Premium
Relative Importance of Greenhouse Gases, Sulfate, Organic Carbon, and Black Carbon Aerosol for South Asian Monsoon Rainfall Changes
Author(s) -
Westervelt Daniel M.,
You Yujia,
Li Xiaoqiong,
Ting Mingfang,
Lee Dong Eun,
Ming Yi
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl088363
Subject(s) - aerosol , environmental science , greenhouse gas , atmospheric sciences , climatology , radiative forcing , monsoon , precipitation , climate change , sulfate aerosol , meteorology , geology , oceanography , geography
The contribution of individual aerosol species and greenhouse gases to precipitation changes during the South Asian summer monsoon is uncertain. Mechanisms driving responses to anthropogenic forcings need further characterization. We use an atmosphere‐only climate model to simulate the fast response of the summer monsoon to different anthropogenic aerosol types and to anthropogenic greenhouse gases. Without normalization, sulfate is the largest driver of precipitation change between 1850 and 2000, followed by black carbon and greenhouse gases. Normalized by radiative forcing, the most effective driver is black carbon. The precipitation and moisture budget responses to combinations of aerosol species perturbed together scale as a linear superposition of their individual responses. We use both a circulation‐based and moisture budget‐based argument to identify mechanisms of aerosol and greenhouse gas induced changes to precipitation and find that in all cases the dynamic contribution is the dominant driver to precipitation change in the monsoon region.