Regional modelling of rainfall erosivity: Sensitivity of soil erosion to aerosol emissions
File(s)
Accepted version
Author(s)
Nissan, H
Toumi, R
Type
Journal Article
Abstract
A rainfall erosivity scheme is implemented into the widely-used regional atmosphere-land
model, WRF. Rainfall erosivity is parameterised from hourly precipitation and surface runoff in
a high resolution (4 km) convection-permitting model. The scheme is used to examine the
potential effects of changes in atmospheric aerosol concentrations on soil erosion in a case
study of northern India and the surrounding countries for the 2010 monsoon season, using a
model which isolates the indirect effect on cloud microphysics only. This study offers a
preliminary investigation into this emerging topic, but longer simulations would be needed to
establish a robust signal.
Summer precipitation is reduced in most areas and the monsoon circulation weakens for
increases in cloud condensation nuclei concentrations. This can be attributed to localised cloud
microphysical changes in the northeast of India, which induce a dynamic response opposing the
monsoon circulation. The two regions of greatest decrease in erosion with increasing aerosol
are in the Western Ghats and the Ganges Delta, both significant cropland areas. However, the
effect is not uniform, with isolated local increases in soil erosion. These results suggest that,
while efforts to reduce anthropogenic aerosol emissions may improve water availability for
crops through enhanced rainfall, these benefits are likely to be tempered by an increase in soil
erosion, though robust local changes were difficult to predict.
model, WRF. Rainfall erosivity is parameterised from hourly precipitation and surface runoff in
a high resolution (4 km) convection-permitting model. The scheme is used to examine the
potential effects of changes in atmospheric aerosol concentrations on soil erosion in a case
study of northern India and the surrounding countries for the 2010 monsoon season, using a
model which isolates the indirect effect on cloud microphysics only. This study offers a
preliminary investigation into this emerging topic, but longer simulations would be needed to
establish a robust signal.
Summer precipitation is reduced in most areas and the monsoon circulation weakens for
increases in cloud condensation nuclei concentrations. This can be attributed to localised cloud
microphysical changes in the northeast of India, which induce a dynamic response opposing the
monsoon circulation. The two regions of greatest decrease in erosion with increasing aerosol
are in the Western Ghats and the Ganges Delta, both significant cropland areas. However, the
effect is not uniform, with isolated local increases in soil erosion. These results suggest that,
while efforts to reduce anthropogenic aerosol emissions may improve water availability for
crops through enhanced rainfall, these benefits are likely to be tempered by an increase in soil
erosion, though robust local changes were difficult to predict.
Date Issued
2016-12-02
Date Acceptance
2016-09-05
Citation
Quarterly Journal of the Royal Meteorological Society, 2016, 143 (702), pp.265-277
ISSN
1477-870X
Publisher
Wiley
Start Page
265
End Page
277
Journal / Book Title
Quarterly Journal of the Royal Meteorological Society
Volume
143
Issue
702
Copyright Statement
This is the peer reviewed version of the following article: Nissan, H. and Toumi, R. (2017), Regional modelling of rainfall erosivity: sensitivity of soil erosion to aerosol emissions. Q.J.R. Meteorol. Soc., 143: 265–277, which has been published in final form at https://dx.doi.org/10.1002/qj.2919. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Sponsor
Indian Institute of Tropical Meteorology
Grant Number
MM/SERP/20013/INT-7/002
Subjects
Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
soil erosion
aerosols
climate model
regional climate modelling
indirect aerosol effects
precipitation
India
Bangladesh
ASIAN SUMMER MONSOON
CROP PRODUCTION
CLIMATE-CHANGE
SIMULATION
PRECIPITATION
INDIA
DISTRIBUTIONS
EXPLICIT
IMPACTS
CLOUDS
0401 Atmospheric Sciences
0405 Oceanography
Publication Status
Published