This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is...This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is determined during the 21 December 2011 flooding event. Ten sensitivity experiments have been conducted using Cumulus, Convective and Planetary boundary layer schemes to find the best combination and optimize the WRF model for the study area for heavy rainfall events. Model simulation results were verified against observed data using standard statistical tests. The model simulations show encouraging and better statistical results with the combination of Kain-Fritsch cumulus parameterization scheme, Lin microphysics scheme and Asymmetric Convection Model 2 (ACM2) planetary boundary scheme than any other combinations of physical parameterization schemes over Dar es Salaam region.展开更多
Tropical cyclones(TCs)not only passively respond to climate change,but also play an important role in vertical mixing of the upper ocean and in driving oceanic heat transport.Using a fully coupled climate model,the au...Tropical cyclones(TCs)not only passively respond to climate change,but also play an important role in vertical mixing of the upper ocean and in driving oceanic heat transport.Using a fully coupled climate model,the authors investigate the potential effect of TC-induced vertical mixing on the El Nino–Southern Oscillation(ENSO)and East Asian monsoon in the mid-Piacenzian,during which global TCs are estimated to have been stronger.Sensitivity experiments indicate that the TC-induced oceanic mixing over global storm basins leads to additional warming over the eastern tropical Pacific and a deeper thermocline in the mid-Piacenzian,whereas it dampens the interannual variability of ENSO.Regarding the East Asian monsoon circulations,low-level(850 hPa)summer and winter winds are intensified in response to enhanced vertical mixing,with a southward/westward shift of the western North Pacific high and westerly jet in summer and a deepened East Asian trough in winter.These climatic features are largely reproduced in the experiment with enhanced vertical mixing only over the central-eastern North Pacific.These results may shed light on TC feedbacks associated with vertical mixing and advance our understanding on mid-Piacenzian climate.展开更多
文摘This paper evaluates the skills of physical Parameterization schemes in simulating extreme rainfall events over Dar es Salaam Region, Tanzania using the Weather Research and Forecasting (WRF) model. The model skill is determined during the 21 December 2011 flooding event. Ten sensitivity experiments have been conducted using Cumulus, Convective and Planetary boundary layer schemes to find the best combination and optimize the WRF model for the study area for heavy rainfall events. Model simulation results were verified against observed data using standard statistical tests. The model simulations show encouraging and better statistical results with the combination of Kain-Fritsch cumulus parameterization scheme, Lin microphysics scheme and Asymmetric Convection Model 2 (ACM2) planetary boundary scheme than any other combinations of physical parameterization schemes over Dar es Salaam region.
基金funded by the National Natural Science Foundation of China [grant number 41772179]the Young Elite Scientists Sponsorship Program by China Association for Science and Technology [grant number 2017QNRC001]
文摘Tropical cyclones(TCs)not only passively respond to climate change,but also play an important role in vertical mixing of the upper ocean and in driving oceanic heat transport.Using a fully coupled climate model,the authors investigate the potential effect of TC-induced vertical mixing on the El Nino–Southern Oscillation(ENSO)and East Asian monsoon in the mid-Piacenzian,during which global TCs are estimated to have been stronger.Sensitivity experiments indicate that the TC-induced oceanic mixing over global storm basins leads to additional warming over the eastern tropical Pacific and a deeper thermocline in the mid-Piacenzian,whereas it dampens the interannual variability of ENSO.Regarding the East Asian monsoon circulations,low-level(850 hPa)summer and winter winds are intensified in response to enhanced vertical mixing,with a southward/westward shift of the western North Pacific high and westerly jet in summer and a deepened East Asian trough in winter.These climatic features are largely reproduced in the experiment with enhanced vertical mixing only over the central-eastern North Pacific.These results may shed light on TC feedbacks associated with vertical mixing and advance our understanding on mid-Piacenzian climate.
