Assessing future rainfall projections using multiple GCMs and a multi-site stochastic downscaling model
نویسندگان
چکیده
0022-1694/$ see front matter Crown Copyright 2 http://dx.doi.org/10.1016/j.jhydrol.2013.02.046 ⇑ Corresponding author. Tel.: +61 293855140; fax: E-mail addresses: [email protected] (R. edu.au (A. Sharma), [email protected] (D. Nage iisc.ernet.in (T.V. Reshmidevi). Impact of global warming on daily rainfall is examined using atmospheric variables from five General Circulation Models (GCMs) and a stochastic downscaling model. Daily rainfall at eleven raingauges over Malaprabha catchment of India and National Center for Environmental Prediction (NCEP) reanalysis data at grid points over the catchment for a continuous time period 1971–2000 (current climate) are used to calibrate the downscaling model. The downscaled rainfall simulations obtained using GCM atmospheric variables corresponding to the IPCC-SRES (Intergovernmental Panel for Climate Change – Special Report on Emission Scenarios) A2 emission scenario for the same period are used to validate the results. Following this, future downscaled rainfall projections are constructed and examined for two 20 year time slices viz. 2055 (i.e. 2046–2065) and 2090 (i.e. 2081–2100). The model results show reasonable skill in simulating the rainfall over the study region for the current climate. The downscaled rainfall projections indicate no significant changes in the rainfall regime in this catchment in the future. More specifically, 2% decrease by 2055 and 5% decrease by 2090 in monsoon (JJAS) rainfall compared to the current climate (1971–2000) under global warming conditions are noticed. Also, pre-monsoon (JFMAM) and postmonsoon (OND) rainfall is projected to increase respectively, by 2% in 2055 and 6% in 2090 and, 2% in 2055 and 12% in 2090, over the region. On annual basis slight decreases of 1% and 2% are noted for 2055 and 2090, respectively. Crown Copyright 2013 Published by Elsevier B.V. All rights reserved.
منابع مشابه
Statistical downscaling of precipitation
Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract Global Circulation Models (GCMs) are a major tool used for future projections of climate change using different emission scenarios. However, for assessing the hydrological impacts of climate change at the watershed and the regional scale, ...
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