ECMWF Open Data download and conversion functions

book_source/03_topical_pages/06_data/01_meteorology.Rmd

@@ -132,3 +132,13 @@ Resolution: 30 min
 Availability: Varies by [site](https://meta.icos-cp.eu/collections/q4V7P1VLZevIrnlsW6SJO1Rz)
 
 Notes: To use this option, set `source` as `ICOS` and a `product` tag containing `etc` in `pecan.xml`
+
+## ECMWF Open Data
+
+Scale: Global
+
+Resolution: 6 hour, 0.4 degree
+
+Availability: Varies by [day](https://data.ecmwf.int/)
+
+Notes: 15 day forecast is provided at two hours 00 and 12, but current implementation only uses forecast hour 00 when download function is called from within the PEcAn workflow

modules/data.atmosphere/DESCRIPTION

@@ -48,6 +48,7 @@ Imports:
     RCurl,
     REddyProc,
     reshape2,
+    reticulate,
     rgdal,
     rlang (>= 0.2.0),
     sp,
@@ -66,7 +67,6 @@ Suggests:
     foreach,
     parallel,
     progress,
-    reticulate
 Remotes:
     github::chuhousen/amerifluxr,
     github::ropensci/geonames,

modules/data.atmosphere/NAMESPACE

@@ -20,6 +20,7 @@ export(debias.met.regression)
 export(download.Ameriflux)
 export(download.AmerifluxLBL)
 export(download.CRUNCEP)
+export(download.ECMWF)
 export(download.ERA5.old)
 export(download.FACE)
 export(download.Fluxnet2015)

modules/data.atmosphere/R/ECMWF_helper_functions.R

@@ -0,0 +1,290 @@
+#' Helper functions for met2CF.ECMWF
+#' 
+#' mergenc_ECMWF writes 1 CF and 50 PF netCDF files by extracting data from GRIB2 files and filling NaNs at 3h position wherever data is unavailable. 
+#'
+#' @param lat latitude
+#' @param lon longitude
+#' @param outfolder Path to directory where nc files need to be saved.
+#' @param overwrite Logical if files needs to be overwritten.
+#' @param verbose Logical flag defining if output of function be extra verbose.
+#'
+#' @return list of dataframes
+#' @export
+#' 
+#' \dontrun{
+#' results <- mergenc_ECMWF(lat.in,
+#'                          lon.in,
+#'                          outfolder,
+#'                          overwrite = overwrite)
+#'
+#' @author Swarnalee Mazumder
+#' 
+nanfill <- function(variable) { # nanfill function fills NaN at every 3h period from 144h to 360h (original step 6h)
+
+  len6 <- variable
+  len3nan <- rep(NA,length(len6)*2-1)
+  len3nan[seq(1, length(len6)*2-1, 2)]  <- len6
+
+  return(len3nan)
+}
+
+combine2nc_ECMWF <- function(lat.in,
+                          lon.in,
+                          outfolder,
+                          overwrite = FALSE,
+                          verbose = TRUE) {
+
+  if (!file.exists(outfolder)) {
+    dir.create(outfolder, showWarnings = FALSE, recursive = TRUE)
+  }
+
+
+  # Python script "download_ecmwf.py" to get latest forecast date and download forecast datasets
+  script.path = file.path(system.file("ECMWF/download_ecmwf.py", package = "PEcAn.data.atmosphere"))
+  reticulate::source_python(script.path)
+
+  time <- 0
+  stream <- "enfo"
+  type <- c("cf", "pf")
+  step_15day <- 360
+
+  all_parameters <-  c("10u", "10v", "2t", "sp", "tp")
+
+  date_latestdata <- ecmwflatest(time= time, step15= step_15day, stream= stream, type= type, params= all_parameters)
+
+  latest_filedate <- strtoi(gsub("-", "", substr(as.character.Date(date_latestdata), 1, 10)))
+
+  current_date <- strtoi(gsub("-", "", Sys.Date()))
+
+  in_fname <- paste(latest_filedate, time, stream, sep = "_")
+
+  script.path = file.path(system.file("ECMWF/met2CFutils.py", package = "PEcAn.data.atmosphere"))
+  reticulate::source_python(script.path)
+
+  fnames_3h <- all_filenames_3h(in_fname)
+  fnames_6h <- all_filenames_6h(in_fname)
+
+  ######### CF ######### 
+
+  ##### 3h CF -> 0 - 141h at 3h timestep
+  cf_3h <- combine_files_cf(fnames_3h, lat_in, lon_in)
+  names(cf_3h) <- c("valid_time", "lon", "lat", "u10", "v10", "t2m", "sp", "tp")
+
+  days_since <- paste("days since", cf_3h$valid_time$time$data, "00:00:00")
+  cf_3h$valid_time <- cf_3h$valid_time$values
+
+  ##### 3h CF -> 144h - 360h at 6h timestep
+  cf_6h_nc <- combine_files_cf(fnames_6h, lat_in, lon_in)
+  names(cf_6h) <- c("valid_time", "lon", "lat", "u10", "v10", "t2m", "sp", "tp")
+
+  cf_6h$valid_time <- cf_6h$valid_time$values
+
+  ### Final CF netCDF filename
+  cf_nc_fname <- paste(latest_filedate, time, stream, "cf.nc", sep = "_")
+
+  # values from cf_3h
+  lat <- cf_3h$lat
+  lon <- cf_3h$lon
+  validtime <- seq(0, 360, 3)
+  validtimeunits <- cf_3h$valid_time
+
+  # create and write the netCDF file -- ncdf4 version
+  # define dimensions
+  londim <- ncdf4::ncdim_def("longitude","degrees_east",as.double(lon)) 
+  latdim <- ncdf4::ncdim_def("latitude","degrees_north",as.double(lat)) 
+  timedim <- ncdf4::ncdim_def("valid_time",validtimeunits,as.double(validtime))
+  time <- ncdf4::ncdim_def("time", days_since, as.double(validtime))
+
+  # define variables
+  fillvalue <- NA
+
+  cf_u10_3 <- cf_3h$u10
+  cf_u10_6_nan <- nanfill(cf_6h$u10)
+  cf_u10 <- c(cf_u10_3, cf_u10_6_nan)
+
+  cf_v10_3 <- cf_3h$v10
+  cf_v10_6_nan <- nanfill(cf_6h$v10)
+  cf_v10 <- c(cf_v10_3, cf_v10_6_nan)
+
+  cf_t2m_3 <- cf_3h$t2m
+  cf_t2m_6_nan <- nanfill(cf_6h$t2m)
+  cf_t2m <- c(cf_t2m_3, cf_t2m_6_nan)
+
+  cf_sp_3 <- cf_3h$sp
+  cf_sp_6_nan <- nanfill(cf_6h$tp)
+  cf_sp <- c(cf_sp_3, cf_sp_6_nan)
+
+  cf_tp_3 <- cf_3h$tp
+  cf_tp_6_nan <- nanfill(cf_6h$tp)
+  cf_tp <- c(cf_tp_3, cf_tp_6_nan)
+
+  dlname <- "Eastward Component of Wind"
+  u10.def <- ncdf4::ncvar_def("eastward_wind","m s**-1",list(timedim),fillvalue,dlname,prec="double")
+
+  dlname <- "Northward Component of Wind"
+  v10.def <- ncdf4::ncvar_def("northward_wind","m s**-1",list(timedim),fillvalue,dlname,prec="double")
+
+  dlname <- "Near surface air temperature"
+  t2m.def <- ncdf4::ncvar_def("air_temperature","K",list(timedim),fillvalue,dlname,prec="double")
+
+  dlname <- "Surface pressure"
+  sp.def <- ncdf4::ncvar_def("air_pressure","Pa",list(timedim),fillvalue,dlname,prec="double")
+
+  dlname <- "Rainfall rate"
+  tp.def <- ncdf4::ncvar_def("precipitation_flux","kg m**-2 s**-1",list(timedim),fillvalue,dlname,prec="double")
+
+  if (!file.exists(cf_nc_fname) || overwrite) {
+
+    tryCatch({
+
+      # create netCDF file and put arrays
+      ncout_cf <- ncdf4::nc_create(cf_nc_fname, list(u10.def, v10.def, t2m.def, sp.def, tp.def),force_v4=TRUE)
+
+      # put variables in netCDF file
+      ncdf4::ncvar_put(ncout_cf,u10.def, cf_u10, verbose = TRUE)
+      ncdf4::ncvar_put(ncout_cf,v10.def, cf_v10, verbose = TRUE)
+      ncdf4::ncvar_put(ncout_cf,t2m.def, cf_t2m, verbose = TRUE)
+      ncdf4::ncvar_put(ncout_cf,sp.def, cf_sp, verbose = TRUE)
+      ncdf4::ncvar_put(ncout_cf,tp.def, cf_tp, verbose = TRUE)
+
+      # add global attributes
+      ncdf4::ncatt_put(ncout_cf,0,"GRIB_edition",2)
+      ncdf4::ncatt_put(ncout_cf,0,"Institution","ecmwf")
+      ncdf4::ncatt_put(ncout_cf,0,"Source","European Centre for Medium-Range Weather Forecasts")
+      history <- paste("PEcAn Project", date(Sys.Date()), sep=", ")
+      ncdf4::ncatt_put(ncout_cf,0,"Conventions","CF-1.7")
+
+      ncdf4::nc_close(ncout_cf) # writes ensemble wise pf files to disk
+
+    },
+
+    error = function(e) {
+      PEcAn.logger::logger.severe("Something went wrong during the writing of the nc file.",
+                                  conditionMessage(e))
+    })
+
+  } else {
+    PEcAn.logger::logger.info(paste0(
+      "The file ",
+      flname,
+      " already exists.  It was not overwritten."
+    ))
+  }
+
+  rows    <- 51
+  results <- data.frame(
+    file = character(rows),
+    host = character(rows),
+    mimetype = character(rows),
+    formatname = character(rows),
+    startdate = character(rows),
+    enddate = character(rows),
+    dbfile.name = "ECMWF",
+    stringsAsFactors = FALSE
+  )
+
+  start_date <- latest_filedate
+  end_date <- strtoi(gsub("-", "", lubridate::ymd(start_date) + days(14)))
+
+  results$file[1]       <-
+    file.path(outfolder, cf_nc_fname)
+  results$host[1]       <- PEcAn.remote::fqdn()
+  results$startdate[1]  <- start_date
+  results$enddate[1]    <- end_date
+  results$mimetype[1]   <- "application/x-netcdf"
+  results$formatname[1] <- "CF Meteorology"
+
+  ######### Perturbed Forecast ######### 
+
+  ##### 3h PF -> 0 - 141h at 3h timestep
+  pf_3h_out_fname <- paste(latest_filedate, time, stream, "pf_3h", sep = "_")
+  pf_3h <- combine_files_pf(fnames_3h, lat_in, lon_in)
+  names(pf_3h) <- c("valid_time", "lon", "lat", "u10", "v10", "t2m", "sp", "tp")
+
+  days_since <- paste("days since", pf_3h$valid_time$time$data, "00:00:00")
+  pf_3h$valid_time <- pf_3h$valid_time$values
+
+  ##### 6h PF -> 144h - 360h at 6h timestep
+  pf_6h_out_fname <- paste(latest_filedate, time, stream, "pf_6h", sep = "_")
+  pf_6h <- combine_files_pf(fnames_6h, lat_in, lon_in)
+  names(pf_6h) <- c("valid_time", "lon", "lat", "u10", "v10", "t2m", "sp", "tp")
+
+  pf_6h$valid_time <- pf_6h$valid_time$values
+
+
+  ##### Creating ensemble wise netCDF files
+
+  pf_u10_3 <- t(pf_3h$u10)
+  pf_u10_6 <- t(pf_6h$u10)
+
+  pf_v10_3 <- t(pf_3h$v10)
+  pf_v10_6 <- t(pf_6h$v10)
+
+  pf_t2m_3 <- t(pf_3h$t2m)
+  pf_t2m_6 <- t(pf_6h$t2m)
+
+  pf_sp_3 <- t(pf_3h$sp)
+  pf_sp_6 <- t(pf_6h$sp)
+
+  pf_tp_3 <- t(pf_3h$tp)
+  pf_tp_6 <- t(pf_6h$tp)
+
+  for (ens in 1:50){
+
+    ncfname_pf <- paste(latest_filedate, time, stream, "pf_ens", ens, sep = "_")
+
+    if (!file.exists(ncfname_pf) || overwrite) {
+
+      tryCatch({
+
+        ncfname_pf <- paste0(latest_filedate, time, stream, "pf_ens", ens, sep = "_")
+
+        pf_u10 <- c(pf_u10_3[, ens], nanfill(u10_6[, ens]))
+        pf_v10 <- c(pf_v10_3[, ens], nanfill(v10_6[, ens]))
+        pf_t2m <- c(pf_t2m_3[, ens], nanfill(pf_t2m_6[, ens]))
+        pf_sp  <- c(pf_sp_3[, ens], nanfill(pf_sp_6[, ens]))
+        pf_tp  <- c(pf_tp_3[, ens], nanfill(pf_tp_6[, ens]))
+
+        ncout_pf <- ncdf4::nc_create(ncfname_pf, list(u10.def, v10.def, t2m.def, sp.def, tp.def),force_v4=TRUE)
+
+        ncdf4::ncvar_put(ncout_pf,u10.def, pf_u10, verbose = TRUE)
+        ncdf4::ncvar_put(ncout_pf,v10.def, pf_v10, verbose = TRUE)
+        ncdf4::ncvar_put(ncout_pf,t2m.def, pf_t2m, verbose = TRUE)
+        ncdf4::ncvar_put(ncout_pf,sp.def, pf_sp, verbose = TRUE)
+        ncdf4::ncvar_put(ncout_pf,tp.def, pf_tp, verbose = TRUE)
+
+        # add global attributes
+        ncdf4::ncatt_put(ncout_pf,0,"GRIB_edition",2)
+        ncdf4::ncatt_put(ncout_pf,0,"Institution","ecmwf")
+        ncdf4::ncatt_put(ncout_pf,0,"Source","European Centre for Medium-Range Weather Forecasts")
+        history <- paste("PEcAn Project", date(Sys.Date()), sep=", ")
+        ncdf4::ncatt_put(ncout_pf,0,"Conventions","CF-1.7")
+
+        ncdf4::nc_close(ncout_pf) # writes ensemble wise pf files to disk
+
+        row <- ens # final data frame has 1+50 rows pertaining to 1cf + 50pf files
+        results$file[row+1]  <- file.path(outfolder, ncout_pf)
+        results$host[row+1]       <- "PEcAn.remote::fqdn()"
+        results$startdate[row+1]  <- start_date
+        results$enddate[row+1]    <- end_date
+        results$mimetype[row+1]   <- "application/x-netcdf"
+        results$formatname[row+1] <- "CF Meteorology"
+
+      },
+
+      error = function(e) {
+        PEcAn.logger::logger.severe("Something went wrong during the writing of the nc file.",
+                                    conditionMessage(e))
+      })
+
+    } else {
+      PEcAn.logger::logger.info(paste0(
+        "The file ",
+        flname,
+        " already exists.  It was not overwritten."
+      ))
+    }
+  }
+
+  return(results)
+}