气候变化领域集成服务门户(CCPortal): Bay of Bengal Sea surface salinity variability using a decade of improved SMOS re-processing

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DOI	10.1016/j.rse.2020.111964
	Bay of Bengal Sea surface salinity variability using a decade of improved SMOS re-processing
	Akhil V.P.; Vialard J.; Lengaigne M.; Keerthi M.G.; Boutin J.; Vergely J.L.; Papa F.
发表日期	2020
ISSN	00344257
卷号	248
英文摘要	Monsoon rain and rivers bring large freshwater input to the Northern Bay of Bengal (BoB), yielding low Sea Surface Salinity (SSS) after the monsoon. The resulting sharp upper-ocean salinity stratification is thought to influence tropical cyclones intensity and biological productivity by inhibiting vertical mixing. Despite recent progresses, the density of in situ data is far from sufficient to monitor the BoB SSS variability, even at the seasonal timescale. The advent of satellite remotely-sensed SSS (SMOS, Aquarius, SMAP) offers a unique opportunity to provide synoptic maps of the BoB SSS every ~8 days. Previous SMOS SSS retrievals did not perform well in the BoB. Here, we show that improved systematic error corrections and quality control procedures yield a much better performance of the new “debiased v4” CATDS level-3 SSS from SMOS (~0.8 correlation, 0.04 bias and 0.64 root-mean-square difference to more than 28,000 collocated in situ data points over 2010–2019). The SMOS product now performs equivalently to Aquarius, and is slightly inferior to SMAP over the BoB. In particular, SMAP and SMOS are able to capture salinity variations close to the east coast of India (r > 0.8 within 75–150 km of the coast). They thus capture the seasonal freshening there, associated with equatorward advection of the Northern BoB low-salinity water by the East Indian Coastal Current (EICC) after the summer monsoon. The 10-year long SMOS record further allows to describe the BoB interannual SSS variability, which is strongest in boreal fall in relation with the Indian Ocean Dipole (IOD). Positive IOD events induce a weakening of the southward export of freshwater by the EICC, and hence negative SSS anomalies in the Northern BoB and positive ones along the East Indian coast. This confirms results from earlier studies based on modelling, sparse in situ data, or shorter satellite records, but this time from a 10-year long SSS record. Overall, our study indicates that the new SMOS retrieval can be confidently used to monitor the BoB SSS and to study its mechanisms. We end by a brief description of the BoB SSS anomalies associated with the extreme 2019 IOD event and highlight the very good performance over the BoB of a new multi-satellite product developed by the European Space Agency merging SMOS, Aquarius and SMAP data. © 2020 Elsevier Inc.
英文关键词	AQUARIUS; Bay of Bengal; East Indian coastal current; Indian Ocean dipole; Sea surface salinity; SMAP; SMOS
语种	英语
scopus关键词	Atmospheric thermodynamics; Error correction; Hurricanes; Satellites; Storms; Water; Biological productivity; East coast of india; European Space Agency; Indian ocean dipoles; Low-salinity water; Root mean square differences; Salinity variations; Sea surface salinity; Surface waters; advection; biological production; coastal current; correction; data processing; error analysis; freshwater input; Indian Ocean Dipole; monsoon; quality control; rainfall; satellite data; sea surface salinity; SMOS; tropical cyclone; vertical mixing; Bay of Bengal; Indian Ocean
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179211
作者单位	CSIR-NIO, Goa, India; LOCEAN-IPSL/Sorbonne Universités, CNRS/ IRD/ MNHN, Paris, France; Indo-French Cell for Water Sciences, IISc/NIO/IITM/IRD Joint International Laboratory, India; ACRI-st, Guyancourt, France; LEGOS, IRD/CNES/CNRS/UPS, Toulouse, France; Universidade de Brasília, Institute of Geosciences, Campus Universitario Darcy Ribeiro70910-900, Brazil
推荐引用方式 GB/T 7714	Akhil V.P.,Vialard J.,Lengaigne M.,et al. Bay of Bengal Sea surface salinity variability using a decade of improved SMOS re-processing[J],2020,248.
APA	Akhil V.P..,Vialard J..,Lengaigne M..,Keerthi M.G..,Boutin J..,...&Papa F..(2020).Bay of Bengal Sea surface salinity variability using a decade of improved SMOS re-processing.Remote Sensing of Environment,248.
MLA	Akhil V.P.,et al."Bay of Bengal Sea surface salinity variability using a decade of improved SMOS re-processing".Remote Sensing of Environment 248(2020).