NASA Global analysis of ocean surface fluxes of heat and freshwater NEWSProject Team: J. Curry, C.A. Clayson, P.J. Webster, E. DiLorenzo, A. Romanou

Science Issue: Ocean surface turbulent heat fluxes

Approach: analysis and blending of global satellite and NWP surface flux products

Satellite Data: SSM/I, scatterometers, surface radiation fluxes,

Other Data: SEAFLUX in situ data set, satellite derived precipand radiation flux products

Models: Reanalysis products, CMEP simulations, Regional Ocean Model

Study Particulars: produce 20 year blended flux product

Project Status:

Year 1 & 2: new 3 hourly SST product with diurnal cycle, 1999 flux evaluation study

Year 3: complete production of new flux data set for 1996-2006; apply data sets

Year 4 & 5: evaluate new flux data set, reprocess as needed, continue regional ocean applications, evaluate U.S. CMEP models

With Wave Spectra

No Wave Spectra

Flux Algorithm (Bourassa et al), whichconsiders wave spectra.

With wave spectra, latent heat flux is reduced in areas with wind driven waves, and is enhanced in areas with swell.

NEWS (Latent Heat Flux)Jan. 1999 (Global Test)

Data sourcesSST (NOAA)Wind (NCDC)Qa (Jackson et al) Ta (NCEP2)

NCEP2

ERA40

Jan. 1999 (Global)

NCEP2 and ERA40 overestimateSurface latent heat fluxes relativeTo satellite-derived values

OAFLUX

HOAPS3

GSSTF2

Jan. 1999 (Global)

Largest variation among the differinglatent heat flux data sets are in regionsof high wind, with the largest latent heatflux values

NCEP2

ERA40

NEWS (Latent Heat Flux)Sep. 11, 1999 (Hurricane Floyd Test)

Satellite (with wave spectra)

Compared to our new product, the reanalysis (NCEP2 and ERA40)greatly underestimates latent heat flux associated with the hurricane Floyd.

Track of Floyd

Difference between satellite fluxes for Hurricane Floyd, September 11, 1999:with wave spectra minus no wave spectra