Evaporative cooling over the Tibetan Plateau induced by vegetation growth

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Shen, Miaogen, Piao, Shilong, Jeong, Su-Jong, Zhou, Liming, Zeng, Zhenzhong, Ciais, Philippe, Chen, Deliang, Huang, Mengtian, Jin, Chun-Sil, Li, Laurent Z. X., Li, Yue, Myneni, Ranga B., Yang, Kun, Zhang, Gengxin, Zhang, Yangjian, Yao, Tandong
• Other Authors: Shen, MG (reprint author), Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China., Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China., Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China., Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China., CALTECH, Jet Prop Lab, Pasadena, CA 91011 USA., SUNY Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 USA., Univ Versailles St Quentin En Yvelines, Lab Sci Climat & Environm, UMR Commissariat Energie Atom CNRS 1572, F-91191 Gif Sur Yvette, France., Univ Gothenberg, Dept Earth Sci, S-40530 Gothenburg, Sweden., Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151747, South Korea., Univ Paris 06, CNRS, Lab Meteorol Dynam, F-75252 Paris, France., Boston Univ, Dept Earth & Environm, Boston, MA 02215 USA., Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China.
• Format: Journal/Newspaper
• Language: English
• Published: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2015
• Subjects: climate change; feedback; evapotranspiration; vegetation; Tibetan Plateau; DIURNAL TEMPERATURE-RANGE; CLIMATE-CHANGE; CONVECTIVE PARAMETERIZATION; ALPINE MEADOW; IMPACTS; MODIS; RADIATION; MODEL; PRECIPITATION; SENSITIVITY; Arctic; albedo; Climate change
• Online Access: https://hdl.handle.net/20.500.11897/418078; https://doi.org/10.1073/pnas.1504418112

In the Arctic, climate warming enhances vegetation activity by extending the length of the growing season and intensifying maximum rates of productivity. In turn, increased vegetation productivity reduces albedo, which causes a positive feedback on temperature. Over the Tibetan Plateau (TP), regional vegetation greening has also been observed in response to recent warming. Here, we show that in contrast to arctic regions, increased growing season vegetation activity over the TP may have attenuated surface warming. This negative feedback on growing season vegetation temperature is attributed to enhanced evapotranspiration (ET). The extra energy available at the surface, which results from lower albedo, is efficiently dissipated by evaporative cooling. The net effect is a decrease in daily maximum temperature and the diurnal temperature range, which is supported by statistical analyses of in situ observations and by decomposition of the surface energy budget. A daytime cooling effect from increased vegetation activity is also modeled from a set of regional weather research and forecasting (WRF) mesoscale model simulations, but with a magnitude smaller than observed, likely because the WRF model simulates a weaker ET enhancement. Our results suggest that actions to restore native grasslands in degraded areas, roughly one-third of the plateau, will both facilitate a sustainable ecological development in this region and have local climate cobenefits. More accurate simulations of the biophysical coupling between the land surface and the atmosphere are needed to help understand regional climate change over the TP, and possible larger scale feedbacks between climate in the TP and the Asian monsoon system. Chinese Academy of Sciences [XDB03030404]; National Basic Research Program of China [2013CB956303]; National Natural Science Foundation of China [41125004]; Youth Innovation Promotion Association of the Chinese Academy of Sciences [2015055] SCI(E) PubMed ARTICLE [e-mail]; [e-mail] 30 9299-9304 112