The tropical Indian Ocean receives the world's most significant tropical ocean rain and river runoff per unit area. The 3-dimensional spreading of Rain and River Water (RRW) entering the tropical Indian Ocean and associated salinity and circulation anomalies are explored for 60 years using ocean reanalysis data tailored to a tracer transport model. RRW mixes in the surface, subducts and spreads, offering a dilution in salinity and expansion in dynamic heights. RRW offers a net transport tendency of water from the Bay of Bengal to the Arabian Sea at a rate of 0.80 ± 0.14 Sv year−1.
Valsala V., Deep-Sea Research I, 190: 103912, December 2022, DOI:10.1016/j.dsr.2022.103912, 1-10
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Product of Bowen ratio with the sum of precipitation rate and evaporation rate has been used as proxy to evaluate the seasonal and annual spatial distributions of lightning flash rate over South/Southeast Asian region (60–120° E, 0–40° N) with 9 models from the Coupled Model Inter-comparison Project-Phase 5 (CMIP5). The model-simulated mean LFR with each model is positively correlated with the satellite-observed LFR on both seasonal and annual scales. The satellite-observed LFR is correlated with the ensemble mean LFR of the models with a correlation coefficient of 0.93 over the region. The model-simulated LFR has also been used for projection of lightning in the late twenty-first century.
Chandra S., Kumar Praveen, Siingh D., Roy I., Victor N.J., Kamra A.K., Natural Hazards, 114, October 2022, DOI:10.1007/s11069-022-05379-8, 57–75
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Methane (CH4) is a potent greenhouse gas and also plays a significant role in tropospheric chemistry. High-frequency (sub-hourly) measurements of CH4 and carbon isotopic ratio (δ13CH4) have been conducted at Pune (18.53°N, 73.80°E), an urban environment in India, during 2018–2020. Methane concentration but not the isotopic values show seasonality in Pune. Isotopic analysis shows waste sector is the significant source of methane in Pune. No lockdown effect was found on methane records.
Metya A., Datye A., Chakraborty S., Tiwari Y.K., Patra P.K., Murkute C., Science of The Total Environment, 842: 156721, October 2022, DOI:10.1016/j.scitotenv.2022.156721, 1-15
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Anthropogenic sea-level rise poses challenges to coastal areas globally. The combined influence of rising mean sea level (MSL) and storm surges exacerbate the extreme sea level (ESL). Increasing ESL poses a major challenge for climate change adaptation of nearly 2.6 billion inhabitants in the Indian Ocean region. The study highlights an important policy-relevant message: strong mitigation and adaptation measures are needed along the Indian Ocean coastline as ESL100 events can occur annually or even less than a year along the densely populated coastline, irrespective of the future GHG emission pathways and socio-economic conditions.
Sreeraj P., Swapna P., Krishnan R., Nidheesh A.G., Sandeep N., Environmental Research Letters, 17: 114016, October 2022, DOI:10.1088/1748-9326/ac97f5, 1-15
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