Attribution and projections of temperature extreme trends in South America based on CMIP5 models

RUSTICUCCI, MATILDE; ZAZULIE, NATALIA

ANNALS OF THE NEW YORK ACADEMY OF SCIENCES.

BLACKWELL PUBLISHING

Año: 2021

0077-8923

Temperature extreme indices are analyzed for five continental regions of Southern South America defined according to their climatic characteristics. Gridded observations, reanalysis and global coupled climate models from CMIP5 were used with the approach of the temperature extreme trend attribution analysis on fixed threshold and percentile-based temperature extremes indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). The largest positive trends are exhibited in the tropical nights index and a clear anthropogenic signal is evident in the Subtropical region. In the Subtropical Central Andes, there is a decrease in frost days index, increases in tropical nights and summer days indices and the effect of anthropogenic signal is evident. In the Patagonian region, all trends from historical runs were significant while the ones from the natural experiments resulted non-significant, showing the markedly effect of the anthropogenic forcing in this region in the extreme events of temperature. Projected changes in extreme indices for the 21st century are consistent with a warming climate and larger changes are expected in warm nights index.