Antarctic polynyas play an important role in regional atmosphere?ice?ocean interactions and are considered to help generate the global deep ocean conveyer belt.Polynyas therefore have a potential impact on the Earth’...Antarctic polynyas play an important role in regional atmosphere?ice?ocean interactions and are considered to help generate the global deep ocean conveyer belt.Polynyas therefore have a potential impact on the Earth’s climate in terms of the production of sea ice and high-salinity shelf water.In this study,we investigated the relationship between the area of the Terra Nova Bay polynya and the air temperature as well as the eastward and northward wind based on the ERA5 and ERAInterim reanalysis datasets and observations from automatic weather stations during the polar night.We examined the correlation between each factor and the polynya area under different temperature conditions.Previous studies have focused more on the effect of winds on the polynya,but the relationship between air temperature and the polynya area has not been fully investigated.Our study shows,eliminating the influence of winds,lower air temperature has a stronger positive correlation with the polynya area.The results show that the relationship between the polynya area and air temperature is more likely to be interactively influenced.As temperature drops,the relationship of the polynya area with air temperature becomes closer with increasing correlation coefficients.In the low temperature conditions,the correlation coefficients of the polynya area with air temperature are above 0.5,larger than that with the wind speed.展开更多
The tropical cyclone boundary layer(TCBL)connecting the underlying terrain and the upper atmosphere plays a crucial role in the overall dynamics of a tropical cyclone system.When tropical cyclones approach the coastli...The tropical cyclone boundary layer(TCBL)connecting the underlying terrain and the upper atmosphere plays a crucial role in the overall dynamics of a tropical cyclone system.When tropical cyclones approach the coastline,the wind field inside the TCBL makes a sea-land transition to impact both onshore and offshore structures.So better understanding of the wind field inside the TCBL in the sea-land transition zone is of great importance.To this end,a semiempirical model that integrates the sea-land transition model from the Engineering Sciences Data Unit(ESDU),Huang's refined TCBL wind field model,and the climate change scenarios from the Coupled Model Intercomparison Project Phase 6(CMIP6)is used to investigate the influence of climate changes on the sea-land transition of the TCBL wind flow in Hong Kong.More specifically,such a semiempirical method is employed in a series of Monte-Carlo simulations to predict the wind profiles inside the TCBL across the coastline of Hong Kong under the impact of future climate changes.The wind profiles calculated based on the Monte-Carlo simulation results reveal that,under the influences of the most severe climate change scenario,slightly higher and significantly lower wind speeds are found at altitudes above and below 400 m,respectively,compared to the wind speeds recommended in the Hong Kong Wind Code of Practice.Such findings imply that the wind profile model currently adopted by the Hong Kong authorities in assessing the safety of low-to high-rise buildings may be unnecessarily over-conservative under the influence of climate change.On the other hand,the coded wind loads on super-tall buildings slightly underestimate the typhoon impacts under the severe climate change conditions anticipated for coastal southern China.展开更多
基金the National Natural Science Foundation of China(Grant No.41830536,Grant No.41676190,and Grant No.41941009)the Fundamental Research Funds for the Central Universities(Grant No.12500-312231103)The authors thank the University of Bremen for providing the AMSR-E,AMSR-2 and SSMIS SIC data,as well as the University of Wisconsin-Madison Automatic Weather Station Program(NSF Grant No.ANT-1543305)。
文摘Antarctic polynyas play an important role in regional atmosphere?ice?ocean interactions and are considered to help generate the global deep ocean conveyer belt.Polynyas therefore have a potential impact on the Earth’s climate in terms of the production of sea ice and high-salinity shelf water.In this study,we investigated the relationship between the area of the Terra Nova Bay polynya and the air temperature as well as the eastward and northward wind based on the ERA5 and ERAInterim reanalysis datasets and observations from automatic weather stations during the polar night.We examined the correlation between each factor and the polynya area under different temperature conditions.Previous studies have focused more on the effect of winds on the polynya,but the relationship between air temperature and the polynya area has not been fully investigated.Our study shows,eliminating the influence of winds,lower air temperature has a stronger positive correlation with the polynya area.The results show that the relationship between the polynya area and air temperature is more likely to be interactively influenced.As temperature drops,the relationship of the polynya area with air temperature becomes closer with increasing correlation coefficients.In the low temperature conditions,the correlation coefficients of the polynya area with air temperature are above 0.5,larger than that with the wind speed.
基金supported by the grants from the Research Grants Council(RGC)of the Hong Kong Special Administrative Region(HKSAR),China with GRF No.16207118Shenzhen Science and Technology Innovation Commission(Project No.WDZC20200819174646001)Guangdong Basic and Applied Basic Research Foundation(Project No.2022B 1515130006)。
文摘The tropical cyclone boundary layer(TCBL)connecting the underlying terrain and the upper atmosphere plays a crucial role in the overall dynamics of a tropical cyclone system.When tropical cyclones approach the coastline,the wind field inside the TCBL makes a sea-land transition to impact both onshore and offshore structures.So better understanding of the wind field inside the TCBL in the sea-land transition zone is of great importance.To this end,a semiempirical model that integrates the sea-land transition model from the Engineering Sciences Data Unit(ESDU),Huang's refined TCBL wind field model,and the climate change scenarios from the Coupled Model Intercomparison Project Phase 6(CMIP6)is used to investigate the influence of climate changes on the sea-land transition of the TCBL wind flow in Hong Kong.More specifically,such a semiempirical method is employed in a series of Monte-Carlo simulations to predict the wind profiles inside the TCBL across the coastline of Hong Kong under the impact of future climate changes.The wind profiles calculated based on the Monte-Carlo simulation results reveal that,under the influences of the most severe climate change scenario,slightly higher and significantly lower wind speeds are found at altitudes above and below 400 m,respectively,compared to the wind speeds recommended in the Hong Kong Wind Code of Practice.Such findings imply that the wind profile model currently adopted by the Hong Kong authorities in assessing the safety of low-to high-rise buildings may be unnecessarily over-conservative under the influence of climate change.On the other hand,the coded wind loads on super-tall buildings slightly underestimate the typhoon impacts under the severe climate change conditions anticipated for coastal southern China.
