Socio-economic Vulnerability of Cities

Cities are cardinal and nodal points of a country. Any stress or shock on a city can have cascading adverse effects on the socio-economy of the entire nation. An attempt has been to develop indices, indicating the vulnerability to climate change/environmental hazards, for Indian cities located in different bio-climatic zones. The indices generated in the study are based on socio-economic variables and provide an overview of the potential vulnerabilities faced by these cities in the context of climate disasters. Eleven cities located in six different bio-climatic zones have been studied.

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Evaluation of CORDEX Regional Climate Models for the simulation of Indian Summer Monsoon Characteristics

Dynamic Regional Climate Models (RCMs) work at fine resolution for a limited region and hence they are presumed to simulate regional climate better than General Circulation Models (GCMs). Simulations by RCMs are used for impacts assessment, often without any evaluation. There is a growing debate on the added value made by the regional models to the projections of GCMs specifically for the regions like, United States and Europe.

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Satellite-based Fog monitoring over south Asia (2015-16 fog season)

We are developing this satellite-based fog monitoring system with an ultimate goal of integrating fog information to air, rail and vehicular transportation management, as well as for dissemination of fog information to government agencies and general public. In addition to datasets obtained from both polar orbiting and geostationary satellites, we also plan to integrate surface-based meteorological and pollution related measurements in future implementations.

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The 1976/1977 Pacific Ocean regime shift induced a delayed shift in Indian Summer Monsoon Onset

Onset of the ISMR displays substantial interannual variability and this variability is traditionally linked to sea surface temperature (SST) anomalies over the tropical Pacific Ocean. The tropical Pacific SST underwent a regime shift during 1976/77. We report a prominent delay in the Indian summer monsoon (ISM) onset following the regime shift. The onset dates are computed with the Hydrologic Onset and Withdrawal Index, based on vertically integrated moisture transport over the Arabian Sea (AS). The shift in onset is found to be due to the change in moisture availability over the AS.

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Urbanization Impacts on Extreme Rainfall

Here we take up an observational study to understand the influence of urbanization on the characteristics of precipitation (specifically extremes) in India. We identify 42 urban regions and compare their extreme rainfall characteristics with those of surrounding rural areas. We observe that, on an overall scale, the urban signatures on extreme rainfall are not prominently and consistently visible, but they are spatially nonuniform.

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Why do CMIP5 Models fail to simulate Monsoon trend?

Impacts of climate change on Indian Summer Monsoon Rainfall (ISMR) and the growing population pose a major threat to water and food security in India. Adapting to such changes needs reliable projections of ISMR by general circulation models. Here we find that, majority of new generation climate models from Coupled Model Intercomparison Project phase5 (CMIP5) fail to simulate the post-1950 decreasing trend of ISMR. The weakening of monsoon is associated with the warming of Southern Indian Ocean and strengthening of cyclonic formation in the tropical western Pacific Ocean.

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