Mechanisms of the seasonal variability of mixed-layer salinity in the Indian Ocean

Xu Jindian; Qiu Yun; Jing Chunsheng; Gao Lu; Lin Xinyu

doi:10.12284/hyxb2021162

Volume 43 Issue 11

Dec. 2021

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Xu Jindian，Qiu Yun，Jing Chunsheng, et al. Mechanisms of the seasonal variability of mixed-layer salinity in the Indian Ocean[J]. Haiyang Xuebao，2021, 43(11)：32–45 doi: 10.12284/hyxb2021162

Citation:

Xu Jindian，Qiu Yun，Jing Chunsheng, et al. Mechanisms of the seasonal variability of mixed-layer salinity in the Indian Ocean[J]. Haiyang Xuebao，2021, 43(11)：32–45 doi: 10.12284/hyxb2021162

Citation:

Xu Jindian，Qiu Yun，Jing Chunsheng, et al. Mechanisms of the seasonal variability of mixed-layer salinity in the Indian Ocean[J]. Haiyang Xuebao，2021, 43(11)：32–45 doi: 10.12284/hyxb2021162

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Mechanisms of the seasonal variability of mixed-layer salinity in the Indian Ocean

doi: 10.12284/hyxb2021162

1.
Laboratory of Marine Dynamics, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
2.
Haikou Marine Environment Monitoring Station, State Oceanic Administration, Haikou 570311, China

Received Date: 2020-12-03
Rev Recd Date: 2021-01-26

Available Online: 2021-08-17

Publish Date: 2021-12-31

Abstract

Abstract

In this study, we quantify the mixed-layer salinity (MLS) budget in the Indian Ocean using the salinity budget equation along with Argo salinity, SODA ocean current, evaporation, and precipitation data. The results show that the distribution and seasonal variability for the terms of freshwater flux, advection and entrainment in the Indian Ocean, and their contributions to the variations of MLS. Regarding the climatological annual mean, the negative contribution (15.14%) of the horizontal advection term to MLS is much larger than its positive contribution (9.89%). This implies that the horizontal advection transports low-salinity water to the salty regions, resulting in a decrease in MLS there. The distribution and seasonal variability of the freshwater flux term are generally consistent with those of precipitation, with a positive contribution (13.70%) higher than negative contribution (7.81%). It suggests that the freshwater flux term increases MLS in the Indian Ocean because of the evaporation overwhelming the precipitation. Analysis on the regions with significant seasonal variations of MLS indicates that from June to November, the Southwest Monsoon Current transports low-salinity water from the western equatorial Indian Ocean to the western Arabian Sea, causing salinity in that region to decrease. The advection of high-salinity water from the southern and central to the northern of Bengal Bay is the main reason for the increase in salinity there.
- salinity budget,
- mechanism,
- mixed-layer,
- Indian Ocean

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References(18)

References

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