The climatic general situation of cold dew wind weather in past years,main circulation features in early cold dew wind years as well as changes of circulation feature in prophase were conducted statistical analysis,be...The climatic general situation of cold dew wind weather in past years,main circulation features in early cold dew wind years as well as changes of circulation feature in prophase were conducted statistical analysis,besides,many meteorological factors influenced the time of cold dew wind weather were analyzed.The damage and defensive countermeasures of cold dew wind on late rice production.展开更多
The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation...The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation from multi-source satellite database together with an reference to the monitoring indexes of cold dew wind disaster to verify the precision of CLDAS data,so as to provide a reference for monitoring chilling damage caused by cold dew wind in late rice production in Guangxi. The results showed that the cold wind dew caused heavy damage to an area of 3 159. 76 km^2,moderate damage to an area of 559. 77 km^2 and light damage to an area of 2 452. 14 km^2. The correlation coefficients between CLDAS inversion temperature and actual temperature of 12 verification meteorological stations were all larger than 0. 93,and the difference in daily average temperature was 0. 3 ℃. The time difference between maximum and minimum temperature provided by CLDAS and corresponding actual temperature from 12 meteorological stations was less than 1 h. The temperature data provided by CLDAS was in accordance with actual temperature data. With an advantage of rapidly,minutely and accurately monitoring the grade distribution of local cold dew wind disaster for late rice,CLDAS can be used in monitoring cold dew wind in late rice production in Guangxi.展开更多
An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main struc...An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main structures and characteristics are the same as during strong wind episodes with cold air outbreaks on land. The high frequency turbulent fluctuations （period 〈 1 min） are nearly random and isotropic with weak coherency, but the gusty wind disturbances （1 rain〈period 〈 10 min） are anisotropic with rather strong coherency. However, in the windy atmospheric boundary layer at sea, compared with that over land, there are some pronounced differences： （1） the average horizontal speed is almost independent of height, and the vertical velocity is positive in the lower marine atmospheric boundary layer; （2） the vertical flux of horizontal momentum is nearly independent of height in the low layer indicating the existence of a constant flux layer, unlike during strong wind over the land surface; （3） the kinetic energy and friction velocity of turbulent fluctuations are larger than those of gusty disturbances; （4） due to the independence of horizontal speed to height, the horizontal speed itself （not its vertical gradient used over the land surface） can be used as the key parameter to parameterize the turbulent and gusty characteristics with high accuracy.展开更多
This study is intended to recognize the importance of cold-wind, which is one of the solutions to improve urban amenity, and verify the model that can analyze creation and flow of cold-wind. For this reason, KLAM_21 M...This study is intended to recognize the importance of cold-wind, which is one of the solutions to improve urban amenity, and verify the model that can analyze creation and flow of cold-wind. For this reason, KLAM_21 Model, which was developed by the German’s Meteorological Service, was selected and used for assessment of cold-wind creation and flow. As a result, the followings have been drawn through comparison with measured data and simulated data in the study area;for a mountain area, the simulation result of velocity and direction of wind has been indicated as similar as those in measured data. For a stream area in the city, only wind direction from simulation has been consistent with measured data whereas wind velocity showed a large difference between measurement and simulation. Finally, for the downtown area, wind velocity has shown a lot of differences between simulation result and measured data. Wind direction has also shown a large difference until midnight. But after midnight, model data have become similar as measured data. According to the verification of this study, the model used in this study for using urban-amenity improvement through assessment of creation and flow of cold wind is suitable to analyze the direction of cold wind that is generated in the periphery of the city and the overall flow within the existing urban area. But the results of wind velocity have shown the uppermost limit of the modeling in the simulation. That is, it could not reflect the site characteristics sufficiently. Therefore, if parameters considering the specific regional characteristics are sufficiently reflected, the result of simulations for reliability can be substantially improved.展开更多
风电出力与运行条件密切相关,寒潮作为一种极端天气事件,往往会导致电力负荷激增。该场景下的风电功率预测结果与实际出力存在较大偏差,从而对电力系统的安全稳定运行带来了挑战。文章提出了一种基于现实时间序列生成对抗网络(real-worl...风电出力与运行条件密切相关,寒潮作为一种极端天气事件,往往会导致电力负荷激增。该场景下的风电功率预测结果与实际出力存在较大偏差,从而对电力系统的安全稳定运行带来了挑战。文章提出了一种基于现实时间序列生成对抗网络(real-world time series generative adversarial network,RTSGAN)样本扩充和注意力动态权重集成的寒潮极端天气条件风电功率预测方法。首先针对寒潮天气下风电样本稀缺的问题,采用RTSGAN对寒潮事件原始数据进行样本扩充;然后基于扩充得到的样本数据集分别构建基础预测模型和注意力网络;最后通过注意力动态权重集成方法进行风电功率预测。算例结果表明,所提方法能够解决寒潮极端天气风电样本稀缺的问题,可有效提升寒潮极端天气条件下的风电功率预测精度。展开更多
The daily and monthly-mean characteristics of cold water patches （CWPs） off the Jiangsu coast in 35 a of 1982-2016 are examined based on advanced very high resolution radiometer （AVHRR） data. Most of the CWPs are ...The daily and monthly-mean characteristics of cold water patches （CWPs） off the Jiangsu coast in 35 a of 1982-2016 are examined based on advanced very high resolution radiometer （AVHRR） data. Most of the CWPs are found to occur in the warm and hot months （May-September）, with some CWPs in the cool and cold months （October-April）. The average radius and intensity of the monthly-mean CWPs are about 81 km and 0.6℃, respectively. The average difference in the sea surface temperature （SST） between the centers of the CWPs and the nearshore is about 2.0℃. The correlation analysis between the CWPs, winds and tides indicates that most of the CWPs occurred during the southerly winds, with some CWPs occurring during the northerly winds. The average intensity of the CWPs during spring tides is slightly stronger than that during neap tides in the warm and hot months, and the difference is very small in the cool and cold months.展开更多
文摘The climatic general situation of cold dew wind weather in past years,main circulation features in early cold dew wind years as well as changes of circulation feature in prophase were conducted statistical analysis,besides,many meteorological factors influenced the time of cold dew wind weather were analyzed.The damage and defensive countermeasures of cold dew wind on late rice production.
基金Supported by the National Agricultural Science and Technology Achievements Transformation Project of China(2014GB2E100281)the Science and Technology Key R&D Program of Guangxi(Guike AB17195037)
文摘The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation from multi-source satellite database together with an reference to the monitoring indexes of cold dew wind disaster to verify the precision of CLDAS data,so as to provide a reference for monitoring chilling damage caused by cold dew wind in late rice production in Guangxi. The results showed that the cold wind dew caused heavy damage to an area of 3 159. 76 km^2,moderate damage to an area of 559. 77 km^2 and light damage to an area of 2 452. 14 km^2. The correlation coefficients between CLDAS inversion temperature and actual temperature of 12 verification meteorological stations were all larger than 0. 93,and the difference in daily average temperature was 0. 3 ℃. The time difference between maximum and minimum temperature provided by CLDAS and corresponding actual temperature from 12 meteorological stations was less than 1 h. The temperature data provided by CLDAS was in accordance with actual temperature data. With an advantage of rapidly,minutely and accurately monitoring the grade distribution of local cold dew wind disaster for late rice,CLDAS can be used in monitoring cold dew wind in late rice production in Guangxi.
基金supported by the National Nature Science Foundation of China (NSFC, Grant Nos. 40830103 and 41375018)a National Program on Key Basic Research project (973 Program) (Grant No. 2010CB951804)+2 种基金the plan of the State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (Grant No. LAPC-KF-2013-11)China Special Fund for Meteorological Research in the Public Interest (Grant No. GYHY200906008)the program of the Chinese Academy of Sciences (Grant No. XDA10010403)
文摘An observational analysis of the structures and characteristics of a windy atmospheric boundary layer during a cold air outbreak in the South China Sea region is reported in this paper. It is found that the main structures and characteristics are the same as during strong wind episodes with cold air outbreaks on land. The high frequency turbulent fluctuations （period 〈 1 min） are nearly random and isotropic with weak coherency, but the gusty wind disturbances （1 rain〈period 〈 10 min） are anisotropic with rather strong coherency. However, in the windy atmospheric boundary layer at sea, compared with that over land, there are some pronounced differences： （1） the average horizontal speed is almost independent of height, and the vertical velocity is positive in the lower marine atmospheric boundary layer; （2） the vertical flux of horizontal momentum is nearly independent of height in the low layer indicating the existence of a constant flux layer, unlike during strong wind over the land surface; （3） the kinetic energy and friction velocity of turbulent fluctuations are larger than those of gusty disturbances; （4） due to the independence of horizontal speed to height, the horizontal speed itself （not its vertical gradient used over the land surface） can be used as the key parameter to parameterize the turbulent and gusty characteristics with high accuracy.
文摘This study is intended to recognize the importance of cold-wind, which is one of the solutions to improve urban amenity, and verify the model that can analyze creation and flow of cold-wind. For this reason, KLAM_21 Model, which was developed by the German’s Meteorological Service, was selected and used for assessment of cold-wind creation and flow. As a result, the followings have been drawn through comparison with measured data and simulated data in the study area;for a mountain area, the simulation result of velocity and direction of wind has been indicated as similar as those in measured data. For a stream area in the city, only wind direction from simulation has been consistent with measured data whereas wind velocity showed a large difference between measurement and simulation. Finally, for the downtown area, wind velocity has shown a lot of differences between simulation result and measured data. Wind direction has also shown a large difference until midnight. But after midnight, model data have become similar as measured data. According to the verification of this study, the model used in this study for using urban-amenity improvement through assessment of creation and flow of cold wind is suitable to analyze the direction of cold wind that is generated in the periphery of the city and the overall flow within the existing urban area. But the results of wind velocity have shown the uppermost limit of the modeling in the simulation. That is, it could not reflect the site characteristics sufficiently. Therefore, if parameters considering the specific regional characteristics are sufficiently reflected, the result of simulations for reliability can be substantially improved.
文摘风电出力与运行条件密切相关,寒潮作为一种极端天气事件,往往会导致电力负荷激增。该场景下的风电功率预测结果与实际出力存在较大偏差,从而对电力系统的安全稳定运行带来了挑战。文章提出了一种基于现实时间序列生成对抗网络(real-world time series generative adversarial network,RTSGAN)样本扩充和注意力动态权重集成的寒潮极端天气条件风电功率预测方法。首先针对寒潮天气下风电样本稀缺的问题,采用RTSGAN对寒潮事件原始数据进行样本扩充;然后基于扩充得到的样本数据集分别构建基础预测模型和注意力网络;最后通过注意力动态权重集成方法进行风电功率预测。算例结果表明,所提方法能够解决寒潮极端天气风电样本稀缺的问题,可有效提升寒潮极端天气条件下的风电功率预测精度。
基金The National Natural Science Foundation of China under contract Nos 41076048,41376012 and 41206163the Fundamental Research Funds for the Central Universities under contract No.2011B05714
文摘The daily and monthly-mean characteristics of cold water patches （CWPs） off the Jiangsu coast in 35 a of 1982-2016 are examined based on advanced very high resolution radiometer （AVHRR） data. Most of the CWPs are found to occur in the warm and hot months （May-September）, with some CWPs in the cool and cold months （October-April）. The average radius and intensity of the monthly-mean CWPs are about 81 km and 0.6℃, respectively. The average difference in the sea surface temperature （SST） between the centers of the CWPs and the nearshore is about 2.0℃. The correlation analysis between the CWPs, winds and tides indicates that most of the CWPs occurred during the southerly winds, with some CWPs occurring during the northerly winds. The average intensity of the CWPs during spring tides is slightly stronger than that during neap tides in the warm and hot months, and the difference is very small in the cool and cold months.
