An in situ-satellite blended analysis of global sea surface salinity

作者:Xie P*; Boyer T; Bayler E; Xue Y; Byrne D; Reagan J; Locarnini R; Sun F; Joyce R; Kumar A
来源:JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 2014, 119(9): 6140-6160.
DOI:10.1002/2014JC010046

摘要

The blended monthly sea surface salinity (SSS) analysis, called the NOAA Blended Analysis of Surface Salinity (BASS), is constructed for the 4 year period from 2010 to 2013. Three data sets are employed as inputs to the blended analysis: in situ SSS measurements aggregated and quality controlled by NOAA/NODC, and passive microwave (PMW) retrievals from both the National Aeronautics and Space Administration's (NASA) Aquarius/SAC-D and the European Space Agency's (ESA) Soil Moisture-Ocean Salinity (SMOS) satellites. The blended analysis comprises two steps. First, the biases in the satellite retrievals are removed through probability distribution PDF) matching against temporally spatially colocated in situ measurements. The blended analysis is then achieved through optimal interpolation (OI), where the analysis for the previous time step is used as the first guess while the in situ measurements and bias-corrected satellite retrievals are employed as the observations to update the first guess. Cross validations illustrate improved quality of the blended analysis, with reduction in bias and random errors over most of the global oceans as compared to the individual inputs. Large uncertainty, however, remains in high-latitude oceans and coastal regions where the in situ networks are sparse and current-generation satellite retrievals have limitations. Our blended SSS analysis shows good agreements with the NODC in situ-based analysis over most of the tropical and subtropical oceans, but large differences are observed for high-latitude oceans and along coasts. In the tropical oceans, the BASS is shown to have coherent variability with precipitation and evaporation associated with the evolution of the El Nino-Southern Oscillation (ENSO).

  • 出版日期2014-9