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On the Variability of Charleston South Carolina Winds, Atmospheric Temperatures, Water Levels, Waves and Precipitation 被引量:1
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作者 L. J. Pietrafesa P. T. Gayes +4 位作者 S. Bao T. Yan D. A. Dickey D. D. Carpenter T. G. Carver 《International Journal of Geosciences》 2021年第5期499-516,共18页
Atmospheric winds, air temperatures, water levels, precipitation and oceanic waves in the Charleston South Carolina (SC) coastal zone are evaluated for their intrinsic, internal variability over temporal scales rangin... Atmospheric winds, air temperatures, water levels, precipitation and oceanic waves in the Charleston South Carolina (SC) coastal zone are evaluated for their intrinsic, internal variability over temporal scales ranging from hours to multi-decades. The purpose of this study was to bring together a plethora of atmospheric and coastal ocean state variable data in a specific locale, to assess temporal variabilities and possible relationships between variables. The questions addressed relate to the concepts of weather and climate. Data comprise the basis of this study. The overall distributions of atmospheric and coastal oceanic state variable variability, including wind speed, direction and kinematic distributions and state variable amplitudes over a variety of time scales are assessed. Annual variability is shown to be highly variable from year to year, making arithmetic means mathematically tractable but physically meaningless. Employing empirical and statistical methodologies, data analyses indicate the same number of intrinsic, internal modes of temporal variability in atmospheric temperatures, coastal wind and coastal water level time series, ranging from hours to days to weeks to seasons, sub-seasons, annual, multi-year, decades, and centennial time scales. This finding demonstrates that the atmosphere and coastal ocean in a southeastern U.S. coastal city are characterized by a set of similar frequency and amplitude modulated phenomena. Kinematic hodograph descriptors of atmospheric winds reveal coherent <span style="font-family:Verdana;">rotating and rectilinear particle motions. A mathematical statistics-based</span><span style="font-family:Verdana;"> wind to wave-to-wave algorithm is developed and applied to offshore marine buoy data to create an hour-by-hour forecast capability from 1 to 24 hours;with confidence levels put forward. This </span><span style="font-family:Verdana;">affects</span><span style="font-family:Verdana;"> a different approach to the conventional deterministic model forecasting of waves.</span> 展开更多
关键词 Charleston atmospheric temperature Winds Water Level PRECIPITATION Oceanic Waves Temporal Scales of Variability Kinematics of the Winds Winds Predict Waves
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A Three-Dimensional Satellite Retrieval Method for Atmospheric Temperature and Moisture Profiles
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作者 张蕾 邱崇践 黄建平 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2008年第5期897-904,共8页
A three-dimensional variational method is proposed to simultaneously retrieve the 3-D atmospheric temperature and moisture profiles from satellite radiance measurements. To include both vertical structure and the hori... A three-dimensional variational method is proposed to simultaneously retrieve the 3-D atmospheric temperature and moisture profiles from satellite radiance measurements. To include both vertical structure and the horizontal patterns of the atmospheric temperature and moisture, an EOF technique is used to decompose the temperature and moisture field in a 3-D space. A number of numerical simulations are conducted and they demonstrate that the 3-D method is less sensitive to the observation errors compared to the 1-D method. When the observation error is more than 2.0 K, to get the best results, the truncation number for the EOF's expansion have to be restricted to 2 in the 1-D method, while it can be set as large as 40 in a 3-D method. This results in the truncation error being reduced and the retrieval accuracy being improved in the 3-D method. Compared to the 1-D method, the rms errors of the 3-D method are reduced by 48% and 36% for the temperature and moisture retrievals, respectively. Using the real satellite measured brightness temperatures at 0557 UTC 31 July 2002, the temperature and moisture profiles are retrieved over a region (20°-45°N, 100°- 125°E) and compared with 37 collocated radiosonde observations. The results show that the retrieval accuracy with a 3-D method is significantly higher than those with the 1-D method. 展开更多
关键词 atmospheric temperature and moisture profile RETRIEVAL EOF three-dimensional method satellite radiance
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RETRIEVING ATMOSPHERIC TEMPERATURE FROM NOAA-15 ATOVS MEASUREMENTS 被引量:1
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作者 吴雪宝 Lydie LAV ANANT +2 位作者 张凤英 冉茂农 Pascal BRUNEL 《Acta meteorologica Sinica》 SCIE 2001年第4期477-484,共10页
This paper describes briefly the sounding capabilities of TOVS/ATOVS onboard the NOAA polar-orbiting meteorological satellites,followed by a more detailed review of the retrieval schemes.The ICI physical retrieval sch... This paper describes briefly the sounding capabilities of TOVS/ATOVS onboard the NOAA polar-orbiting meteorological satellites,followed by a more detailed review of the retrieval schemes.The ICI physical retrieval scheme with some adaptations is implemented in our experiment.The analyses of the Chinese regional NWP model are utilized to create a rolling library of initial guess field.Retrieval results validated against both NWP analyses and radiosondes indicate good agreement between ICI retrievals and conventional observations.Preliminary result from the PC-ATOVS Windows display system of NSMC will also be shown. 展开更多
关键词 ATOVS preprocessing ICI(Imagery Coupled Inversion)physical retrieval method numerical weather prediction initial guess field atmospheric temperature profile
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Atmospheric temperature dependence of the aerosol backscattering coefficient 被引量:1
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作者 Binglong Chen Siying Chen +3 位作者 Yinchao Zhang He Chen Pan Guo Hao Chen 《Particuology》 SCIE EI CAS CSCD 2016年第5期72-76,共5页
In extracting vertical profiles of aerosol backscattering coefficient from lidar signals, the effects of atmo- spheric temperature are usually ignored, In this study, these effects are analyzed using a rotational Rama... In extracting vertical profiles of aerosol backscattering coefficient from lidar signals, the effects of atmo- spheric temperature are usually ignored, In this study, these effects are analyzed using a rotational Raman-Mie lidar system, which is capable of simultaneously measuring atmospheric temperature and vertical profiles of aerosols, A method is presented to correct the aerosol backscattering coefficient using atmospheric temperature profiles, obtained from Raman scattering signals. The differences in the extracted aerosol backscattering coefficient with and without considering temperature effects are fur- ther discussed. The backscattering coefficients for scattering off clouds are shown to be more sensitive to temperature than that of aerosols and atmosphere molecules; the aerosol backscattering coefficient is more sensitive to temperature in summer due to higher atmospheric temperatures, 展开更多
关键词 Lidar atmospheric temperature Aerosol Raman scattering Backscattering coefficient
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A two-dimensional air streamer discharge modified model based on artificial stability term under non-uniform electric field at low temperature and sub-atmospheric pressure 被引量:3
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作者 赵志航 魏新劳 +3 位作者 宋爽 崔林 杨凯伦 张中华 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第7期85-97,共13页
In this paper, an improved air discharge fluid model under non-uniform electric field is constructed based on the plasma module COMSOL Multiphysics with artificial stability term, and the boundary conditions developed... In this paper, an improved air discharge fluid model under non-uniform electric field is constructed based on the plasma module COMSOL Multiphysics with artificial stability term, and the boundary conditions developed in the previous paper are applied to the calculation of photoionization rate. Based on the modified model, the characteristics of low temperature subatmospheric air discharge under 13 kV direct current voltage are discussed, including needle-plate and needle-needle electrode structures. Firstly, in order to verify the reliability of the model, a numerical example and an experimental verification were carried out for the modified model respectively. Both verification results show that the model can ensure the accuracy and repeatability of the calculation. Secondly, according to the calculation results of the modified model, under the same voltage and spacing, the reduced electric field under low temperature subatmosphere pressure is larger than that under normal temperature and atmospheric pressure. The high electric field leads to the air discharge at low temperature and sub atmospheric pressure entering the streamer initiation stage earlier, and has a faster propagation speed in the streamer development stage, which shortens the overall discharge time. Finally, the discharge characteristics of the two electrode structures are compared, and it is found that the biggest difference between them is that there is a pre-ionization region near the cathode in the needle-needle electrode structure. When the pre-ionization level reaches 1013 cm-3, the propagation speed of the positive streamer remains unchanged throughout the discharge process, and is no longer affected by the negative streamer. The peak value of electric field decreases with the increase of pre-ionization level, and tends to be constant during streamer propagation. Based on the previous paper, this paper constructs the air discharge model under non-uniform electric field, complements with the previous paper, and forms a relatively complete set of air discharge simulation system under low temperature and sub atmospheric pressure, which provides a certain reference for future research. 展开更多
关键词 low temperature and sub atmospheric pressure artificial stability term reduced electric field pre-ionization simulation system
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Behavior of Temperature of the South Pole During 2018 and 2019
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作者 Raul C.Perez 《Journal of Earth Science and Engineering》 2021年第1期1-6,共6页
There are diverse and contradictory opinions about of the existence of the global warming.Is not easy to find papers that explain with enough detail,how to measure the atmospheric temperature that support this stateme... There are diverse and contradictory opinions about of the existence of the global warming.Is not easy to find papers that explain with enough detail,how to measure the atmospheric temperature that support this statement.In this context,the south pole is a one the most marked geographical areas,as harmed by global warming.Nevertheless,our last research work showed that during the year 2018,the Antartica cooled almost 1℃.In this situation,and in order to clarify this question,we decided to undertake our own research work.We had used as data source,the value collected by Amundsen-Scott sounding.This base is the most near to the geographic south pole.All its measurements are available in the web site of Wyoming University.With these data,we calculate the average temperature from the surface level to the mayor high level that arrive the sounding balloon.Each day,each month;since January l of 2018 to December 31 of 2019.The result obtained from our study,cast doubt the existence of the atmospheric warm over the south pole. 展开更多
关键词 South pole atmospheric temperature global warm
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Temperatures and Winds over Tropical Middle Atmosphere during Two Contrasting Summer Monsoons, 1975 and 1979
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作者 B.K.Mukherjee C.P.Kulkarni +1 位作者 K.Indira K.K.Dani 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1989年第3期325-334,共10页
Using the monthly geopotential heights and winds for 700 and 200 hPa for India during July and August, and the weekly M-100 Soviet rocketsonde temperature and wind data for Thumba (8.5 ° N, 76.9 ° E) during ... Using the monthly geopotential heights and winds for 700 and 200 hPa for India during July and August, and the weekly M-100 Soviet rocketsonde temperature and wind data for Thumba (8.5 ° N, 76.9 ° E) during the last week of June and the first week of September for the two contrasting summer monsoon years 1975 (a very strong monsoon year) and 1979 (a very weak monsoon year), a study has been made to examine the mean circulation features of the troposphere over India, and the structures of the temperatures and the winds of the middle atmosphere over Thumba. The study suggested that the axis of the monsoon trough (AMT) at 700 hPa shifted southward in 1975 and northward towards the foothills of the Himalayas in 1979, from its normal position. Superimposed on the low-pressure area (AMT) at 700 hPa, a well-defined divergence was noticed at 200 hPa over the northern India in 1975.The mean temperatures at 25,50 and 60 km (middle atmosphere) over Thumba were cooler in 1975 than in 1979. While a cooling trend in 1975 and warming trend in 1979 were observed at 25 and 50 km, a reversed picture was noticed at 60 km. There was a weak easterly / westerly (weak westerly phase) zonal wind in 1975 and a strong easterly zonal wind in 1979. A phase reversal of the zonal wind was observed at 50 km. A tentative physical mechanism was offered, in terms of upward propagation of the two equatorially trapped planetary waves i.e. the Kelvin and the mixed Rossby-gravity waves, to explain the occurrence of the two spells of strong warmings in the mesosphere in 1975. 展开更多
关键词 OVER In and 1979 temperatures and Winds over Tropical Middle Atmosphere during Two Contrasting Summer Monsoons
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Empirical model for mean temperature and assessment of precipitable water vapor derived from GPS
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作者 Tang Yanxin Liu Lilong Yao Chaolong 《Geodesy and Geodynamics》 2013年第4期51-56,共6页
The estimation of Precipitable Water Vapor (PWV) derived from Global Positioning System (GPS) data at the IGS site WUHN is assessed by comparing with PWV obtained from radiosonde data (No.57494) in Wuhan. The ap... The estimation of Precipitable Water Vapor (PWV) derived from Global Positioning System (GPS) data at the IGS site WUHN is assessed by comparing with PWV obtained from radiosonde data (No.57494) in Wuhan. The applicability of Saastamoinen (SAAS), Hopfield and Black models used for estimating Zenith Hydrostatic Delay (ZHD) and Zenith Wet Delay (ZWD) and different models is verified in the estimation of GPS-derived PWV for the applied area. The experimental results demonstrated that : 1 ) the precision of PWV estimated from Black model used for calculating ZHD ( ZHDs ) is lower than that of SAAS ( ZHDsAAs ) model and Hopfield model (ZHDn) with the RMS of 4. 16 ram; 2) the RMS of PWV estimated from SAAS model used for calculating ZWD (SAAS) is 3.78 ram; 3 ) the well-known Bevis model gives similar accuracy compared with the site-specific models for Tm in terms of surface temperature ( Ts ) and surface pressure (Ps), which can reach the accuracy inside 1 mm in the GPS-derived PWV estimates. 展开更多
关键词 GPS radiosonde data Zenith Hydrostatic Delay (ZHD) Zenith Wet Delay(ZWD) the weighted mean temperature of the atmosphere Precipitable Water Vapor(PWV)
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ARTP-ALE Optimized Selection of Low Acetaldehyde Producing Brewer's Yeast and Fermentation Validation
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作者 Chen Zuo-hui Dong Chun-xiu +4 位作者 Sun Yao Hui Mi-zhou Zhang Hui Tang Fei Shuang Bao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第2期8-19,共12页
Higher levels of acetaldehyde in beer are one of the major concerns in the current beer industry.Yeast produces acetaldehyde during alcoholic fermentation,and its modification significantly affects beer flavor and qua... Higher levels of acetaldehyde in beer are one of the major concerns in the current beer industry.Yeast produces acetaldehyde during alcoholic fermentation,and its modification significantly affects beer flavor and quality.A different mutant strain with lower acetaldehyde production and improved ethanol tolerance was constructed using the ARTP-ALE mutagenesis strategy with 4-methylpyrazole-disulfiram.As a result of the mutation,the alcohol dehydrogenase activity of the mutant strain decreased to about 71.22%of that of the wild-type strain.At the same time,the fermentation properties and genetic stability of the newly screened strain showed slight differences from the wild-type strain,and there were no safety concerns regarding industrial use of the mutant strain. 展开更多
关键词 brewer's yeast ACETALDEHYDE atmospheric pressure room temperature plasma adaptive laboratory evolution ethanol dehydrogenase acetaldehyde dehydrogenase
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The Analysis of Global Warming Patterns from 1970s to 2010s
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作者 Ali Cheshmehzangi 《Atmospheric and Climate Sciences》 2020年第3期392-404,共13页
While global warming is only one part of climate change effects, it poses the highest risk to our habitats and ecologies. It is alarming that global warming has heightened in multiple locations and is intensified sinc... While global warming is only one part of climate change effects, it poses the highest risk to our habitats and ecologies. It is alarming that global warming has heightened in multiple locations and is intensified since the early 1970s. Since then, there are certain global warming patterns that could guide us with an overview of what mitigation and adaptation strategies should be developed in the future decades. There are certain regions affected more than another, and there are certain patterns with adverse effects on regions, sub-regions, and even continents. This study provides an insightful analysis of recent global warming patterns, those that are affecting us the most with regional climate change of different types, upsurge in frequency and intensity of natural disasters, and drastic impacts on our ecosystems around the world. By analysing the global warming patterns of these last four decades, this research study sheds light on where these patterns are coming from, how they are developing, and what are their impacts. This study is conducted through grey literature and analysis of the recorded global warming data publicly available by the NASA-GISS data centre for global temperature. This brief—but comprehensive—analysis helps us to have a better understanding of what comes next for global warming impacts, and how we should ultimately react. The study contributes to the field by discovering three key points analysed based on available data and literature on recorded global temperature, including: differences between north and south hemispheres, specific patterns due to ocean surface temperature increase, and recent impacts on particular regions. The study concludes with the importance of global scale analysis to have a more realistic understanding of the global warming patterns and their impacts on all living habitats. 展开更多
关键词 Global Warming Climate Change Global Warming Patterns atmospheric temperature Ocean Surface temperature Global Warming Impacts
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Empirical T_m modeling in the region of Guangxi 被引量:5
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作者 Liu Lilong Yao Chaolong Wen Hongyan 《Geodesy and Geodynamics》 2012年第4期47-52,共6页
This paper presents three strategies for modeling the regional empirical Tm (the weighted mean tem- perature of the atmosphere) to obtain more accurate determinations in a regional empirical model that is better ada... This paper presents three strategies for modeling the regional empirical Tm (the weighted mean tem- perature of the atmosphere) to obtain more accurate determinations in a regional empirical model that is better adapted to the geographical and climatic characteristics of the applied area. The proposed models utilize data from four radiosonde stations in Guangxi, at Nanning, Guilin, Wuzhou and Baise, over an 11 month period (from Jan. to Nov. of 2011 ). The experimental results demonstrated the following: (1) there is no significant 展开更多
关键词 weighted mean temperature of the atmosphere linear regression regional Hybrid model
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常压室温等离子体诱变选育生香型Kluyveromyces marxianus 被引量:1
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作者 王伟雄 胡少坤 +6 位作者 古丽米热·祖努纳 黎进雪 王妍凌 吕泽 杜展成 张海军 武运 《食品与发酵工业》 CAS CSCD 北大核心 2022年第4期102-108,共7页
非酿酒酵母(non-Saccharomyces cerevisiae)生长代谢可以为葡萄酒贡献更多风味物质,但发酵能力弱,耐受性差这一特点使其不能过多参与酒精发酵。针对这一问题,该研究采用常压室温等离子体(atmospheric room temperature plasma,ARTP)诱... 非酿酒酵母(non-Saccharomyces cerevisiae)生长代谢可以为葡萄酒贡献更多风味物质,但发酵能力弱,耐受性差这一特点使其不能过多参与酒精发酵。针对这一问题,该研究采用常压室温等离子体(atmospheric room temperature plasma,ARTP)诱变技术对从葡萄皮表面筛选的马克斯克鲁维酵母(Kluyveromyces marxianus)YK进行诱变,通过诱变菌株耐受性初筛试验和产香复筛试验获得2株耐受性高,产香能力强的诱变菌株,对诱变菌株传代5次测试其传代遗传稳定性。研究结果表明,2株诱变菌株YK-1,YK-29具有较强的遗传稳定性,将2株诱变菌株应用到葡萄酒发酵中产酒精能力较原始菌株YK分别提高了149%、169%。通过定量描述分析,诱变菌株发酵的葡萄酒较原始菌株具有明显的浆果香和水果香气。该研究结论可以为后期非酿酒酵母与酿酒酵母(Saccharomyces cerevisiae)混合发酵提供理论支撑,有望打破葡萄酒品质单一化局面,具有广泛地应用前景。 展开更多
关键词 非酿酒酵母 常压室温等离子体(atmospheric room temperature plasma ARTP) 选育 耐受性 生香
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INTERDECADAL TRANSITIONS AND TWO EXCEPTIONAL YEARS OF JUNE PRECIPITATION OVER SOUTH CHINA 被引量:1
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作者 姚才 钱维宏 《Journal of Tropical Meteorology》 SCIE 2012年第3期341-348,共8页
An analysis of high-resolution precipitation data for 1978-2006 indicates that the precipitation over southern China in June experienced a low-value period in 1980-1989 and a high-value period in 1992-2001.It also rev... An analysis of high-resolution precipitation data for 1978-2006 indicates that the precipitation over southern China in June experienced a low-value period in 1980-1989 and a high-value period in 1992-2001.It also reveals that exceptional heavy(light) precipitation occurred in June 2005(2004) since 1951.For these variations on both interdecadal and interannual timescales,fairly uniform anomalies of precipitation appeared over Vietnam,southern China,and southeastern China.Corresponding to positive(negative) precipitation anomalies,anomalous southeasterly(northwesterly) flow at 850 hPa reached Vietnam and anomalous southwesterly(northeasterly) flow expanded to the coastal regions of southern and southeastern China.Precedent to the positive(negative) precipitation anomalies during 1992-2001(1980-1989),positive(negative) anomalies of sea surface temperature appeared over the extratropical northwestern Pacific in the winter and spring seasons,associated with a strong(weak) extension of the warm Kuroshio Current that affects the coastal region of eastern China.The above-normal precipitation in June 2005 was associated with the pseudo-ENSO event in the previous winter,and the below-normal precipitation in June 2004 was associated with negative anomalies of sea surface temperature over the equatorial central Pacific and positive anomalies over the equatorial western and eastern Pacific. 展开更多
关键词 Southern China June precipitation anomalies of atmospheric circulation and sea surface temperature interdecadal and interannual timescales
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Research on vertical spatial characteristic of satellite infrared hyperspectral atmospheric sounding data 被引量:1
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作者 Ci SONG Qiu YIN 《Frontiers of Earth Science》 SCIE CSCD 2022年第2期265-276,共12页
Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding technology.In this paper,the formation mech... Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding technology.In this paper,the formation mechanism of the vertical spatial characteristics involved in the space-borne infrared hyperspectral sounding data are analyzed in detail,which shows that the vertical spatial characteristics of sounding data depends not only on the spectral channels and their waveband coverage,but also the specific atmospheric parameter and its specific variation interested.The indicators of vertical spatial characteristics are defined and their mathematical models are established based on the mechanism analyses.These models are applied to the vertical spatial characteristic evaluation of atmospheric temperature sounding for FY-4A GIIRS,which is the first space-borne infrared hyperspectral atmospheric sounder in geostationary orbit.It is concluded that FY-4A GIIRS can sound the vertical temperature distribution in whole troposphere and lower stratosphere with height<35 km.This study can provide basic information to support the improvement of infrared hyperspectral sounder and the trace of vertical spatial characteristics of atmospheric inversion products. 展开更多
关键词 infrared hyperspectral atmospheric sounding vertical spatial characteristic atmospheric temperature FY-4A GIIRS
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Rlationship between the aerosol scattering ratio and temperature of atmosphere and the sensitivity of a Doppler wind lidar with iodine filter 被引量:6
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作者 朱金山 陈玉宝 +2 位作者 闫召爱 吴松华 刘智深 《Chinese Optics Letters》 SCIE EI CAS CSCD 2008年第6期449-453,共5页
The sensitivity of Doppler wind lidar is an important parameter which affects the performance of Doppler wind lidar. Aerosol scattering ratio, atmospheric temperature, and wind speed obviously affect the measurement o... The sensitivity of Doppler wind lidar is an important parameter which affects the performance of Doppler wind lidar. Aerosol scattering ratio, atmospheric temperature, and wind speed obviously affect the measurement of Doppler wind lidar with iodine filter. We discuss about the relationship between the measurement sensitivity and the above atmospheric parameters. The numerical relationship between them is given through the theoretical simulation and calculation. 展开更多
关键词 Rlationship between the aerosol scattering ratio and temperature of atmosphere and the sensitivity of a Doppler wind lidar with iodine filter Rb line
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Effects of thermal treatment conditions on redox properties of ceriazirconia materials
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作者 Shanshan Li Jie Deng +2 位作者 Jianli Wang Yaoqiang Chen Yun Li 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第12期1969-1975,I0005,共8页
The nanostructures and redox properties of CeO_(2)-ZrO_(2)materials can be tuned via optimized thermal treatments.In this study,the CeO_(2)-ZrO_(2)-Y_(2)O_(3)-La_(2)O_(3)(CZ) materials were prepared by co-precipitatio... The nanostructures and redox properties of CeO_(2)-ZrO_(2)materials can be tuned via optimized thermal treatments.In this study,the CeO_(2)-ZrO_(2)-Y_(2)O_(3)-La_(2)O_(3)(CZ) materials were prepared by co-precipitation method and submitted to different thermal treatment conditions(atmosphere:nitrogen(N) and air(A);temperature(x):700,800 and 900℃).Due to the protective effects of the "in-situ-formed" carbon powder,treating the surfactants assisted-CZ precursors under N2atmosphere can keep the pore structures and then the CZ-N700 and CZ-N800 can achieve larger surface area than CZ-A700 and CZ-A800,respectively.In comparison,with high treatment temperature(900℃),the effects of thermal atmosphere on surface area can be ignored.However,the redox properties of CZ materials correlate closely with thermal treatment atmosphere and temperature simultaneously.As demonstrated by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) characterizations,the N_(2)atmosphere facilitates the formation of Ce^(3+)without disturbing the mixing degree of Ce and Zr.Thereby the CZ-Nx materials exhibit superior reducibility than corresponding CZ-Ax materials.In additio n,the XRD and XPS results also demonstrate the formation of a more homogeneous CZ solid solution by Zr atoms rearrangement with temperature ignoring the atmosphere.As a result,the reducibility of CZ materials increases with the treatment temperature increasing and is not affected by the worsening of the textural properties.Specially,due to the synergistic effects of N_(2)atmosphere and high treatment temperature,the CZ-N900 shows the best reducibility.This improvement also emphasizes the important role of structural properties of CZ in explaining the temperature-dependent reducibility. 展开更多
关键词 CeO_(2)-ZrO_(2)material Thermal treatment Atmosphere and temperature REDUCIBILITY Rare earths
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Cathode catalysis performance of SmBaCuMO_(5+δ) (M=Fe, Co, Ni) in ammonia synthesis 被引量:7
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作者 张正方 钟正平 刘瑞泉 《Journal of Rare Earths》 SCIE EI CAS CSCD 2010年第4期556-559,共4页
The SmBaCuMO5+δ (M=Fe, Co, Ni) (SBCM) powders were synthesized by the citrate sol-gel method and the powders were sintered to ceramic pellets. The powders and sintered ceramic pellets were characterized with XRD, TEM... The SmBaCuMO5+δ (M=Fe, Co, Ni) (SBCM) powders were synthesized by the citrate sol-gel method and the powders were sintered to ceramic pellets. The powders and sintered ceramic pellets were characterized with XRD, TEM and SEM measurements. The cathode catalytic performances of SBCM ceramic pellets for ammonia synthesis were studied from wet hydrogen and dry nitrogen at atmospheric pressure and low temperature, using SBCM ceramic pellets as cathode, Nafion proton exchange membrane as electrolyte, Ni-Ce0.8Sm0.... 展开更多
关键词 Ni-SDC SmBaCuMO5+δ (M=Fe CO Ni) (SBCM) Nafion proton exchange membrane ammonia synthesis at atmospheric pressure and low temperature rare earths
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Spatiotemporal characteristics of GNSS-derived precipitable water vapor during heavy rainfall events in Guilin,China 被引量:7
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作者 Liangke Huang Zhixiang Mo +3 位作者 Shaofeng Xie Lilong Liu Chuanli Kang Shitai Wang 《Satellite Navigation》 2021年第1期175-191,共17页
Precipitable Water Vapor(PWV),as an important indicator of atmospheric water vapor,can be derived from Global Navigation Satellite System(GNSS)observations with the advantages of high precision and all-weather capacit... Precipitable Water Vapor(PWV),as an important indicator of atmospheric water vapor,can be derived from Global Navigation Satellite System(GNSS)observations with the advantages of high precision and all-weather capacity.GNSS-derived PWV with a high spatiotemporal resolution has become an important source of observations in mete-orology,particularly for severe weather conditions,for water vapor is not well sampled in the current meteorological observing systems.In this study,an empirical atmospheric weighted mean temperature(Tm)model for Guilin is estab-lished using the radiosonde data from 2012 to 2017.Then,the observations at 11 GNSS stations in Guilin are used to investigate the spatiotemporal features of GNSS-derived PWV under the heavy rainfalls from June to July 2017.The results show that the new Tm model in Guilin has better performance with the mean bias and Root Mean Square(RMS)of−0.51 and 2.12 K,respectively,compared with other widely used models.Moreover,the GNSS PWV estimates are validated with the data at Guilin radiosonde station.Good agreements are found between GNSS-derived PWV and radiosonde-derived PWV with the mean bias and RMS of−0.9 and 3.53 mm,respectively.Finally,an investigation on the spatiotemporal characteristics of GNSS PWV during heavy rainfalls in Guilin is performed.It is shown that variations of PWV retrieved from GNSS have a direct relationship with the in situ rainfall measurements,and the PWV increases sharply before the arrival of a heavy rainfall and decreases to a stable state after the cease of the rainfall.It also reveals the moisture variation in several regions of Guilin during a heavy rainfall,which is significant for the moni-toring of rainfalls and weather forecast. 展开更多
关键词 GNSS Precipitable water vapor Heavy rainfall Spatiotemporal characteristic atmospheric weighted mean temperature
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An ignored key link in greenhouse effect:Soil and soil CO_(2) slow heat loss 被引量:1
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作者 Weixin Zhang Chengde Yu +4 位作者 Zhifeng Shen Shu Liu Suli Li Yuanhu Shao Shenglei Fu 《Soil Ecology Letters》 CAS 2020年第4期308-316,共9页
The ever-increasing atmospheric CO_(2) concentration is a key driver of modern global warming.However,the low heat capacity of atmosphere and strong convection processes in the troposphere both limit heat retention.Gi... The ever-increasing atmospheric CO_(2) concentration is a key driver of modern global warming.However,the low heat capacity of atmosphere and strong convection processes in the troposphere both limit heat retention.Given the higher heat capacity and CO_(2) concentration in soil compared to the atmosphere,the direct contributions of soil to the greenhouse effect may be significant.By experimentally manipulating CO_(2) concentrations both in the soil and the atmosphere,we demonstrated that the soil-retained heat and the slower soil heat transmission decrease the amount of heat energy leaking from the earth.Furthermore,the soil air temperature was affected by soil CO_(2) concentration,with the highest value recorded at 7500 ppm CO_(2).This study indicates that soil and soil CO_(2),together with atmospheric CO_(2),play a crucial role in the greenhouse effect.The spatial and temporal heterogeneity of soils and soil CO_(2) should be further investigated,given their potentially significant influence on global climate change. 展开更多
关键词 Soil CO_(2)concentration Soil temperature Atmosphere temperature Soil heat loop Earth heat balance
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Simulation of the Effects of the Preceding SST Anomalies over the Tropical Eastern Pacific on Precipitation to the South of the Yangtze River in June 被引量:2
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作者 李琰 王亚非 董敏 《Acta meteorologica Sinica》 SCIE 2009年第6期691-700,共10页
Numerical experiments are performed to simulate the response of the atmospheric circulation and pre-cipitation over East China in June to the sea surface temperature(SST)anomalies over the tropical eastern Pacific(... Numerical experiments are performed to simulate the response of the atmospheric circulation and pre-cipitation over East China in June to the sea surface temperature(SST)anomalies over the tropical eastern Pacific(TEP)from preceding September to June by using an atmospheric general circulation model (AGCM).We constructed composite positive/negative SST anomalies(P-SSTAs/N-SSTAs)based on the observational SST anomalies over the TEP from September 1997 to June 1998.The results show that:(1) the response of the precipitation in the Yangtze River basin and its southern area(YRBS)to El Nino with different durations varies with the maximum amplitude of the precipitation anomalies appearing when the imposed duration is from November to next June,and the minimum appearing when the SST anomalies is only imposed in June.The anomalies of the precipitation are reduced when the duration of the forcing SST anomalies over the TEP is shortened and the positive SST anomalies in the preceding autumn tend to cause significantly more rainfall in the YRBS.This is in agreement with previous diagnostic analysis results.(2)The simulated precipitation anomalies over the YRBS are always obviously positive under strong or weak positive SST anomalies over the TEP.The intensity of the precipitation anomalies increases with increasing intensity of the SST anomalies in the experiments.The simulation results are consistent with the observations during the warm SST events,suggesting reasonable modeling results.(3)When negative SST anomalies in the TEP are put into the model,the results are different from those of the diagnostic analysis of La Nina events.Negative precipitation anomalies in YRBS could be reproduced only when the negative SST anomalies are strong enough. 展开更多
关键词 atmospheric general circulation model(AGCM) sea surface temperature(SST)anomalies numerical simulation
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