EGU2020-4942
https://doi.org/10.5194/egusphere-egu2020-4942
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Investigating the factors affecting Monsoon precipitation under climate change

Harry Mutton1, Mat Collins1, Hugo Lambert1, and Rob Chadwick1,2
Harry Mutton et al.
  • 1University of Exeter, College of Engineering, Mathematics, and Physical Sciences, Exeter, United Kingdom of Great Britain and Northern Ireland
  • 2Met Office Hadley Centre, Exeter, United Kingdom of Great Britain and Northern Ireland

The Monsoons produce some of the largest levels of uncertainty in projected precipitation change across the globe, and addressing this uncertainty is a key issue that must be faced in order to allow correct adaptation policy to be put in place.

 

A set of CMIP6 GCM experiments, that allow the full effect of CO2 forcing to be decomposed into individual components, highlight the leading factors that produce changes in monsoon precipitation. The results reveal a high spatial variability in these factors, with changes in the Indian Monsoon dominated by the effect of sea surface temperatures and the direct radiative effect of increased CO2, and changes in the South American Monsoon governed by the plant physiological effect and the direct radiative effect of increased CO2. The processes behind these precipitation changes are also investigated by looking at variations in atmospheric circulation and surface temperature. Results of the patterned sea surface temperature experiment demonstrate a slow-down of the Indian Monsoon circulation possibly driven by an anomalously warm Indian Ocean.

 

This analysis has been performed for all land monsoon regions, decomposing the full CO2 forcing into; uniform and patterned sea surface temperature change, the plant physiological effect, the direct radiative effect and the impact of sea-ice melt. These results can help identify emergent constraints, as well as indicate which aspects of climate models need to be improved in order to reduce model uncertainty.

How to cite: Mutton, H., Collins, M., Lambert, H., and Chadwick, R.: Investigating the factors affecting Monsoon precipitation under climate change, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4942, https://doi.org/10.5194/egusphere-egu2020-4942, 2020

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