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Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

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Science china Earth Sciences 2009年第1期52卷 108-117页

作者： GUO JianXia1,2.BIAN LinGen3 & DAI YongJiu2.1 meteorological Observation center of{2.,Beijing 100081,china 2.State Key Laboratory of Remote Sensing Science,School of Geography and Remote Sensing Science,Beijing Normal University,Beijing 100875,china 3 Chinese Academy of meteorological Sciences,Beijing 100081,china meteorological Observation center of{2. Beijing 100081 China State Key Laboratory of Remote Sensing Science School of Geography and Remote Sensing Science Beijing Normal University Beijing 100875 China

Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance *** the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure *** this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed *** shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below *** to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy *** is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

关键词： maize energy balance multiple time scale energy hysteresis

Monitoring of the 2.11 spring low ozone events in the Arctic region

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Chinese Science Bulletin 2011年第27期56卷 2893-2896页

作者： LIU NianQing 1,2., HUANG FuXiang 1,2.WANG WeiHe 1,2.1 national Satellite meteorological {2., Beijing 100081, china 2.Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, china meteorological administration, Beijing 100081, china national Satellite meteorological {2. Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration

Data from FY-3B SBUS and NOAA SBUV/2.were used to monitor ozone levels in the Arctic region from March 1 to April 5, 2.11. Results revealed a significant ozone depletion in the area, with total ozone levels between 2.0-2.0 DU. The ozone levels recorded were 100-2.0 DU below normal, and in some parts the levels were as low as 2.0 DU, indicating a mini ozone-hole. During the sampling period, the ozone depletion area underwent identifiable expansion and detraction, a rotation around the North Pole from the west to the east, and a longitudinal movement from the Pole, spreading to the mid latitudes. The effects of these rare low ozone events were not only felt in the Arctic, but also extended to densely populated areas between Europe and the middle of Russia. In this region, rapidly increasing levels of ultraviolet radiation were detected at the Earth's surface. Given the significant risk that this poses to both the environment and people's health, this occurrence has significant global implications.

关键词：北极地区臭氧水监测事件人口稠密地区中纬度地区 NOAA 调查结果

Advancement and prospect of short-term numerical climate prediction

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Chinese Science Bulletin 2001年第18期46卷 1497-1502页

作者： CHOU Jifan & XU Ming1. Department of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, china 2. Training center of Chinese {2. administration, Beijing 100081, china Department of Atmospheric Sciences Lanzhou University Lanzhou China Training center of Chinese meteorological {2. Beijing China

The defects of present methods of short-term numerical climate prediction are discussed in this paper, and four challenging problems are put forward. Considering our under developed computer conditions, we should innovate in the approcuch of numerical climate prediction on the basis of our own achievements and experiences in the field of short-term numerical climate prediction. It is possibly an effective way to settle the present defects of short-term numerical climate prediction.

关键词： short-term climate numerical prediction defects innovation.

Progress in china’s climate change study in the 2.th century

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Journal of Geographical Sciences 2004年第S1期 5-13页

作者： ZHAI Panmao1,2. CHAO Qingchen1,2. ZOU Xukai1,2.1. Laboratory for Climate Studies, china meteorological administration, Beijing 100081,{2. 2. national Climate center, china meteorological administration, Beijing 100081,{2.)

Studies on the 2.th century climate change in china have revealed that under the background of global warming over the past century, climate in china has also experienced significant change with mean annual temperature increased by about 0.5 oC. More reliable results for the latter part of the 2.th century indicate that the largest warming occurred in Northwest china, North china and Northeast china, and the warming in winter is most significant. Although no obvious increase or decrease trends were detected for mean precipitation over china in the past half century, regional differences are very distinct. In the middle and lower reaches of the Yangtze River, precipitation increased, while that in the Yellow River Basin markedly decreased. Studies suggest that climate change in china seems to be related not only with the internal factors such as ENSO, PDO, and the others, but also with the anthropogenic effects such as greenhouse gas emissions, and land use. The future climate change studies in china seem to be important in narrowing understanding the nature of china's climate change and its main causes, since it is significant for projection and for impact assessment of climate change in the future.

关键词： th century climate change china

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 Chinese Academy of meteorological Sciences, Beijing 100081,{2. 2.national Climate center, Beijing 100081,{2. 3 Graduate University of Chinese Academy of Sciences, Beijing 100049,{2. 1. Chinese Academy of meteorological Sciences Beijing 100081 China 2. national Climate center Beijing 100081 China 3. Graduate University of Chinese Academy 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

Sensitivity experiments and assessment of climatic changes in china induced by greenhouse effect

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Journal of Environmental Sciences 1990年第4期2卷 73-84页

作者： Zhao Zongci and Ding YihuiAcademy of meteorological Science,State meteorological {2.,Beijing 100081,china

Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in china .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2.5℃ in summer in china as simulated by the GCMs induced by doubling CO2.have been found. There are getting drier or wetter regions in china due to doubled CO2.as simulated by most of models. Comparing the simulated results with the observed data in china, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.

关键词： greenhouse effect climatic changes global warming.

A preliminary analysis of physical mechanism of transformation process from a landed typhoon into an extratropical cyclone

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Acta Oceanologica Sinica 1992年第4期11卷 525-535页

作者： Zhang Qiuqing and Ding Yihui 1. national Research center for Marine. Environment Forecasts, Beijing {2., china2. Academy of meteorological Science, State meteorological administration, Beijing {2., china national Research center for Marine Environment Forecasts Beijing 100081 China China

A diagnostic study is performed in the paper on the process of typhoon Norris (1980) transforming into an ex-tratropical cyclone after its landing over Southeast china. The main findings are as follows:The changes of kinetic energy are mainly attributed to the generation due to non-divergent wind. During the early stage of the typhoon landing, there exits only a small quantity of kinetic energy exchanging with the environment. And after it is transformed into an extratropical cyclone, a large amount of kinetic energy is exported from the system toward the *** horizontal and vertical flux-divergence terms of eddy available potenlial energy are the prominent sinks in the budgets of eddy kinetic energy. The generations of eddy kinetic energy due to both the barotropic and baroclinic processes are source terms. The former is remarkable during the initial stage. But after the depression is transformed into an extratropical cyclone, the roles of the generation by the barotropic and baroclinic processes are reversed, 1. e. , the latter has become more significant than the *** heating is the most dominant heat source. The terms of vertical heat flux by cumulus and large-scale motion are the major sinks. And the latter is prominent after the system is transformed into an extratropical cycfone.

关键词： A preliminary analysis of physical mechanism of transformation process from a landed typhoon into an extratropical cyclone

Principle and application of three-band gradient difference vegetation index

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Science china Earth Sciences 2005年第2期48卷 241-249页

作者： TANG Shihao, ZHU Qijiang, WANG Jindi, ZHOU Yuyu & ZHAO Feng Research center for Remote Sensing and GIS, Department of Geography, Beijing Normal University, Beijing 100875, china {2. Satellite meteorological center, china meteorological administration, Beijing 100081, china 1. Research center for Remote Sensing and GIS Department of Geography Beijing Normal University 100875 Beijing China 2. national Satellite meteorological {2. China Meteorological Administration 100081 Beijing China

Vegetation index is a simple, effective and experiential measurement of terrestrial vegetation activity, and plays a very important role in qualitative and quantitative remote sensing. Aiming at shortages of current vegetation indices, and starting from the analysis of vegetation spectral characteristics, we put forward a new vegetation index, the three-band gradient difference vegetation index (TGDVI), and established algorithms to inverse crown cover fraction and leaf area index (LAI) from it. Theoretical analysis and model simulation show that TGDVI has high saturation point and the ability to remove the influence of background to some degree, and the explicit functional relation with crown cover fraction and LAI can be established. Moreover, study shows that TGDVI also has the ability to partly remove the influence of thin cloud. Experiment in the Shunyi District, Beijing, china shows that reasonable result can be reached using the vegetation index to retrieve LAI. We also theoretically analyzed the reason why the normalized difference vegetation index (NDVI) owns the low saturation point, and show that it is determined by the definition of NDVI and the characteristic of vegetation spectra, and is unavoidable to some degree. Meanwhile, through model simulation, we also indicate that the relationship between simple ratio vegetation index (SR) and LAI closes to a piecewise linear one instead of a linear one, which is mainly caused by the influence of background and different change rates of reflectance in red and infrared bands with LAI increasing.

关键词： vegetation index, remote sensing, LAI, crown cover fraction, remote sensing inversion.

Frontal genesis of moisture atmosphere during the early 2.08 persistent freezing-rain event in southern china

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Science china Earth Sciences 2010年第3期53卷 454-464页

作者： QIAN WeiHong1 & FU JiaoLan1,2.1 Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871, china 2.national meteorological center of CMA, Beijing, {2., china 1. Department of Atmospheric Sciences School of Physics Peking University Beijing 100871 China2. National Meteorological Center of CMA Beijing 100081 China

From January 10 to February 2. 2.08, a severe and persistent freezing-rain event occurred in southern and southwestern china. Here we use an observational analysis to compare the persistent freezing-rain event in the early 2.08 with the winter precipita- tion in the late 2.07 over south of the Yangtze River (Jiangnan). The persistent freezing-rain event was directly linked to the activity of quasi-stationary front. The gradient of equivalent temperature (ET) can well indicate the frontal genesis of moist atmosphere (moisture front) and its activity as well as its relationship with precipitation belt. The precipitation types (snow and freezing rains) are related to the vertical structure of moisture front. The inversion profile of ET vertical distribution is a typical synoptic condition that caused the freezing-rain event. The horizontal gradient of ET with a criterion of 10℃ / 100 km, which reflects the accumulation and release of atmospheric energy, can be applied to predict the precipitation 5-10 days in advance.

关键词： freezing-rain event frontal genesis extended-range weather forecast winter Jiangnan