Future climate projection of the southern Caspian basin under global warming, case study: HadCM3 model

Abstract

In the recent years, the southern basin of Caspian Sea has been faced with several extreme climatic events including droughts, heavy rain falls, snowfalls and floods and heat waves. The study area covers all stations with at least 30 years’ observation data which are located in the southern basin of Caspian Sea. The Downscaling on to precipitation and temperature parameters has been performed for the period of 2010-2099 by using both of statistical and dynamical methods under SRES A2 and B2. SDSM as a statistical tool has been used for the whole period (1961-2099). The results have been evaluated in monthly and yearly time-scales. In yearly time-scale, we found that mean of precipitation will decrease significantly, especially over central and western parts of the study area. Also, minimum and maximum of decreasing in annual precipitation belong to the Gorgan and Babolsar stations between 24.7 – 59.6 percent, respectively. The total number of daily maximum precipitation with 10, 20 and 30 mm/day and with 95 and 99 percentiles will be increased over all stations and under A2 and B2 scenarios during the next decades of 2011-2039, 2040-69 and 2070-2099. Mean increasing in annual temperature of the study area is projected to be 1-1.8, 1.9-3.3 as well as 2.4-5.1 C0in the period of 2011-2039, 2040-69 and 2070-2099, respectively. The total number of frost days has been decreased significantly as well. The final results of SDSM as statistical method and PRECIS as a dynamical method are matched to each other.

Keywords

• caspian
• emission scenarios
• downscaling
• sdsm
• precis