...

With grib_dump you will see that the area in 10u_10v.grb and previously downloaded file from European area: t.ll.europe.grb are not identical.

Advanced MARS usage

Multi-target

Ensemble forecasts

1)

Retrieve the 2 metre temperature field and 2 metre dew point temperature fields of the first 10 members of a week old 12 UTC ensemble prediction (type: perturbed forecast) for 2, 3 and 4 days in advance > see in MARS Catalogue

retrieve,
    class=od,
    date=-7,
    expver=1,
    levtype=sfc,
    number=1/to/10,
    param=167.128/168.128,
    step=48/to/96/by/24,
    stream=enfo,
    time=12,
    type=pf,
    target = "$SCRATCH/ensemble.[type].{shortName}.grb"

...

retrieve,
    class=od,
    date=-7,
    expver=1,
    levtype=sfc,
    param=167.128/168.128,
    step=48/to/96/by/24,
    stream=enfo,
    time=12,
    type=cf,
    target = "$SCRATCH/ensemble.[type].{shortName}.grb"

...

Note that this time we user MARS keyword "type" and ecCodes key "shortName" in the name of the target file. Add one more parameter "param" (find in MARS catalogue link which parameters are available) to the second request and re-run it again. How many target files did the request requests create?

...

Efficiency

In one of previous' requests output find a line looking like this:

...