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Simulating the Escaping Atmosphere of GJ 436 b with Two-fluid Magnetohydrodynamic Models

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Research in Astronomy and Astrophysics 2024年第6期24卷 273-286页

作者： Lei Xing Jianheng Guo Chuyuan Yang Dongdong Yan Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China International centre of Supernovae Yunnan Key LaboratoryKunming 650216China

Observations of transmission spectra reveal that hot Jupiters and Neptunes are likely to possess escaping atmospheres driven by stellar *** models predict that magnetic fields may exert significant influences on the atmospheres of hot ***,the escaping atmospheres are not entirely ionized,and magnetic fields only directly affect the escape of ionized components within *** the chemical reactions between ionized components and neutral atoms,as well as collision processes,magnetic fields indirectly impact the escape of neutral atoms,thereby influencing the detection signals of planetary atmospheres in transmission *** order to simulate this process,we developed a magnetohydrodynamic multi-fluid model based on MHD code *** an initial exploration,we investigated the impact of magnetic fields on the decoupling of H^(+)and H in the escaping atmosphere of the hot Neptune *** to the strong resonant interactions between H and H^(+),the coupling between them is tight even if the magnetic field is *** course,alternatively,our work also suggests that merging H and H^(+)into a single flow can be a reasonable assumption in MHD simulations of escaping ***,our simulation results indicate that under the influence of magnetic fields,there are noticeable regional differences in the decoupling of H^(+)and *** the increase of magnetic field strength,the degree of decoupling also *** heavier particles such as O,the decoupling between O and H^(+)is more *** findings provide important insights for future studies on the decoupling processes of heavy atoms in the escaping atmospheres of hot Jupiters and hot Neptunes under the influence of magnetic fields.

关键词： magnetohydrodynamics(MHD) planets and satellites:atmospheres hydrodynamics

Orbit and clock products for quad-system satellites with undifferenced ambiguity fixing approach

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Satellite Navigation 2024年第1期5卷 125-139页

作者： Jiaqi Wu Xingxing Li Yongqiang Yuan Keke Zhang Xin Li Jiaqing Lou Yun Xiong School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Hubei Luojia Laboratory 129 Luoyu RoadWuhan430079China German Research centre for Geosciences GFZ Telegrafenberg14473PotsdamGermany Technische Universitat Berlin(TUB) Straße Des 17.Juni10623BerlinGermany

Integer Ambiguity Resolution(IAR)can significantly improve the accuracy of GNSS Precise Orbit Determination(POD).Traditionally,the IAR in POD is achieved at the Double Differenced(DD)*** this contribution,we develop an Un-Differenced(UD)IAR method for Global Positioning System(GPS)+BeiDou Navigation Satellite System(BDS)+Galileo navigation satellite system(Galileo)+Global'naya Navigatsionnaya Sputnikovaya Sistema(GLONASS)quad-system POD by calibrating UD ambiguities in the raw carrier phase and generating the so-called carrier *** on this method,we generate the UD ambiguity-fixed orbit and clock products for the Wuhan Innovation Application Center(IAC)of the International GNSS Monitoring and Assessment System(iGMAS).One-year observations in 2020 from 150 stations are employed to investigate performance of orbit and clock ***,the UD Ambiguity Resolution(AR)yields more resolved integer ambiguities than the traditional DD AR,scaling up to 9%,attributable to its avoidance of station baseline *** from the removal of ambiguity parameters,the computational efficiency of parameter estimation undergoes a substantial 70%*** with the float solution,the orbit consistencies of UD AR solution achieve the accuracy of 1.9,5.2,2.8,2.1,and 2.7 cm for GPS,BeiDou-2 Navigation Satellite System(BDS-2),BeiDou-3 Navigation Satellite System(BDS-3),Galileo,and GLONASS satellites respectively,reflecting enhancements of 40%,24%,54%,34%,and 42%.Moreover,the standard deviations of Satellite Laser Ranging(SLR)residuals are spanning 2.5–3.5 cm,underscoring a comparable accuracy to the DD AR solution,with discrepancies below 5%.A notable advantage of UD AR lies in its capability to produce the Integer Recovered Clock(IRC),facilitating Precise Point Positioning(PPP)AR without requiring additional Uncalibrated Phase Delay(UPD)*** assess the performance of quad-system kinematic PPP based on IRC,a network comprising 120 stations is uti

关键词： Multi-GNSS Precise orbit determination Integer recover clock Undifferenced ambiguity resolution iGMAS innovation application center

Added Benefit of the Early-Morning-Orbit Satellite Fengyun-3E on the Global Microwave Sounding of the Three-Orbit Constellation

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Advances in Atmospheric Sciences 2024年第1期41卷 39-52页

作者： Juan LI Zhengkun QIN Guiqing LIU Jing HUANG CMA Earth System Modeling and Prediction centre Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Joint Center for Data Assimilation Research and Applications School of Atmospheric SciencesNanjing University of Information Science&TechnologyNanjing 210044China

The three-orbit constellation can comprehensively increase the spatial coverage of polar-orbiting satellites,but the polar-orbiting satellites currently in operation are only mid-morning-orbit and afternoon-orbit ***-3E(FY-3E)was launched successfully on 5 July 2021 in *** an early-morning-orbit satellite,FY-3E can help form a complete three-orbit observation system together with the mid-morning and afternoon satellites in the current mainstream operational *** this study,we investigate the added benefit of FY-3E microwave sounding observations to the midmorning-orbit Meteorological Operational satellite-B(Met Op-B)and afternoon-orbit Fengyun-3D(FY-3D)microwave observations in the Chinese Meteorological Administration global forecast system(CMA-GFS).The results show that the additional FY-3E microwave temperature sounder-3(MWTS-3)and microwave humidity sounder-2(MWHS-2)data can increase the global coverage of microwave temperature and humidity sounding data by 14.8% and 10.6%,*** enables the CMA-GFS to achieve nearly 100% global coverage of microwave-sounding observations at each analysis ***,after effective quality control and bias correction,the global biases and standard deviations of the differences between observations and model simulations are also *** on the Advanced Microwave Sounding Unit A and the Microwave Humidity Sounder onboard Met Op-B,and the MWTS-2 and MWHS-2 onboard FY-3D,adding the microwave sounding data of FY-3E can further reduce the errors of analysis results and improve the global prediction skills of CMA-GFS,especially for the southern-hemisphere forecasts within 96 hours,all of which are significant at the 95% confidence level.

关键词： data assimilation microwave temperature sounder MWTS-3

Arctic Sea Ice Variations in the First Half of the 20th Century:A New Reconstruction Based on Hydrometeorological Data

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Advances in Atmospheric Sciences 2024年第8期41卷 1483-1495,1686-1693页

作者： Vladimir A.SEMENOV Tatiana A.ALDONINA Fei LI Noel Sebastian KEENLYSIDE Lin WANG A.M.Obukhov Institute of Atmospheric Physics RAS Moscow 119017Russia Institute of Geography RAS Moscow 119017Russia Geophysical Institute University of Bergen and Bjerknes Centre for Climate ResearchBergen 5007Norway Nansen Environmental and Remote Sensing Center Bergen 5007Norway Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The shrinking Arctic sea-ice area(SIA) in recent decades is a striking manifestation of the ongoing climate *** of the Arctic sea ice have been continuously observed by satellites since 1979, relatively well monitored since the 1950s, but are highly uncertain in the earlier period due to a lack of observations. Several reconstructions of the historical gridded sea-ice concentration(SIC) data were recently presented based on synthesized regional sea-ice observations or by applying a hybrid model–empirical approach. Here, we present an SIC reconstruction for the period1901–2019 based on established co-variability between SIC and surface air temperature, sea surface temperature, and sea level pressure patterns. The reconstructed sea-ice data for March and September are compared to the frequently used Had ISST1.1 and SIBT1850 datasets. Our reconstruction shows a large decrease in SIA from the 1920 to 1940 concurrent with the Early 20th Century Warming event in the Arctic. Such a negative SIA anomaly is absent in Had ISST1.1 data. The amplitude of the SIA anomaly reaches about 0.8 mln km^(2) in March and 1.5 mln km^(2) in September. The anomaly is about three times stronger than that in the SIBT1850 dataset. The larger decrease in SIA in September is largely due to the stronger SIC reduction in the western sector of the Arctic Ocean in the 70°–80°N latitudinal zone. Our reconstruction provides gridded monthly data that can be used as boundary conditions for atmospheric reanalyses and model experiments to study the Arctic climate for the first half of the 20th century.

关键词： Arctic sea ice Arctic climate early 20th century warming climate variability

Quantitative Applications of Weather Satellite Data for Nowcasting:Progress and Challenges

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Journal of Meteorological Research 2024年第3期38卷 399-413页

作者： Jun LI Jing ZHENG Bo LI Min MIN Yanan LIU Chian-Yi LIU Zhenglong LI WPaul MENZEL Timothy J.SCHMIT John L.CINTINEO Scott LINDSTROM Scott BACHMEIER Yunheng XUE Yayu MA Di DI Han LIN Innovation centre for Fengyun Meteorological Satellite(FYSIC) National Satellite Meteorological CentreChina Meteorological AdministrationBeijing100081China School of Atmospheric Sciences and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University and Southern Laboratory of Ocean Science and EngineeringZhuhai519082China Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai200241China Research Center for Environmental Changes Academia SinicaTaipei11529China Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-MadisonMadisonWI53706USA Sensors and Calibration Branch STAR/NESDISMadisonWI53706USA Wuxi University Wuxi214105China School of Computer Science Chengdu University of Information TechnologyChengdu610225China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China Key Laboratory of Spatial Data Mining and Information Sharing of Ministry of Education National and Local Joint Engineering Research Center of Satellite Geospatial Information TechnologyFuzhou UniversityFuzhou350108China

Monitoring and predicting highly localized weather events over a very short-term period,typically ranging from minutes to a few hours,are very important for decision makers and public *** these events usually relies on radar observations through monitoring and *** advanced high-resolution imaging and sounding observations from weather satellites,nowcasting can be enhanced by combining radar,satellite,and other data,while quantitative applications of those data for nowcasting are advanced through using machine learning *** applications include monitoring the location,impact area,intensity,water vapor,atmospheric instability,precipitation,physical properties,and optical properties of the severe storm at different stages(pre-convection,initiation,development,and decaying),identification of storm types(wind,snow,hail,etc.),and predicting the occurrence and evolution of the *** observations can provide information on the environmental characteristics in the preconvection stage and are very useful for situational awareness and storm *** paper provides an overview of recent progress on quantitative applications of satellite data in nowcasting and its challenges,and future perspectives are also addressed and discussed.

关键词： weather satellite quantitative applications nowcasting pre-convection

Automated Soil Moisture Monitoring Wireless Sensor Network for Long-Term Cal/Val Applications

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Wireless Sensor Network 2012年第8期4卷 202-209页

作者： Aurelio Cano Jose Luís Anon Candid Reig Cristina Millán-Scheiding Ernesto López-Baeza Department of Electronic Engineering University of ValenciaValenciaSpain Climatology from satellites Group University of ValenciaValenciaSpain Research centre on Desertification-CIDE CSIC-University of ValenciaValenciaSpain

The design and development of a wireless sensor network for soil moisture measurement in an unlevelled 10 km × 10 km area, is described. It was specifically deployed for the characterization of a reference area, in campaigns of calibration and validation of the space mission SMOS (Soil Moisture and Ocean Salinity), but the system is easily extensible to monitor other climatic or environmental variables, as well as to other regions of ecological interest. The network consists of a number of automatic measurement stations, strategically placed following soil homogeneity and land uses criteria. Every station includes acquisition, conditioning and communication systems. The electronics are battery operated with the help of solar cells, in order to have a total autonomous system. The collected data is then transmitted through long radio links, with ling ranges above 8 km. A standard PC linked to internet is finally used in order to control the whole network, to store the data, and to allow the remote access to the real-time data.

关键词： Wireless Sensor Network Soil Moisture Monitoring SMOS Calibration/Validation Radio Frequency Links

Unusual Evolution of the Multiple Eyewall Cycles in Super Typhoon Hinnamnor(2022)

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Journal of Meteorological Research 2023年第4期37卷 431-440页

作者： Hui WANG Yubin YU Dajun ZHAO Tzu-Hsiung YEN Hongxiong XU Qian WANG Zhiqiang CAO State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081 China Meteorological Administration Training centre Beijing 100081 Shanghai Typhoon Institute China Meteorological AdministrationShanghai 200030 Department of Atmospheric Sciences “National”Taiwan UniversityTaipei 10617 National Meteorological centre China Meteorological AdministrationBeijing 100081 Key Laboratory of Radiometric Calibration and Validation for Environmental satellites National Satellite Meteorological Center/National Center for Space WeatherChina Meteorological AdministrationBeijing 100081

Hinnamnor was the first super typhoon in the western North Pacific basin in *** had several prominent characteristics,such as rapid intensification after its formation,three eyewall cycles,and a sudden recurvature of its *** on multi-source observational and reanalysis datasets,two secondary eyewall formation(SEF)cycles occurred during Super Typhoon Hinnamnor’s *** first SEF happened near the time when Hinnamnor achieved its maximum intensity,and it seems that its internal dynamics dominated the SEF process after the development of shear-induced asymmetric spiral *** merger of a tropical depression with Hinnamnor led to a continuous increase in both its inner-core size and outer-core circulation,causing generation of the second *** is inferred that the external and internal dynamics worked together during the second SEF *** concentric eyewall structure maintained for approximately 84 h under the moderate vertical wind ***,unique changes in intensity accompanied the two structural changes.

关键词： concentric eyewall secondary eyewall formation tropical cyclone intensity change

Assimilation of FY-3D MWTS-Ⅱ Radiance with 3D Precipitation Detection and the Impacts on Typhoon Forecasts

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Advances in Atmospheric Sciences 2023年第5期40卷 900-919页

作者： Luyao QIN Yaodeng CHEN Gang MA Fuzhong WENG Deming MENG Peng ZHANG Key Laboratory of Meteorological Disaster of Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Earth System Modeling and Prediction centre China Meteorological AdministrationBeijing 100081China Key Laboratory of Radiometric Calibration and Validation for Environmental satellites(LRCVES/CMA) National Satellite Meteorological CenterChina Meteorological Administration(NSMC/CMA)Beijing 100081China

Precipitation detection is an essential step in radiance assimilation because the uncertainties in precipitation would affect the radiative transfer calculation and observation *** traditional precipitation detection method for microwave only detects clouds and precipitation horizontally,without considering the three-dimensional distribution of *** precipitation detection from 2D to 3D is expected to bring more useful information to the data assimilation without using the all-sky *** this study,the 3D precipitation detection method is adopted to assimilate Microwave Temperature Sounder-2(MWTS-Ⅱ)onboard the Fengyun-3D,which can dynamically detect the channels above precipitating clouds by considering the near-real-time cloud *** data assimilation and forecasting experiments for Typhoons Lekima(2019)and Mitag(2019)are carried *** with the control experiment,the quantity of assimilated data with the 3D precipitation detection increases by approximately 23%.The quality of the additional MWTS-Ⅱradiance data is close to the clear-sky *** case studies show that the average root-mean-square errors(RMSE)of prognostic variables are reduced by 1.7%in the upper troposphere,leading to an average reduction of4.53%in typhoon track *** detailed diagnoses of Typhoon Lekima(2019)further show that the additional MWTS-Ⅱradiances brought by the 3D precipitation detection facilitate portraying a more reasonable circulation situation,thus providing more precise *** paper preliminarily proves that 3D precipitation detection has potential added value for increasing satellite data utilization and improving typhoon forecasts.

关键词： numerical weather prediction radiance assimilation microwave temperature sounding FY-3D MWTS-II precipitation detection

Pre-Processing,Quality Assurance,and Use of Global Atmospheric Motion Vector Observations in CRA

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Journal of Meteorological Research 2022年第6期36卷 947-962页

作者： Minyan WANG Shuang YAO Lipeng JIANG Tao ZHANG Chunxiang SHI Ting ZHU National Meteorological Information centre China Meteorological AdministrationBeijing 100081 CMA Earth System Modeling and Prediction centre China Meteorological Administration(CMA)Beijing 100081

Assimilation of atmospheric motion vectors(AMVs)is important in the initialization of the atmospheric state in numerical weather prediction models,especially over oceans and at high latitudes where conventional data are *** paper presents a detailed description of the pre-processing,quality assurance,and use of global AMVs in China’s first generation of the 40-yr(1979-2018)CRA global atmospheric reanalysis product.A new AMV archive is integrated from near real-time operational Global Telecommunication System data and reprocessed AMV datasets released or produced mainly during 2014-2016 according to a priority *** avoid the misuse of data with systematic quality problems,the observations of all 18 types of AMVs from 54 satellites are pre-evaluated over the whole time *** pre-evaluation system developed by the CRA team is based on the NCEP Gridpoint Statistical Interpolation(GSI)three-dimensional variational assimilation system and the ERA-Interim reanalysis *** AMVs in the new AMV archive are denser than the AMVs prepared for the Climate Forecast System Reanalysis product,the bias and root-mean-square values are smaller,and the time series are *** new AMV archive is assimilated in the CRA product based on the NCEP GSI assimilation procedure and quality control configuration with reference to the pre-evaluation *** is the first time that the reprocessed AMVs from Fengyun-2 satellites from June 2005 to July 2017 are assimilated in a reanalysis *** assimilation features inspire confidence in the accuracy and stability of these *** mean root-mean-square values of the observation minus analysis infrared,water vapor,and visible AMV were 1.5-3.4,2.7-3.6,and 1.3-2.1 m s-1,*** experience of integrating,pre-evaluating,and assimilating AMV observations is valuable for the next generation of reanalysis products.

关键词： reanalysis CRA(China’s first generation of 40-yr global atmospheric ReAnalysis product) atmospheric motion vector integration assimilation reprocessed data