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Simulation of the Direct Radiative Effect of Mineral Dust and Sea Salt Aerosols in a Doubled Carbon Dioxide Climate |
YUE Xu1,2,3, LIAO Hong4,1, TANG Jin-Ping5,6 |
1Climate Change Research Center, Chinese Academy of Sciences (CAS), Beijing 100029, China
2Nansen-Zhu International Research Center, Institute of Atmospheric Physics (IAP), CAS, Beijing 100029, China
3School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02143, USA
4State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), IAP, CAS, Beijing 100029, China
5Key Laboratory of Middle Atmosphere and Global Environment Observation, IAP, CAS, Beijing 100029, China
6University of CAS, Beijing 100049, China |
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Abstract The authors examine the equilibrium climatic response to the direct radiative effect (DRE) of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions. In response to the drier and windier conditions, dust emissions increase by 26% in the Sahara Desert and by 18% on the global scale relative to present day. Sea salt emissions increase in high latitudes (>60°) but decrease in middle latitudes (30°-60°) of both hemispheres due to the poleward shift of westerlies, leading to a 3% decrease in global emissions. The burdens of dust and sea salt increase by 31% and 7% respectively, because reductions in rainfall over the tropical oceans increase the lifetime of particles in the warmer climate. The higher aerosol loading in the doubled-CO2 climate reinforces aerosol DRE by -0.2 W m-2, leading to an additional cooling of 0.1°C at the surface compared with the climatic effects of aerosols in present day. The additional cooling from changes in natural aerosols compensates for up to 15% of the regional warming induced by doubled CO2.
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Received: 14 December 2012
Revised: 22 January 2013
Accepted: 04 February 2013
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Corresponding Author:
LIAO Hong
E-mail: hongliao@mail.iap.ac.cn
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