Using boundary layer data with regard to sea fog observed at the Science Experiment Base for Marine Meteorology at Bohe,Guangdong Province,the structure of the atmospheric boundary layer and the characteristics of the...Using boundary layer data with regard to sea fog observed at the Science Experiment Base for Marine Meteorology at Bohe,Guangdong Province,the structure of the atmospheric boundary layer and the characteristics of the tops of the fog and the clouds were analyzed.In addition,the effects of advection,radiation,and turbulence during sea fog were also investigated.According to the stability definition of saturated,wet air,the gradient of the potential pseudo-equivalent temperature equal to zero was defined as the thermal turbulence interface.There is evidence to suggest that two layers of turbulence exist in sea fog.Thermal turbulence produced by long-wave radiation is prevalent above the thermal turbulence interface,whereas mechanical turbulence aroused by wind shear is predominant below the interface.The height of the thermal turbulence interface was observed between 180 m and 380 m.Three important factors are closely related to the development of the top of the sea fog：（1） the horizontal advection of the water vapor,（2） the long-wave radiation of the fog top,and（3） the movement of the vertical turbulence.Formation,development,and dissipation are the three possible phases of the evolution of the boundary-layer structure during the sea fog season.In addition,the thermal turbulence interface is the most significant turbulence interface during the formation and development periods;it is maintained after sea fog rises into the stratus layer.展开更多
Based on hourly observation data from 2016 to 2019 and hourly automatic meteorological observation data from 2018 to 2019, we analyzed the annual, monthly and daily variation characteristics of fog days in Ninglang Ai...Based on hourly observation data from 2016 to 2019 and hourly automatic meteorological observation data from 2018 to 2019, we analyzed the annual, monthly and daily variation characteristics of fog days in Ninglang Airport, and diagnosed a case of summer fog. The results show that the average annual fog days in Ninglang Airport are 128 days and the annual characteristic of fog days is bimodal. Analyzed on fog cases in 2019, it was a summer fog process lasting more than 20 hours and visibility less than 500 m. The data from the automatic observational stations around Ninglang airport can describe the near-surface layer features of fog and illustrate the progress of fog. The meteorological elements of automatic observational stations changed suddenly 2 hours before fog, so the data of the automatic observational stations can be used to forscast fog.展开更多
Industry 4.0 refers to the fourth evolution of technology development,which strives to connect people to various industries in terms of achieving their expected outcomes efficiently.However,resource management in an I...Industry 4.0 refers to the fourth evolution of technology development,which strives to connect people to various industries in terms of achieving their expected outcomes efficiently.However,resource management in an Industry 4.0 network is very complex and challenging.To manage and provide suitable resources to each service,we propose a FogQSYM(Fog—Queuing system)model;it is an analytical model for Fog Applications that helps divide the application into several layers,then enables the sharing of the resources in an effective way according to the availability of memory,bandwidth,and network services.It follows theMarkovian queuing model that helps identify the service rates of the devices,the availability of the system,and the number of jobs in the Industry 4.0 systems,which helps applications process data with a reasonable response time.An experiment is conducted using a Cloud Analyst simulator with multiple segments of datacenters in a fog application,which shows that the model helps efficiently provide the arrival resources to the appropriate services with a low response time.After implementing the proposed model with different sizes of fog services in Industry 4.0 applications,FogQSYM provides a lower response time than the existing optimized response time model.It should also be noted that the average response time increases when the arrival rate increases.展开更多
[Objective] The aim was to discuss the formation, duration and disappearance of fog. [Method] Based on the weather data and physics of Liaoning Province, and considering the continuous 4 foggy days in 11 places in Lia...[Objective] The aim was to discuss the formation, duration and disappearance of fog. [Method] Based on the weather data and physics of Liaoning Province, and considering the continuous 4 foggy days in 11 places in Liaoning from November 29 to December 2, 2009, detailed analysis of this consecutive foggy days was given proceeding from the weather situation, element characteristics, especially the occurrence, duration and disappearance of dense fog. [Result] This dense fog was because that Liaoning was in the saddle pressure field. The weak cold air divergence set the ground in many weak mild scale convergence areas. The high temperature in the early time resulted in melting snow and long duration of dense fog days, along with radiation low temperature and southwest convergence transmission. In the meantime, because of the existence of small wind speed and existence of upper inversion temperature layer, it was inconvenient for the divergence of wet air; in addition, there was dense fog in north China. The upper southwest airstream transmitted wet air in the north China to the air of Liaoning, increasing the intensity of dense fog in Liaoning. [Conclusion] The study offered reference for the further forecast of air pollution.展开更多
This study uses numerical simulations to examine a case of sea fog that was observed from 20 to 22 March2011 on the southern China coast. The observation dataset includes observatory data, cloud-top temperature from M...This study uses numerical simulations to examine a case of sea fog that was observed from 20 to 22 March2011 on the southern China coast. The observation dataset includes observatory data, cloud-top temperature from MODIS, GPS sonde, and data from the Integrated Observation Platform for Marine Meteorology(IOPMM). The simulations are based on the Weather Research and Forecasting(WRF) model with four distinct parameter settings.Both the observations and simulations focus on the characteristics of the fog extent, boundary layer structure, and meteorological elements near the air-sea interface. Our main results are as follows:(1) The extent of mesoscale sea fog can be well simulated when the sea surface temperature has at least 0.5 ×0.5 horizontal resolution.(2) To accurately model the vertical structure of the sea fog, particularly the surface-based inversion, vertical levels must be added in the boundary layer.(3) When these model conditions are met, the simulations faithfully reproduce the measured downward shortwave radiation, downward longwave radiation, and surface sensible heat flux during the sea fog period.展开更多
2022年4月10—14日浙江沿海海面出现一次持续时间长、范围广、浓度大的海雾过程。利用卫星资料、欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)发布的ERA-Interim(ECMWF Reanalysis-Interim)资料和...2022年4月10—14日浙江沿海海面出现一次持续时间长、范围广、浓度大的海雾过程。利用卫星资料、欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)发布的ERA-Interim(ECMWF Reanalysis-Interim)资料和浙江沿海自动气象观测站资料,分析此次过程的特征和成因。结果表明,低层逆温层使得低层水汽不易扩散到高空,有利于大雾的生成和维持。成雾阶段,有明显的水汽辐合,同时气温高于海面温度且差值为0~2.0℃。海雾维持且浓度较大时,水汽辐合逐渐减弱;气海温差(2 m气温减海面温度)则在0℃左右。消散阶段,有明显的水汽辐散;气海温差大于2.0℃或小于0℃。展开更多
基金sponsored jointly by the Chinese Special Scientific Research Project for Public Interest (Grant No. GYHY200906008)the National Natural Science Foundation of China (Grant No.40675013)+1 种基金the Science and Technology Project of Guangdong Province (Grant No. 2008B030303072)the Meteorological Sciences Research Project of the Weather Bu-reau of Guangdong Province (Grant No. 201003)
文摘Using boundary layer data with regard to sea fog observed at the Science Experiment Base for Marine Meteorology at Bohe,Guangdong Province,the structure of the atmospheric boundary layer and the characteristics of the tops of the fog and the clouds were analyzed.In addition,the effects of advection,radiation,and turbulence during sea fog were also investigated.According to the stability definition of saturated,wet air,the gradient of the potential pseudo-equivalent temperature equal to zero was defined as the thermal turbulence interface.There is evidence to suggest that two layers of turbulence exist in sea fog.Thermal turbulence produced by long-wave radiation is prevalent above the thermal turbulence interface,whereas mechanical turbulence aroused by wind shear is predominant below the interface.The height of the thermal turbulence interface was observed between 180 m and 380 m.Three important factors are closely related to the development of the top of the sea fog：（1） the horizontal advection of the water vapor,（2） the long-wave radiation of the fog top,and（3） the movement of the vertical turbulence.Formation,development,and dissipation are the three possible phases of the evolution of the boundary-layer structure during the sea fog season.In addition,the thermal turbulence interface is the most significant turbulence interface during the formation and development periods;it is maintained after sea fog rises into the stratus layer.
文摘Based on hourly observation data from 2016 to 2019 and hourly automatic meteorological observation data from 2018 to 2019, we analyzed the annual, monthly and daily variation characteristics of fog days in Ninglang Airport, and diagnosed a case of summer fog. The results show that the average annual fog days in Ninglang Airport are 128 days and the annual characteristic of fog days is bimodal. Analyzed on fog cases in 2019, it was a summer fog process lasting more than 20 hours and visibility less than 500 m. The data from the automatic observational stations around Ninglang airport can describe the near-surface layer features of fog and illustrate the progress of fog. The meteorological elements of automatic observational stations changed suddenly 2 hours before fog, so the data of the automatic observational stations can be used to forscast fog.
基金This work was supported by the National Research Foundation of Korea under Grant 2019R1A2C1085388.
文摘Industry 4.0 refers to the fourth evolution of technology development,which strives to connect people to various industries in terms of achieving their expected outcomes efficiently.However,resource management in an Industry 4.0 network is very complex and challenging.To manage and provide suitable resources to each service,we propose a FogQSYM(Fog—Queuing system)model;it is an analytical model for Fog Applications that helps divide the application into several layers,then enables the sharing of the resources in an effective way according to the availability of memory,bandwidth,and network services.It follows theMarkovian queuing model that helps identify the service rates of the devices,the availability of the system,and the number of jobs in the Industry 4.0 systems,which helps applications process data with a reasonable response time.An experiment is conducted using a Cloud Analyst simulator with multiple segments of datacenters in a fog application,which shows that the model helps efficiently provide the arrival resources to the appropriate services with a low response time.After implementing the proposed model with different sizes of fog services in Industry 4.0 applications,FogQSYM provides a lower response time than the existing optimized response time model.It should also be noted that the average response time increases when the arrival rate increases.
文摘[Objective] The aim was to discuss the formation, duration and disappearance of fog. [Method] Based on the weather data and physics of Liaoning Province, and considering the continuous 4 foggy days in 11 places in Liaoning from November 29 to December 2, 2009, detailed analysis of this consecutive foggy days was given proceeding from the weather situation, element characteristics, especially the occurrence, duration and disappearance of dense fog. [Result] This dense fog was because that Liaoning was in the saddle pressure field. The weak cold air divergence set the ground in many weak mild scale convergence areas. The high temperature in the early time resulted in melting snow and long duration of dense fog days, along with radiation low temperature and southwest convergence transmission. In the meantime, because of the existence of small wind speed and existence of upper inversion temperature layer, it was inconvenient for the divergence of wet air; in addition, there was dense fog in north China. The upper southwest airstream transmitted wet air in the north China to the air of Liaoning, increasing the intensity of dense fog in Liaoning. [Conclusion] The study offered reference for the further forecast of air pollution.
基金National Natural Science Foundation of China(4127502541175013)+2 种基金Guangdong Science and Technology Plan Project(2008030303072,2012A061400012)Meteorological Sciences Research Project(2013B06,2013Q04,2014B08)Early Warning and Forecasting Technology for Marine Meteorology of the Guangdong Meteorological Bureau
文摘This study uses numerical simulations to examine a case of sea fog that was observed from 20 to 22 March2011 on the southern China coast. The observation dataset includes observatory data, cloud-top temperature from MODIS, GPS sonde, and data from the Integrated Observation Platform for Marine Meteorology(IOPMM). The simulations are based on the Weather Research and Forecasting(WRF) model with four distinct parameter settings.Both the observations and simulations focus on the characteristics of the fog extent, boundary layer structure, and meteorological elements near the air-sea interface. Our main results are as follows:(1) The extent of mesoscale sea fog can be well simulated when the sea surface temperature has at least 0.5 ×0.5 horizontal resolution.(2) To accurately model the vertical structure of the sea fog, particularly the surface-based inversion, vertical levels must be added in the boundary layer.(3) When these model conditions are met, the simulations faithfully reproduce the measured downward shortwave radiation, downward longwave radiation, and surface sensible heat flux during the sea fog period.
文摘2022年4月10—14日浙江沿海海面出现一次持续时间长、范围广、浓度大的海雾过程。利用卫星资料、欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)发布的ERA-Interim(ECMWF Reanalysis-Interim)资料和浙江沿海自动气象观测站资料,分析此次过程的特征和成因。结果表明,低层逆温层使得低层水汽不易扩散到高空,有利于大雾的生成和维持。成雾阶段,有明显的水汽辐合,同时气温高于海面温度且差值为0~2.0℃。海雾维持且浓度较大时,水汽辐合逐渐减弱;气海温差(2 m气温减海面温度)则在0℃左右。消散阶段,有明显的水汽辐散;气海温差大于2.0℃或小于0℃。
