dir = paste0(path.package("ingestr"), "/extdata/"),
  settings = settings_fluxnet,
  timescale = "d",
  year_start = 2007,
  year_end = 2007,
  verbose = FALSE
  )
df_fluxnet

Daily minimum temperature

Daily minimum temperature is not provided in the daily FLUXNET2015 data files. Instead, we can derive it based on the half-hourly data. To do this, we can set the getvars argument to list(tmin = "TMIN_F") and additionally provide the directory where half-hourly files are located locally through the argument settings. We do this just for one year here (only year 2000 data is provided as external data in this package).

settings_fluxnet <- list(dir_hh = paste0(path.package("ingestr"), "/extdata/"), getswc = FALSE)

df_fluxnet <- ingest_bysite(
  sitename = "FR-Pue",
  source = "fluxnet",
  getvars = list(tmin  = "TMIN_F"),
  dir = paste0(path.package("ingestr"), "/extdata/"),
  settings = settings_fluxnet,
  timescale = "d",
  year_start = 2007,
  year_end = 2007,
  verbose = FALSE
  )
df_fluxnet

Daily maximum temperature

Daily maximum temperature is not provided in the daily FLUXNET2015 data files. Instead, we can derive it based on the half-hourly data. To do this, we can set the getvars argument to list(tmin = "TMIN_F") and additionally provide the directory where half-hourly files are located locally through the argument settings. We do this just for one year here (only year 2000 data is provided as external data in this package).

settings_fluxnet <- list(dir_hh = paste0(path.package("ingestr"), "/extdata/"), getswc = FALSE)

df_fluxnet <- ingest_bysite(
  sitename = "FR-Pue",
  source = "fluxnet",
  getvars = list(tmax  = "TMAX_F"),
  dir = paste0(path.package("ingestr"), "/extdata/"),
  settings = settings_fluxnet,
  timescale = "d",
  year_start = 2007,
  year_end = 2007,
  verbose = FALSE
  )
df_fluxnet