Hello everybody,
i downloaded two variables from the ERA5 land reanalysis collection individually using the same script. The requested area was set to the Northern Hemisphere in both cases: “area”: [90, -180, 0, 180].
When looking at the meta data for both variables, i noticed that while the geometry, transformation and so on was all consistent, the bounding box defined in the bands meta data was wrong for the evaporation variable:
GRIB_latitudeOfFirstGridPointInDegrees = 90
GRIB_latitudeOfLastGridPointInDegrees = 0
GRIB_longitudeOfFirstGridPointInDegrees = 180
GRIB_longitudeOfLastGridPointInDegrees = 179.9
The meta data of the precipitation variable shows the expected extent in the meta data:
"bands": [
{
"band": 1,
"block": [
400,
101
],
"type": "Float32",
"noDataValue": "NaN",
"unit": "m",
"metadata": {
"": {
"NETCDF_VARNAME": "tp",
"_FillValue": "nan",
"GRIB_paramId": "228",
"GRIB_dataType": "fc",
"GRIB_numberOfPoints": "3243600",
"GRIB_typeOfLevel": "surface",
"GRIB_stepUnits": "1",
"GRIB_stepType": "accum",
"GRIB_gridType": "regular_ll",
"GRIB_uvRelativeToGrid": "0",
"GRIB_NV": "0",
"GRIB_Nx": "3600",
"GRIB_Ny": "901",
"GRIB_cfName": "unknown",
"GRIB_cfVarName": "tp",
"GRIB_gridDefinitionDescription": "Latitude/Longitude Grid",
"GRIB_iDirectionIncrementInDegrees": "0.1",
"GRIB_iScansNegatively": "0",
"GRIB_jDirectionIncrementInDegrees": "0.1",
"GRIB_jPointsAreConsecutive": "0",
"GRIB_jScansPositively": "0",
"GRIB_latitudeOfFirstGridPointInDegrees": "90",
"GRIB_latitudeOfLastGridPointInDegrees": "0",
"GRIB_longitudeOfFirstGridPointInDegrees": "-180",
"GRIB_longitudeOfLastGridPointInDegrees": "179.9",
"GRIB_missingValue": "3.402823466385289e+38",
"GRIB_name": "Total precipitation",
"GRIB_shortName": "tp",
"GRIB_totalNumber": "0",
"GRIB_units": "m",
"long_name": "Total precipitation",
"units": "m",
"standard_name": "unknown",
"GRIB_surface": "0",
"coordinates": "number valid_time latitude longitude expver",
"NETCDF_DIM_valid_time": "315532800"
}
}
}
Here the comparison to the evaporation meta data:
"bands": [
{
"band": 1,
"block": [
400,
101
],
"type": "Float32",
"colorInterpretation": "Undefined",
"noDataValue": "NaN",
"unit": "m of water equivalent",
"metadata": {
"": {
"NETCDF_VARNAME": "evavt",
"_FillValue": "nan",
"GRIB_paramId": "228103",
"GRIB_dataType": "fc",
"GRIB_numberOfPoints": "3243600",
"GRIB_typeOfLevel": "surface",
"GRIB_stepUnits": "1",
"GRIB_stepType": "accum",
"GRIB_gridType": "regular_ll",
"GRIB_uvRelativeToGrid": "0",
"GRIB_NV": "0",
"GRIB_Nx": "3600",
"GRIB_Ny": "901",
"GRIB_cfName": "unknown",
"GRIB_cfVarName": "evavt",
"GRIB_gridDefinitionDescription": "Latitude/longitude",
"GRIB_iDirectionIncrementInDegrees": "0.1",
"GRIB_iScansNegatively": "0",
"GRIB_jDirectionIncrementInDegrees": "0.1",
"GRIB_jPointsAreConsecutive": "0",
"GRIB_jScansPositively": "0",
"GRIB_latitudeOfFirstGridPointInDegrees": "90",
"GRIB_latitudeOfLastGridPointInDegrees": "0",
"GRIB_longitudeOfFirstGridPointInDegrees": "180",
"GRIB_longitudeOfLastGridPointInDegrees": "179.9",
"GRIB_missingValue": "3.402823466385289e+38",
"GRIB_name": "Evaporation from vegetation transpiration",
"GRIB_shortName": "evavt",
"GRIB_units": "m of water equivalent",
"long_name": "Evaporation from vegetation transpiration",
"units": "m of water equivalent",
"standard_name": "unknown",
"GRIB_surface": "0",
"coordinates": "valid_time latitude longitude expver",
"NETCDF_DIM_valid_time": "318211200"
}
}
}
So i’m wondering what happened here and if this has any consequences have the data is read by e.g. QGIS.
Best,
Martina