Regions where at least 70% of annual precipitation occurs in the 5-month seasons indicated.
This is only one of many possible definitions of monsoon regimes around the globe. Data are from GPCP version 2.5 For 1979-2008 provided by P. Dirmeyer
The monsoons are global phenomena, in all cases with seasonal reversals in the prevailing wind direction giving rise to dramatic changes in rainfall. The monsoon circulation evolves as a result of tropospheric temperature gradients that develop during springtime, to first order attributable to differential heating of the underlying land and ocean. Monsoons can be grouped into the Asia-Australia, African and American regions.
Progress in our scientific understanding of monsoons will benefit from the interaction of individuals and groups studying these various regions. CLIVAR (Climate and Ocean: Variability, Predictability and Change) research into ocean-atmosphere interaction and the role of slowly varying modes that lend predictability to the monsoons are of direct relevance to the Monsoons Panel; furthermore, GEWEX (Global Water and Energy Exchanges) activities in land-atmosphere interaction and convective scale processes are key to understanding monsoons at fine and global scales. As a result, a single Monsoons Panel spanning CLIVAR and GEWEX is convened of membership drawn from both communities; the panel reports to both CLIVAR and GEWEX Scientific Steering Groups.
The Monsoons Panel has established a structure of Regional Monsoon Working Groups, comprising the Asia-Australia, Americas and Africa regions. The Panel explores a more global view of monsoon activities, enabling knowledge and best practice to be shared between the various monsoon regions. It attempts to better coordinate monsoons research between GEWEX and CLIVAR, particularly in emphasizing the role of convection and land surface in the monsoons, in addition to ocean-atmosphere interaction.
Working groups under the Panel are leading regionally focused monsoon research in each of the three areas of globe. The Panel has been defining concrete activities to be fostered in the coming years, coordinating the regional working groups, and acting as a hub to facilitate meetings and linkages among international research efforts. Advancing understanding of monsoon variability and improving prediction remain the principal goals promoted by the Monsoons Panel, but greater emphasis is being placed on linkages across scales and to phenomena that have historically been outside the purview of classical monsoon research. Observation and modelling are still the cornerstones of the research efforts. The Panel seeks to bring new methods and fresh perspectives to the problem that can enhance monitoring, advance diagnostic efforts, and improve component and coupled models. Thus, key to these efforts will be the development of new and better process studies (particularly, emphasizing the role of convection and land-surface processes in monsoon models), coordinating with relevant modelling efforts including those related to climate change, and empowering the next generation of young scientists from around the world to advance our knowledge of monsoon systems. Scientific works include observational field campaign and process modelling work, coordination of and contribution to climate change efforts in CMIP6, and utilising our understanding of sub-to-seasonal variability to aid enhancement of monsoon prediction on these scales.
The Monsoons Panel is supported by the International Monsoons Project Office (IMPO), hosted by the Indian Institute of Tropical Meteorology (IITM) located in Pune, India.
Plans for 2018 and beyond:
Better integration of CLIVAR and GEWEX monsoons activities, such as GEWEX GLASS and GEWEX GASS (land-atmosphere and convection, in particular).
Exploiting the early outputs of the Global Monsoons MIP and CMIP6 DECK experiments. Plans for coordinated analysis at the regional monsoon scale, and the global monsoon scale, following a discussion forum held during the 6thInternational Workshop on Monsoons, November 2017 in Singapore.
The Monsoons panel will continue to identify cross-regional commonalities in activity. The key identified activity of interest across the regions is understanding subseasonal-to-seasonal variability and exploiting it for better prediction. Regional priorities will continue to be identified by the Regional WGs.