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In response to abundant freshwater input from rainfall and river discharge, the northern Bay of Bengal (BoB) is featured by low sea surface salinity (SSS) and strong intraseasonal variability (ISV). This study investigates the characteristic and dynamic mechanisms of SSS ISV in the northern BoB based on satellite observations and the output of Simple Ocean Data Assimilation (SODA). The strong SSS ISV is mainly concentrated near the mouth of the Ganges–Brahmaputra River and along the east coast of India, where the horizontal salinity gradient varies greatly. SSS ISV in the northern BoB is notably in phase with freshwater transport, which peaks from July to November. The contribution of riverine freshwater is significant both geographically and temporally. The SSS budget analysis indicates that the horizontal advection plays a dominant role in SSS ISV. Once currents cross the salinity field, large horizontal advection anomalies become important and favor SSS ISV. Altered SSS patterns can impact water density, potentially influencing the strength and direction of currents. This, in turn, may have cascading effects on local and regional climate patterns. [ABSTRACT FROM AUTHOR]

India has a power capacity of 4,02,817 MW, with over half coming from coal-based thermal power plants like the Kolaghat Thermal Power Plant (KTPP), West Bengal, India. These plants produce harmful fly ash, requiring safe disposal. KTPP alone generated 0.5921 million tons of fly ash in 2020-21, managed using ash ponds. Concerns have arisen regarding contamination of nearby agricultural fields, impacting rice cultivation. The objective of the study was to understand how fly ash affects soil and seed germination and emphasizes the importance of making careful decisions when using industrial residues in agriculture to ensure sustainable and responsible practices that prioritize environmental health and plant well-being.Samples were collected from areas near KTPP, and plant growth substrates were prepared by mixing control soil with varying fly ash concentrations. The study was conducted between 15 February and 19 May 2023 in PnaskuraBanamali College (Autonomous), Purba Medinipur, West Bengal, India. The physical and chemical properties of these substrates were analyzed, and rice seed germination studies were carried out over 30 days. The subsequent transplantation and growth assessments included measuring shoots and roots, analyzing leaf chlorophyll and carotenoids, and conducting statistical evaluations. The experiments were triplicated, and statistical analyses using SPSS 16 indicated statistical significance at p < 0.05.The study helps to understand how fly ash affects soil and seed germination, revealing both positive and negative effects on soil properties and plant growth. It emphasizes the need for careful decision-making when using industrial residues in agriculture to ensure sustainable and responsible practices that prioritize both environmental health and plant well-being. [ABSTRACT FROM AUTHOR]

Previous studies have hypothesized that climatologically thick salinity-stratified barrier layers (BLs) in the north Indian Ocean (NIO) influence the upper ocean heat budget, sea surface temperature (SST), and monsoons. Here, we investigate how state-of-the-art Coupled Model Intercomparison Project phase 6 (CMIP6) climate models simulate the NIO barrier layer thickness (BLT). CMIP6 models generally reproduce the BLT seasonal cycle and spatial distribution, but with shallow November–February (NDJF) biases in regions with thick observed BLT: the eastern equatorial Indian Ocean (EEIO), Bay of Bengal (BoB), and southeastern Arabian Sea (SEAS). We show that the intensity of the CMIP6 equatorial easterly wind bias controls the EEIO shallow isothermal layer depth (ILD) and BLT biases. It also controls the BoB shallow BLT bias, both through the propagation of the EEIO shallow ILD bias into the NIO coastal waveguide and because it is linked to the BoB dry and cold bias through the Bjerknes feedback, hence also controlling the mixed layer depth (MLD) deep bias there. Finally, the SEAS shallow BLT bias is due to a too-deep MLD, in response to subdued monsoonal currents around India, which do not bring enough BoB low-salinity water. The BL insulating effect mentioned in literature does not seem to dominate in CMIP6. Rather, the CMIP6 salinity-related deep MLD biases diminish the BoB cooling rate by winter upward surface heat fluxes, reducing cold SST biases. This suggests that salinity effects alleviate the easterly equatorial wind, cold, and dry BoB biases that develop through the positive Bjerknes feedback loop in CMIP6. [ABSTRACT FROM AUTHOR]