最新科研进展
A process-oriented evaluation of dust emission parameterizations in CESM:Simulation of a typical severe dust storm in East Asia
Authors:
ChenglaiWu1,2,ZhaohuiLin1,JuanxiongHe1,MinghuaZhang1,3,XiaohongLiu2,RenjianZhang4,and HunterBrown2
1 International Center for Climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China,
2 Department of Atmospheric Science, University of Wyoming Laramie,Wyoming,USA,
3 School of Marine and Atmospheric Sciences, State University of New York at Stony Brook, Stony Brook, New York, USA,
4 Key Laboratory of Regional Climate-Environment for Temperate East Asia,Institute of Atmospheric Physics,Chinese Academy of Sciences ,Beijing, China
Abstract:
Dust emissions in climate and earth system models are associated with large uncertainties. These models often use the source erodibility(S) to constrain dust emissions and also lack explicit represen- tations of the impact of surface roughness elements(SREs) on the threshold friction velocity(u*t). This study present saprocess-oriented evaluation of dust emission parameterizations in the Community Earth System Model(CESM) by applying the model to simulatea severe dust storm during19–22 March 2010 in East Asia. Through numerical experiments, we assess the applicability of S and investigate the impact of SREs on dust emissions by implementing the roughness correction factor(fk) to u*t. Simulation results are compared against the surface synoptic observations and station observations of dust concentrations.We found that the model can capture the main dust emission regions and reproduce the temporal-spatial evolution of surface dust concentrations in Mongolia and northern China.With a geomorphic S (Sg),the model tends to produce excessive dust emissions over the low-lying basins.Moreover,the high-resolution Sg performs worse with‘‘pointsources’’ of strong dust emissions than the low-resolution one.With the inclusion of fk, total dust emission sarereduced by 24–34%,and the model reduces the overestimation of surface dust concentrations and improves their temporal variations over the vegetated regions.These results suggest that Sg may not be necessary when meteorology and land surface state are well simulated by the model and that fk provides an important constraint on dust emissions through SREs.
Key words:
CESM is applied to simulate a typical severe dust storm in East Asia, Adoption of geomorphic source erodibility produces excessive dust emissions over the low-lying basins,Implementation of the roughness correction factor improves dust simulation.
Citation:
J. Adv. Model. Earth Syst. 08, doi:10.1002/2016MS000723.1432-1452
