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Microphysical Characteristics of Rainfall Based on Long-Term Observations with a 2DVD in Yangbajain,Tibet
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作者 Ming LI Yongheng BI +4 位作者 Yonghai SHEN Yinan WANG Ciren Nima Tianlu CHEN Daren LYU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第9期1721-1734,共14页
Raindrop size distribution(DSD)plays a crucial role in enhancing the accuracy of radar quantitative precipitation estimates in the Tibetan Plateau(TP).However,there is a notable scarcity of long-term,high-resolution o... Raindrop size distribution(DSD)plays a crucial role in enhancing the accuracy of radar quantitative precipitation estimates in the Tibetan Plateau(TP).However,there is a notable scarcity of long-term,high-resolution observations in this region.To address this issue,long-term observations from a two-dimensional video disdrometer(2DVD)were leveraged to refine the radar and satellite-based algorithms for quantifying precipitation in the hinterland of the TP.It was observed that weak precipitation(R<1,mm h-1)accounts for 86%of the total precipitation time,while small raindrops(D<2 mm)comprise 99%of the total raindrop count.Furthermore,the average spectral width of the DSD increases with increasing rain rate.The DSD characteristics of convective and stratiform precipitation were discussed across five different rain rates,revealing that convective precipitation in Yangbajain(YBJ)exhibits characteristics similar to maritime-like precipitation.The constrained relationships between the slopeΛand shapeμ,D_(m)and N_(w)of gamma DSDs were derived.Additionally,we established a correlation between the equivalent diameter and drop axis ratio and found that raindrops on the TP attain a nearly spherical shape.Consequently,the application of the rainfall retrieval algorithms of the dual-frequency precipitation radar in the TP is improved based on the statistical results of the DSD. 展开更多
关键词 Tibetan Plateau raindrop size distribution 2DVD dual frequency radar microphysical features
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Erratum to:Deriving Temporal and Vertical Distributions of Methane in Xianghe Using Ground-based Fourier Transform Infrared and Gas-analyzer
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作者 Denghui JI Minqiang ZHOU +6 位作者 Pucai WANG Yang YANG Ting WANG Xiaoyu SUN Christian HERMANS Bo YAO Gengchen WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期377-377,共1页
“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the capti... “Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the caption of Fig.8 on Page 604 should be“Diurnal variation of CH4 at the surface from spring to winter.The time units are in UTC.The error bar is 1σfor all the observed hourly mean data within that season at that local time.” 展开更多
关键词 WINTER SEASON INFRARED
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Advances in the Researches of the Middle and Upper Atmosphere in China in 2012–2014 被引量:1
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作者 CHEN Zeyu CHEN Hongbin +11 位作者 XU Jiyao BIAN Jianchun QIE Xiushu Lü Daren CHEN Wen REN Rongcai ZHANG Shaodong DOU Xiankang LI Tao HU Xiong HU Yongyun TIAN Wenshou 《空间科学学报》 CAS CSCD 北大核心 2014年第5期669-687,共19页
In this report we summarize the research results by Chinese scientists in 2012–2014. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches related to ground-based ob... In this report we summarize the research results by Chinese scientists in 2012–2014. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches related to ground-based observation capability development, dynamical processes, the property of circulation and chemistry-climate coupling of the middle atmospheric layers. 展开更多
关键词 MIDDLE and UPPER ATMOSPHERE Composition Structure Dynamics INFRASTRUCTURE Monitoring CAMPAIGN
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Advances in the Researches of the Middle and Upper Atmosphere in China in 2014-2016
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作者 CHEN Zeyu XU Jiyao +8 位作者 HU Xiong CHEN Hongbin CHEN Wen WEI Ke BIAN Jianchun TIAN Wenshou ZHANG Shaodong REN Rongcai DOU Xiankang 《空间科学学报》 CAS CSCD 北大核心 2016年第5期738-752,共15页
In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-bas... In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-based observation capabihty development,dynamical processes,and properties of circulation and chemistry-climate coupling of the middle atmospheric layers. 展开更多
关键词 中高层大气 中国科学家 研究成果 观察能力 耦合特性 大气化学 中间层 气候
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Advances in the Researches of the Middle and Upper Atmosphere in China
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作者 CHEN Zeyu CHEN Hongbin +13 位作者 XU Jiyao L Daren ZHANG Shaodong XUE Xianghui TIAN Wenshou LIU Renqiang CHEN Wen HU Yongyun WANG Rui HU Dingzhu HU Xiong YANG Guotao GONG Yun LU Gaopeng 《空间科学学报》 CAS CSCD 北大核心 2018年第5期763-780,共18页
In this paper we summarize the research results by Chinese scientists in 2016–2018. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches associated with groundbased... In this paper we summarize the research results by Chinese scientists in 2016–2018. The focuses are placed on the researches of the middle and upper atmosphere, specifically the researches associated with groundbased observation capability development, dynamical processes, and properties of circulation and chemistryclimate coupling of the middle atmospheric layers. 展开更多
关键词 中国科学家 空气 能力开发
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Distribution of lightning spatial modes and climatic causes in China 被引量:2
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作者 Mingyi Xu Xiushu Qie +6 位作者 Chenxi Zhao Shanfeng Yuan Ji Li Yuyu Tao Guangyu Shi Wenjing Pang Lijuan Shi 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第2期63-70,共8页
本文利用中国气象局国家雷电监测网(CNLDN)的地闪观测数据集,分析了2010-2020年中国陆地区域地闪空间模态分布特征及其可能的气候成因.研究发现,夏季地闪第一模态的方差贡献率为32.86%,其分布从北到南呈现出“-+-”的经向跷跷板模式,当... 本文利用中国气象局国家雷电监测网(CNLDN)的地闪观测数据集,分析了2010-2020年中国陆地区域地闪空间模态分布特征及其可能的气候成因.研究发现,夏季地闪第一模态的方差贡献率为32.86%,其分布从北到南呈现出“-+-”的经向跷跷板模式,当东太平洋和印度洋的海温异常增暖,西北太平洋的海温异常变冷时,在中国黄海,东海及热带西太平洋地区激发出气旋性环流,随着水汽南下至华南地区,与来自孟加拉湾的水汽汇合,上升运动在此加强,从而使得该地区的雷电活动增强.表明厄尔尼诺-南方涛动(ENSO)现象,是发生在中国陆地区域的地闪活动的气候驱动因子。 展开更多
关键词 雷电气候学 中国 云地闪 厄尔尼诺-南方涛动 太平洋
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Comparison between ozonesonde measurements and satellite retrievals over Beijing,China 被引量:2
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作者 Jinqiang Zhang Yuejian Xuan +5 位作者 Jianchun Bian Holger Vomel Yunshu Zeng Zhixuan Bai Dan Li Hongbin Chen 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期14-20,共7页
从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭... 从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭氧廓线,并对比臭氧探空,AIRS和Aura卫星搭载臭氧监测仪(OMI)臭氧柱总量结果.尽管臭氧探空与卫星反演垂直臭氧廓线在局部高度处差异较大,但整体来说两者较为接近(相对偏差大多<10%).臭氧探空,AIRS和OMI三种仪器测量臭氧柱总量的年变化特征较为一致,其年均臭氧柱总量分别为351.8±18.4 DU,348.8±19.5 DU和336.9±14.2 DU.后续对国内多站点观测数据分析将有助于进一步理解臭氧探空与卫星反演臭氧资料在不同区域的一致性. 展开更多
关键词 臭氧探空 卫星反演 垂直臭氧廓线 臭氧柱总量 华北平原
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Initial Results of Lidar Measured Middle Atmosphere Temperatures over Tibetan Plateau 被引量:8
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作者 QIAO Shuai PAN Weilin +2 位作者 ZHU Ke-Yun ZOU Rong-Shi TAN Jing 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第3期213-217,共5页
During August 2013,a mobile Rayleigh lidar was deployed in Lhasa,Tibet(29.6°N,91.0°E) for making measurements of middle atmosphere densities and temperatures from 30 to 90 km.In this paper,the authors presen... During August 2013,a mobile Rayleigh lidar was deployed in Lhasa,Tibet(29.6°N,91.0°E) for making measurements of middle atmosphere densities and temperatures from 30 to 90 km.In this paper,the authors present the initial results from this scientific campaign,Middle Atmosphere Remote Mobile Observatory in Tibet(MARMOT),and compared the results to the MSIS-00(Mass Spectrometer and Incoherent Scatter) model.This work will advance our understanding of middle atmosphere dynamic processes,especially over the Tibetan Plateau area. 展开更多
关键词 lidarmiddle atmospheretemperatureMass SPECTROMETER and INCOHERENT SCATTER model
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Dynamic and Thermodynamic Features of Low and Middle Clouds Derived from Atmospheric Radiation Measurement Program Mobile Facility Radiosonde Data at Shouxian, China 被引量:7
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作者 Jinqiang ZHANG Hongbin CHEN +1 位作者 Xiang'ao XIA Wei-Chyung WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第1期21-33,共13页
By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal w... By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal wind speed above the cloud layers was higher than those within and below cloud layers.The maximum balloon ascent speed(5.3 m s^-1) was located in the vicinity of the layer with the maximum cloud occurrence frequency(24.4%),indicating an upward motion(0.1-0.16 ms^-1).The average thickness,magnitude and gradient of the temperature inversion layer above single-layer clouds were117±94 m,1.3±1.3℃ and 1.4±1.5℃(100 m)^-1,respectively.The average temperature inversion magnitude was the same(1.3℃) for single-low and single-middle clouds;however,a larger gradient[1.7±1.8℃(100 m)^-1]and smaller thickness(94±67 m) were detected above single-low clouds relative to those above single-middle clouds[0.9±0.7℃(100 m)^-1 and157±120 m].For the two-layer cloud,the temperature inversion parameters were 106±59 m,1.0±0.9℃ and 1.0±1.0℃(100 m)^-1 above the upper-layer cloud and 82 ± 60 m,0.6±0.9℃ and 0.7±0.6℃(100 m)^-1 above the low-layer cloud.Absolute differences between the cloud-base height(cloud-top height) and the lifting condensation level(equilibrium level)were less than 0.5 km for 66.4%(36.8%) of the cases analyzed in summer. 展开更多
关键词 RADIOSONDE cloud dynamics THERMODYNAMICS
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The Impact of Cut-off Lows on Ozone in the Upper Troposphere and Lower Stratosphere over Changchun from Ozonesonde Observations 被引量:2
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作者 Yushan SONG Daren LU +3 位作者 Qian LI Jianchun BIAN Xue WU Dan LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第2期135-150,共16页
In situ measurements of the vertical structure of ozone were made in Changchun (43.53°N, 125.13°E), China, by the Institute of Atmosphere Physics, in the summers of 2010-13. Analysis of the 89 validated oz... In situ measurements of the vertical structure of ozone were made in Changchun (43.53°N, 125.13°E), China, by the Institute of Atmosphere Physics, in the summers of 2010-13. Analysis of the 89 validated ozone profiles shows the vari- ation of ozone concentration in the upper troposphere and lower stratosphere (UTLS) caused by cut-off lows (COLs) over Changchun. During the COL events, an increase of the ozone concentration and a lower height of the tropopause are observed. Backward simulations with a trajectory model show that the ozone-rich airmass brought by the COL is from Siberia. A case study proves that stratosphere-troposphere exchange (STE) occurs in the COL. The ozone-rich air mass transported from the stratosphere to the troposphere first becomes unstable, then loses its high ozone concentration. This process usually happens during the decay stage of COLs. In order to understand the influence of COLs on the ozone in the UTLS, statistical analysis of the ozone profiles within COLs, and other profiles, are employed. The results indicate that the ozone concentrations of the in-COL profiles are significantly higher than those of the other profiles between ±4 km around the tropopause. The COLs induce an increase in UTLS column ozone by 32% on average. Meanwhile, the COLs depress the lapse-rate tropopause (LRT)/dynamical tropopause height by 1.4/1.7 km and cause the atmosphere above the tropopause to be less stable. The influence of COLs is durable because the increased ozone concentration lasts at least one day after the COL has passed over Changchun. Furthermore, the relative coefficient between LRT height and lower stratosphere (LS) column ozone is -0.62, which implies a positive correlation between COL strength and LS ozone concentration. 展开更多
关键词 OZONESONDE cut-off low upper troposphere lower stratosphere TROPOPAUSE
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Analysis of Low-level Temperature Inversions and Their Effects on Aerosols in the Lower Atmosphere 被引量:2
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作者 Jun LI Hongbin CHEN +4 位作者 Zhanqing LI Pucai WANG Xuehua FAN Wenying HE Jinqiang ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第11期1235-1250,共16页
High-quality and continuous radiosonde, aerosol and surface meteorology datasets are used to investigate the statistical characteristics of meteorological parameters and their effects on aerosols. The data were collec... High-quality and continuous radiosonde, aerosol and surface meteorology datasets are used to investigate the statistical characteristics of meteorological parameters and their effects on aerosols. The data were collected at the Atmospheric Radiation Measurement Southern Great Plains climate research facility during 2000–15. The parameters and vertical distribution of temperature inversion layers were found to have strong diurnal and seasonal changes. For surface-based temperature inversion (SBI), the mean frequency and depth of temperature inversion layers were 39.4% and 198 m, respectively. The temperature difference between the top and bottom of SBI was 4.8℃, and so the temperature gradient was 2.4℃(100 m)^-1. The detailed vertical distributions of temperature inversion had been determined, and only the temperature inversion layers below 1000 m showed diurnal and seasonal variations. Mean surface aerosol number concentrations increased by 43.0%, 21.9% and 49.2% when SBIs were present at 0530, 1730 and 2330 LST, respectively. The effect of SBI on surface aerosol concentration was weakest in summer (18.1%) and strongest in winter (58.4%). During elevated temperature inversion events, there was no noticeable difference in surface aerosol number concentrations. Temperature differences and temperature gradients across SBIs correlated fairly well with aerosol number concentrations, especially for temperature gradients. The vertical distribution of aerosol optical properties with and without temperature inversions was different. Surface aerosol measurements were representative of the air within (below), but not above, SBIs and EIs. These results provide a basis for developing a boundary layer aerosol accumulation model and for improving radiative transfer models in the lower atmosphere. 展开更多
关键词 temperature INVERSION AEROSOL LOWER ATMOSPHERE VERTICAL distribution
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Simulation of the Madden-Julian Oscillation in Wintertime Stratospheric Ozone over the Tibetan Plateau and East Asia: Results from the Specified Dynamics Version of the Whole Atmosphere Community Climate Model 被引量:2
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作者 LIU Chuan-Xi LIU Yi ZHANG Yu-Li 《Atmospheric and Oceanic Science Letters》 CSCD 2015年第5期264-270,共7页
The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2... The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2004 and 2010. Comparison with European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) data suggested that the model simulation represented well the three-dimensional structure of the MJO-related ozone anomalies in the upper troposphere and stratosphere(i.e., between 200 and 20 h Pa). The negative ozone anomalies were over the Tibetan Plateau and East Asia in MJO phases 3–7, when the MJO convective anomalies travelled from the equatorial Indian Ocean towards the equatorial western Pacific Ocean. Due to the different vertical structures of the MJO-related circulation anomalies, the MJO-related stratospheric ozone anomalies showed different vertical structure over the Tibetan Plateau(25–40°N, 75–105°E) and East Asia(25–40°N, 105–135°E). As a result of the positive bias in the model-calculated ozone in the upper troposphere and lower stratosphere, the amplitude of MJO-related stratospheric ozone column anomalies(10–16 Dobson Units(DU)) in the SD-WACCM simulation was slightly larger than that(8–14 DU) in the ERA-Interim reanalysis. 展开更多
关键词 Madden-Julian OSCILLATION STRATOSPHERIC OZONE trop
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Earth Summit Mission 2022:Scientific Expedition and Research on Mt.Qomolangma Helps Reveal the Synergy between Westerly Winds and Monsoon and the Resulting Climatic and Environmental Effects
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作者 Yaoming MA Weiqiang MA +22 位作者 Huaguang DAI Lei ZHANG Fanglin SUN Jinqiang ZHANG Nan YAO Jianan HE Zhixuan BAI Yuejian XUAN Yunshuai ZHANG Yuan YUAN Chenyi YANG Weijun SUN Ping ZHAO Minghu DING Kongju ZHU Jie HU Bian Bazhuga Bai Juepingcuo Zhuo Ma Ren Qingnima Suo Langwangdui Yang Zong Haikun WEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第2期187-193,共7页
“Earth summit mission 2022”is one of the landmark scientific research activities of the Second Tibetan Plateau Scientific Expedition and Research(STEP).This scientific expedition firstly used advanced technology and... “Earth summit mission 2022”is one of the landmark scientific research activities of the Second Tibetan Plateau Scientific Expedition and Research(STEP).This scientific expedition firstly used advanced technology and methods to detect vertical meteorological elements and produce forecasts for mountain climbing.The“Earth summit mission 2022”Qomolangma scientific expedition exceeded an altitude of over 8000 meters for the first time and carried out a comprehensive scientific investigation mission on the summit of Mt.Qomolangma.Among the participants,the westerly–monsoon synergy and influence team stationed in the Mt.Qomolangma region had two tasks:1)detecting the vertical structure of the atmosphere for parameters such as wind,temperature,humidity,and pressure with advanced instruments for high-altitude detection at the Mt.Qomolangma base camp;and 2)observing extreme weather processes to ensure that members of the mountaineering team could successfully reach the top.Through this scientific expedition,a better understanding of the vertical structure and weather characteristics of the complex area of Mt.Qomolangma is gained. 展开更多
关键词 EARTH ALTITUDE weather
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LLSDA: Design and Implementation of Lightning Location Data Analysis and Visualization
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作者 Rong FAN Jingxiao LI Mingyuan LIU 《Meteorological and Environmental Research》 CAS 2023年第5期36-41,44,共7页
Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class li... Visualizing lightning location data is necessary in analyzing and researching lightning activity patterns.This article uses C#and the cross-platform.NET framework to develop a lightning location data analysis class library and the data-driven client to help lightning researchers improve work efficiency by avoiding repeated wheel invention.Lightning Location System Data Analyzer(LLSDA)is a suite of software tools that includes a.NET class library for software developers and a desktop application for end users.It supports a wide range of lightning location data formats,such as the University of Washington Global Lightning Location System(WWLLN)and Beijing Huayun Dongfang ADTD Lightning Location System data format,and maintains scalability.The class library can easily read,parse,and analyze lightning location data,and combined with third-party frameworks can realize grid analysis.The desktop application can be combined with MeteoInfo(a GIS open-source project)for secondary development. 展开更多
关键词 Lightning location system The World Wide Lightning Location Network(WWLLN) ADTD MeteoInfo Global Lightning Detection Network(GLD360) Austrian Lightning Detection&Information System(ALDIS) Data-driven development Reusable software library
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A Deep-Learning and Transfer-Learning Hybrid Aerosol Retrieval Algorithm for FY4-AGRI:Development and Verification over Asia
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作者 Disong Fu Hongrong Shi +9 位作者 Christian AGueymard Dazhi Yang Yu Zheng Huizheng Che Xuehua Fan Xinlei Han Lin Gao Jianchun Bian Minzheng Duan Xiangao Xia 《Engineering》 SCIE EI CAS CSCD 2024年第7期164-174,共11页
The Advanced Geosynchronous Radiation Imager(AGRI)is a mission-critical instrument for the Fengyun series of satellites.AGRI acquires full-disk images every 15 min and views East Asia every 5 min through 14 spectral b... The Advanced Geosynchronous Radiation Imager(AGRI)is a mission-critical instrument for the Fengyun series of satellites.AGRI acquires full-disk images every 15 min and views East Asia every 5 min through 14 spectral bands,enabling the detection of highly variable aerosol optical depth(AOD).Quantitative retrieval of AOD has hitherto been challenging,especially over land.In this study,an AOD retrieval algorithm is proposed that combines deep learning and transfer learning.The algorithm uses core concepts from both the Dark Target(DT)and Deep Blue(DB)algorithms to select features for the machinelearning(ML)algorithm,allowing for AOD retrieval at 550 nm over both dark and bright surfaces.The algorithm consists of two steps:①A baseline deep neural network(DNN)with skip connections is developed using 10 min Advanced Himawari Imager(AHI)AODs as the target variable,and②sunphotometer AODs from 89 ground-based stations are used to fine-tune the DNN parameters.Out-of-station validation shows that the retrieved AOD attains high accuracy,characterized by a coefficient of determination(R2)of 0.70,a mean bias error(MBE)of 0.03,and a percentage of data within the expected error(EE)of 70.7%.A sensitivity study reveals that the top-of-atmosphere reflectance at 650 and 470 nm,as well as the surface reflectance at 650 nm,are the two largest sources of uncertainty impacting the retrieval.In a case study of monitoring an extreme aerosol event,the AGRI AOD is found to be able to capture the detailed temporal evolution of the event.This work demonstrates the superiority of the transfer-learning technique in satellite AOD retrievals and the applicability of the retrieved AGRI AOD in monitoring extreme pollution events. 展开更多
关键词 Aerosol optical depth Retrieval algorithm Deep learning Transfer learning Advanced Geosynchronous Radiation IMAGER
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A Localization Method of High Energy Transients for All-sky Gamma-ray Monitor
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作者 Yi Zhao Wangchen Xue +62 位作者 Shaolin Xiong Qi Luo Yuanhao Wang Jiacong Liu Heng Yu Xiaoyun Zhao Yue Huang Jinyuan Liao Jianchao Sun Xiaobo Li Qibin Yi Ce Cai Shuo Xiao Shenglun Xie Chao Zheng Yanqiu Zhang Chenwei Wang Wenjun Tan Zhiwei Guo Chaoyang Li Zhenghua An Gang Chen Yanqi Du Min Gao Ke Gong Dongya Guo Jiang He Jianjian He Bing Li Gang Li Xinqiao Li Jing Liang Xiaohua Liang Yaqing Liu Xiang Ma Rui Qiao Liming Song Xinying Song Xilei Sun Jin Wang Ping Wang Xiangyang Wen Hong Wu Yanbing Xu Sheng Yang Dali Zhang Fan Zhang Hongmei Zhang Peng Zhang Shu Zhang Zhen Zhang Shijie Zheng Keke Zhang Xingbo Han Haiyan Wu Hu Tai Hao Geng Gaopeng Lu Wei Xu Fanchao Lyu Hongbo Zhang Fangjun Lu Shuangnan Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第10期25-35,共11页
Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has b... Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors.There are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian method.Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)method.With comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak bursts.We further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location templates.Our method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations. 展开更多
关键词 methods:data analysis methods:analytical (stars:)gamma-ray burst:general
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Effects of Ocean Particles on the Upwelling Radiance and Polarized Radiance in the Atmosphere–Ocean System
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作者 SHI Chong WANG Pucai +3 位作者 Teruyuki NAKAJIMA Yoshifumi OTA TAN Saichun SHI Guangyu 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第9期1186-1196,共11页
Based on a vector radiative transfer model of the atmosphere–ocean system,the influence of oceanic components on radiation processes,including polarization effects,was investigated in the wavelength region ranging fr... Based on a vector radiative transfer model of the atmosphere–ocean system,the influence of oceanic components on radiation processes,including polarization effects,was investigated in the wavelength region ranging from 0.380 to 0.865 μm.The components considered were phytoplankton,inorganic suspended material(sediment),and colored,dissolved organic matter.Due to their important roles in oceanic radiation processes,the sensitivity of the bidirectional reflectance to the rough ocean surface,represented by the wind velocity 10 m above the ocean surface,and aerosol,were taken into account.The results demonstrated that both radiance and polarized radiance just below the ocean surface were sensitive to the change of the concentrations of the considered components,while the dependence of polarized radiance on the observation geometry was more sensitive than radiance.Significant differences in the specular plane existed between the impacts of the phytoplankton and sediment on the degree of polarization just above the ocean surface at 670 nm.At the top of the atmosphere(TOA),polarization was relatively insensitive to changing concentrations of ocean particles at longer wavelengths.Furthermore,the radiance at the TOA in the solar plane was more sensitive to the aerosol optical thickness than wind velocity.In contrast,wind velocity strongly influenced the radiance at the TOA in the sun glint region,while the polarization degree showed less dependence in that region.Finally,a nonlinear optimal inversion method was proposed to simultaneously retrieve the aerosol and wind velocity using radiance measurement. 展开更多
关键词 ocean particles atmosphere–ocean system radiative transfer polarization ocean color
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Evaluating the Impacts of Cloud Microphysical and Overlap Parameters on Simulated Clouds in Global Climate Models
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作者 Haibo WANG Hua ZHANG +3 位作者 Bing XIE Xianwen JING Jingyi HE Yi LIU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第12期2172-2187,I0023,I0024,共18页
The improvement of the accuracy of simulated cloud-related variables,such as the cloud fraction,in global climate models(GCMs)is still a challenging problem in climate modeling.In this study,the influence of cloud mic... The improvement of the accuracy of simulated cloud-related variables,such as the cloud fraction,in global climate models(GCMs)is still a challenging problem in climate modeling.In this study,the influence of cloud microphysics schemes(one-moment versus two-moment schemes)and cloud overlap methods(observation-based versus a fixed vertical decorrelation length)on the simulated cloud fraction was assessed in the BCC_AGCM2.0_CUACE/Aero.Compared with the fixed decorrelation length method,the observation-based approach produced a significantly improved cloud fraction both globally and for four representative regions.The utilization of a two-moment cloud microphysics scheme,on the other hand,notably improved the simulated cloud fraction compared with the one-moment scheme;specifically,the relative bias in the global mean total cloud fraction decreased by 42.9%–84.8%.Furthermore,the total cloud fraction bias decreased by 6.6%in the boreal winter(DJF)and 1.64%in the boreal summer(JJA).Cloud radiative forcing globally and in the four regions improved by 0.3%−1.2% and 0.2%−2.0%,respectively.Thus,our results showed that the interaction between clouds and climate through microphysical and radiation processes is a key contributor to simulation uncertainty. 展开更多
关键词 cloud fraction cloud microphysics scheme cloud radiative forcing vertical cloud overlap
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Characterization and Source Apportionment of Volatile Organic Compounds in Urban and Suburban Tianjin, China 被引量:19
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作者 HAN Meng LU Xueqiang +2 位作者 ZHAO Chunsheng RAN Liang HAN Suqin 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第3期439-444,共6页
Tianjin is the third largest megacity and the fastest growth area in China,and consequently faces the problems of surface ozone and haze episodes.This study measures and characterizes volatile organic compounds (VOCs... Tianjin is the third largest megacity and the fastest growth area in China,and consequently faces the problems of surface ozone and haze episodes.This study measures and characterizes volatile organic compounds (VOCs),which are ozone precursors,to identify their possible sources and evaluate their contribution to ozone formation in urban and suburban Tianjin,China during the HaChi (Haze in China) summer campaign in 2009.A total of 107 species of ambient VOCs were detected,and the average concentrations of VOCs at urban and suburban sites were 92 and 174 ppbv,respectively.Of those,51 species of VOCs were extracted to analyze the possible VOC sources using positive matrix factorization.The identified sources of VOCs were significantly related to vehicular activities,which specifically contributed 60% to urban and 42% to suburban VOCs loadings in Tianjin.Industrial emission was the second most prominent source of ambient VOCs in both urban and suburban areas,although the contribution of industry in the suburban area (36%) was much higher than that at the urban area (16%).We conclude that controlling vehicle emissions should be a top priority for VOC reduction,and that fast industrialization and urbanization causes air pollution to be more complex due to the combined emission of VOCs from industry and daily life,especially in suburban areas. 展开更多
关键词 volatile organic compounds source apportionment positive matrix factorization OZONE MEGACITY
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Formation of the Summertime Ozone Valley over the Tibetan Plateau:The Asian Summer Monsoon and Air Column Variations 被引量:21
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作者 卞建春 严仁嫦 +2 位作者 陈洪滨 吕达仁 Steven T.MASSIE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第6期1318-1325,共8页
The summertime ozone valley over the Tibetan Plateau is formed by two influences,the Asian summer monsoon(ASM) and air column variations.Total ozone over the Tibetan Plateau in summer was ~33 Dobson units(DU) low... The summertime ozone valley over the Tibetan Plateau is formed by two influences,the Asian summer monsoon(ASM) and air column variations.Total ozone over the Tibetan Plateau in summer was ~33 Dobson units(DU) lower than zonal mean values over the ocean at the same latitudes during the study period 2005-2009.Satellite observations of ozone profiles show that ozone concentrations over the ASM region have lower values in the upper troposphere and lower stratosphere(UTLS) than over the non-ASM region.This is caused by frequent convective transport of low-ozone air from the lower troposphere to the UTLS region combined with trapping by the South Asian High.This offset contributes to a ~20-DU deficit in the ozone column over the ASM region.In addition,along the same latitude,total ozone changes identically with variations of the terrain height,showing a high correlation with terrain heights over the ASM region,which includes both the Tibetan and Iranian plateaus.This is confirmed by the fact that the Tibetan and Iranian plateaus have very similar vertical distributions of ozone in the UTLS,but they have different terrain heights and different total-column ozone levels.These two factors(lower UTLS ozone and higher terrain height) imply 40 DU in the lower-ozone column,but the Tibetan Plateau ozone column is only ~33 DU lower than that over the non-ASM region.This fact suggests that the lower troposphere has higher ozone concentrations over the ASM region than elsewhere at the same latitude,contributing ~7 DU of total ozone,which is consistent with ozonesonde and satellite observations. 展开更多
关键词 Asian summer monsoon Tibetan Plateau air column variation ozone valley
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