Monsoon
Overview
The PMP currently can be used to produce baseline metrics on the overall evolution and pattern of regional monsoons.
These evolution results are based on the work of Sperber and Annamalai (2014). Climatological pentads of precipitation in observations and CMIP5 for six monsoon-related domains (AIR: All-India Rainfall, AUS: Australian Monsoon, GoG: Gulf of Guinea, NAM: North American Monsoon, SAM: South American Monsoon, and Sahel). In the Northern Hemisphere the 73 climatological pentads run from January-December, while in the Southern Hemisphere the climatological pentads run from July-June. For each domain the precipitation is accumulated at each subsequent pentad and then divided by the total precipitation to give the fractional accumulation of precipitation as a function of pentad. Except for GoG, onset (decay) of monsoon occurs for a fractional accumulation of 0.2 (0.8). Between these fractional accumulations the accumulation of precipitation is nearly linear as the monsoon season progresses.
Demo
References
Sperber, K.R. and Annamalai, H., 2014. The use of fractional accumulated precipitation for the evaluation of the annual cycle of monsoons. Climate Dynamics, 43, 3219-3244, doi:10.1007/s00382-014-2099-3