This is the Daily (24-hour) product; data are projected to equidistant Grid that covers the globe at 1x1 degree cell size, resulting in data arrays of 360x180 size.
The daily temporal and one-degree spatial resolution of the product can be used to examining climate variability at these scales. The global water cycle's provision of water to terrestrial storage, reservoirs, and rivers rests upon the global excess of evaporation to precipitation over the oceans. Variations in the magnitude of this ocean evaporation excess will ultimately lead to variations in the amount of freshwater that is transported (by the atmosphere) and precipitated over continental regions. The air-sea fluxes of momentum, radiation, and freshwater (precipitation-evaporation) play a very essential role in a wide variety of atmospheric and oceanic problems (e.g., oceanic evaporation contributes to the net fresh water input to the oceans and drives the upper ocean density structure and consequently the circulation of the oceans). Information on these fluxes is crucial in understanding the interactions between the atmosphere and oceans, global energy, and water cycle variability, and in improving model simulations of climate variations.
The GSSTF, Version 2b, daily fluxes have first been produced for each individual available SSM/I satellite tapes (e.g., F08, F10, F11, F13, F14 and F15). Then, the Combined daily fluxes are produced by averaging (equally weighted) over available flux data/files from various satellites. These Combined daily flux data are considered as the "final" GSSTF, Version 2b, and are stored in this HDF-EOS5 collection.
There are two sets of GSSTF, Version 2b, Combined data, "Set1" and "Set2". They are different for being produced using a different combination of individual satellite products. Set1/Set2 may contain a larger/smaller global temporal trend in latent heat flux, but with less/more missing data. They are stored together in the HDF-EOS5 files, under two separate Grids, SET1 and SET2.
The double-quoted labels are the short names of the data fields in the HDF-EOS5 files.
The "individual" daily flux data files, produced for each individual satellite, are also available in HDF-EOS5, although from different collections: GES_DISC_GSSTF_xxx_2b, where xxx are the individual satellites (F08, F10, etc..)
The input data sets used for this recent GSSTF production include the upgraded and improved datasets such as the Special Sensor Microwave Imager (SSM/I) Version-6 (V6) product of brightness temperature [Tb], total precipitable water [W], and wind speed [U] produced by the Wentz of Remote Sensing Systems (RSS), as well as the NCEP/DOE Reanalysis-2 (R2) product of sea skin temperature [SKT], 2-meter air temperature [Tair], and sea level pressure [SLP]. Relevant to this MEaSUREs project, these are converted to HDF-EOS5, and are stored in the GES_DISC_GSSTF_NCEP_2b collection.
Please use these products with care and proper citations, i.e., properly indicating your applications with, e.g., "using the combined 2001 data file of Set1 (or Set2)" or "using the 2001 F13 data file".
The previous GSSTF dataset (GSSTF2) has been widely used by scientific communities for global energy and water cycle research and regional and short period data analysis since its official release in 2000/2001. Accurate sea surface fluxes measurements are crucial to understanding the global water and energy cycles. The oceanic evaporation that is a major component of the global oceanic fresh water flux is particularly useful to predicting oceanic circulation and transport. Remote sensing is a valuable tool for global monitoring of these flux measurements. The GSSTF algorithm has been developed and applied to remote sensing research and applications. We are looking forward to serving the scientific communities with another useful dataset in GSSTF2b.
APPENDIX SET1 --------------- The following list summarizes individual satellites used to produce the Combined SET1.
(1) Y1987/: F08/ 1987/07-12: F08 (Note: 1987/12 is filled with missing value due to data scarcity)
(2) Y1988/: F08/ 1988/01-12: F08
(3) Y1989/: F08/ 1989/01-12: F08
(4) Y1990: F08/ F10/ 1990/01-12: F08 (Note: F10 started in 1990/12, but N/A due to data scarcity)
(a) For Y2006, Y2007 and Y2008, the current Combined daily data files do not include the F15 Individual daily data files due to problematic calibration in F15. The Combined daily files will be updated for those three years once an improved set of Individual daily data files are produced using corrected and updated SSM/I F15 input files.
(b) The current Combined daily data files are produced with at most 4 combined satellites, i.e., F10, F11, F13 and F14 for May-Nov 1997, and F11, F13, F14 and F15 for Jan-May 2000.
APPENDIX SET2 --------------- The following list summarizes individual satellites used to produce the Combined SET2. Note that there are many instances where SET2=SET1. The HDF-EOS5 collection contains dedicated flag that reflects that, "Set2eqSet1". (1) Y1987/: (same as Set1) F08/ 1987/07-12: F08 (Note: 1987/12 is filled with missing value due to data scarcity)
(2) Y1988/: (same as Set1) F08/ 1988/01-12: F08
(3) Y1989/: (same as Set1) F08/ 1989/01-12: F08
(4) Y1990: (same as Set1) F08/ F10/ 1990/01-12: F08 (Note: F10 started in 1990/12, but N/A due to data scarcity)
