Extreme summer temperatures in the East Mediterranean—dynamical analysis

摘要: This research analyses the scenarios that break monotonic summer regime over East Mediterranean (EM). The study compares five upper, median and lower percentiles of 850-hPa temperature for July–August 1975–2005. differences were found to be confined 4 km. They are controlled by intensity negative advection, but not prevailing subsidence. Air trajectory analysis shows regional northwest winds strongest prior cool events weakest, or nonexistent, hot events. An index representing location air source is proposed as an effective predictor temperature. days subdivided according their evolution scenarios. All associated with deepening upper troughs EM. Different generate days; ‘tropical’, intrusion tropical-like air, ‘subtropical’, resulting from expansion subtropical high North Africa towards EM, ‘baroclinic’, a pronounced upper-level ridge, part Rossby wave Basin. ‘tropical’ scenario was well identified through mid-level relative humidity. alternative classification approach, objective K-Means clustering method, applied back-trajectories reaching isolated successfully only type. Back-tracking anomalies indicate two different evolutions one propagation west sector other quasi-stationary, tropical air. all propagating northwest. indicates extreme EM mostly regulated mid-latitudes disturbances travelling eastward rather than Asian Monsoon.