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To download auxiliary land invariant parameters, please use ERA5 (see table1 of ERA5 documentation). The land-sea mask used to produce the ERA5-Land dataset is also attached here below, already interpolated to a regular lat/lon grid of 0.1°x0.1°:
name | units | shortName | paramId | GRIB1 | GRIB2 |
|---|---|---|---|---|---|
| land-sea mask | (0-1) | lsm | 172 | x |
Parameters described as "instantaneous" below, are valid at the specified time.
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Independently whether a model grid point is over a lake or not, the IFS computes lake variables all over the globe, at each grid-box. This is to ease output field aggregation at diverse model resolutions and to have a warm start of the model with shorter spin-up time if lake cover is upgraded, i.e., it is still a decent lake initial condition if lake location are updated or a new lake is added operationally. Lake depths (input parameter for our lake parametrization) are specified for each grid-box either with in-situ values or with a default 25 m value; over ocean we use ocean bathymetry. Worth to mention that the later default values will be changed soon (extra information in this HESS reference). The computed lake variable values are not taken into account in the total grid-box flux calculations if lake is not present in the grid-box.
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