Revision of the contribution of external forcings to the Southern Annular Mode trend

MARISOL OSMAN; LEANDRO DÍAZ

Cambridge

Workshop; Antarctic Climate 21 century; 2019

Scientific Committee on Antarctic Research (SCAR)

The Southern Annular Mode (SAM) is the leading pattern of circulation variability in the Southern Hemisphere (SH) and is characterized by a centre of circulation anomalies extended over Antarctica and anomalies of opposite sign at middle latitudes. Climate change over the latter part of the 20th century in the SH includes an intensification of the polar vortex, reflected in a positive trend in the SAM. Contribution of different forcings in that trend has not been completely understood.