The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heatin...The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heating within Typhoon Molave（2009）. Simulations based on a single-moment, six-class microphysical scheme are shown to be reasonable, following verification of results for the typhoon track, wind intensity, precipitation pattern, as well as inner-core thermodynamic and dynamic structures. After calculating latent heating rate, it is concluded that the total latent heat is mainly derived from condensation below the zero degree isotherm, and from deposition above this isotherm. It is revealed that cloud microphysical processes related to graupel are the most important contributors to the total latent heat. Other important latent heat contributors in the simulated Typhoon Molave are condensation of cloud water, deposition of cloud ice, deposition of snow, initiation of cloud ice crystals, deposition of graupel, accretion of cloud water by graupel, evaporation of cloud water and rainwater,sublimation of snow, sublimation of graupel, melting of graupel, and sublimation of cloud ice. In essence, the simulated latent heat profile is similar to ones recorded by the Tropical Rainfall Measuring Mission, although specific values differ slightly.展开更多
Experiments were conducted to test the impact of a cloud diagnosis scheme in place of prescribed zonal average cloud on medium and long range integrations with the Australian Bureau of Meteorology Research Centre(BMRC...Experiments were conducted to test the impact of a cloud diagnosis scheme in place of prescribed zonal average cloud on medium and long range integrations with the Australian Bureau of Meteorology Research Centre(BMRC)global atmosphere model.The cloud scheme was shown to improve the temperature bias in the lower troposphere but there was deterioration in the upper troposphere,especially in the tropics,asso- ciated with underestimation of high cloud amount. Thirty day mean fields in a January integration showed greater amplitude in the Northern Hemisphere planetary waves and a deeper Antarctic circumpolar trough than the control experiment or a simulation with no cloud.The results for the diagnosed cloud case agree more closely with corresponding observed fields. There was also some reduction in the zonal average zonal wind component reflecting the additional zonal asymmetry introduced by the diagnostic cloud scheme.Similar trends were also noted in medium and long range forecasts for January and July conditions,although the impact on predictive skill was slight and in some cases detrimental. Areas for improving the diagnostic cloud scheme are noted.展开更多
基金The National Key Basic Research Program of China under contract No.2014CB953904the Natural Science Foundation of Guangdong Province under contract No.2015A030311026the National Natural Science Foundation of China under contract Nos 41275145 and 41275060
文摘The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heating within Typhoon Molave（2009）. Simulations based on a single-moment, six-class microphysical scheme are shown to be reasonable, following verification of results for the typhoon track, wind intensity, precipitation pattern, as well as inner-core thermodynamic and dynamic structures. After calculating latent heating rate, it is concluded that the total latent heat is mainly derived from condensation below the zero degree isotherm, and from deposition above this isotherm. It is revealed that cloud microphysical processes related to graupel are the most important contributors to the total latent heat. Other important latent heat contributors in the simulated Typhoon Molave are condensation of cloud water, deposition of cloud ice, deposition of snow, initiation of cloud ice crystals, deposition of graupel, accretion of cloud water by graupel, evaporation of cloud water and rainwater,sublimation of snow, sublimation of graupel, melting of graupel, and sublimation of cloud ice. In essence, the simulated latent heat profile is similar to ones recorded by the Tropical Rainfall Measuring Mission, although specific values differ slightly.
文摘Experiments were conducted to test the impact of a cloud diagnosis scheme in place of prescribed zonal average cloud on medium and long range integrations with the Australian Bureau of Meteorology Research Centre(BMRC)global atmosphere model.The cloud scheme was shown to improve the temperature bias in the lower troposphere but there was deterioration in the upper troposphere,especially in the tropics,asso- ciated with underestimation of high cloud amount. Thirty day mean fields in a January integration showed greater amplitude in the Northern Hemisphere planetary waves and a deeper Antarctic circumpolar trough than the control experiment or a simulation with no cloud.The results for the diagnosed cloud case agree more closely with corresponding observed fields. There was also some reduction in the zonal average zonal wind component reflecting the additional zonal asymmetry introduced by the diagnostic cloud scheme.Similar trends were also noted in medium and long range forecasts for January and July conditions,although the impact on predictive skill was slight and in some cases detrimental. Areas for improving the diagnostic cloud scheme are noted.
