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First results of the low energy ion spectrometer onboard a Chinese geosynchronous satellite

Science China(Technological Sciences) 2023年第5期66卷 1378-1384页

作者： SHAN Xu MIAO Bin CAO Zhe SUN ZhenYu LI YiRen LIU Kai GUO XingYu QU SanBiao SU ZhenPeng SHEN ChengLong PAN ZongHao LI Xin HAO XinJun YANG XiaoPing TIAN Chao JIANG Yu LIU ShuBin AN Qi CHEN XiangJun WANG YuMing Hefei National Research Center for Physical Sciences at the Microscale Department of Modern PhysicsUniversity of Science and Technology of ChinaHefei230026China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei230026China State Key Laboratory of Particle Detection and Electronics(IHEP-USTC) Department of Modern PhysicsUniversity of Science and Technology of ChinaHefei230026China Shandong Institute of space Electronic Technology Yantai264003China State Key Laboratory of Astronautic Dynamics Xi’an Satellite Control CenterXi’an710043China CAS Center for Excellence in Comparative Planetology University of Science and Technology of ChinaHefei230026China

A Chinese geosynchronous satellite was launched on June 23,*** carried a plasma detection package to monitor the space environment around the *** we report the inflight performance of a low energy ion spectrometer(LEIS),one of the primary instruments in the plasma detection package,and its initial observations in *** from the state-of-the-art design of a top-hat electrostatic analyzer cooperated with angular scanning deflectors,three-dimensional measurement of ions in space with a large field of view of 360°×90°and a wide energy range from 50 eV to 25 keV per charge has been *** differential energy flux spectra of ions around the orbit have shown clear signatures of surface charging and storm/substorm ion *** occurrence of surface charging could be caused by the lack of photoemission at the Earth's eclipse(near the midnight)or the storm energetic electron injection at the dawn *** present results demonstrated a good performance of the LEIS payload in flight for monitoring the space ion environment around the *** situ measurements of the LEIS payload provide us an opportunity to understand the magnetospheric ion dynamics and forecast the associate space weather impacts.

关键词： low energy ion spectrometer geosynchronous orbit inflight measurement differential energy flux surface charging storm/substorm

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Spatiotemporal Variability of Methane over the Amazon from Satellite Observations

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Advances in Atmospheric Sciences 2016年第7期33卷 852-864页

作者： Igor Oliveira RIBEIRO] Rodrigo Augusto Ferreira de SOUZA Rita Valeria ANDREOLI Mary Toshie KAYANO Patrfcia dos Santos COSTA Post-Graduate Program in Climate and Environment CLIAMBINPA/UEAAv.Andre Araujo2936Campus 11Aleixo69060-001ManausAMBrasil Amazonas State University Superior School of TechnologyAv.Darcy Vargas1200Parque 10 de Novembro69065-020ManausAMBrasil National Institute for space Research Center For Weather Forecasting and Climate ResearchAv.dos Astronautas175812227-010Sao Josd dos CamposSPBrasil

The spatiotemporal variability of the greenhouse gas methane （CH4） in the atmosphere over the Amazon is studied using data from the space-borne measurements of the Atmospheric Infrared Sounder on board NASA＇s AQUA satellite for the period 2003-12. The results show a pronounced variability of this gas over the Amazon Basin lowlands region, where wetland areas occur. CH4 has a well-defined seasonal behavior, with a progressive increase of its concentration during the dry season, followed by a decrease during the wet season. Concerning this variability, the present study indicates the important role of ENSO in modulating the variability of CH4 emissions over the northern Amazon, where this association seems to be mostly linked to changes in flooded areas in response to ENSO-related precipitation changes. In this region, a CH4 decrease （increase） is due to the E1 Nifio-related （La Nifia-related） dryness （wetness）. On the other hand, an increase （decrease） in the biomass burning over the southeastern Amazon during very dry （wet） years explains the increase （decrease） in CH4 emissions in this region. The present analysis identifies the two main areas of the Amazon, its northern and southeastern sectors, with remarkable interannual variations of CH4. This result might be useful for future monitoring of the variations in the concentration of CH4, the second-most important greenhouse gas, in this area.

关键词： climate variability methane satellite data Amazon region

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A study of oil spill detection using ASAR images

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Acta Oceanologica Sinica 2009年第4期28卷 32-37页

作者： WANG Guiwu ZHANG Yuanzhi LIN Hui Institute of space and Earth Information Science The Chinese University of Hong Kong Shatin NT Hong Kong

The oil spilled worldwide causes ecological disasters that result in enormous damages to the quality of marine environment, and great expenses on clear-up operations are needed. Due to its wide coverage and day-night all-weather observation capability, Synthetic Aperture Radar （SAR） is an important tool for oil spill monitoring and detection. C-band SAR is well adapted to detect oil pollution because oil slicks dampen the Bragg waves and reduce radar backscattering coefficients. In order to detect the area of oil slicks, the algorithm consists of these steps： Preprocessing, Masking of land areas, Detection of dark spots, Spot feature extraction, Dark spot classification. In this paper, the authors examined two coastal regions around Hong Kong and Yantai, China. The obtained results performed on Envisat ASAR images have demonstrated that it is efficient to detect oil spill around the coastal regions. The methodology still needs to be refined with the collection of more SAR data in the near future.

关键词： Oil spill dectection SAR imagery

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Validation of the Satellite-Derived Rainfall Estimates over the Tibet

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Acta meteorologica Sinica 2011年第6期25卷 734-741页

作者：除多普布顿珠罗布坚参 SAGAR Bajracharya MANDIRA Shrestha 郭建平 Institute of Plateau Meteorology CMA Tibet Institute of Plateau Atmospheric and Environmental Sciences Tibet weather Observatory Tibet Meteorological Service International Centre for Integrated Mountain Development (ICIMOD) Chinese Academy of Meteorological Sciences CMA

Measuring rainfall from space appears to be the only cost effective and viable means in estimating regional precipitation over the Tibet, and the satellite rainfall products are essential to hydrological and agricultural modeling. A long-standing problem in the meteorological and hydrological studies is that there is only a sparse raingauge network representing the spatial distribution of precipitation and its quantity on small scales over the Tibet. Therefore, satellite derived quantitative precipitation estimates are extremely usefill for obtaining rainfall patterns that can be used by hydrological models to produce forecasts of river discharge and to delineate the flood hazard area. In this paper, validation of the US National Oceanic and Atmospheric Administration （NOAA） Climate Prediction Center （CPC） RFE （rainfall estimate） 2.0 data was made by using daily rainfall observations at 11 weather stations over different climate zones from southeast to northwest of the Tibet during the rainy season from 1 June to 30 September 2005 and 2006. Analysis on the time series of daily rainfall of RFE-CPC and observed data in different climate zones reveals that the mean correlation coefficients between satellite estimated and observed rainfall is 0.74. Only at Pali and Nielamu stations located in the southern brink of the Tibet along the Himalayan Mountains, are the correlation coefficients less than 0.62. In addition, continuous validations show that the RFE performed well in different climate zones, with considerably low mean error （ME） and root mean square error （RMSE） scores except at Nielamu station along the Himalayan range. Likewise, for the dichotomous validation, at most stations over the Tibet, the probability of detection （POD） values is above 73% while the false alarm rate （FAR） is between 1% and 12%. Overall, NOAA CPC RFE 2.0 products performed well in the estimation and monitoring of rainfall over the Tibet and can be used to analyze the precipitation pattern,

关键词： precipitation validation satellite rainfall estimation Tibetan Plateau

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Introduction to Meridian space weather monitoring Project

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空间科学学报 2006年第Z1期26卷 17-24页

作者： WU Ji WANG Chi FAN Quanlin Center for space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China

The Meridian Project is a ground- based network program to monitor solar-terrestrial space environment, which consists of a chain of ground-based observatories with multiple instruments including magnetometers, ionosondes, HF and VHF radar, Lidar, IPS monitors, sounding rockets etc. The chain is mainly located in the neighborhood of 120°E meridian, and is thus named the Meridian Project. It has officially been approved by the Chinese government and will be finished by 2009. This talk will give an overview of the Meridian Project and the proposed International space weather Meridian Circle Program.

关键词： space weather, Ground-based observation

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A Hybrid Statistical-Dynamical Downscaling of Air Temperature over Scandinavia Using the WRF Model

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Advances in Atmospheric Sciences 2020年第1期37卷 57-74页

作者： Jianfeng WANG Ricardo M.FONSECA Kendall RUTLEDGE Javier MARTÍN-TORRES Jun YU Department of Mathematics and Mathematical Statistics UmeåUniversitySE 90187UmeåSweden Group of Atmospheric Science Division of Space TechnologyDepartment of Computer ScienceElectrical and Space EngineeringLuleåUniversity of TechnologySE 97187 LuleåSweden Novia University of Applied Sciences PO BOX 6FI-65201 VaasaFinland Instituto Andaluz de Ciencias de la Tierra 18100 GranadaSpain The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry Institute for Planetary MaterialsOkayama University at MisasaTottori 682-0193Japan

An accurate simulation of air temperature at local scales is crucial for the vast majority of weather and climate *** this work,a hybrid statistical–dynamical downscaling method and a high-resolution dynamical-only downscaling method are applied to daily mean,minimum and maximum air temperatures to investigate the quality of localscale estimates produced by *** two downscaling approaches are evaluated using station observation data obtained from the Finnish Meteorological Institute over a near-coastal region of western *** dynamical downscaling is performed with the weather Research and Forecasting(WRF)model,and the statistical downscaling method implemented is the Cumulative Distribution Function-transform(CDF-t).The CDF-t is trained using 20 years of WRF-downscaled Climate Forecast System Reanalysis data over the region at a 3-km spatial resolution for the central month of each *** performance of the two methods is assessed qualitatively,by inspection of quantile-quantile plots,and quantitatively,through the Cramer-von Mises,mean absolute error,and root-mean-square error *** hybrid approach is found to provide significantly more skillful forecasts of the observed daily mean and maximum air temperatures than those of the dynamical-only downscaling(for all seasons).The hybrid method proves to be less computationally expensive,and also to give more skillful temperature forecasts(at least for the Finnish near-coastal region).

关键词： WRF air temperature Cumulative Distribution Function-transform hybrid statistical–dynamical downscaling,model evaluation Scandinavian Peninsula

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Near-infrared observations of the Be/X-ray binary pulsar A0535+262

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Research in Astronomy and Astrophysics 2012年第2期12卷 177-186页

作者： Sachindra Naik Blesson Mathew D.P.K.Banerjee N.M.Ashok Rajeev R.Jaiswal Astronomy and Astrophysics division Physical Research Laboratory

We present the results obtained from extensive near-infrared （IR） spectro- scopic and photometric observations of the Be/X-ray binary A0535＋262/HDE 245770 at different phases of its - 111 d orbital period. This observation campaign is part of the monitoring program of selective Be/X-ray binary systems aimed at understanding X-ray and near-IR properties at different orbital phases, especially during the perias- tron passage of the neutron star. The near-IR observations presented here were carried out using the 1.2 m telescope at the Mt. Abu IR Observatory. Though the source was relatively faint for spectroscopic observations with the 1.2 m telescope, we monitored the source closely during the 2011 February-March giant X-ray outburst to primarily investigate whether any drastic changes in the near-IR JHK spectra took place at the periastron passage. Changes of such a striking nature were expected to be detectable in our spectra. Photometric observations of the Be star show a gradual and systematic fading in the JHK light curves since the onset of the X-ray outburst, which could suggest a mild evacuation/truncation of the circumstellar disk of the Be companion. Near-IR spectroscopy of the object shows that the JHK spectra are dominated by the emission lines of hydrogen Brackett and Paschen series and HeI lines at 1.0830, 1.7002 and 2.0585 μm. The presence of all the hydrogen emission lines in the JHK spectra, along with the absence of any significant change in the continuum of the Be companion during X-ray quiescent and X-ray outburst phases, suggests that the near- IR line emitting regions of the disk are not significantly affected during the X-ray outburst.

关键词： infrared: stars - Be binaries - stars: individual (A0535+262) - tech-niques: spectroscopic

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Sensitivity of Snowfall Characteristics to Meteorological Conditions in the Yeongdong Region of Korea

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Advances in Atmospheric Sciences 2021年第3期38卷 413-429页

作者： Yoo-Jun KIM So-Ra IN Hae-Min KIM Jin-Hwa LEE Kyu Rang KIM Seungbum KIM Byung-Gon KIM High Impact weather Research Department National Institute of Meteorological SciencesGangneung 25457Korea Operational Systems Development Department National Institute of Meteorological SciencesSeogwipo 63568Korea Department of Atmospheric Environmental Sciences Gangneung-Wonju National UniversityGangneung 25457Korea

This study investigates the characteristics of cold clouds and snowfall in both the Yeongdong coastal and mountainous regions under different meteorological conditions based on the integration of numerical modeling and three-hourly rawinsonde observations with snow crystal photographs for a snowfall event that occurred on 29−30 January *** found that rimed particles predominantly observed turned into dendrite particles in the latter period of the episode when the 850 hPa temperature decreased at the coastal site,whereas the snow crystal habits at the mountainous site were largely needle or rimed *** soundings showed a well-defined,two-layered cloud structure along with distinctive wind-directional shear,and an inversion in the equivalent potential temperature above the low-level cloud *** first experiment with a decrease in lower-layer temperature showed that the low-level cloud thickness was reduced to less than 1.5 km,and the accumulated precipitation was decreased by 87%compared with the control *** difference in precipitation amount between the single-layered experiment and control experiment(two-layered)was not so significant to attribute it to the effect of the seeder−feeder *** precipitation in the last experiment by weakening winddirectional shear was increased by 1.4 times greater than the control experiment specifically at the coastal site,with graupel particles accounting for the highest proportion(~62%).The current results would improve snowfall forecasts in complicated geographical environments such as Yeongdong in terms of snow crystal habit as well as snowfall amount in both time and space domains.

关键词： Yeongdong snow crystal rawinsonde cloud-resolving model

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A precise monitoring of snow surface height in the region of Lambert Glacier basin-Amery Ice Shelf,East Antarctica

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Science China Earth Sciences 2005年第1期48卷 100-111页

作者： I.Allison Australian Antarctic division and Antarctic Climate and Ecosystems CRC

The net surface snow accumulation on the Antarctic ice sheet is determined by a combination of precipitation, sublimation and wind redistribution. We present a one-year record of hourly snow-height measurements at LGB69 (70°50'S, 77°04(E,1850 m a.s.l.), east side of Lambert Glacier basin (LGB), and 4 year record at G3 (70°53'S, 69°52'E, 84 m a.s.l.), Amery Ice Shelf (AIS). The measurements were made with ultrasonic sensors mounted on automatic weather stations installed at two sites. The snow accumulation at LGB69 is approximately 70 cm. Throughout the winter, between April and September, there was little change in surface snow height (SSH) at the two sites. The negative SSH change is due to densification at LGB69, and is due to both ablation and densification at G3. The strongest accumulation at two sites occurred during the period between Octobers and March (accounting for 101.6% at LGB69), with four episodic increasing events occurring during 2002 for LGB69, and eight events during 1999-2002 for G3 (2 to 3 events per year). At LGB69, these episodic events coincided with obvious humidity "pulses" and decreases of incoming solar radiation as recorded by the AWS. Observations of the total cloud amount at Davis station, 160 km NNE of LGB69, showed good correlation with major accumulation events recorded at LGB69. There was an obvious anti-correlation between the lowest cloud height at Davis and the daily accumulation rate at LGB69. Although there was no correlation over the total year between wind speed and accumulation at LGB69, large individual accumulation events are associated with episodes of strong wind (>7 m/s), we estimate drift snow may contribute to total SSH up to 35%. Strong accumulation events at LGB69 are associated with major storms in the region and inland transport of moist air masses from the coast.

关键词： Antarctica, Lambert Glacier basin, Amery Ice Shelf, accumulation, katabatic wind.

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Structure and floristic composition of tree stand in tropical forest in the Eastern Ghats of northern Andhra Pradesh, India

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Journal of Forestry Research 2011年第4期22卷 491-500页

作者： C. Sudhakar Reddy Shilpa Babar Giriraj Amarnath Chiranjibi Pattanaik Forestry and Ecology division National Remote Sensing Centre Indian Space Research Organization Hyderabad - 500 625 Andhra Pradesh India. MENRIS division International Centre for Integrated Mountain Develop- ment Kathmandu Nepal Salim Ali Centre for Ornithology & Natural History Deccan Regional Sta- tion 12-13-588/B Nagarjuna Nagar Colony Tarnaka Hyderabad-500 017Andhra Pradesh India.

The changes in species composition, abundance and forest stand structure were analyzed across altitudinal regimes in tropical forests of Eastern Ghats of northern Andhra Pradesh, India. Three 1-ha plots were established with one each in low, medium and high altitudes. A total of 153 species, 2129 stems （709 stems .ha^-1） of ≥10 cm girth were enumerated. Species richness and diversity pattern varied along altitudinal gradient and increased with the altitude. Species richness varied from 52 to 110 species-ha^-1 and stand density from 639 to 836 ***^-1 with average basal area of 34.39 m^***^-1. Shannon-Wiener index （H＇） ranged from 4.55 to 5.17. Low altitude （i.e., Site 1） is dominated byXylia xylocarpa （59.22） and Lagerstroemia parviflora （23.90）, medium altitude （i.e., Site 2） by Xylia xylocarpa （45;50） Bursera serrata （17.29）, and high altitude （i.e., Site 3） has Schleichera oleosa （28.25） Pterocarpus marsupium （26.55） as predominant species. Taxonomically, Rubiaceae （12 species）, Fabaceae （12）, Euphorbiaceae （11）, Rutaceae （7） and Lanraceae （7） were dominant families. Density-wise, Fabaceae, Combretaceae, Euphorbiaceae, Anacardiaceae and Myrtaceae were abundant. Thus, conservation assessment based on altitudinal regimes and the information on species structure and function can provide baseline information for monitoring and sustaining the biodiversity.

关键词： altitude conservation diversity Eastern Ghats speciescomposition

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