South Asian PRecIpitation: a SEamless Assessment - SAPRISE

Lead Research Organisation: University of Reading
Department Name: Meteorology

Abstract

The Indian summer monsoon provides about 80% of annual rainfall to around a billion people in South Asia. Variations in its timing, intensity and duration have a dramatic impact on society. The weather and climate in the South Asian region is influenced by the weather and climate in the Indian and remote ocean basins via what are known as teleconnections (remote connections). Teleconnections emerge from phenomena such as El Nino - a kind of gigantic ocean weather system that occurs every 2-8 years in the tropical Pacific. Tiny aerosol particles are also key component of the South Asian atmosphere due to the prevalence of cooking fires over the Indo-Gangetic Plain and dust blown from local and remote deserts.

It remains a considerable challenge to predict seasonal, decadal and longer-term changes in the South Asian monsoon. This proposal brings together UK and Indian scientists to make progress in understanding what affects the South Asian monsoon on different time scales. Key tools are new climate models that simulate the interactions between the different teleconnections and aerosols and new observations, especially those from satellites. The ultimate goal of the project is to improve predictive capability and to therefore potentially improve the lives of those people affected by monsoon rains.

Planned Impact

The main strategy to increase the impact of the work will be to feed information to bodies that have direct links to the relevant impact community, whether that is the wider scientific community, policy makers, or the public. The following activities are proposed:

1) Wider scientific community: We will publish papers, attend meetings and organise sessions at the Asia Oceania Geophysical Society, and the European Geophysical Union towards the end of the project to publicise the findings. We will also engage with the CLIVAR Pacific, CLIVAR Indian Ocean and CLIVAR Asian-Australian Monsoon panels (see academic beneficiaries).

2) Policy makers: The Met Office Hadley Centre, a leading partner in the project, has strong links to the UK government (it is largely funded by them) and provides regular briefing material for ministers. We will also provide updates on the project for the Ministry of Earth Sciences in India.

3) General public: During key points e.g. in the workshops and publication of papers we will produce press releases for the UK and Indian media to engage journalists (i.e. the professionals) in communicating the results of the project to the general public, as well as engaging with popular science outlets such as NERC's Planet Earth magazine and use social networking sites such as Facebook, Twitter and Youtube.

Publications

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Bush S (2015) The effect of increased convective entrainment on Asian monsoon biases in the MetUM general circulation model in Quarterly Journal of the Royal Meteorological Society

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Collins M (2013) Observational challenges in evaluating climate models in Nature Climate Change

 
Description 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.
The so-called elevated heat pump mechanism does exist in climate models but is weak and high concentrations of black carbon are needed for it to influence monsoon.
Exploitation Route May be used to compare with other model runs or to attribute changes in rainfall to different climate forcing mechanisms. Potentially has implications for air quality legislation.
Sectors Agriculture, Food and Drink,Environment

 
Title HadGEM2-ES anthropogenic aerosol only integration for the historical (20th century) period 
Description Model integration of the Met Office model HadGEM2-ES to complement those already performed as part of CMIP5 for the historical period (~1850 to present day). This experiment contains only variations in anthropogenic aerosol, making it useful, with the existing integrations, for detection and attribution experiments. 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact Simulation included with others from CMIP5 database in submitted publication for PAGODA project. 
 
Description Media interest (Asian pollution) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Provided comment on article to BBC, then interviews across international radio and social media.

Continued media contacts and opportunity to be in a documentary
Year(s) Of Engagement Activity 2014