Impact of the desiccation of the Aral Sea on summertime surface air temperatures Somnath Baidya Roy a, * , Maxwell Smith b , Lucinda Morris c , Nikolai Orlovsky d , Abdulkhodi Khalilov e a Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India b Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA c Department of Atmospheric Sciences, University of Illinois, Urbana, IL 61801, USA d The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel e Scientific Center of Plant Production, Uzbekistan Academy of Sciences, Bogishamol 232, Tashkent 700047, Uzbekistan article info Article history: Received 4 July 2013 Received in revised form 4 March 2014 Accepted 30 June 2014 Available online 17 July 2014 Keywords: Aral Sea Central Asia Lake desiccation Lakeeatmosphere interaction Land use/land cover change Regional climate change WRF abstract The Aral Sea located in Central Asia has undergone drastic changes in the last 50 years. This study quantitatively estimates the change in lake surface area since the 1970s and investigates how this change can affect local and regional near-surface air temperatures during the summer. LANDSAT satellite im- agery shows more than 80% reduction in lake surface area since the 1970s. Simulations with the Weather Research and Forecasting (WRF) regional climate model show that this change in the lake surface can lead to a statistically significant warming of more than 6  C in 2 m air temperatures over the dry lake bed and a significant warming signal of up to 1  C covering an area up to 200 km around the original lake boundary, especially to the south. Observations in this region are sparse but still warming trends consistent with the simulations are seen in 2 m air temperatures from the Global Historical Climatology Network dataset. Atmospheric reanalysis and land cover data suggest that large-scale climate variability and land use change in the Amu Darya and Syr Darya basins contribute to the regional warming trends. Improvements in data and modeling capability are required to study the effects on diurnal and seasonal temperature cycle. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction The Aral Sea is an inland lake located in Central Asia on the border of Kazakhstan and Uzbekistan. It is an endorheic lake fed by the rivers Amu Darya from the south and Syr Darya from the east. Aral Sea was once the fourth largest lake in the world with a surface area approximately 68,000 sq. km. However the lake has been gradually shrinking starting in the late 1960s. Even though inland lakes can dramatically expand and shrink due to natural climatic and hydrologic variability, research shows that the ongoing water loss of the Aral Sea is due to anthropogenic causes. Massive irri- gation projects have diverted water from the rivers feeding the lake into farmlands in neighboring countries leading to significant reduction in original lake surface area and volume (Glasovsky, 1995). Recently efforts have been made to stabilize the North Aral Sea, a 2500 sq. km section in the northern tip of the lake, by building the a dam to separate it from the rest of the lake and improving the flow of the Syr Darya (Micklin and Aladin, 2008; Pala, 2011, 2006). The future of the rest of the lake looks bleak because the water supply is not sufficient to compensate for the evaporative losses (Glantz et al., 1993; Micklin, 2007, 1988). The desiccation of the Aral Sea has resulted in significant hy- drologic, economic, environmental and public health impacts (Aladin and Potts, 1992; Elpiner, 2004; Glantz, 2004; Orlovsky, 2004; Small et al., 2001a, 1999; Vostokova, 2004; Whish-Wilson, 2002). The fishing industry that dominated the local economy is almost totally destroyed. The dry lake bed is salt-crusted bare soil that is heavily contaminated with chemical fertilizers and pesticide residues. Deposition of windblown toxic particulates and salt from the exposed lake bed during storms (O'Hara et al., 2000a,b; Wiggs et al., 2003) is threatening the health and survival of human, animal and plant communities in the surrounding region up to 1 million sq. km in area. The desiccation of the Aral Sea has significantly altered local and even the regional climate of Central * Corresponding author. þ91 11 2369 1284. E-mail addresses: drsbr@iitd.ac.in (S. Baidya Roy), maxwell.a.smith@gmail.com (M. Smith), lucinda.morris22@gmail.com (L. Morris), nicolai@bgu.ac.il (N. Orlovsky), akhalilov@bk.ru (A. Khalilov). Contents lists available at ScienceDirect Journal of Arid Environments journal homepage: www.elsevier.com/locate/jaridenv http://dx.doi.org/10.1016/j.jaridenv.2014.06.008 0140-1963/© 2014 Elsevier Ltd. All rights reserved. Journal of Arid Environments 110 (2014) 79e85