Extreme sea level rise along the Indian Ocean coastline: observations and 21st century projections

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. Yet, knowledge about past occurrences of ESL and its progression is limited. Combining multiple tide-gauge and satellite-derived sea-level data, we show that ESL has become more frequent, longer-lasting and intense along the Indian Ocean coastlines. We detect a 2–3-fold increase in ESL occurrence, with higher risk along the Arabian Sea coastline and the Indian Ocean Islands. Our results reveal that rising MSL is the primary contributor to ESL increase (more than 75%), with additional contribution from intensifying tropical cyclones. A two-fold increase in ESL along the Indian Ocean coastline is detected with an additional 0.5 °C warming of the Indian Ocean relative to pre-industrial levels. Utilizing the likely range (17th–83rd percentile as the spread) of Intergovernmental Panel on Climate Change MSL projections with considerable inter-model spread, we show that the Indian Ocean region will be exposed annually to the present-day 100 year ESL event by 2100, irrespective of the greenhouse-gas emission pathways, and by 2050 under the moderate-emission-mitigation-policy scenario. The study provides a robust regional estimate of ESL and its progression with rising MSL, which is important for climate change adaptation policies

Neutron diffraction and electrochemical studies on LilrSn4

Large quantities of single phase, polycrystalline LiIrSn4 have been synthesised from the elements by melting in sealed tantalum tubes and subsequent annealing. LiIrSn4 crystallises with an ordered version of the PdGa5 structure: I4/mcm, a = 655.62(8), c = 1128.6(2) pm. The lithium atoms were clearly localised from a neutron powder diffraction study: R-p = 0.147 and R-F = 0.058. Time-dependent electrochemical polarisation techniques, i.e. coulometric titration, chronopotentiometry, chronoamperometry and cyclic voltammetry were used to study the kinetics of lithium ion diffusion in this stannide. The range of homogeneity (Li1+Delta delta IrSn4, -0.091 <= delta <= + 0.012) without any structural change in the host structure and the chemical diffusion coefficient (similar to 10(-7)-10(-9) cm(2)/s) point out that LiIrSn4 is a first example of a large class of intermetallic compounds with lithium and electron mobility. Optimised materials from these ternary lithium alloys may be potential electrode material for rechargeable lithium batteries. (C) 2005 Elsevier Inc. All rights reserved

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Not AvailableThe status of reefs in Palk Bay and the Gulf of Mannar was studied during April–May 2016 following a bleach alert, as the sea surface temperature recorded a sudden increase from 30.5C to 34.0C in Gulf of Mannar. About 71.48% 8.9% of the corals in Palk Bay and 46.04% 3.78% in Thoothukkudi group of Islands in Gulf of Mannar were found bleached, showing a clearly decreasing trend from north to south, which could be attributed to the corresponding pattern in intensity of SST recorded in the study sites. Observations of bleaching patterns among different life-forms showed 68% of the bleached corals were massive forms. It was observed that 22 out of the 26 massive forms were bleached, while the Acropora corymbose (ACC), digitate (ACD) and encrusting coral (CE) forms were not bleached in any of the study sites in Palk Bay and Gulf of Mannar. The study suggests that the ACC, ACD and CE forms have adapted to thermal stress, subsequent to the earlier mass bleaching events. The study highlights the need for understanding the molecular mechanism of the association between corals and the symbiotic algae, for further understanding on coral bleaching in Indian waters.Not Availabl

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