Geosciences Dept. Seminar: On a possibly underestimated role of the tropical moisture sources in the climate variability in the Mediterranean region

Abstract: 

The availability of results of global and regional climate modeling experiments opens earlier non-existing perspectives for understanding the physical mechanisms controlling the climate one of the world’s major variability in the Mediterranean region which is typically regarded as one of the world’s major climate change hot-spots. However, the observed precipitation trends of the last two decades appear to be not fully consistent with the changes in precipitation projected with the climate models which account for the role of anthropogenic forcing (the rise in the concentration of greenhouse gases and sulphate aerosols). The inconsistency is higher over the western and central parts of the Mediterranean region where projected drying disagrees with the observed increase in cool season precipitation. At the same time, a higher level of agreement with the observations characterizes the climate change projections for the eastern part of the region. The modeling results also appear to be not fully representing observed changes in precipitation structure with observed growth of the duration of wet spells and the rise in the contribution of extreme precipitation in the seasonal totals. Analyses performed allow conclusion on an importance of a more accurate accounting of the role of the exports of oceanic tropical moisture into the Mediterranean region (mainly taking place in the form of atmospheric rivers) for understanding of the recent past trends in the annual precipitation variability as well as more reliable estimation of the expected future climate changes in the Mediterranean region.

Seminar Organizer: Prof. Eyal Haifetz