Improvements in Wintertime GOES SRB Retrievals for Hydrometeorological Modeling of Large Scale BOREAS Domain

As part of the ongoing BOREAS hydrometeorological modeling intercomparison study, various satellite datasets are used to provide continuous coverage of key forcing variables on the landscape, surface radiation fluxes being perhaps the most important along with rainfall. This study describes improvements to a pair of GOES-based surface radiation budget (SRB) algorithms used to retrieve directional solar and infrared fluxes. Our focus here is on snow cover conditions because the original algorithms did not always perform well in the presence of cloud and also exhibited a systematic error in the retrieved snow albedo.

The original algorithms are described in Gu and Smith (1997) and Gu et al. (1997). The improvements to the algorithm have focused on a more detailed scheme to retrieve the albedo, and an improved but practical means to screen clouds over snow cover using 3 or 4 of the GOES imager channels, depending on the type of surface under observation. The results of the new SRB retrievals are then analyzed in the context of their impact on the hydrometeorological modeling intercomparisons.

Gu, J., and E.A. Smith, 1997: High resolution estimates of total solar and PAR surface fluxes over large scale BOREAS study area from GOES measurements. J. Geophys. Res., 102, 29685-29705.

Gu, J., E.A. Smith, G.B. Hodges, and H.J. Cooper, 1997: Retrieval of daytime surface net longwave flux over BOREAS from GOES estimates of surface solar flux and surface temperature. Canadian J. Rem. Sens., 23, 176-187.