Droughts in the South American Monsoon region

MARIAH GOMES; CAVALCANTI IRACEMA F.A; MÜLLER, GABRIELA V.

Sao Paulo

Workshop; Advanced School and Workshop on American Monsoon ? Progress and Future Plans; 2019

ICTP-SAIFR

Climateextremes have been observed with more frequency in several regions of theworld. The understanding and prediction of these events are important issuesthat need to be addressed, not only for the interest of the scientific communitybut also from a socio-economic point of view. Droughts are examples of extremeevents that affect the environment and the society. Periods with rainfalldeficit perturb the agricultural production, livestock management andhydropower generation. The South American Monsoon System (SAMS), which has itsmature stage in December-February, displays variability of the associatedcirculation features responsible for droughts or excess rain.  Recurrent droughts have been registered in January,the peak of the rainy season in large areas of SAMS, such as in 2014, 2015 and2019. In the first two years, changes in the humidity fluxes, sea level pressureand atmospheric circulation were identified as the main drought drivers. Thesechanges were related tropical-extratropical teleconnections of atmospheric wavetrains over the Pacific Ocean. In 2019, another drought took place in January,and the South Atlantic Convergence Zone, a system that makes part SAMS, did notdevelop. Also, there were changes in the atmospheric circulation patterns that preventedthe development of convection mechanisms over the region. The objective of thiswork is to analyze the atmospheric circulation patterns and the dynamic forcingof this case in order to explore similarities and differences with the other twocases, and explore how they can be monitored before the peak of the rainyseason in the SAMS region.