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Impacts of 20Th Century Aerosol Emissions on the South Asian Monsoon in the Cmip5 Models : Volume 14, Issue 22 (03/12/2014)

By Guo, L.

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Book Id: WPLBN0003980292
Format Type: PDF Article :
File Size: Pages 28
Reproduction Date: 2015

Title: Impacts of 20Th Century Aerosol Emissions on the South Asian Monsoon in the Cmip5 Models : Volume 14, Issue 22 (03/12/2014)  
Author: Guo, L.
Volume: Vol. 14, Issue 22
Language: English
Subject: Science, Atmospheric, Chemistry
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2014
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Guo, L., Highwood, E. J., & Turner, A. G. (2014). Impacts of 20Th Century Aerosol Emissions on the South Asian Monsoon in the Cmip5 Models : Volume 14, Issue 22 (03/12/2014). Retrieved from http://community.ebooklibrary.org/


Description
Description: Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading, RG6 6BB, UK. Comparison of single-forcing varieties of 20th century historical experiments in a subset of models from the Fifth Coupled Model Intercomparison Project (CMIP5) reveals that South Asian summer monsoon rainfall increases towards the present day in Greenhouse Gas (GHG)-only experiments with respect to pre-industrial levels, while it decreases in anthropogenic aerosol-only experiments. Comparison of these single-forcing experiments with the all-forcings historical experiment suggests aerosol emissions have dominated South Asian monsoon rainfall trends in recent decades, especially during the 1950s to 1970s. The variations in South Asian monsoon rainfall in these experiments follows approximately the time-evolution of inter-hemispheric temperature gradient over the same period, suggesting a contribution from the large-scale background state relating to the asymmetric distribution of aerosol emissions about the equator.

By examining the twenty-five available all-forcings historical experiments, we show that models including aerosol indirect effects dominate the negative rainfall trend. Indeed, models including only the direct radiative effect of aerosol show an increase in monsoon rainfall, consistent with the dominance of increasing greenhouse gas emissions and planetary warming on monsoon rainfall in those models. For South Asia, reduced rainfall in the models with indirect effects is related to decreased evaporation at the land surface rather than from anomalies in horizontal moisture flux, suggesting the impact of indirect effects on local aerosol emissions. This is confirmed by examination of aerosol loading and cloud droplet number trends over the South Asia region. Thus while remote aerosols and their asymmetric distribution about the equator play a role in setting the inter-hemispheric temperature distribution on which the South Asian monsoon, as one of the global monsoons, operates, the addition of indirect aerosol effects acting on very local aerosol emissions also plays a role in declining monsoon rainfall. The disparity between the response of monsoon rainfall to increasing aerosol emissions in models containing direct aerosol effects only and those also containing indirect effects needs to be urgently investigated since the suggested future decline in Asian anthropogenic aerosol emissions inherent to the representative concentration pathways (RCPs) used for future climate projection may turn out to be optimistic.

In addition, both groups of models show declining rainfall over China, also relating to local aerosol mechanisms. We hypothesize that aerosol emissions over China are large enough, in the CMIP5 models, to cause declining monsoon rainfall even in the absence of indirect aerosol effects. The same is not true for India.


Summary
Impacts of 20th century aerosol emissions on the South Asian monsoon in the CMIP5 models

Excerpt
Albrecht, B. A.: Aerosols, cloud microphysics, and fractional cloudiness, Science, 245, 1227–1230, doi:10.1126/science.245.4923.1227, 1989.; Bollasina, M. A., Ming, Y., and Ramaswamy, V.: Anthropogenic aerosols and the weakening of the South Asian summer monsoon, Science, 334, 502–505, doi:10.1126/science.1204994, 2011.; Acharya, P. and Sreekesh, S.: Seasonal variability in aerosol optical depth over India: a spatio-temporal analysis using the MODIS aerosol product, Int. J. Remote Sens., 34, 4832–4849, doi:10.1080/01431161.2013.782114, 2013.; Charlson, R. J., Schwartz, S. E., Hales, J. M., Cess, R. D., Coakley, J. A., Hansen, J. E., and Hofmann, D. J.: Climate forcing by anthropogenic aerosols, Science, 255, 423–430, doi:10.1126/science.255.5043.423, 1992.; Cherian, R., Venkataraman, C., Quaas, J., and Ramachandran, S.: GCM simulations of anthropogenic aerosol-induced changes in aerosol extinction, atmospheric heating and precipitation over India, J. Geophys. Res.-Atmos., 118, 2938–2955, doi:10.1002/jgrd.50298, 2013.; Dash, S. K., Kulkarni, M. A., Mohanty, U. C., and Prasad, K.: Changes in the characteristics of rain events in India, J. Geophys. Res., 114, doi:10.1029/2008JD010572, 2009.; Devara, P. C. S. and Manoj, M. G.: Aerosol-cloud-precipitation interactions: A challenging problem in regional environment and climate research, Particuology, 11, 25–33, doi:10.1016/j.partic.2012.07.006, 2013.; Ding, Y., Wang, Z., and Sun, Y.: Inter-decadal variation of the summer precipitation in East China and its association with decreasing Asian summer monsoon, Part I: Observed evidences, Int. J. Climatol., 28, 1139–1161, doi:10.1002/joc.1615, 2008.; Douville, H., Royer, J.-F., Polcher, J., Cox, P., Gedney, N., Stephenson, D. B., and Valdes, P. J.: Impact of CO2 doubling on the Asian summer monsoon: robust versus model-dependent responses, J. Meteorol. Soc. Jpn., 78, 421–439, 2000.; Ekman, A. M. L.: Do sophisticated parameterizations of aerosol-cloud interactions in CMIP5 models improve the representation of recent observed temperature trends?, J. Geophys. Res.-Atmos., 119, 817–832, doi:10.1002/2013JD020511, 2014.; Fan, F. X., Mann, M. E., Lee, S., and Evans, J. L.: Observed and modeled changes in the South Asian summer monsoon over the historical period, J. Climate, 23, 5193–5205, doi:10.1175/2010jcli3374.1, 2010.; Gautam, R., Hsu, N. C., Lau, K.-M., and Kafatos, M.: Aerosol and rainfall variability over the Indian monsoon region: distributions, trends and coupling, Ann. Geophys., 27, 3691–3703, doi:10.5194/angeo-27-3691-2009, 2009.; Goswami, B. N., Venugopal, V., Sengupta, D., Madhusoodanan, M. S., and Xavier, P. K.: Increasing trend of extreme rain events over India in a warming environment, Science, 314, 1442–1445, doi:10.1126/science.1132027, 2006.; Guo, L., Highwood, E. J., Shaffrey, L. C., and Turner, A. G.: The effect of regional changes in anthropogenic aerosols on rainfall of the East Asian Summer Monsoon, Atmos. Chem. Phys., 13, 1521–1534, doi:10.5194/acp-13-1521-2013, 2013.; Jones, G. S., Christidis, N., and Stott, P. A.: Detecting the influence of fossil

 

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