EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Nonlinear Interaction between the Drivers of the Monsoon and Summertime Stationary Waves

Chaim Garfinkel1, Ian White1, Ori Adam1, Ed Gerber2, and Martin Jucker3
Chaim Garfinkel et al.
  • 1Hebrew University of Jerusalem, Earth Science Institute, Earth Science Institute, Jerusalem, Israel (
  • 2New York University
  • 3Climate Change Research Center and ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, Australia

An intermediate complexity moist General Circulation Model is used to investigate the forcing of the Asian monsoon and the associated upper level anticyclone by land-sea contrast, net horizontal heat transport by the ocean, and topography. The monsoonal pattern is not simply the linear additive sum of the response to each forcing; only when all three forcings are included simultaneously does the monsoonal circulation extend westward to India. This nonadditivity impacts the location of the upper level anticyclone, which is shifted eastward and weaker if the forcings are imposed individually. Sahelian precipitation, and also austral summer precipitation over Australia, southern Africa, and South America, are likewise stronger if all forcings are imposed simultaneously. The source of the nonlinearity can be diagnosed using gross moist stability, but cannot be accounted for using the land-sea breeze paradigm. This non-additivity implies that the question of which forcing is most important is ill-posed.

How to cite: Garfinkel, C., White, I., Adam, O., Gerber, E., and Jucker, M.: Nonlinear Interaction between the Drivers of the Monsoon and Summertime Stationary Waves, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-336,, 2020.

Corresponding formerly uploaded have been withdrawn.