Water vapor plays a crucial role in atmospheric processes that act over a wide range of temporal and spatial scales, from global climate to micrometeorology. The determination of water vapor distribution in the atmosp...Water vapor plays a crucial role in atmospheric processes that act over a wide range of temporal and spatial scales, from global climate to micrometeorology. The determination of water vapor distribution in the atmosphere and its changing pattern is very important. Although atmospheric scientists have developed a variety of means to measure precipitable water vapor(PWV) using remote sensing data that have been widely used, there are some limitations in using one kind satellite measurements for PWV retrieval over land. In this paper, a new algorithm is proposed for retrieving PWV over land by combining different kinds of remote sensing data and it would work well under the cloud weather conditions. The PWV retrieval algorithm based on near infrared data is more suitable to clear sky conditions with high precision. The 23.5 GHz microwave remote sensing data is sensitive to water vapor and powerful in cloud-covered areas because of its longer wavelengths that permit viewing into and through the atmosphere. Therefore, the PWV retrieval results from near infrared data and the indices combined by microwave bands remote sensing data which are sensitive to water vapor will be regressed to generate the equation for PWV retrieval under cloud covered areas. The algorithm developed in this paper has the potential to detect PWV under all weather conditions and makes an excellent complement to PWV retrieved by near infrared data. Different types of surface exert different depolarization effects on surface emissions, which would increase the complexity of the algorithm. In this paper, MODIS surface classification data was used to consider this influence. Compared with the GPS results, the root mean square error of our algorithm is 8 mm for cloud covered area. Regional consistency was found between the results from MODIS and our algorithm. Our algorithm can yield reasonable results on the surfaces covered by cloud where MODIS cannot be used to retrieve PWV.展开更多
After the Fukushima Dai-ichi nuclear power plant accident on March 11,2011,the radioactivity released from the accident was transported around the globe by atmospheric processes.The radioactivity monitoring program on...After the Fukushima Dai-ichi nuclear power plant accident on March 11,2011,the radioactivity released from the accident was transported around the globe by atmospheric processes.The radioactivity monitoring program on atmospheric particulate in Lanzhou,China was activated by GSCDC to detect the input radionuclides through atmospheric transport.Several artificial radionuclides were detected and measured in aerosol samples from March 26 to May 2,2011.The peaked activity concentrations(in m Bq/m3)were:1.194(131I),0.231(137Cs),0.173(134Cs)and 0.008(136Cs),detected on April 6,2011.The average activity ratio of131I/137Cs and134Cs/137Cs in air were 13.5 and 0.78.The significant increase of137Cs activity concentration,one order of magnitude higher than pre-Fukushima accident levels,in ground level aerosol was observed in 2013,as its resuspension from soil.The back-trajectory analysis simulated by NOAA-ARL HYSPLIT shows a direct transfer of the air masses released from Fukushima to Lanzhou across the Pacific Ocean,North America and Europe at the height close to 9000 m AGL.The value of effective dose for inhalation is close to one millionth of the annual limit for the general public.展开更多
The paper discusses the influence of ions on the formation of clouds, precipitation and thunderstorm electricity. Thermal ionization method is based on two core concepts： electrical micro- and macro-instability of cl...The paper discusses the influence of ions on the formation of clouds, precipitation and thunderstorm electricity. Thermal ionization method is based on two core concepts： electrical micro- and macro-instability of clouds. Cloud droplets increase in sizes in the ascending air under the influence of electric micro-instability. Macro-instability is responsible for the formation of space charges in convective clouds. Artificial rainfall and discharge of space charges of clouds may be caused by means of the electrical modification techniques. The key role in these processes belongs to thermionic production of artificial light and heavy ions, which are formed as the result of applying a pyrotechnic composition of potassium-magnesium compounds. Negative ions are hydrated and adsorbed by cloud droplets leading to their growth and further rainfall. An artificial ionized channel allows to change cloud conductivity, which prevents clouds from accumulating thunderstorm electricity. Electrical methods of cloud modification can be used for the artificial induction of precipitation, prevention of natural hazards, thunderstorms, tornadoes and heavy rains.展开更多
The given investigation presents the results of estimating the water circulation in the water area of the Bering Sea and the Sea of Okhotsks, considering the influence of various types of the atmospheric processes. To...The given investigation presents the results of estimating the water circulation in the water area of the Bering Sea and the Sea of Okhotsks, considering the influence of various types of the atmospheric processes. To solve the given problem it is used a hydrodynamic model calculating the integral functions of the flow from the surface to the bottom. By results of calculations, the maps of the integral water circulation were built for the following types of atmospheric circulation： ＂north-western＂ and ＂okhotsk-aleutian＂. In accordance with the performed calculations for the water area being studied, the hydrodynamic structures are distinguished both non-depending and depending on the type of the atmospheric circulation. The non-depending structures are characterized by the cyclonic activity in the Bering Sea and the Sea of Okhotsk in whole. Hydrodynamic structures depending on types of the atmospheric circulation have their peculiarities in the spatial-temporal distribution.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.4147130541405036&41301653)+1 种基金the Sichuan Youth Science Foundation(Grant No.2015JQ0037)the Chongqing Meteorological Bureau Open Fund(Grant No.KFJJ-201402)
文摘Water vapor plays a crucial role in atmospheric processes that act over a wide range of temporal and spatial scales, from global climate to micrometeorology. The determination of water vapor distribution in the atmosphere and its changing pattern is very important. Although atmospheric scientists have developed a variety of means to measure precipitable water vapor(PWV) using remote sensing data that have been widely used, there are some limitations in using one kind satellite measurements for PWV retrieval over land. In this paper, a new algorithm is proposed for retrieving PWV over land by combining different kinds of remote sensing data and it would work well under the cloud weather conditions. The PWV retrieval algorithm based on near infrared data is more suitable to clear sky conditions with high precision. The 23.5 GHz microwave remote sensing data is sensitive to water vapor and powerful in cloud-covered areas because of its longer wavelengths that permit viewing into and through the atmosphere. Therefore, the PWV retrieval results from near infrared data and the indices combined by microwave bands remote sensing data which are sensitive to water vapor will be regressed to generate the equation for PWV retrieval under cloud covered areas. The algorithm developed in this paper has the potential to detect PWV under all weather conditions and makes an excellent complement to PWV retrieved by near infrared data. Different types of surface exert different depolarization effects on surface emissions, which would increase the complexity of the algorithm. In this paper, MODIS surface classification data was used to consider this influence. Compared with the GPS results, the root mean square error of our algorithm is 8 mm for cloud covered area. Regional consistency was found between the results from MODIS and our algorithm. Our algorithm can yield reasonable results on the surfaces covered by cloud where MODIS cannot be used to retrieve PWV.
基金Supported by the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization(No.CTBTO/IMS/CNP21)
文摘After the Fukushima Dai-ichi nuclear power plant accident on March 11,2011,the radioactivity released from the accident was transported around the globe by atmospheric processes.The radioactivity monitoring program on atmospheric particulate in Lanzhou,China was activated by GSCDC to detect the input radionuclides through atmospheric transport.Several artificial radionuclides were detected and measured in aerosol samples from March 26 to May 2,2011.The peaked activity concentrations(in m Bq/m3)were:1.194(131I),0.231(137Cs),0.173(134Cs)and 0.008(136Cs),detected on April 6,2011.The average activity ratio of131I/137Cs and134Cs/137Cs in air were 13.5 and 0.78.The significant increase of137Cs activity concentration,one order of magnitude higher than pre-Fukushima accident levels,in ground level aerosol was observed in 2013,as its resuspension from soil.The back-trajectory analysis simulated by NOAA-ARL HYSPLIT shows a direct transfer of the air masses released from Fukushima to Lanzhou across the Pacific Ocean,North America and Europe at the height close to 9000 m AGL.The value of effective dose for inhalation is close to one millionth of the annual limit for the general public.
文摘The paper discusses the influence of ions on the formation of clouds, precipitation and thunderstorm electricity. Thermal ionization method is based on two core concepts： electrical micro- and macro-instability of clouds. Cloud droplets increase in sizes in the ascending air under the influence of electric micro-instability. Macro-instability is responsible for the formation of space charges in convective clouds. Artificial rainfall and discharge of space charges of clouds may be caused by means of the electrical modification techniques. The key role in these processes belongs to thermionic production of artificial light and heavy ions, which are formed as the result of applying a pyrotechnic composition of potassium-magnesium compounds. Negative ions are hydrated and adsorbed by cloud droplets leading to their growth and further rainfall. An artificial ionized channel allows to change cloud conductivity, which prevents clouds from accumulating thunderstorm electricity. Electrical methods of cloud modification can be used for the artificial induction of precipitation, prevention of natural hazards, thunderstorms, tornadoes and heavy rains.
文摘The given investigation presents the results of estimating the water circulation in the water area of the Bering Sea and the Sea of Okhotsks, considering the influence of various types of the atmospheric processes. To solve the given problem it is used a hydrodynamic model calculating the integral functions of the flow from the surface to the bottom. By results of calculations, the maps of the integral water circulation were built for the following types of atmospheric circulation： ＂north-western＂ and ＂okhotsk-aleutian＂. In accordance with the performed calculations for the water area being studied, the hydrodynamic structures are distinguished both non-depending and depending on the type of the atmospheric circulation. The non-depending structures are characterized by the cyclonic activity in the Bering Sea and the Sea of Okhotsk in whole. Hydrodynamic structures depending on types of the atmospheric circulation have their peculiarities in the spatial-temporal distribution.
