Regional Climate Change in the Northern Hemisphere

Monday, 15 December 2014
Kang Wang, LZU Lanzhou University, Lanzhou, China and Tingjun Zhang, LZU Lanzhou University, College of Earth and Environment Sciences, Lanzhou, China; University of Colorado, National Snow and Ice Data Center, Boulder, CO, United States
It has been widely recognized that climate warming was greater in cold regions than elsewhere on the Earth. Using the CRU TS 3.21 datasets, we investigated regional climate change over a period from 1901 through 2012 with latitudes, elevation, and long-term mean annual precipitation, aridity index (AI), and annual air temperature (MAAT) in the Northern Hemisphere. We found that the amplified warming occurred in the mid-high latitude regions between 50 and 60 ºN, where air temperature increased by about 1.6℃; in semi-arid regions where annual precipitation between 200 and 500 mm; in mid-high altitude regions between 1000 and 1500 m with air temperature increase of about 1.2℃ and the changes in regions higher than 3500 m seemed to intensity with elevation. Over the transition regions between humid and semi-humid regions with AI between 0.5 and 1.0, air temperature has increased by 1.4℃. Cold regions, defined as the long-term MAAT at or below 0 ºC, air temperature has increased by 1.4℃.Cold regions are more sensitive to the warming, and regional temperature increased greater than that changes across the NH (1.11 ºC). The cryosphere in cold regions plays a critical role in the increased warming as well as in the positive feedback.