Climate of the Past | 2021
Northern Hemisphere atmospheric pattern enhancing Eastern Mediterranean Transient-type events during the past 1000 years
Abstract
Abstract. High-resolution climate model simulations for the last millennium\nwere used to elucidate the main winter Northern Hemisphere atmospheric\npattern during enhanced Eastern Mediterranean Transient (EMT-type) events, a\nsituation in which an additional overturning cell is detected in the\nMediterranean at the Aegean Sea. The differential upward heat flux between\nthe Aegean Basin and the Gulf of Lion was taken as a proxy of EMT-type\nevents and correlated with winter mean geopotential height at 500\u2009mbar in the\nNorthern Hemisphere (20–90∘\u2009N and\n100∘\u2009W–80∘\u2009E). Correlations revealed a\npattern similar to the East Atlantic/Western Russian (EA/WR) mode as\nthe main driver of EMT-type events, with the past 1000\xa0years of EA/WR-like mode\nsimulations being enhanced during insolation minima. Our model results are\nconsistent with alkenone sea surface temperature (SST) reconstructions that\ndocumented an increase in the west–east basin gradients during EMT-type\nevents.\n