Boundary layer dissipation "forecast only" in Documentation but downloadable in ERA5 hourly reanalysis data?

Datasets and Usage C3S - Datasets and Usage
, , ,
1

Hi,

Boundary layer dissipation is listed as having only forecast values in documentation but I see that it can be downloaded from the ERA5 hourly reanalysis dataset (“‘reanalysis-era5-single-levels’”)?

So, is this varaible giving me the forecast or the reanalysis values.
I’m using the CDSAPI request as follows,

c.retrieve(
‘reanalysis-era5-single-levels’,
{
‘product_type’: ‘reanalysis’,
‘variable’: ‘boundary_layer_dissipation’,
‘year’: ‘2022’,
‘month’: ‘02’,
‘day’: ‘14’,
‘time’: [
‘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’,
],
‘format’: ‘netcdf’,
‘area’: [
47.44, 10.28, 47.38,
10.36,
],
},
‘download.nc’)

Thanks,
Jerome

2

Hi Jerome,
The CDS ERA5 dataset includes analysis and forecast fields ; see the page

ERA5: data documentation

Under the section
“Date and time specification” for the mapping of ‘forecast times’ to ‘CDS times’,
Thanks
Kevin

3

Do you know where we can find the difference between era5-single-levels and era5-pressure-levels?
What is the altitude used for variables in era5-single-levels where altitude in is not specified as in “boundary-layer-dissipation”? ("10m u component wind speed is self-explanatory in this case)

Thanks,
Jerome