Aerosol effects (AER_OPT)

[gtrem]

Hi All,

I am testing several options to account for the direct effect of aerosols (AER_OPT). I am using UEMS V15.99.5 and I am facing two problems :

1. First, setting AER_OPT = 2 (Ruiz-Arias method) using RRTMG radiation schemes and the defaults additional options (AER_TYPE=1, AER_AOD550_OPT=1, AER_AOD550_VAL=0.12, etc.) has a small impact on the SW radiation quantities (SWDOWN, SWDDNI, SWDDIF, etc.). However, setting AER_AOD550_VAL to higher or lower values leads to identical results. In fact, SWDOWN should decrease with an increase in AOD for example, and this is not what I see…

2. Second, I am wondering how to use time varying AOD values (AER_AOD550_OPT=2) instead of constant value (AER_AOD550_OPT=1). The WRF-Solar user's guide (https://www.google.fr/url?sa=t&rct=j&q= ... AwtJlUU5gw) only tells that the time varying AOD should be read via auxiliary file(s) in WRF I/O API-conforming netCDF format. I would like to have more information on that specific format and where to place the(se) file(s).

Can anybody familiar with aerosols activation in UEMS help me ?

Best regards,
Guillaume