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Application of the moist vorticity vector in the analysis of a heavy rainfall event in North China

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Progress in Natural Science:Materials International 2007年第12期17卷 1457-1465页

作者： Zhao Yu1.2.3. Wang Jianguo4 and Xue Deqiang2.1. Laboratory of Cloud-Precipitation Physics and Severe Storms, Institute of Atmospheric Physics, {1. academy of Sciences, {2. 1.002., China 2. Shandong Provincial Meteorological Observatory, Jinan 2.003., China 3. Graduate University of {1. academy of Sciences, {2. 1.003., China 4. Shandong Provincial Meteorological Bureau, Jinan 2.003., China) Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Shandong Provincial Meteorological Observatory Jinan 250031 China Graduate University of chinese {1. of Sciences Beijing 100039 China Shandong Provincial Meteorological Bureau Jinan 250031 China

The moist vorticity vector (MVV), defined as (ζa×▽qv)/ρ introduced by Gao et al. is used to study a heavy rainfall event in North China. The MVV has zonal, meridional and vertical components in a three-dimensional framework. Analysis of domain-mean and mass-integrated quantities shows that the variation of the vertical component of the MVV closely follows the variation of the cloud hydrometeors, with a linear correlation coefficient of 0.95, indicating that the vertical component of the MVV is strongly associated with midlatitude convection. Further analysis shows that the vertical component of the MVV reflects the interaction between the horizontal vorticity and the horizontal specific humidity gradient, which can associate dynamic and thermodynamic processes with cloud microphysical processes. Thus, this study can help to understand how the interaction between circulations and clouds aids the development of convection, and the MVV can be used to trace the development and evolution of heavy rainfall.

关键词： moist vorticity vector heavy rainfall modeling study.

Preparation of Pt/K_2.a_2.i_3._(1.) and its photo-catalytic activity for hydrogen evolution from methanol water solution

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Science China Chemistry 2006年第2期49卷 162-168页

作者： CUI Wenquan1.3. LIU Li2. FENG Liangrong1. XU Chenghua1. LI Zijian1. Lü Shaojie1.& QIU Fali1.1. Chengdu Institute of Organic Chemistry, {1. academy of Sciences, Chengdu 61.041. China 2. Chemistry Department, Sichuan University of Science & Engineering, Zigong 643.3., China 3. Graduate School of the {1. academy of Sciences, beijing 1.003., China Correspondence should be addressed to Qiu Fali 1. Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu 610041 China 3. Graduate School of the {1. {2. of Sciences Beijing 100039 China 2. Chemistry Department Sichuan University of Science & Engineering Zigong 643033 China

A layered perovskite-type oxide K2.a2.i3.1. was prepared with high-temperature solid-state reaction, and characterized with X-ray diffraction (XRD) and ultraviolet-visible diffuse re-flectance spectroscopy (UV-Vis DRS). Platinum was loaded onto K2.a2.i3.1. as a co-catalyst with different methods. The dispersion of platinum on K2.a2.i3.1. was determined with HOT method. The photocatalytic activity of Pt/K2.a2.i3.1. was studied. This catalyst showed much higher activity in hydrogen evolution reaction than Ni/K2.a2.i3.1.. The effects of different amounts of loaded platinum and several preparation methods were evaluated. The best achieved hydrogen evolution rate was 2.0}.88 μmol·h?1.by Pt(2.)/K2.a2.i3.1.. A possible band structure and mechanism were discussed based on the results.

关键词： photocatalysis hydrogen platinum K_2.a_2.i_3._(1.) support

Global analysis theory of climate system and its applications

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chinese Science Bulletin 2003年第10期48卷 1034-1039页

作者： LI Jianping1.2.& CHOU Jifan2.3.1. LASG, Institute of Atmospheric Physics, {1. academy of Sciences, {2. 1.002., China 2. Department of Atmospheric Sciences, Lanzhou University, Lanzhou 73.000, China 3. Training Center for China Meteorological Administration, {2. 1.0081. China Department of Atmospheric Sciences Lanzhou University Lanzhou 730000 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

关键词：整体分析理论气侯体系应用不定性计算法则气侯科学数字模型

Improvement of different source function expressions in SWAN model for the Bohai Sea

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Progress in Natural Science:Materials International 2005年第8期15卷 720-724页

作者： YIN Baoshu1., YANG Dezhou1. SHA Rina 1.2.and CHENG Minghua1.1. Institute of Oceanology, chinese {1. of Sciences, Qingdao 2.6071. China 2. Graduate School of the chinese {1. of Sciences, beijing 1.00{12., China) Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China. Graduate School of the chinese {1. of Sciences Beijing 100039 China

The simulating wave nearshore （SWAN） wave model has been widely used in coastal areas, lakes and estuaries. However, we found a poor agreement between modeling results and measurements in analyzing the chosen four typical cases when we used the default parameters of the source function formulas of the SWAN to make wave simulation for the Bohai Sea. Also, it was found that at the same wind process the simulated results of two wind generation expressions （Komen, Janssen） demonstrated a large difference. Further study showed that the proportionality coefficient α in linear growth term of wave growth source function plays an unperceived role in the process of wave development. Based on experiments and analysis, we thought that the coefficient α should change rather than be a constant. Therefore, the coefficient α changing with the variation of friction velocity U*was introduced into the linear growth term of wave growth source function. Four weather processes were adopted to validate the improvement in the linear growth term. The results from the improved coefficient α agree much better with the measurements than those from the default constant coefficient α. Furthermore, the large differences of results between Komen wind generation expression and Janssen wind generation expression were eliminated. We also experimented with the four weather processes to test the new white-capping mechanisms based on the cumulative steepness method. It was found that the parameters of the new white-capping mechanisms are not suitable for the Bohai Sea, but Alkyon's white-capping mechanisms can be applicable to the Bohai Sea after amendments, demonstrating that this improvement of parameter α can improve the simulated results of the Bohai Sea.

关键词： waves SWAN model wave growth source function new proportionality coefficient formula.

Relationships between tree-ring width index and NDVI of grassland in Delingha

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chinese Science Bulletin 2006年第9期51卷 1106-1114页

作者： HE Jicheng1.3.& SHAO Xuemei1.2.0} Institute of Geographical Sciences and Natural {1.s Research, chinese {2. of Sciences, {3. 1.01.1. China 2. Institute of Tibetan Plateau Research, chinese {2. of Sciences, {3. 1.0085, China 3. Graduate School of chinese {2. of Sciences, {3. 1.003., China Institute of Geographical Sciences and Natural resources Research Chinese Academy of Sciences Beijing China Graduate School of chinese {1. of Sciences Beijing China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Using five well-replicated Qilian juniper (Sabina przewalskii Kom.) tree-ring width index se- ries, monthly normalized difference vegetation index (NDVI) of grassland, and climatic data from 1.82.to 2.01. the relationships between tree-ring width index, NDVI of grassland, and climatic data were analyzed firstly. Then, the relationship between tree-ring width index and NDVI of grassland was explored. The re- sults showed that: (1. Temperature and precipitation in June influenced tree-ring width index and NDVI of grassland deeply in Delingha. (2. There were sig- nificant relationships between five tree-ring width index series (DLH1.DLH5) and monthly NDVI of grassland from June to September, with the most significant relationship being between tree-ring width index series and NDVI of grassland in August. (3. The PC1.(the first principal component derived from DLH1.DLH5 series) exhibited good agreement with monthly NDVI of grassland in the grass growth sea- son (from June to September) and the averaged NDVI in the growth season, which was attributed to their common responses to water-supply limit in Delingha. This study may allow an increase in studying the past dynamics of grassland in Delingha in that the variation of grassland NDVI during the last millennium has been reconstructed from PC1.

关键词：圆柏祁连山 NDVI 草原年轮宽度指数

Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

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Science China Earth Sciences 2008年第7期51卷 1021-1035页

作者： LIU YunYun1.2.3.& DING YiHui2.1.{1. academy of Meteorological Sciences, {2. 1.0081. China 2.National Climate Center, {2. 1.0081. China 3.Graduate University of {1. academy of Sciences, {2. 1.0049, China 1. chinese {1. of Meteorological Sciences Beijing 100081 China 2. National Climate Center Beijing 100081 China 3. Graduate University of {1. {2. of Sciences Beijing 100049 China

Based on the Indian and chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern China. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South China Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

Monitoring Dynamic Change of Land Cover Based on SVM and Satellite Images in Hanoi,Vietnam

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Wuhan University Journal of Natural Sciences 2010年第4期15卷 355-362页

作者： ZHAO Jinling1.2. LIU Chuang1. {2.1. Institute of Geographic Sciences and Natural {1.s Research, chinese {2. of Sciences, {{2. 1.01.1. China 2. Graduate University of chinese {2. of Sciences, {{2. 1.0049, China {2. College of {1.s Science and Technology, {{2. Normal University, {{2. 1.0875, China Institute of Geographic Sciences and Natural resources Research Chinese Academy of Sciences Beijing China Graduate University of chinese {1. of Sciences Beijing China College of resources Science and Technology Beijing Normal University Beijing China

An integral method,combining support vector ma-chine (SVM) with remote-sensing analysis techniques,was ex-plored to monitor Hanoi’s dynamic change of land cover. The landsat thematic mapper (TM) image in 1.93.the enhanced the-matic mapper plus (ETM+) image in 2.00,and the image with the charge-coupled device camera (CCD) on the China-Brazil earth {1.s satellite (CBERS) in 2.08 were used. Six land-cover types,including built-up areas,woodland,cropland,sand,water body and unused land,were identified. The detected results showed visually the rapid urban expansion as well as land-cover change of Hanoi from 1.93.to 2.08. There were 1. 63..54 hm2.cropland de-creased between 1.93.and 2.00,and 8 2.7.6 hm2.cropland de-creased between 2.00 and 2.08. Compared with cropland,wood-land firstly decreased and then increased,and the other types did not change significantly. The results indicate that CBERS dataset has the application potential in world {1.s researches.

关键词： land cover the China-Brazil earth resources satellite (CBERS) support vector machine (SVM) change detection

Study of the circulation theory of the cooling system in vertical evaporative cooling generator

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Science China(Technological Sciences) 2006年第3期49卷 358-364页

作者： YU Shunzhou1. CAI Jing2. GUO Chaohong1.& GU Guobiao1.1. Institute of Electrical Engineering, chinese {1. of Sciences, {2. 1.0080, China 2. {2. Changcheng Institute of Metrology and Measurement, {2. 1.0095, China Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100080 China beijing Changcheng Institute of Metrology Measurement Beijing 100095 China

The article briefly states the current development of evaporative cooling generator; its advantages comparing with generators of traditional cooling. Vertical evaporative cooling generator, which adopts Close-Loop-Self-Cycle with no-pump; free convection boil in the hollow stator bar, is one of the great developments in generator design. This article emphasizes the importance of cooling system in generator; expatiates the circulation theory in two aspects, energy; flow;; analyzes the essential reason, motivity; stability of Close-Loop-Self-Cycle. The article points out that the motivity of the circulation is the heat absorbed by coolant. After absorbing heat the coolant will have the ability of doing work because of the phase change. In another words, it is the buoyancy causing by density difference leads to the Close-Loop-Self-Cycle. This conclusion is validated by experimental data.

关键词： vertical evaporative cooling generator, cooling system, circulation theory.

Possible mechanism of the effect of convection over Asian-Australian “land bridge” on the East Asian summer monsoon onset

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Science China Earth Sciences 2006年第11期49卷 1223-1232页

作者： HE Jinhai1. WEN Min2. DING Yihui3.& ZHANG Renhe2.1. Jiangsu Key Laboratory of Meteorological Disaster (KLME), Nanjing Institute of Meteorology, Nanjing University of Informa- tion Science and Technology, Nanjing 2.0}044, China 2. State Key Laboratory of Severe Weather (LaSW), {1. academy of Meteorological Sciences, {2. 1.0081. China 3. National Climate Center, {1. Meteorological Administration, {2. 1.0081. China 1. Jiangsu Key Laboratory of Meteorological Disaster (KLME) Nanjing Institute of Meteorology Nanjing University of Information Science and Technology Nanjing 210044 China 2. State Key Laboratory of Severe Weather (LaSW) Chinese Academy of Meteorological Sciences Beijing 100081 China 3. National Climate Center Chinese Meteorological Administration Beijing 100081 China

The Asian-Australian “land bridge” is an area with the most vigorous convection in Asian monsoon region in boreal spring, where the onset and march of convection are well associated with the onset of East Asian summer monsoon. The convection occurs over Indo-China Peninsula as early as mid-April, which exerts critical impact on the evolution of monsoon circulation. Before mid-April there are primarily sensible heatings to the atmosphere over Indo-China Peninsula and Indian Peninsula, so the apparent heating ratios over them decrease with height. However, after mid-April it changes into latent heating over Indo-China Peninsula due to the onset of convection, and the apparent heating ratio increases with height in mid- and lower troposphere. The vertical distribution of heating ratio and its differences between Indo-China Peninsula and Indian Peninsula are the key factors leading to the splitting of boreal subtropical high belt over the Bay of Bengal. Such mechanism is strongly supported by the fact that the evolution of the vertical heating ratio gradient above Indo-China Peninsula leads that of 850 hPa vorticity over the Bay of Bengal. Convections over Indo-China Peninsula and its surrounding areas further increase after the splitting. Since then, there is a positive feedback lying among the convective heating, the eastward retreat of the subtropical high and the march of monsoon, which is a possible mechanism of the advance of summer monsoon and convection from Indo-China Peninsula to South China Sea.

关键词： Asian-Australian 'land bridge', tropical convection, Indo-China Peninsula, the splitting of boreal subtropical high belt, East Asian summer monsoon onset.