Goddard Satellite-Based Surface Turbulent Fluxes, 1x1 deg Monthly Grid, Set1 and Interpolated Data V2c (GSSTFM) at GES DISC

These data are the Goddard Satellite-based Surface Turbulent Fluxes Version-2c Dataset recently produced through a MEaSUREs funded project led by Dr. Chung-Lin Shie (UMBC/GEST, NASA/GSFC), converted to HDF-EOS5 format. The stewardship of this HDF-EOS5 dataset is part of the MEaSUREs project.

GSSTF version 2b (Shie et al. 2010, Shie et al. 2009) generally agreed better with available ship measurements obtained from several field experiments in 1999 than GSSTF2 (Chou et al. 2003) did in all three flux components, i.e., latent heat flux [LHF], sensible heat flux [SHF], and wind stress [WST] (Shie 2010a,b). GSSTF2b was also found favorable, particularly for LHF and SHF, in an intercomparison study that accessed eleven products of ocean surface turbulent fluxes, in which GSSTF2 and GSSTF2b were also included (Brunke et al. 2011). However, a temporal trend appeared in the globally averaged LHF of GSSTF2b, particularly post year 2000. Shie (2010a,b) attributed the LHF trend to the trends originally found in the globally averaged SSM/I Tb's, i.e., Tb(19v), Tb(19h), Tb(22v) and Tb(37v), which were used to retrieve the GSSTF2b bottom-layer (the lowest atmospheric 500 meter layer) precipitable water [WB], then the surface specific humidity [Qa], and subsequently LHF. The SSM/I Tb's trends were recently found mainly due to the variations/trends of Earth incidence angle (EIA) in the SSM/I satellites (Hilburn and Shie 2011a,b). They have further developed an algorithm properly resolving the EIA problem and successfully reproducing the corrected Tb's by genuinely removing the "artifactitious" trends. An upgraded production of GSSTF2c (Shie et al. 2011) using the corrected Tb's has been completed very recently.

GSSTF2c shows a significant improvement in the resultant WB, and subsequently the retrieved LHF - the temporal trends of WB and LHF are greatly reduced after the proper adjustments/treatments in the SSM/I Tb's (Shie and Hilburn 2011). In closing, we believe that the insightful "Rice Cooker Theory" by Shie (2010a,b), i.e., "To produce a good and trustworthy 'output product' (delicious 'cooked rice') depends not only on a well-functioned 'model/algorithm' ('rice cooker'), but also on a genuine and reliable 'input data' ('raw rice') with good quality" should help us better comprehend the impact of the improved Tb on the subsequently retrieved LHF of GSSTF2c.

This is the Monthly product; data are projected to equidistant Grid that covers the globe at 1x1 degree cell size, resulting in data arrays of 360x180 size. The monthly product is a result of averaging of a month worth of daily GSSTF2c files. Starting with Version 2c, there is only one set of Combined data, "Set1". A finer resolution, 0.25 deg, of this product has been released as Version 3.

The monthly temporal and one-degree spatial resolution of the product can be used to examining climate variability at these scales. 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.

The short name for this product is GSSTFM.

本数据集为基于戈达德卫星的表面湍流通量版本2c数据集，该数据集由UMBC/GEST及NASA/GSFC的Dr. Chung-Lin Shie（领导）通过MEaSUREs资助的项目最新制作而成，并已转换为HDF-EOS5格式。该HDF-EOS5数据集的管理权属于MEaSUREs项目。GSSTF版本2b（Shie等，2010，Shie等，2009）在所有三个通量分量上，即潜热通量[LHF]、感热通量[SHF]和风应力[WST]方面，与1999年多个现场实验获得的船舶测量数据相比，普遍认为比GSSTF2（Chou等，2003）更为吻合。GSSTF2b在海洋表面湍流通量产品的相互比较研究中也被证明优于其他产品，尤其是对于LHF和SHF，该研究评估了包括GSSTF2和GSSTF2b在内的十一项产品（Brunke等，2011）。然而，GSSTF2b的全局平均LHF中出现了时间趋势，特别是在2000年之后。Shie（2010a,b）将LHF趋势归因于全球平均SSM/I Tb（即Tb(19v)、Tb(19h)、Tb(22v)和Tb(37v)）的趋势，这些趋势被用于检索GSSTF2b底层（最低大气500米层）的降水量[WB]，然后是表面比湿[Qa]，最后是LHF。SSM/I Tb的趋势最近被发现主要是由于SSM/I卫星的地球入射角（EIA）的变化/趋势（Hilburn和Shie，2011a,b）。他们进一步开发了一个正确解决EIA问题的算法，并成功地通过真正消除“人为”趋势来重现了校正后的Tb。最近已完成使用校正后的Tb升级的GSSTF2c（Shie等，2011）的生产。GSSTF2c在所得的WB方面显示出显著的改进，进而检索出的LHF——在SSM/I Tb的适当调整/处理之后，WB和LHF的时间趋势大大减少（Shie和Hilburn，2011）。最后，我们认为Shie（2010a,b）提出的富有洞察力的“电饭煲理论”，即“要生产出优良且值得信赖的‘输出产品’（美味的‘煮熟的大米’），不仅需要一个功能完善的‘模型/算法’（‘电饭煲’），还需要具有良好质量的‘输入数据’（‘生米’）”，有助于我们更好地理解改进后的Tb对随后检索出的GSSTF2c LHF的影响。本产品为月度产品；数据投影至等距网格，覆盖全球，网格单元大小为1x1度，形成360x180大小的数据数组。月度产品是整个月每日GSSTF2c文件的平均结果。从版本2c开始，只有一套综合数据，“Set1”。本产品的更高分辨率，0.25度，已作为版本3发布。本产品的月度时间和一度的空间分辨率可用于考察这些尺度的气候变率。海洋蒸发对海洋净淡水输入的贡献驱动了上层海洋密度结构，从而影响海洋环流。本产品的简称是GSSTFM。