On the association between synoptic circulation and wildfires in the Eastern Mediterranean

In the present paper cluster analysis of 2-month air mass back-trajectories for three contrasting fire and non-fire events is conducted (high, low, and zero burnt area). The large fire event displays an air mass history dissimilar to other events whereby a 39-day period of warm and dry chiefly northerly anticyclonic conditions is evident, before a week of warmer predominantly southwesterly cyclonic activity, immediately prior to ignition. The pressure level of these anticyclonic air masses is above 800 hPa for more than 75 % of the trajectory length; this region is above the principal moisture transport regime of 800 hPa altitude. Analysis of variance on the mean rate of change of potential temperature identified weak statistically significant differences between two air mass pairs regarding the large fire: anticyclonic and cyclonic air masses in both cases (p = 0.038 and p = 0.020). Such regularity of type and occurrence, approach pressure levels and statistically significant differences are not evident for the small and non-fire event air masses. Such understanding is expected to permit appropriate steps to be undertaken including superior prediction and improved suppression strategy.