surface evaporation (AEVAP_S)

Added by Rolf Zentek about 2 years ago

Hey, I use cclm5.0_clm1.
When I look at my AEVAP_S (surface evaporation) variable it seems to me that a [negative value equals evaporation] and a [positive value equals condensation]?
Is this correct? (if yes, is this a misleading name of the variable or based on some useful conventions?)


Replies (1)

RE: surface evaporation (AEVAP_S) - Added by Burkhardt Rockel almost 2 years ago

In COSMO it is convention that fluxes to the surface are in general positive, fluxes from the surface are negative.
For the latent heat flux it can be made clear by the standard_name:

    float ALHFL_S(time, rlat, rlon) ;
        ALHFL_S:standard_name = "surface_downward_latent_heat_flux" ;

There is no standard_name for evaporation containing “upward” or “downward” as far as I know. However, this is a good point you make. CF-conventions allow to add a “positive” attribute. Therefore the following would be a possible alternative:
    float AEVAP_S(time, rlat, rlon) ;
        AEVAP_S:standard_name = "water_evaporation_amount" ;
        AEVAP_S:positive = "down" ;