I downloaded a bunch of ERA-5 Land Hourly data several months ago for the variables 2m temperature, total precipitation, snow depth and snow depth water equivalent. I downloaded these files for the year 1960 to 2022 and I did it using the same script in R. However, for some reason the snow depth files have its longitude in 0-360 format (which the ERA5 documentation says all should be) while the other variables of 2m temp, total precip and snow depth water equivalent have their longitudes in -180-180 format. Has anyone has a problem like this before? I don’t like how they are in different formats and before I download more data I want to make sure this won’t happen again.
Here is the code I used in R:
var = c("snow_depth", "2m_temperature", "total_precipitation", "snow_depth_water_equivalent")
for (index in 1:length(years)) {
for (index1 in 1:length(var)) {
request <- list(
"dataset_short_name" = "reanalysis-era5-land",
"product_type" = "reanalysis",
"variable" = var[index1],
"year" = years[index],
"month" = c("01", "02", "03", "04", "05", "06", "07", "08", "09", "10", "11", "12"),
"day" = c("01", "02", "03", "04", "05", "06", "07", "08", "09", "10",
"11", "12", "13", "14", "15", "16", "17", "18", "19", "20",
"21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31"),
"time" = c("00:00", "01:00", "02:00",
"03:00", "04:00", "05:00",
"06:00", "07:00", "08:00",
"09:00", "10:00", "11:00",
"12:00", "13:00", "14:00",
"15:00", "16:00", "17:00",
"18:00", "19:00", "20:00",
"21:00", "22:00", "23:00"),
"area" = "60.9/-121.6/56.9/-115.5", # Hay River Basin N/W/S/E
"format" = "netcdf",
# "target" = paste("era5-", years[index], "_", var[index1],"Sept-Dec.nc", sep="") # Output file name
"target" = paste("era5-", years[index], "_", var[index1],"_merge.nc", sep="") # Output file name
# "target" = paste("era5-", years[index], "_", var[index1],".nc", sep="") # Output file name
)
file <- wf_request(user = "195655", # user ID (for authentication)
request = request, # the request
transfer = TRUE, # download the file
path = path # Note: If path = "." then data is stored in current working directory
)
}
}
To show you what I mean here the result of cdo griddes showing how the longitudes are different:
cdo griddes era5-2022_snow_depth_merge.nc
#
# gridID 1
#
gridtype = lonlat
gridsize = 2542
datatype = float
xsize = 62
ysize = 41
xname = longitude
xlongname = "longitude"
xunits = "degrees_east"
yname = latitude
ylongname = "latitude"
yunits = "degrees_north"
**xfirst = 238.4**
xinc = 0.1000001
yfirst = 60.9
yinc = -0.1
cdo griddes era5-2022_snow_depth_water_equivalent_merge.nc
#
# gridID 1
#
gridtype = lonlat
gridsize = 2542
datatype = float
xsize = 62
ysize = 41
xname = longitude
xlongname = "longitude"
xunits = "degrees_east"
yname = latitude
ylongname = "latitude"
yunits = "degrees_north"
**xfirst = -121.6**
xinc = 0.09999997
yfirst = 60.9
yinc = -0.1