CONICET | Buscador de Institutos y Recursos Humanos

In this study, we use convection-permitting high resolution (3 km) simulations to quantify and analyse the water budget,precipitation efficiency and water sources of 100 intense Mediterranean cyclones. To this end, we calculate the water content,advection and microphysical processes of water vapour and rain water by implementing new diagnostics to the WeatherResearch and Forecasting (WRF) model. The 100 intense cyclones have been randomly selected from a 500 intense cyclonesdataset, identified and tracked in an 11-year time period in part I of this study. Results are presented in a composite approachshowing that most rainfall takes place to the north-east side of the cyclones, close to their centre. Rainfall location is con-comitant to the area of horizontal moisture flux convergence and is quasi-equal to the amount of water vapour loss due tomicrophysical processes. Similar results were found regardless if cyclones produce high or low rainfall amounts. Vertical pro-files of the water budget terms revealed deeper clouds for the cyclones producing high rainfall, consistent with higher valuesof vertical advection of both water vapour and rain water. Finally, cyclones were analysed with respect to their precipitationefficiency, i.e. the ratio between the rainwater produced in an atmospheric column and the consequent rainfall, and showedthat cyclones tend to be more efficient when their rainfall production takes place over land. Therefore, there is a complexrelation between water vapour advection, precipitation efficiency and rainfall which is discussed through the comparison oftwo tropical-like cyclones with two cyclones that produced low rainfall amounts. Finally, our analysis is complemented byapplying a Lagrangian approach to all 100 cyclones in order to quantify the water vapour source regions that contribute tothe cyclones? rainfall due to local surface evaporation. Results showed that these regions are located over both the Atlanticand the Mediterranean, however we show that cyclones producing high rainfall are related with higher water transport fromboth the subtropical Atlantic and the Mediterranean Sea.