- To downscale 08 GCMs which participated in the Coupled Model Inter-comparison Project Phase 5 under two emission scenarios of RCP 8.5 and RCP 4.5.
- To estimate the projected seasonal i.e. Summer (JJAS) and Winter (DJF) precipitation patterns.
- To estimate the projected differences in future (2040-2070) and historic (1960-1990) simulations.
Supervisor Name: Ms. Ghulam Hussain Dars, Assistant Professor, USPCAS-W, MUET, Jamshoro
This study predicts the impacts of climate change on future precipitation trend over Pakistan using CMIP5 climatic scenarios. The simulations of eight (8) CMIP5 climate model outputs for two RCPs (Representative concentration pathways) 8.5 and 4.5 are analyzed for the future period of 31 years i.e. 2040-2070.CMIP5 output having coarse resolutions approximately 200 by 200km grid size are statistically downscaled to 1/8-degree equivalent to 1 by 1 km grid size. Global Precipitation Climatology Center (GPCC) 0.5-degree historical time-series grid dataset is used for bias correction using Quantile Mapping approach. Downscaling has been performed by Delta downscaling method. The bias corrected, and downscaled data has been validated with Global Historical Climatology Network (GHCN) data. The study estimated precipitation trend for annual, winter (December-January-February) and summer (June-July-August-September) seasons. Differences for the future precipitation patterns are computed with respect to the historical period (1960-1990) simulations.
Results show that Northern part of the country including Gilgit-Baltistan and disputed Kashmir are likely to have a decreasing trend in the future period. Khyber Pakhtunkhwa, capital administrated area Islamabad and Azad Jammu Kashmir belt could get more precipitation ranges from 121-255 mm/month of maximum precipitation by CSIRO-MK3.6 and GFDL-ESM-2G. Northern and central parts of the Punjab province are likely to get more precipitation whereas the west and southern part probably could get less precipitation. Baluchistan and coastal belt could have more dry days. However, Baluchistan has great variation in precipitation trends except GISS-E2H which project 127mm/month of rainfall. Season wise scale showed frequent high magnitude peaks in summer and winter seasons. Annual average monthly precipitation projection trend showed more than 450 mm/month.