This article describes a new and low-cost microwave passive sensor for hail prediction (forecasting) and detection developed in Armenia, which can be used to implement fully autonomous and automatically functioning ha...This article describes a new and low-cost microwave passive sensor for hail prediction (forecasting) and detection developed in Armenia, which can be used to implement fully autonomous and automatically functioning hail protection of locally limited or large agricultural and urban areas in order to prevent, suppress or catch hail in traps. The article also presents the results of measurements of the intrinsic emission characteristics of water and ice, rain and hail clouds, carried out in laboratory and field conditions in the Ku-band of radio frequencies. The results obtained showed that the intrinsic emission of a hail cloud in the Ku-band of radio frequencies differs significantly from the intrinsic emission of a rain cloud. The presented results show that indeed the radar is not very suitable for the timely detection and determination of hail with a high probability, which is very important for the timely starting up of anti-hail protection means. On the contrary, radiometers (passive microwave sensors) can become an effective sensing tool for timely detection and recognition of hail with a high probability of long-range approaches up to ~12 - 15 km.展开更多
[Objective] The hail weather and forecast storm in Guilin were studied. [Method] In allusion to the occurrence of hailstorm in Guilin and considering the observation data of a new generation of Doppler weather radar i...[Objective] The hail weather and forecast storm in Guilin were studied. [Method] In allusion to the occurrence of hailstorm in Guilin and considering the observation data of a new generation of Doppler weather radar in Guilin, the weather situation and radar echo characteristics in Guilin was summarized so as to explore the short time forecast method. [Result] There were one or two icy storms every year in Guilin. The occurrence of icy storm was distinctly influenced by terrain. A new generation of Doppler weather radar detection ice storm was very effective. The singular intensity of echo of icy storm in Guilin was above or equal to 50 dBz and the height of echo was above or equal to 10 km. The vertical liquid content was above or equal to 40 kg/m2, accompanied by mild cyclone. When there was strong icy storm, there were three flux characteristics. The forecast of icy storm was mainly short time forecast. [Conclusion] The study offered reference for the forecast of icy storm, artificial storm and disaster prevention and mitigation work.展开更多
1 INTRODUCTION Lightning is a phenomenon of atmospheric electricity with convective storms. Since the 1960＇s, its characteristics during weather processes of torrential rain, hails and tornadoes have been widely stud...1 INTRODUCTION Lightning is a phenomenon of atmospheric electricity with convective storms. Since the 1960＇s, its characteristics during weather processes of torrential rain, hails and tornadoes have been widely studied and a lot of attempts made to probe into the mechanisms responsible for the formation of lightningIll, giving rise to two theories explaining the lightning genesis, from the points of convection and ice-phase precipitation, respectively, In addition, some studies show, from various aspects, that lightning of severe convective weather. indicates the occurrence There has been lack of concrete indices to identify lightning features and determine hail-producing clouds. Apart from diagnostic . analysis based on conventional data , this work studies the evolution of lightning in 11 hails using relevant records and Doppler radar information and sums up a number of lightning features for hail weather in the sub-plateau area of Gansu province by taking as the criterion whether convective clouds cause hails in determining hail-producing clouds. In Gansu, hailproducing clouds usually originate from mountainous areas, follow fixed routes of movement and are often accompanied with heavy rainfall as they produce hails in more than a spot in the life cycle. To mitigate losses, it is essential to use scientific detectors to warn of hail weather in advance and conduct weather modification to check the growth of hails. The weather radar is an efficient tool to watch and forecast severe convective weather like hails, for it not only detects the structure but also tracks down the generation and evolution of hail-producing clouds to aid in isolating where the hail falls. It is, however, not realistic to perform real-time radar watch in Northwest China and existing radars are not capable of observing thunderstorms. Costing relatively low to purchase and maintain, the lightning locator has wide range of measurement and works nonstop without human attendance, making it easier to watch large-scale convective clouds in the region. With hails, heavy rains and tornadoes isolated and warned of based on features captured by the locator, operations of weather modification can be made more efficient with further identification from radar echoes and observed facts of electric mechanisms can be better understood for convective weather.展开更多
利用1999—2010年共45个冰雹日个例(全省同一天有≥2站出现冰雹),分析冰雹日高低空、地面形势特征和降雹落区,发现降雹与500 h Pa环流形势关系密切。因此依据冰雹日08时500 h Pa高空形势及对流层低层的特点,将河南省冰雹天气形势划分为...利用1999—2010年共45个冰雹日个例(全省同一天有≥2站出现冰雹),分析冰雹日高低空、地面形势特征和降雹落区,发现降雹与500 h Pa环流形势关系密切。因此依据冰雹日08时500 h Pa高空形势及对流层低层的特点,将河南省冰雹天气形势划分为西北气流型、东北冷涡型、华北冷涡型及低槽型4个天气类型,并依据不同的天气类型给出可能发生冰雹的大致落区。由于冰雹的形成除有利的天气形势背景条件外,还必须具备低层水汽辐合、大气不稳定层结、触发机制3个基本条件,因此本文进一步对河南省冰雹日当日500 h Pa低槽低涡位置、地面冷锋位置、地面温度、露点温度、探空资料等进行分月统计,获得冰雹预报的判别指标。基于以上条件,引进中国科学院大气物理研究所研发的完全弹性三维冰雹云模式,依据河南省内及周边的共7个探空站资料制作河南省的区域客观预报。通过4个月的业务应用,发现利用micaps实时资料并结合三维冰雹云模式来预报河南省的冰雹天气,空报率较高,漏报率较低,提高了冰雹的预报时效,为重点防雹作业区争取到了充分的作业准备时间。展开更多
文摘This article describes a new and low-cost microwave passive sensor for hail prediction (forecasting) and detection developed in Armenia, which can be used to implement fully autonomous and automatically functioning hail protection of locally limited or large agricultural and urban areas in order to prevent, suppress or catch hail in traps. The article also presents the results of measurements of the intrinsic emission characteristics of water and ice, rain and hail clouds, carried out in laboratory and field conditions in the Ku-band of radio frequencies. The results obtained showed that the intrinsic emission of a hail cloud in the Ku-band of radio frequencies differs significantly from the intrinsic emission of a rain cloud. The presented results show that indeed the radar is not very suitable for the timely detection and determination of hail with a high probability, which is very important for the timely starting up of anti-hail protection means. On the contrary, radiometers (passive microwave sensors) can become an effective sensing tool for timely detection and recognition of hail with a high probability of long-range approaches up to ~12 - 15 km.
文摘[Objective] The hail weather and forecast storm in Guilin were studied. [Method] In allusion to the occurrence of hailstorm in Guilin and considering the observation data of a new generation of Doppler weather radar in Guilin, the weather situation and radar echo characteristics in Guilin was summarized so as to explore the short time forecast method. [Result] There were one or two icy storms every year in Guilin. The occurrence of icy storm was distinctly influenced by terrain. A new generation of Doppler weather radar detection ice storm was very effective. The singular intensity of echo of icy storm in Guilin was above or equal to 50 dBz and the height of echo was above or equal to 10 km. The vertical liquid content was above or equal to 40 kg/m2, accompanied by mild cyclone. When there was strong icy storm, there were three flux characteristics. The forecast of icy storm was mainly short time forecast. [Conclusion] The study offered reference for the forecast of icy storm, artificial storm and disaster prevention and mitigation work.
基金Technology of Hail Mitigation and Neutralization for Northwest China, a public welfarescientific project of the Ministry of Science and Technology (2002DIB10046)Application Study on LightningLocatorsStudy on Rain-Measuring Radars For Guiding Operations on the Spot
文摘1 INTRODUCTION Lightning is a phenomenon of atmospheric electricity with convective storms. Since the 1960＇s, its characteristics during weather processes of torrential rain, hails and tornadoes have been widely studied and a lot of attempts made to probe into the mechanisms responsible for the formation of lightningIll, giving rise to two theories explaining the lightning genesis, from the points of convection and ice-phase precipitation, respectively, In addition, some studies show, from various aspects, that lightning of severe convective weather. indicates the occurrence There has been lack of concrete indices to identify lightning features and determine hail-producing clouds. Apart from diagnostic . analysis based on conventional data , this work studies the evolution of lightning in 11 hails using relevant records and Doppler radar information and sums up a number of lightning features for hail weather in the sub-plateau area of Gansu province by taking as the criterion whether convective clouds cause hails in determining hail-producing clouds. In Gansu, hailproducing clouds usually originate from mountainous areas, follow fixed routes of movement and are often accompanied with heavy rainfall as they produce hails in more than a spot in the life cycle. To mitigate losses, it is essential to use scientific detectors to warn of hail weather in advance and conduct weather modification to check the growth of hails. The weather radar is an efficient tool to watch and forecast severe convective weather like hails, for it not only detects the structure but also tracks down the generation and evolution of hail-producing clouds to aid in isolating where the hail falls. It is, however, not realistic to perform real-time radar watch in Northwest China and existing radars are not capable of observing thunderstorms. Costing relatively low to purchase and maintain, the lightning locator has wide range of measurement and works nonstop without human attendance, making it easier to watch large-scale convective clouds in the region. With hails, heavy rains and tornadoes isolated and warned of based on features captured by the locator, operations of weather modification can be made more efficient with further identification from radar echoes and observed facts of electric mechanisms can be better understood for convective weather.
文摘利用1999—2010年共45个冰雹日个例(全省同一天有≥2站出现冰雹),分析冰雹日高低空、地面形势特征和降雹落区,发现降雹与500 h Pa环流形势关系密切。因此依据冰雹日08时500 h Pa高空形势及对流层低层的特点,将河南省冰雹天气形势划分为西北气流型、东北冷涡型、华北冷涡型及低槽型4个天气类型,并依据不同的天气类型给出可能发生冰雹的大致落区。由于冰雹的形成除有利的天气形势背景条件外,还必须具备低层水汽辐合、大气不稳定层结、触发机制3个基本条件,因此本文进一步对河南省冰雹日当日500 h Pa低槽低涡位置、地面冷锋位置、地面温度、露点温度、探空资料等进行分月统计,获得冰雹预报的判别指标。基于以上条件,引进中国科学院大气物理研究所研发的完全弹性三维冰雹云模式,依据河南省内及周边的共7个探空站资料制作河南省的区域客观预报。通过4个月的业务应用,发现利用micaps实时资料并结合三维冰雹云模式来预报河南省的冰雹天气,空报率较高,漏报率较低,提高了冰雹的预报时效,为重点防雹作业区争取到了充分的作业准备时间。
