Stable isotopes and salinity in the surface waters of the Bay of Bengal: Implications for water dynamics and palaeoclimate

作者：Achyuthan Hema; Deshpande R D^*; Rao M S; Kumar Bhishm; Nallathambi T; Kumar K Shashi; Ramesh R; Ramachandran P; Maurya A S; Gupta S K

来源：Marine Chemistry, 2013, 149: 51-62.

DOI：10.1016/j.marchem.2012.12.006

• Bay of Bengal
• Stable isotopes
• Salinity
• Surface waters
• Himalayan rivers
• Peninsular rivers
• India

Surface water mixing in the Bay of Bengal (BOB) inferred from spatio-temporal distribution of delta O-18 and salinity based on synthesis of 194 new samples together with published data is reported. In general, both delta O-18 and salinity have low values in northern part of the BOB, progressively increasing towards SW. The lowest values are observed during July-September (southwest monsoon season) and the highest in pre-monsoon. The most prominent delta O-18-salinity relationship is seen for samples collected during June to October when the Himalayan river influx dominates. When this influx decreases in other seasons the delta O-18-salinity relationship is poor.
The delta O-18-delta D regression of samples north of 10 degrees N is similar to the GMWL However, for samples south of similar to 10 degrees N, this regression has a significantly lower slope. This is interpreted as due to absence of direct riverine inflow in this region of the BOB, coupled with -ve (P-E; Precipitation minus Evaporation) almost throughout the year.
This study shows that the seasonal distribution of delta O-18 and salinity over the northern BOB is dominantly governed by the variation in the (P + R-vertical bar E vertical bar) in spite of the fact that ocean currents transfer several times more water between the two basins of northern Indian Ocean.

• 出版日期2013-2-20