Abstract
Impact factors on the salinity budget, especially the eddy salt fluxes and smaller-scale diffusive salt fluxes for the upper 50 m of the Bay of Bengal (BoB) in 2014 are investigated using a box model based on the Regional Ocean Modeling System (ROMS) daily outputs. The model results reproduce that the precipitation and river runoffs are the dominant factors modulating the sharp salinity decrease during the summer monsoon season. The analysis shows that the salinity increase after the summer monsoon is mostly due to the meridional advective and diffusive salt fluxes. The vertical advective salt flux, which is sensitive to the different signals of the wind stress curl, plays an important role in balancing the salinity change induced by the meridional advective salt flux during both the summer and winter monsoon seasons. Distinctive spatial mesoscale structures are presented in the eddy salt flux throughout the year, and their contributions are sizeable (over 30% in the meridional direction and about 10%–30% in the vertical direction). The meridional eddy salt flux is larger in the monsoon seasons than that in the inter-monsoon seasons, and in a positive pattern near the western boundary during the winter monsoon and autumn inter-monsoon. The vertical eddy salt flux makes an important contribution to the salinity budget, especially along the coastal area and around the Andaman and Nicobar Islands. The vertical eddy salt flux becomes large when a tropical cyclone passes the area.
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Data Availability Statement
The datasets generated and/or analyzed for the current study are available from the corresponding author.
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Acknowledgment
The BOA-Argo dataset used in this study is produced by the China Argo Real-time Data Center. These data were collected and made freely available by the International Argo Program and the national programs that contribute to it (http://www.argo.ucsd.edu, http://argo.jcommops.org). The Argo Program is part of the Global Ocean Observing System. The Drifter-Derived Climatology of Global Near-Surface Currents data are from ftp://ftp.aoml.noaa.gov/phod/pub/lumpkin/drifter_climatology The best track data are from the Joint Typhoon Warning Center (https://www.metoc.navy.mil/jtwc/jtwc.html?north-indian-ocean).
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Supported by the National Key Research and Development Program of China (Nos. 2016YFA0601803, 2017YFA0604100), the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (No. 311020004), the National Natural Science Foundation of China (Nos. 41706008, 41706094), the Key Program of Marine Economy Development (Six Marine Industries) Special Foundation of Department of Natural Resources of Guangdong Province (No. GDNRC[2020]049), the Natural Science Foundation of Jiangsu Province (No. BK20170953), and the National Programme on Global Change and Air-Sea Interaction (No. GASI-IPOVAI-02)
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Wang, Q., Dong, C., Li, J. et al. Numerical study of the seasonal salinity budget of the upper ocean in the Bay of Bengal in 2014. J. Ocean. Limnol. 39, 1169–1187 (2021). https://doi.org/10.1007/s00343-020-0285-1
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DOI: https://doi.org/10.1007/s00343-020-0285-1