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Numerical simulation of topography effects on the “00.7” severe rainfall in beijing

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Progress in Natural Science:Materials International 2005年第9期15卷 818-826页

作者： ZHANG Chaolin1**, ji Chongping1, KUO Yinghwa2, FAN Shuiyong1, XUAN Chunyi3 and CHEN Min1(1. Institute of Urban Meteorology, china meteorological administration, beijing 100089, china 2. Mesoscale and Microscale Meteorology Division, national Center for Atmospheric Research, Boulder, CO 80307-3000, USA 3. beijing meteorological Bureau, beijing 100089, china) Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China. Mesoscale and Microscale Meteorology Division National Center for Atmospheric Research Boulder CO 80307-3000 USA. beijing meteorological Bureau Beijing 100089 China

In an effort to study the severe rainfall event of 4—5th July 2000 in beijing (with 24h accumulated precipitation of 240 mm), we perform numerical simulations to investigate this event using the MM5v3.6 model. The model is initialized with the MM5/WRF 3DVAR analysis, which incorporates the ground-based GPS precipitable water vapor, automatic and conventional meteorological observations in its assimilation step. For 24 h accumulated precipitation forecast, the threat scores are 0.72, 0.76, 0.67 and 0.63, for thresholds of 1, 5, 10, and 20 mm, respectively. Holding other factors unchanged, sensitivity experiments were conducted with different topographic resolutions of 110, 50 and 3.7 km to investigate the topographic effects on precipitation over the beijing area. In these sensitivity experiments, we attempt to preserve the realistic orographic distribution in the model topography under the condition of keeping the dynamic-thermodynamic consistency of the initial model atmosphere to the extent possible. Results indicate that the unique topographic distribution and variations in the beijing area play an important role in determining the location, distribution and intensity of heavy precipitation.

关键词： topography heavy rainfall 3DVAR ground-based GPS numerical simulation.

THEORETICAL ANALYSES AND NUMERICAL EXPERIMENTS FOR TWO-DIMENSIONAL WIND RETRIEVALS FROM SINGLE-DOPPLER DATA

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Journal of Hydrodynamics 2010年第2期22卷 185-195页

作者： HUANG Si-xun CAO Xiao-qun DU Hua-dong ZHONG ji-qin Institute of Meteorology PLA University of Science and Technology Nanjing 211101 China national University of Defense Technolog Changsha 410073 China Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China

Based on variational adjoint methods,theoretical analyses and numerical experiments are performed for retrievals of two-dimensional winds and related parameters from single-Doppler radar data in polar *** the method,the reflectivity conservation equation is used as the governing equation and the mass continuity equation as a weak *** the same time,the stable functional of regularization and background field are also introduced in the cost *** on the ideal experiments with artificial data,real two-dimensional wind fields are retrieved with low-altitude data from the Nanjing Doppler Radar Station,and the results are encouraging and promising.

关键词： single-Doppler retrievals adjoint methods regularization methods two-dimensional wind

A Tri-mode of Mock-Walker Cells

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Advances in Atmospheric Sciences 2024年第4期41卷 671-679页

作者： Han QIN ji NIE Zhiyong MENG Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China china meteorological administration Tornado Key Laboratory Foshan 528061China

This work uses cloud-resolving simulations to study mock-Walker cells driven by a specified sea surface temperature(SST).The associated precipitation in the mock-Walker cells exhibits three different modes,including a single peak of precipitation over the SST maximum(mode 1),symmetric double peaks of precipitation straddling the SST maximum(mode 2),and a single peak of precipitation on one side of the SST maximum(mode 3).The three modes are caused by three distinct convective activity center migration *** indicate that the virtual effect of water vapor plays an important role in differentiating the three *** the SST gradient is large,the virtual effect may be strong enough to overcome the temperature effect,generating a low-level low-pressure anomaly below the ascending branch of the Walker cell off the *** results here highlight the importance of the virtual effect of water vapor and its interaction with convection and large-scale circulation in the Walker circulation.

关键词： Walker circulation cloud-resolving simulation virtual effect

Research and application on the technology system of multi-scale assessment of the impact on the atmospheric environment by urban planning

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Science china Earth Sciences 2005年第Z2期48卷 173-184页

作者： WANG Guangtao, WANG Xiaoyun, MIAO Shiguang, jiANG Weimei, GUO Wenli, ji Chongping & CHEN Xianyan School of Architecture, Tsinghua University, beijing 100084, china Ministry of Construction of china, beijing 100044, china beijing meteorological Bureau, beijing 100089, china Institute of Urban Meteorology, china meteorological administration, beijing 100089, china Department of Atmospheric Sciences, Nanjing University, Nanjing 210093, china School of Architecture Tsinghua University Beijing 100084 China Ministry of Construction of china Beijing 100044 China School of Architecture Tsinghua University Beijing 100084 China beijing meteorological Bureau Beijing 100089 China Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China Department of Atmospheric Sciences Nanjing University Nanjing 210093 China beijing meteorological Bureau Beijing 100089 China

Improvement of the atmospheric environment in urban planning is an important issue to implement the sustainable development of cities. In this paper, in order to meet the demand of planning office to compare and assess quantitatively of the designs in multi-scale, based on geographical information system (GIS) data with high resolution, a multi-scale numerical modeling system for the atmospheric environment impact of urban planning is set up, and the multi-scale assessment index system is established, which compose the technology system of multi-scale assessment of the impact on the atmospheric environment by urban planning. In urban planning (urban development of beijing) and optimizing layouts of Olympic Green, it has been applied to quantitatively evaluating the impact on atmospheric environment by urban planning before construction, which offers scientific foundation to optimize the whole and local urban layout.

关键词： urban planning, atmospheric environment, multi-scale, numerical simulation, assessment index system.

The terrestrial NPP simulations in china since Last Glacial Maximum

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Science Bulletin 2005年第18期 108-113页

作者： HE Yong1, DAN Li2, DONG Wenjie1,2, ji jinjun3,2 & QIN Dahe1 1. national Climate Center, china meteorological administration, Bei-jing 100081, china 2. Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, china 3. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china

Based on Atmosphere-Vegetation Interaction Model (AVIM), the magnitude and spatial distribution of terrestrial net primary productivity (NPP) in china is simu-lated during three different geological eras, Last Glacial Maximum (LGM), Mid-Holocene (MH) and the present. The simulation shows that the glacial-interglacial variation of East Asian summer monsoon in china is the key factor af-fecting the NPP change. During the three eras, mean NPPs are 208 g/m2·a, 409 g/m2·a, and 355 g/m2·a. The total NPPs are 2.05 Pg/a, 3.89 Pg/a and 3.33 Pg/a, respectively. The ter-restrial NPP in china during warm-humid climate is larger than that during cold-arid eras, and the correlation analysis between NPP and climate factors suggests that temperature is the primary factor affecting the terrestrial NPP during 21 kaBP (LGM), and for 6 kaBP (MH) and the present the pri-mary factor is precipitation.

关键词： Last Glacial Maximum Mid-Holocene NPP East-Asian monsoon climate change.

The global rainforest mapping project JERS-1: a paradigm of international collaboration for monitoring land cover change

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Journal of Geographical Sciences 2002年第1期12卷 15-22页

作者： DENG Xiang-zheng, ZHAN jin-yan, LIU ji-yuan, zhuang Da-fang (Institute of Geographic Sciences and Natural Resources Research, CAS, beijing 100101, china) Institute of Geographic Sciences and Natural Resources Research CAS 北京 100101

The Global Rainforest Mapping (GRFM) project was initiated in 1995 and, through a dedicated data acquisition policy by the national Space Development Agency of Japan (NASDA), data acquisitions could be completed within a 1.5-year period, resulting in a spatially and temporally homogeneous coverage to contain the entire Amazon Basin from the Atlantic to the Pacific; Central America up to the Yucatan Peninsular in Mexico; equatorial Africa from Madagascar and Kenya in the east to Sierra Leone in the west; and Southeast Asia, including Papua New Guinea. To some extent, GRFM project is an international endeavor led by NASDA, with the goal of producing spatially and temporally contiguous Synthetic Aperture Radar (SAR) data sets over the tropical belt on the Earth by use of the JERS-1 L-band SAR, through the generation of semi-continental, 100m resolution, image mosaics. The GRFM project relies on extensive collaboration with the national Aeronautics and Space administration (NASA), the Joint Research Center of the European Commission (JRC) and the Japanese Ministry of International Trade and Industry (MITI) for data acquisition, processing, validation and product generation. A science program is underway in parallel with product generation. This involves the agencies mentioned above, as well as a large number of international organizations, universities and individuals to perform field activities and data analysis at different levels.

关键词： Global Rainforest Mapping low-resolution data regional mosaic Global Boreal Forest Mapping

Yields,growth and water use under chemical topping in relations to row configuration and plant density in drip-irrigated cotton

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Journal of Cotton Research 2024年第2期7卷 123-136页

作者： Wang Xuejiao Hu Yanping ji Chunrong Chen Yongfan Sun Shuai Zhang Zeshan Zhang Yutong Wang Sen Yang Mingfeng ji Fen Guo Yanyun Li jie Zhang Lizhen Xinjiang Agriculture Network Information Center Xinjiang Agrometeorological ObservatoryUrumqi 830002China College of Resources and Environmental Sciences Xinjiang Agricultural UniversityUrumqi 830091China College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193China china meteorological administration Institute of Desert MeteorologyUrumqi 830002China Wulanwusu Agrometeorological Station Shihezi 832199China Xinjiang Academy of Agricultural Sciences China National Cotton R&D CenterUrumqi 830091China

Background Water deficit is an important problem in agricultural production in arid *** the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting mode could achieve high yield,fiber quality and water use efficiency(WUE).This study aimed to explore if chemical topping affected cotton yield,quality and water use in relation to row configuration and plant *** Experiments were carried out in Xinjiang china,in 2020 and 2021 with two topping method,manual topping and chemical topping,two plant densities,low and high,and two row configurations,i.e.,76 cm equal rows and 10+66 cm narrow-wide rows,which were commonly applied in matching harvest *** topping increased seed cotton yield,but did not affect cotton fiber quality comparing to traditional manual *** equal row spacing,the WUE in higher density was 62.4%higher than in the lower ***,under narrow-wide row spacing,the WUE in lower density was 53.3%higher than in higher one(farmers’practice).For machine-harvest cotton in Xinjiang,the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m-2 or equal rows with 18 plants *** The plant density recommended in narrow-wide rows was less than farmers’practice and the density in equal rows was moderate with local *** results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.

关键词： Yield components Fiber quality Transpiration Water use efficiency Heat ratio method(HRM)

Scientific design and preliminary results of three-dimensional variational data assimilation system of GRAPES

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Chinese Science Bulletin 2008年第22期53卷 3446-3457页

作者： XUE jiShan zhuang shiyu ZHU GuoFu ZHANG Hua LIU ZhiQuan LIU Yan zhuang ZhaoRong State Key Laboratory for Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China national meteorological Center China Meteorological Administration Beijing 100081 China national Satellite meteorological Center China Meteorological Administration Beijing 100081 China

The scientific design and preliminary results of the data assimilation component of the Global-Regional Prediction and Assimilation System (GRAPES) recently developed in china meteorological administration (CMA) are presented in this paper. This is a three-dimensional variational (3DVar) assimilation system set up on global and regional grid meshes favorable for direct assimilation of the space-based remote sensing data and matching the frame work of the prediction model GRAPES. The state variables are assumed to decompose balanced and unbalanced components. By introducing a simple transformation from the state variables to the control variables with a recursive or spectral filter, the convergence rate of iteration for minimization of the cost function in 3DVar is greatly accelerated. The definition of dynamical balance depends on the characteristic scale of the circulation considered. The ratio of the balanced to the unbalanced parts is controlled by the prescribed statistics of background errors. Idealized trials produce the same results as the analytic solution. The results of real data case studies show the capability of the system to improve analysis compared to the traditional schemes. Finally, further development of the system is discussed.

关键词：数值天气预报气象学天气预测气象分析

冷光学用大口径2 k×2 k红外探测器组件封装技术

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红外与激光工程 2024年第5期53卷 73-82页

作者：朱海勇曾智江孙闻赵振力范广宇季鹏张启庄馥隆李雪中国科学院上海技术物理研究所传感技术联合国家重点实验室上海200083 中国科学院大学北京100049

大面阵和长线列红外探测器已成为下一代红外探测器的发展方向之一,针对于大面阵探测器低温封装的难点,提出了一种大面阵探测器组件封装结构。对组件低形变窗口支撑结构、低噪声冷平台结构以及低漏热兼高可靠性的引线键合工艺等方面进行... 详细信息

大面阵和长线列红外探测器已成为下一代红外探测器的发展方向之一,针对于大面阵探测器低温封装的难点,提出了一种大面阵探测器组件封装结构。对组件低形变窗口支撑结构、低噪声冷平台结构以及低漏热兼高可靠性的引线键合工艺等方面进行了研究,以中波红外2 k×2 k探测器组件为研究对象,通过200 K窗口低温光学设计和低形变窗口帽支撑方式实现组件低背景杂散光抑制设计和窗口形变控制。采用SiC基板实现探测器工作温度波动控制和噪声抑制,5 min内探测器温度波动小于0.1 K,噪声等效温差(NETD)小于20 mK。为了降低引线漏热和增强引线可靠性,采用铂铱丝键合工艺,引线漏热相较于金丝和硅铝丝下降至1/10,制冷机功率由72 W降至39 W。引线随组件通过随机和正弦力学试验考核。解决了大面阵探测器封装中杂散光、大口径窗口形变、探测器噪声、引线漏热和强度等一系列问题,该组件已成功运用于某项目2 k×2 k探测器封装中。

关键词：红外探测器 2 k×2 k 铂铱丝杜瓦组件