A recently revived dataset of satellite-based global air-sea surface turbulent fluxes (GSSTF2b) – features and applications

Accurate sea surface flux measurements are crucial to understanding the global water and energy cycles. The oceanic evaporation, which is a major component of the global oceanic fresh water flux, is particularly useful for predicting oceanic circulation and transport. Remote sensing is a valuable tool for global monitoring of these flux measurements. The Goddard Satellite-based Surface Turbulent Fluxes (GSSTF) algorithm being originally developed in late 1990's was subsequently applied to produce the later on widely used daily global (1ox1o) GSSTF2 (Version-2) dataset (July 1987-December 2000) in 2001. Almost a decade later, a new daily global (1ox1o) dataset, i.e., GSSTF2b (July 1987-December 2008) has lately been produced by using upgraded and improved input datasets such as the Special Sensor Microwave Imager (SSM/I) Version-6 (V6) product (including brightness temperature [Tb], total precipitable water [W], and wind speed) and the NCEP/DOE Reanalysis-2 (R2) product (including sea skin temperature, 2-meter air temperature, and sea level pressure). The previous input datasets used for producing GSSTF2 were earlier products of SSM/I Version-4 (V4) and NCEP Reanalysis-1 (R1). The newly produced GSSTF2b was found to generally agree better with available ship measurements obtained from several field experiments in 1999 than its counterpart GSSTF2 in all three flux components – latent heat flux (LHF), sensible heat flux, and wind stress. The globally averaged LHF of GSSTF2b was found with a smaller magnitude, as well as a smaller temporal trend than that of GSSTF2. The SSM/I Tb (i.e., Tb19v and Tb22v) retrieved from different satellites (i.e., F8, F10, F11, F13, F14 and F15) and used to retrieve the bottom-layer precipitable water (WB), and then the surface air humidity (Qa) has played a critical role in the trend of globally averaged LHF. More features and applications (e.g., the ENSO signal) of GSSTF2b will be presented and discussed in the meeting.