DATE2019-01-08 12:44:23
AUTHORSVassiliki Iordanidou (1)|Aristeidis G. Koutroulis (1)|Ioannis K. Tsanis (1,2)
  1. Technical University of Crete, Chania, Greece
  2. McMaster University, Hamilton, Canada
ABSTRACTHigh intensity precipitation in Eastern Mediterranean is mainly associated with the cyclone pathways. These extreme rain events are responsible for physical disasters such as flood events and landslides, having high impact in the socio-economic life of organized communities. The cyclone-rain association as well as the characteristics of the cyclones-triggering precipitation of various accumulations are investigated in this study for the island of Crete. The European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim 6-hourly mean sea-level pressure dataset for a thirty year period (1979-2011) are used. Cyclone center identification and cyclone pathway tracking is achieved with the aim of Melbourne University algorithm (MS scheme). MS scheme is also used for the identification of cyclone characteristics such as radius, intensity and propagation velocity. The spatial and temporal daily precipitation data is realized via a dense gauging network over the island of Crete. With respect to the 50th, 95th and 99.5th percentiles of cumulative daily precipitation, the data is classified in three categories of mild, strong and heavy precipitation. Cyclones are considered to trigger rain events of the above precipitation categories if there is an identified temporal and spatial match with the field data. Cyclones mainly approach the island of Crete from northwest and southwest directions while their actual centers causing the rain events are usually located to the northwest and southeast of the island of Crete. Heavy rain accumulation is found to be related with cyclone pressure decrease as well as cyclone intensity, depth, radius and propagation velocity increase. Seasonal changes are also recognized in the cyclone characteristics such as lower pressure and smaller cyclone radius in the spring in contrast to ones are present in winter and autumn.