2001年12月13—14日，一个强劲的气旋风暴影响了西北太平洋地区，在俄勒冈州喀斯喀特山区产生了强地形降水。这个风暴是“改进微物理参数的观测验证试验（Improvement of Microphysical Parameterization through Observational Verific...2001年12月13—14日，一个强劲的气旋风暴影响了西北太平洋地区，在俄勒冈州喀斯喀特山区产生了强地形降水。这个风暴是“改进微物理参数的观测验证试验（Improvement of Microphysical Parameterization through Observational Verification Experiment，IMPROVE）”第二阶段外场研究的气旋风暴之一。在风暴移过俄勒冈州喀斯喀特山区期间，获得了大量的实测和遥感探测数据，形成了由气象状态参数（温、压、湿、风向风速和垂直气流速度）、极化多普勒雷达探测数据和云微物理参数（云液态水、粒子浓度、粒子谱及图像）组成的完整数据库。12月13—14日的过程具有对流层底层前倾锋演变的特点，锋面向前上方伸展到了强烈发展的高空冷锋雨带中，云发展到了8～9km的高度。与以前华盛顿喀斯喀特山区分析的风暴重要差别是，这个风暴在俄勒冈州喀斯喀特山上空的锋前低层气流是与弱东风气流相反的强西风爬山气流。结果当高空冷锋雨带过境时，在高空产生了大量冰晶的同时在低层地形抬升地区又产生了丰富的液态水。机载实测、地基微波辐射计观测以及雪晶观测证实，同时存在高冰晶浓度和高空相对大的云水含量，地面冰晶凇附也严重。分析表明，锋面和地形的相互促进作用使降水得到了增强。展开更多
Based on Arctic sea ice concentration data and NCEP／NCAR reanalysis data, relationship between sea ice anomaly over the sea of Okhotsk and its vicinage and northern Pacific storm track during winter is discussed by s...Based on Arctic sea ice concentration data and NCEP／NCAR reanalysis data, relationship between sea ice anomaly over the sea of Okhotsk and its vicinage and northern Pacific storm track during winter is discussed by statistic analysis methods. It is found that with northern Pacific SSTA, sea ice area anomaly over southwest of the sea of Okhotsk can except crucial influence on the variation in vigor and extension （contraction） from northwest to southeast of nor{hem Pacific storm track. But with tl^e influence of SSTA, sea ice area anomaly over northeast of the sea of Okhotsk and the gulf of SheUkhow works mainly on the strength and the south-north movement of the storm track.展开更多
Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Ti...Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.展开更多
2014年1月2日至8月2日，中国气象局国家气象中心强天气预报中心郑永光研究员以访问学者身份赴美国俄克拉何马大学（OU）风暴分析和预报中心（CAPS：Center for Analysisand Predictionof Storms）开展了合作研究。访问期间郑永光还与美...2014年1月2日至8月2日，中国气象局国家气象中心强天气预报中心郑永光研究员以访问学者身份赴美国俄克拉何马大学（OU）风暴分析和预报中心（CAPS：Center for Analysisand Predictionof Storms）开展了合作研究。访问期间郑永光还与美国国家环境预报中心（NCEP）环境模拟中心（EMC）集合预报组、风暴预报中心（SPC）、美国国家强风暴实验室（NS-SL）等单位的部分科研人员进行了交流。展开更多
Tropical disturbances over the South China Sea (SCS) during the period of 1997-2006 are analyzed using the Tropical Storm and Hurricane WX products. A total of 158 tropical disturbances were formed over the SCS from 1...Tropical disturbances over the South China Sea (SCS) during the period of 1997-2006 are analyzed using the Tropical Storm and Hurricane WX products. A total of 158 tropical disturbances were formed over the SCS from 1997 to 2006, with 54 de-veloping tropical disturbances which developed into tropical depressions and 104 non-developing tropical disturbances which never developed into tropical depressions. The development rate of tropical disturbances into tropical depressions was 34.18% in these ten years. During the period of this study, total annual numbers of tropical disturbances and developing tropical disturbances over the SCS had significant decreasing trends; however, the development rate of tropical disturbances had an insignificant increasing trend.展开更多
In this paper, time and space distribution regularity of meso-scale heavy rains in five selected typhoons which landed at Fujian from 1996 to 1998 has been analyzed. Besides, with hourly digitized satellite infrared i...In this paper, time and space distribution regularity of meso-scale heavy rains in five selected typhoons which landed at Fujian from 1996 to 1998 has been analyzed. Besides, with hourly digitized satellite infrared imagery, the features of the mesoscale are revealed for the genesis and evolution of mesoscale convective systems in typhoons. It indicates that the intensity of mesoscale storms is closely connected with the temperature and the area of the coldest cloud cluster. The heavy rainfall usually emerges on the eastern side of the mesoscale convective cloud clusters, where the cloud mass is developing and with a dense gradient and big curvature of isoline of the cloud top temperature.展开更多
With multiple meteorological data, including precipitation from automatic weather stations, integrated satellite-based precipitation (CMORPH), brightness temperature (TBB), radar echoes and NCEP reanalysis, a rainstor...With multiple meteorological data, including precipitation from automatic weather stations, integrated satellite-based precipitation (CMORPH), brightness temperature (TBB), radar echoes and NCEP reanalysis, a rainstorm event, which occurred on May 26, 2007 over South China, is analyzed with the focus on the evolution characteristics of associated mesoscale-β convective systems (Mβcss). Results are shown as follows. (1) The rainstorm presents itself as a typical warm-sector event, for it occurs within a surface inverted trough and on the left side of a southwesterly low-level jet (LLJ), which shows no obvious features of baroclinicity. (2) The heavy rainfall event is directly related to at least three bodies of Mβcss with peak precipitation corresponding well to their mature stages. (3) The Mβcss manifest a backward propagation, which is marked with a new form of downstream convection different from the more usual type of forward propagation over South China, i.e., new convective systems mainly form at the rear part of older Mβcss. (4) Rainstorm-causing Mβcss form near the convergence region on the left side of an 850-hPa southwesterly LLJ, over which there are dominantly divergent air flows at 200 hPa. Different from the typical flow pattern of outward divergence off the east side of South Asia High, which is usually found to be over zones of heavy rains during the annually first rainy season of South China, this warm-sector heavy rain is below the divergence region formed between the easterly and southerly flows west of the South Asian High that is moving out to sea. (5) The LLJ transports abundant amount of warm and moist air to the heavy rainfall area, providing advantageous conditions for highly unstable energy to generate and store at middle and high levels, where corresponding low-level warm advection may be playing a more direct role in the development of Mβcss. As a triggering mechanism for organized convective systems, the effect of low-level warm advection deserves more of our attention. Based on the analysis of surface mesoscale airflow in the article, possible triggering mechanisms for Mβcss are also discussed.展开更多
By using regular meteorological data, physical quantity fields, satellite pictures and Doppler radar echo data, we analyze the mesoscale features and the conditions of 4 successive heavy precipitation processes in Yun...By using regular meteorological data, physical quantity fields, satellite pictures and Doppler radar echo data, we analyze the mesoscale features and the conditions of 4 successive heavy precipitation processes in Yunnan aroused by the storm over the Bay in the early summer. The results show that the life of the storm over the Bay is usual 2 or 3 days and the cloud top temperature of the storm is always below -65℃. The storm over the Bay affects Yunnan by mesoscale convective cloud clusters, cloud system in peripheral or weaken itse,fmoving to the northeast. The Tibetan Plateau shear lines and vortexes, NE-SW convergence channels and southwest wind convergence supply favorable circulation background and dynamical conditions. There are many common features about Doppler radar echoes, the flocculent echoes with intensity about 35-45 dBZ move to the east to produce successive precipitation in Yunnan, and the mesoscale features of southwest jet and wind veering with altitude not only are favorable to transport warm and moist airflow brought to the north by the storm over the Bay. but also are favorable to convective development.展开更多
Based on prediction data of T213 and ECMWF and historical information of tropical cyclone,the causes of long lasting and large scale rainstorm brought by Nesat in Guangxi were analyzed.Nesat,of high intensity,carried ...Based on prediction data of T213 and ECMWF and historical information of tropical cyclone,the causes of long lasting and large scale rainstorm brought by Nesat in Guangxi were analyzed.Nesat,of high intensity,carried much vapor and energy and went through Beibu Gulf by subtropical high pressure.After Nesat made landfall,subtropical high pressure maintained high and gradient between typhoon circulation and subtropical high pressure increased;the typhoon was supported by abundant vapors and energies by powerful eastern flows.Furthermore,northern cold airs went downward and met southeast wind behind of the typhoon,resulting in shears and convective precipitation.Therefore,the rains brought by the typhoon itself,jet stream,and cold air contributed to long lasting rainfall under influence of Nesat.展开更多
To reduce typhoon-caused damages, numerical and empirical methods are often used to forecast typhoon storm surge. However, typhoon surge is a complex nonlinear process that is difficult to forecast accurately. We appl...To reduce typhoon-caused damages, numerical and empirical methods are often used to forecast typhoon storm surge. However, typhoon surge is a complex nonlinear process that is difficult to forecast accurately. We applied a principal component back-propagation neural network (PCBPNN) to predict the deviation in typhoon storm surge, in which data of the typhoon, upstream flood, and historical case studies were involved. With principal component analysis, 15 input factors were reduced to five principal components, and the application of the model was improved. Observation data from Huangpu Park in Shanghai, China were used to test the feasibility of the model. The results indicate that the model is capable of predicting a 12-hour warning before a typhoon surge.展开更多
文摘2001年12月13—14日，一个强劲的气旋风暴影响了西北太平洋地区，在俄勒冈州喀斯喀特山区产生了强地形降水。这个风暴是“改进微物理参数的观测验证试验（Improvement of Microphysical Parameterization through Observational Verification Experiment，IMPROVE）”第二阶段外场研究的气旋风暴之一。在风暴移过俄勒冈州喀斯喀特山区期间，获得了大量的实测和遥感探测数据，形成了由气象状态参数（温、压、湿、风向风速和垂直气流速度）、极化多普勒雷达探测数据和云微物理参数（云液态水、粒子浓度、粒子谱及图像）组成的完整数据库。12月13—14日的过程具有对流层底层前倾锋演变的特点，锋面向前上方伸展到了强烈发展的高空冷锋雨带中，云发展到了8～9km的高度。与以前华盛顿喀斯喀特山区分析的风暴重要差别是，这个风暴在俄勒冈州喀斯喀特山上空的锋前低层气流是与弱东风气流相反的强西风爬山气流。结果当高空冷锋雨带过境时，在高空产生了大量冰晶的同时在低层地形抬升地区又产生了丰富的液态水。机载实测、地基微波辐射计观测以及雪晶观测证实，同时存在高冰晶浓度和高空相对大的云水含量，地面冰晶凇附也严重。分析表明，锋面和地形的相互促进作用使降水得到了增强。
基金supported by the key project of Science and Technology Development Foundation of Regional Meteorological Center of Wuhan (No. QY-Z-200902)subsidized project of Key Laboratory of Meteorological Disaster of Jiangsu Province (KLME050202) subsidized project of "Qing-lan" for the Young and Middle-aged Academic Pathfinders in Colleges and Universities of Jiangsu province
文摘Based on Arctic sea ice concentration data and NCEP／NCAR reanalysis data, relationship between sea ice anomaly over the sea of Okhotsk and its vicinage and northern Pacific storm track during winter is discussed by statistic analysis methods. It is found that with northern Pacific SSTA, sea ice area anomaly over southwest of the sea of Okhotsk can except crucial influence on the variation in vigor and extension （contraction） from northwest to southeast of nor{hem Pacific storm track. But with tl^e influence of SSTA, sea ice area anomaly over northeast of the sea of Okhotsk and the gulf of SheUkhow works mainly on the strength and the south-north movement of the storm track.
文摘Based on tidal data statistical analysis for 20 years of Tanggu Marine Environmental Monitoring Station from 1991 to 2010, we concluded that an average of nearly 10 days of 100 cm above water increase took place at Tianjin coast every year. The maximum high tide and average tide of Tianjin coast occurred in summer and autumn, and the maximum water increase also occurred in summer and autumn. Days with water increase more than 100 cm mostly occurred in spring, autumn and winter. Then we summarized the causes of coastal storm surge disaster in Tianjin based on astronomical tide factors, meteorological factors, sea level rise, land subsidence, and geographic factors, et al. Finally, we proposed storm surge disaster prevention measures.
文摘2014年1月2日至8月2日，中国气象局国家气象中心强天气预报中心郑永光研究员以访问学者身份赴美国俄克拉何马大学（OU）风暴分析和预报中心（CAPS：Center for Analysisand Predictionof Storms）开展了合作研究。访问期间郑永光还与美国国家环境预报中心（NCEP）环境模拟中心（EMC）集合预报组、风暴预报中心（SPC）、美国国家强风暴实验室（NS-SL）等单位的部分科研人员进行了交流。
基金supported by Chinese Academy of Sciences(Grant KZCX2-YW-214)NSFC Grants 40875020 and 41075054+2 种基金the Fundamental Research Funds for the Central Universities(Nos.11lgpy13 and 11lgjc10)sponsored by the tropical marine meteorology fund from the Institute of Tropical and Marine Meteorology,CMA,SOED1108Scientific Research Foundation for the Young Teachers Program of Sun Yat-sen University(No. 38000-3181402)
文摘Tropical disturbances over the South China Sea (SCS) during the period of 1997-2006 are analyzed using the Tropical Storm and Hurricane WX products. A total of 158 tropical disturbances were formed over the SCS from 1997 to 2006, with 54 de-veloping tropical disturbances which developed into tropical depressions and 104 non-developing tropical disturbances which never developed into tropical depressions. The development rate of tropical disturbances into tropical depressions was 34.18% in these ten years. During the period of this study, total annual numbers of tropical disturbances and developing tropical disturbances over the SCS had significant decreasing trends; however, the development rate of tropical disturbances had an insignificant increasing trend.
文摘In this paper, time and space distribution regularity of meso-scale heavy rains in five selected typhoons which landed at Fujian from 1996 to 1998 has been analyzed. Besides, with hourly digitized satellite infrared imagery, the features of the mesoscale are revealed for the genesis and evolution of mesoscale convective systems in typhoons. It indicates that the intensity of mesoscale storms is closely connected with the temperature and the area of the coldest cloud cluster. The heavy rainfall usually emerges on the eastern side of the mesoscale convective cloud clusters, where the cloud mass is developing and with a dense gradient and big curvature of isoline of the cloud top temperature.
基金Natural Science Foundation of China (40775068)Research Foundation of Tropical and Marine Meteorology,Technology Project on Meteorology in Guangdong Province Meteorological Bureau (2007A01)
文摘With multiple meteorological data, including precipitation from automatic weather stations, integrated satellite-based precipitation (CMORPH), brightness temperature (TBB), radar echoes and NCEP reanalysis, a rainstorm event, which occurred on May 26, 2007 over South China, is analyzed with the focus on the evolution characteristics of associated mesoscale-β convective systems (Mβcss). Results are shown as follows. (1) The rainstorm presents itself as a typical warm-sector event, for it occurs within a surface inverted trough and on the left side of a southwesterly low-level jet (LLJ), which shows no obvious features of baroclinicity. (2) The heavy rainfall event is directly related to at least three bodies of Mβcss with peak precipitation corresponding well to their mature stages. (3) The Mβcss manifest a backward propagation, which is marked with a new form of downstream convection different from the more usual type of forward propagation over South China, i.e., new convective systems mainly form at the rear part of older Mβcss. (4) Rainstorm-causing Mβcss form near the convergence region on the left side of an 850-hPa southwesterly LLJ, over which there are dominantly divergent air flows at 200 hPa. Different from the typical flow pattern of outward divergence off the east side of South Asia High, which is usually found to be over zones of heavy rains during the annually first rainy season of South China, this warm-sector heavy rain is below the divergence region formed between the easterly and southerly flows west of the South Asian High that is moving out to sea. (5) The LLJ transports abundant amount of warm and moist air to the heavy rainfall area, providing advantageous conditions for highly unstable energy to generate and store at middle and high levels, where corresponding low-level warm advection may be playing a more direct role in the development of Mβcss. As a triggering mechanism for organized convective systems, the effect of low-level warm advection deserves more of our attention. Based on the analysis of surface mesoscale airflow in the article, possible triggering mechanisms for Mβcss are also discussed.
基金Project of China Meteorological Administrator (2006): "Operation System R&D of YunnanLightning Observation and Forecast"
文摘By using regular meteorological data, physical quantity fields, satellite pictures and Doppler radar echo data, we analyze the mesoscale features and the conditions of 4 successive heavy precipitation processes in Yunnan aroused by the storm over the Bay in the early summer. The results show that the life of the storm over the Bay is usual 2 or 3 days and the cloud top temperature of the storm is always below -65℃. The storm over the Bay affects Yunnan by mesoscale convective cloud clusters, cloud system in peripheral or weaken itse,fmoving to the northeast. The Tibetan Plateau shear lines and vortexes, NE-SW convergence channels and southwest wind convergence supply favorable circulation background and dynamical conditions. There are many common features about Doppler radar echoes, the flocculent echoes with intensity about 35-45 dBZ move to the east to produce successive precipitation in Yunnan, and the mesoscale features of southwest jet and wind veering with altitude not only are favorable to transport warm and moist airflow brought to the north by the storm over the Bay. but also are favorable to convective development.
文摘Based on prediction data of T213 and ECMWF and historical information of tropical cyclone,the causes of long lasting and large scale rainstorm brought by Nesat in Guangxi were analyzed.Nesat,of high intensity,carried much vapor and energy and went through Beibu Gulf by subtropical high pressure.After Nesat made landfall,subtropical high pressure maintained high and gradient between typhoon circulation and subtropical high pressure increased;the typhoon was supported by abundant vapors and energies by powerful eastern flows.Furthermore,northern cold airs went downward and met southeast wind behind of the typhoon,resulting in shears and convective precipitation.Therefore,the rains brought by the typhoon itself,jet stream,and cold air contributed to long lasting rainfall under influence of Nesat.
基金Supported by National Marine Public Scientific Research Fund of China(No. 200905010)the Talent Training Fund Project for Basic Sciences of the National Natural Science Foundation of China (No. J0730534)+2 种基金the Fundamental Research Funds for the Central Universitiesthe Open Research Funding Program of KLGIS (No. KLGIS2011A12)the Open Fund from Key Laboratory of Marine Management Technique of State Oceanic Administration (No. 201112)
文摘To reduce typhoon-caused damages, numerical and empirical methods are often used to forecast typhoon storm surge. However, typhoon surge is a complex nonlinear process that is difficult to forecast accurately. We applied a principal component back-propagation neural network (PCBPNN) to predict the deviation in typhoon storm surge, in which data of the typhoon, upstream flood, and historical case studies were involved. With principal component analysis, 15 input factors were reduced to five principal components, and the application of the model was improved. Observation data from Huangpu Park in Shanghai, China were used to test the feasibility of the model. The results indicate that the model is capable of predicting a 12-hour warning before a typhoon surge.
