A41P-06
Anthropogenic Aerosol Forcing as Indicated by the Reversion of Warming-elevation Relationship
Thursday, 17 December 2015: 09:15
3010 (Moscone West)
Zhenzhong Zeng1, Anping Chen2, Philippe Ciais3, Yue Li1, Laurent Z. X. Li4, Robert Vautard5, Liming Zhou6, Hui Yang1, Mengtian Huang1 and Shilong Piao1, (1)Peking University, Beijing, China, (2)Princeton University, Princeton, NJ, United States, (3)CNRS, Paris Cedex 16, France, (4)Université Pierre et Marie Curie-Paris 6, Laboratoire de Météorologie Dynamique, Paris, France, (5)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (6)University at Albany, State University of New York, Department of Atmospheric and Environmental Sciences, Albany, United States
Abstract:
Global climate models prescribed with increasing greenhouse gases (GHGs) produce warming trends that increase with altitude. However, observations do not show a uniform acceleration of warming with elevation. Here, we explore warming-elevation relationship, apply records from 2660 meteorological stations, and determine that the vertical gradient of warming rate varies with location. Warming is faster at higher altitude in Asia and western North America, but the opposite is observed over central Europe and eastern North America which have received more short-wave radiation (brightening) associated with a decrease of aerosols and clouds since the 1980s. We found that altitudinal differences in air pollution brightening, with observations showing more short-wave radiation received at low altitudes than at mountain stations, modulate the otherwise uniform effect of the long-wave forcing of GHGs on the warming-elevation relationship. Characterizing the warming-elevation relationships over different mountainous regions thus provides a valuable tool for understanding the drivers of regional climate change and will contribute to the formulation of strategies for climate change mitigation (e.g., biodiversity conservation) at high elevations.
