Drought in Central South-West Asia

In this investigation on Central Southwest Asia (CSWA) meteorological drought, water budget terms have been identified. Tele-connections with climate patterns indices and their impact on the shifting of the mid-latitude jet stream have been explored. We have evaluated the precipitation simulations of different climate models using results from the Atmospheric Model Inter-comparison Project (AMIP).;Teleconnections between precipitation over CSWA and SLP anomalies associated with different climate patterns, North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Pacific Decadal Oscillation (PDO) and El Nino Southern Oscillation (ENSO) have been quantified by using Singular Value Decomposition (SVD). Analysis showed that variation of precipitation over CSWA is associated with variation in SLP over the Atlantic and Pacific Oceans. The highest coupling strength between regional precipitation and different phases of climate patterns has been investigated during the negative phase of the NAO and the positive phase of the PDO. Variability of sea level pressure over the Pacific and Atlantic oceans is directly linked with four features of the average jet stream (November-April) up wind of CSWA. There is its strength over the western part of the domain, enhancement of a convergence region to the west of the domain, shifting towards north/south, and its direction when crossing the domain.;This study evaluates simulations of precipitation patterns by using Atmospheric Model Inter-comparison Project (AMIP) results compared with the GPCC (Global Precipitation Climatology Centre) monthly precipitation data. Most of the models over-predict cyclones-induced autumn precipitation over the western part of the domain and monsoonal summer rainfall over the eastern part of the domain. The Max Planks Institute model (MPI) showed best overall results for the region. Horizontal resolution is not the sole arbiter of model performance. No clear linkages between model physics configurations and model performance have been found.;The seasonal and annual moisture flux convergence of the CSWA region has been examined using reanalysis data sets allowing us to compute water budgets terms in central southwest Asia to understand the regional topographic effects on local precipitation. The study also examines composites of moisture flux convergence (MFC) that characterize the wettest and driest years in this region. Spatially and vertically distributed features of MFC during wet and dry years have been studied to identify the variability of water transport during the 1999-2001 drought periods from the normal years.