The paper describes and analyzes the sensitivity of an operational atmospheric model to different SST （sea surface temperature） estimates. The model＇s sensitivity has been analyzed in a Medicane （Mediterranean hur...The paper describes and analyzes the sensitivity of an operational atmospheric model to different SST （sea surface temperature） estimates. The model＇s sensitivity has been analyzed in a Medicane （Mediterranean hurricane） test case. Numerical simulations have been performed using the COSMO （consortium for small-scale modeling） atmospheric model, in the COSMO-ME configuration. The model results show that the model is capable of capturing the position, timing and intensity of the cyclone. Sensitivity experiments have been carried out using different SSTs surface boundary conditions for the COSMO forecasts. Four different experiments have been carried out： the first two using SST fields obtained from the OSTIA （operational sea surface temperature and sea ice analysis） system, while the other two using the SST analyses and forecasts from MFS （Mediterranean Forecasting System, Tonani et al., 2015; Pinardi and Coppini, 2010）. The different boundary conditions determine differences in the trajectory, pressure minimum and wind intensity of the simulated Medicane. The sensitivity experiments showed that a colder than real SST field determines a weakening of the minimum pressure at the vortex center. MFS SST analyses and forecasts allow the COSMO model to simulate more realistic minimum pressure values, trajectories and wind speeds. It was found that MFS SST forecast, as surface boundary conditions for COSMO-ME runs, determines a significant improvement, compared to ASCAT observations, in terms of wind intensity forecast as well as cyclone dimension and location.展开更多
The rotating-convection paradigm for tropical cyclone behaviour is shown to provide an attractive and consistent framework for interpreting the dynamics of formation and intensification of at least some medicanes.The ...The rotating-convection paradigm for tropical cyclone behaviour is shown to provide an attractive and consistent framework for interpreting the dynamics of formation and intensification of at least some medicanes.The ideas are illustrated by a case study of the medicane that formed over the eastern Mediterranean in mid-December 2020.This case study is based on analyses of data from the European Centre for Medium Range Weather Forecasts(ECMWF),imagery from the European geostationary meteorological satellite,Meteosat Second Generation,and output from a convection permitting numerical simulation of the event using the United Kingdom(UK)Met Office regional model with the RAL2 physics configuration.Limitations of the currently widely accepted interpretation of medicanes in terms of the so-called Wind-Induced Surface Heat Exchange(WISHE)intensification mechanism are discussed.展开更多
文摘The paper describes and analyzes the sensitivity of an operational atmospheric model to different SST （sea surface temperature） estimates. The model＇s sensitivity has been analyzed in a Medicane （Mediterranean hurricane） test case. Numerical simulations have been performed using the COSMO （consortium for small-scale modeling） atmospheric model, in the COSMO-ME configuration. The model results show that the model is capable of capturing the position, timing and intensity of the cyclone. Sensitivity experiments have been carried out using different SSTs surface boundary conditions for the COSMO forecasts. Four different experiments have been carried out： the first two using SST fields obtained from the OSTIA （operational sea surface temperature and sea ice analysis） system, while the other two using the SST analyses and forecasts from MFS （Mediterranean Forecasting System, Tonani et al., 2015; Pinardi and Coppini, 2010）. The different boundary conditions determine differences in the trajectory, pressure minimum and wind intensity of the simulated Medicane. The sensitivity experiments showed that a colder than real SST field determines a weakening of the minimum pressure at the vortex center. MFS SST analyses and forecasts allow the COSMO model to simulate more realistic minimum pressure values, trajectories and wind speeds. It was found that MFS SST forecast, as surface boundary conditions for COSMO-ME runs, determines a significant improvement, compared to ASCAT observations, in terms of wind intensity forecast as well as cyclone dimension and location.
文摘The rotating-convection paradigm for tropical cyclone behaviour is shown to provide an attractive and consistent framework for interpreting the dynamics of formation and intensification of at least some medicanes.The ideas are illustrated by a case study of the medicane that formed over the eastern Mediterranean in mid-December 2020.This case study is based on analyses of data from the European Centre for Medium Range Weather Forecasts(ECMWF),imagery from the European geostationary meteorological satellite,Meteosat Second Generation,and output from a convection permitting numerical simulation of the event using the United Kingdom(UK)Met Office regional model with the RAL2 physics configuration.Limitations of the currently widely accepted interpretation of medicanes in terms of the so-called Wind-Induced Surface Heat Exchange(WISHE)intensification mechanism are discussed.
