February 12, 2009 Meeting Summary
Hyun-Sook Kim presented some slides on the improvement of the coupled HWRF-HYCOM forecasts. Three corrections were made which included 1)a conversion of wind stress to velocity, 2)melding forcing for nowcast, and 3)the land-surface temperature fix. Looking at results for Katrina where cKat05 represents the old HYCOM and fKat05 represents the HYCOM with corrections showed an improvement in track and almost a 50kt improvement in intensity values. The forecast skill comparison for Katrina shows an increase in track error for the improved HYCOM with time, but a decrease in intensity error for the improved HYCOM. For the far field for Katrina, a comparison of model SSTs with observations shows warmer SSTs for the new HYCOM compared with the old HYCOM, however there is still a cold bias when compared to SST analysis. For the near field for Hurricane Ike, we see more reasonable values of maximum wind-driven sea surface velocity and warmer mean SSTs for the new HYCOM compared to the old HYCOM. Future work on improving HYCOM includes getting better initial conditions, studying bulk parameters of air-sea fluxes, tuning ocean mixing parameters, and as suggested by Isaac Ginis in the meeting, examining the radiation fluxes for a cold bias fix.