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Effect of interplanetary shock on an ongoing substorm:Simultaneous satellite-ground auroral observations

Science China(Technological Sciences) 2023年第3期66卷 654-662页

作者： LIU JianJun CHEN XiangCai WANG ZhiQiang HU ZeJun ZHAO XingXin HU HongQiao HAN DeSheng LUI A.T.Y Ministry of Natural Resources(MNR) Key Laboratory for Polar SciencePolar Research Institute of ChinaShanghai 200136China Antarctic Zhongshan National Field Observation and research station for snow and Ice Space Special Environment and DisastersPolar Research Institute of ChinaShanghai 200136China College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China State Key Laboratory of Marine Geology School of Ocean and Earth ScienceTongji UniversityShanghai 200092China Applied Physics Laboratory Johns Hopkins UniversityLaurelMarylandUSA

Substorm processes have been studied in detail,and it is well known that interplanetary(IP)shock encountering the terrestrial magnetosphere causes global ***,how IP shock compression to the magnetosphere affects the development of an ongoing substorm remains ***,the simultaneous satellite and ground-based auroral evolutions associated with an IP shock impact on the magnetopause during an ongoing substorm on May 7th,2005,were *** IMAGE satellite over the Southern Hemisphere captured the global development substorm,which was initiated at 17:38:47 *** poleward branch of the nightside auroral oval was fortuitously monitored by an all-sky camera at the Zhongshan station(-74.5°magnetic latitude,ZHO)in *** satellite imager observed continuous brightening and broadening of the nightside auroral oval after the IP shock *** simultaneous ground-based optical aurora measurement displayed the intensification and expansion of a preexisting auroral surge poleward of the aurora *** geomagnetic field variations and the instantly increased PC indices indicated an elevated merging rate and enhanced the convection-related DP-2 ***,this IP shock transient impact did not significantly change the ongoing development of the substorm,although it meets the magnetospheric precondition hypothesis.

关键词： interplanetary shock substorm global auroral images all-sky camera Zhongshan station

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Precipitation Type Estimation and Validation in China

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Journal of Mountain Science 2014年第4期11卷 917-925页

作者： CHEN Ren-sheng LIU Jun-feng SONG Yao-xuan Qilian Alpine Ecology & Hydrology research station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Key Laboratory of Inland River Ecohydrology Chinese Academy of Sciences

The results from three methods aimed at improving precipitation type （e.g., rain, sleet, and snow） estimation are presented and compared in this paper. The methods include the threshold air temperature （AT）, threshold wet bulb temperature （WBT） and Koistinen and Saltikoff （KSS） methods. Dot graphs are plotted to acquire the threshold air temperature or the threshold wet bulb temperature using daily averaged air temperature, wet bulb temperature and precipitation data at 643 stations from 1961 to 1979 （precipitation types are not labeled in the database from 1980 to present） in China. The results indicate that the threshold AT or WBT methods are not able to differentiate rain, sleet and snow in the most regions in China; sleet is difficult to differentiate from other precipitation types based on the two threshold methods. Therefore, one threshold AT and WBT method was used in this study to differentiate rain and snow. Based on Gaussian- Kriging interpolation of threshold air temperature （To） and wet bulb temperature （Tw）, the To and Tw contour lines and contour surfaces are calculated for China. Finally, a comparison between the KSS, AT and WBT methods are provided in which the KSS method is calculated based on air temperature and relative humidity. The results suggest that the KSS method is more appropriate for water phase estimation than are the other methods; the maximum precision for rain and snow is 99% and 94%, respectively. The AT method performs better than the WBT method when the critical air temperature is 2℃.

关键词： Threshold temperature Wet bulbtemperature Precipitation type Hydrologicalprocesses

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snowline and snow cover Monitoring at High Spatial Resolution in a Mountainous River Basin Based on a Timelapse Camera at a Daily Scale

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Journal of Mountain Science 2015年第1期12卷 60-69页

作者： LIU Jun-feng CHEN Ren-sheng WANG Gang Qilian Alpine Ecology and Hydrology research station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Heihe Key Laboratory of Ecohydrology and Integrated River Basin Management Chinese Academy of Sciences

snowline change and snow cover distribution patterns are still poorly understood in steep alpine basins of the Qilian Mountainous region because fast changes in snow cover cannot be observed by current sensing methods due to their short time scale. To address this issue of daily snowline and snow cover observations, a ground- based EOS 7D camera and four infrared digital hunting video cameras （LTL5210A） were installed around the Hulugou river basin （HRB） in the Qilian Mountains along northeastern margin of the Tibetan Plateau （38°15′54″N, 99°52′53″E） in September 2011. Pictures taken with the EOS 7D camera were georeferenced and the data from four LIL521oA cameras and snow depth sensors were used to assist snow cover estimation. The results showed that the time-lapse photography can be very useful and precise for monitoring snowline and snow cover in mountainous regions. The snowline and snow cover evolution at this basin can be precisely captured at daily scale. In HRB snow cover is mainly established after October, and the maximum snow cover appeared during February and March. The consistent rise of the snowline and decrease in snow cover appeared after middle part of March. This melt process is strongly associated with air temperature increase.

关键词： Time-lapse camera snow cover snowline Hulugou river basin Qilian Mountain

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Spatial distribution and temporal trends in potential evapotranspiration over Hengduan Mountains region from 1960 to 2009

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Journal of Geographical Sciences 2012年第1期22卷 71-85页

作者： ZHU Guofeng HE Yuanqing PU Tao WANG Xufeng JIA Wenxiong LI Zongxing XIN Huijuan State Key Laboratory of Cryosphere Sciences Yulong Snow Mountain Glaciers and Environmental Obser-vation Station Cold and Arid Regions Environmental and Engineering Research Institute CAS Graduate University of Chinese Academy of Sciences research School of Arid Environment and Climate Change Lanzhou University College of Geography and Environment Science Northwest Normal University

Based on the meteorological data of 20 stations in the Hengduan Mountains region during 1961–2009, the annual and seasonal variation of potential evapotranspiration was analyzed in combination with the Penman-Monteith model. With the method of Spline interpolation under ArcGIS, the spatial distribution of potential evapotranspiration was presented to research the regional difference, and the correlation analysis was used to discuss the dominant factor affecting the potential evapotranspiration. The results indicated that the an-nual potential evapotranspiration showed a decreasing tendency since the 1960s, especially from the 1980s to 1990s, while it showed an increasing tendency since 2000. Regional potential evapotranspiration showed a rate of –0.17 mm a？1. Potential evapotranspiration in north, middle and south of the Hengduan Mountains exhibited decreasing trends over the studied period, and its regional trend was on the decline from southwest to northeast.

关键词： potential evapotranspiration Spline interpolation Penman-Monteith model spatial and temporal variations Hengduan Mountains

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Deposition Process of Dust Microparticles from Aerosol to snow-Firn Pack on Glacier No. 1 in Eastern tianshan Mountains, China

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Journal of Earth Science 2011年第4期22卷 460-469页

作者：尤晓妮董志文 Tianshui Normal University State Key Laboratory of Cryospheric Sciences/Tien Shan Glaciological station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

ABSTRACT： Samples were continuously collected from aerosol, fresh snow, and snow pits on Glacier No. 1 at Urumqi River source in eastern tianshan （天山） Mountains. The deposition processes and the characteristics of mineral dust microparticles from aerosol to fresh snow, and then evolution to the snow pit were determined. Total dust microparticle concentration in the surface snow and aerosol showed a similar temporal variation trend, which was strongly associated with regional and local at- mospheric circulation in the tianshan Mountains region of Central Asia. Especially from November to February, the correlation coefficient of microparticles concentration in surface snow and aerosol is very high （R2=0.7）. Vertical profiles of microparticles in the snow pits showed that observed dust layers were in high correlation with concentration peaks of large microparticles （d〉10 μm）, but low correlation with that of fine microparticles （d〈1μm）. Moreover, explicit post-depositional process of dust particles was studied by tracking some typical dust concentration peaks in the snow pit. We find that late sum- mer is a key period for post-deposition of dust particles in the snow, as particle concentration peaks in the snow pit evolve intensely during this period. Such evolutional pattern of large particles makes it possible to preserve information of atmospheric dust in the snow, which offers an available proof to reconstruct historical climate using ice cores on Glacier No. 1 and other gla- ciers in the tianshan Mountains.

关键词： Glacier No. 1 dust microparticle post-deposition.

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Allometric response of perennial Pennisetum centrasiaticum Tzvel to nutrient and water limitation in the Horqin Sand Land of China

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Journal of Arid Land 2012年第2期4卷 161-170页

作者： Wei MAO TongHui ZHANG YuLin LI XueYong ZHAO YingXin HUANG Naiman Desertification research station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China

Optimal partitioning theory （OPT） suggests that plants should allocate relatively more biomass to the organs that acquire the most limited resources. The assumption of this theory is that plants trade off the biomass allocation between leaves, stems and roots. However, variations in biomass allocation among plant parts can also occur as a plant grows in size. As an alternative approach, allometric biomass partitioning theory （APT） asserts that plants should trade off their biomass between roots, stems and leaves. This approach can minimize bias when comparing biomass allocation patterns by accounting for plant size in the analysis. We analyzed the biomass allo- cation strategy of perennial Pennisetum centrasiaticum Tzvel in the Horqin Sand Land of northern China by treating samples with different availabilities of soil nutrients and water, adding snow in winter and water in summer. We hypothesized that P. centrasiaticum alters its pattern of biomass allocation strategy in response to different levels of soil water content and soil nitrogen content. We used standardized major axis （SMA） to analyze the allometric rela- tionship （slope） and intercept between biomass traits （root, stem, leaf and total biomass） of nitrogen/water treat- ments. Taking plant size into consideration, no allometric relationships between different organs were significantly affected by differing soil water and soil nitrogen levels, while the biomass allocation strategy of P. centrasiaticum was affected by soil water levels, but not by soil nitrogen levels. The plasticity of roots, leaves and root/shoot ratios was ＇true＇ in response to fluctuations in soil water content, but the plasticity of stems was consistent for trade-offs between the effects of water and plant size. Plants allocated relatively more biomass to roots and less to leaves when snow was added in winter. A similar trend was observed when water was added in summer. The plasticity of roots, stems and leaves was a function of plant

关键词： optimal partitioning allometric biomass partitioning limited resources biomass allocation allometric relationships

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Seasonal Characteristics of Surface Radiation Fluxes on the East Rongbuk Glacier in the *** Region

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Acta meteorologica Sinica 2010年第6期24卷 680-698页

作者：杨兴国秦大河张廷军康世昌秦翔刘宏谊 State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environment and Engineering Research InstituteChinese Academy of Sciences National snow and Ice Data Center Cooperative Institute for Research in Environmental SciencesUniversity of Colorado Gansu Province Key Laboratory of Arid Climatic Change and Disaster Reduction Institute of Arid MeteorologyChina Meteorological Administration

Ground-based measurements are essential for understanding alpine glacier dynamics,especially in remote regions where in-situ measurements are extremely *** 1 May to 22 July 2005（the spring-summer period）,and from 2 October 2007 to 20 January 2008（the autumn-winter period）,surface radiation as well as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt. Qomolangma/Everest at an elevation of 6560 m *** using an automatic weather station（AWS）.The results show that surface meteorological and radiative characteristics were controlled by two major synoptic circulation regimes：the southwesterly Indian monsoon regime in summer and the westerlies in *** the AWS site on the East Rongbuk Glacier,north or northwest winds prevailed with high wind speed（up to 35 m s^（-1） in January） in winter while south or southeast winds predominated after the onset of the southwesterly Indian monsoon with relatively low wind speed in *** of incoming shortwave radiation was extremely high due to the high elevation,multiple reflections between the snow/ice surface and clouds,and the high reflective surrounding *** factors also caused the observed 10-min mean solar radiation fluxes around local noon to be frequently higher than the solar constant from May to July *** mean surface albedo ranged from 0.72 during the spring-summer period to 0.69 during the autumn-winter period. The atmospheric incoming longwave radiation was greatly affected by the cloud condition and atmospheric moisture *** overall impact of clouds on the net all-wave radiation balance was negative in the Mt. Qomolangma *** daily mean net all-wave radiation was positive during the entire spring-summer period and mostly positive during the autumn-winter period except for a few overcast *** monthly basis,the net all-wave radiation was always positive.

关键词： Mt.Qomolangma glacier snow surface radiation feature meteorological characteristic

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Leaf nitrogen resorption is more important than litter nitrogen mineralization in mediating the diversity–productivity relationship along a nitrogen-limited temperate forest succession chronosequence

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Forest Ecosystems 2023年第1期10卷 132-140页

作者： Peng Zhang Xiao-Tao Lü Guangze Jin Zhili Liu Mai-He Li Center for Ecological research Northeast Forestry UniversityHarbin150040China Forest Dynamics Swiss Federal Institute for ForestSnow and Landscape Research WSLCH-8903BirmensdorfSwitzerland Erguna Forest-Steppe Ecotone research station CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyChinese Academy of SciencesShenyang110016China Key Laboratory of Sustainable Forest Ecosystem Management Ministry of EducationNortheast Forestry UniversityHarbin150040China Northeast Asia Biodiversity research Center Northeast Forestry UniversityHarbin150040China Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains Ministry of EducationSchool of Geographical SciencesNortheast Normal UniversityChangchun130024China School of Life Science Hebei UniversityBaoding071000China

The resorption of nutrients by plants before litter fall and the mineralization of nutrients from plant litter by soil processes are both important pathways supporting primary productivity. While the positive relationship between plant biodiversity and primary productivity is widely accepted for natural ecosystems, the roles of nutrient resorption and mineralization in mediating that relationship remains largely unknown. Here, we quantified the relative importance of nitrogen(N) resorption and N mineralization in driving plant community N investment and the correlation between species diversity and community productivity along an N-limited successional chronosequence of the mixed broadleaved–Korean pine(Pinus koraiensis) forest in northeastern China. Leaf N resorption efficiency(NRE) at the community level increased significantly along the successional chronosequence,whereas litter N mineralization rate decreased significantly. Leaf NRE was more important than litter N mineralization rate in driving the diversity–productivity relationship. However, higher leaf NRE led to less N mineralization as succession progressed along the chronosequence. Our results highlight the importance of the N resorption pathway rather than the N mineralization pathway for forest N acquisition with community succession,and they provide mechanistic insights into the positive effects of biodiversity on ecosystem functioning. In future forest management practices, we recommend appropriate application of N fertilizer to mitigate the adverse effects of N-poor soil on seedling regeneration during late succession and thus maintain the sustainable development of temperate forest ecosystems.

关键词： Community composition Diversity Ecosystem functioning N cycling N limited Niche complementarity Trade-off

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1960-2009年横断山区潜在蒸发量时空变化（英文）

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地理学报 2012年第1期67卷 71-82页

作者：朱国锋何元庆蒲焘王旭峰贾文雄李宗省辛惠娟 State Key Laboratory of Cryosphere Sciences Yulong Snow Mountain Glaciers and Environmental Obser-vation Station Cold and Arid Regions Environmental and Engineering Research Institute CAS Graduate University of Chinese Academy of Sciences research School of Arid Environment and Climate Change Lanzhou University College of Geography and Environment Science Northwest Normal University

Based on the meteorological data of 20 stations in the Hengduan Mountains region during 1961-2009, the annual and seasonal variation of potential evapotranspiration was analyzed in combination with the Penman-Monteith model. With the method of Spline interpolation under ArcGIS, the spatial distribution of potential evapotranspiration was presented to research the regional difference, and the correlation analysis was used to discuss the dominant factor affecting the potential evapotranspiration. The results indicated that the an-nual potential evapotranspiration showed a decreasing tendency since the 1960s, especially from the 1980s to 1990s, while it showed an increasing tendency since 2000. Regional potential evapotranspiration showed a rate of -0.17 mm a？1. Potential evapotranspiration in north, middle and south of the Hengduan Mountains exhibited decreasing trends over the studied period, and its regional trend was on the decline from southwest to northeast.

关键词：横断山区蒸发量时空变化地理学

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Which adjustment methods are suitable for the wind-induced errors of Geonor T-200BM3 precipitation weighing gauges in a periglacial site?

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Advances in Climate Change research 2023年第5期14卷 707-719页

作者： Lei WANG Ren-Sheng CHEN Wei-Jun SUN Chun-Tan HAN Bao-Juan HUAI Yan-Ni ZHAO College of Geography and Environment Shandong Normal UniversityJinan 250358China Qilian Alpine Ecology and Hydrology research station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Single Alter shielded T-200BM3 weighing precipitation gauges are widely used in the measurement of all precipitation types(rainfall,snow and mixed precipitation)in unattended boreal or alpine regions,but their original datasets must be adjusted for undercatch errors caused by wind in snowy,windy and harsh ***,previous researchers have developed many adjustment methods for all precipitation types on different time ***,which adjustment method is suitable for T-200BM3 weighing gauge wind-induced error adjustment in harsh alpine regions is ***,precipitation measurement intercomparison experiments were conducted in the Qilian Mountains from July 2018 to July 2021,and eight adjustment methods;were evaluated for wind-induced errors for daily,individual precipitation event,hourly,and half-hourly time scales.Z2004 outperformed the other adjustment methods in regard to the daily measurements of snow and mixed *** individual snowfall events,M2007 reduced the absolute value of RMSE(bias)from 1.44 to 1.32 mm(0.77-0.24 mm)and could be recommended for snowfall event adjustment.K2017-1 attained a better performance than K2017-2 in regard to half-hourly snowfall and mixed sample adjustment and was more suitable for half-hourly snowfall sample adjustment.K2017-1 reduced the absolute value of bias from 0.07 to 0.00 mm for ***,Z2004,M2007,and K2017-1 yielded better adjustment results for the daily accumulation precipitation amount(>2 mm d−1),individual snowfall events(>2 mm per event),and half-hourly accumulation snowfall or mixed samples(>1 mm 30 min−1),***,further intercomparison in different climate regions is needed for trace precipitation samples.

关键词： Evaluation Wind-induced errors Adjustment methods Weighing gauges Periglacial site

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