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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 china meteorological administration,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 china meteorological administration Beijing China State Key Laboratory of remote Sensing Science School of Geography and Remote Sensing Science Beijing Normal University Beijing China chinese Academy of meteorological Sciences Beijing 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

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 National Satellite meteorological center, china meteorological administration, beijing 100081, china research center for remote Sensing and GIS Department of Geography Beijing Normal University Beijing China National Satellite meteorological center China Meteorological Administration 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.

persistent anomalous flows over the subtropical western pacific insummer

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chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1 and JI Liren\+2 1. National meteorological Centre, china meteorological administration, beijing 100081, china 2. LASG, Institute of Atmospheric physics, chinese Academy of Sciences, beijing 100080, china National meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLr anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WpA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

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 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 Jiangsu Key Laboratory of meteorological Disaster (KLME) Nanjing Institute of Meteorology Nanjing University of Information Science and Technology Nanjing China State Key Laboratory of Severe Weather (LaSW) Chinese Academy of Meteorological Sciences Beijing China National Climate center Chinese Meteorological Administration Beijing 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.

Interannual variation of annual precipitation and urban effect on precipitation in the beijing region

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progress in Natural Science:Materials International 2007年第9期17卷 1042-1050页

作者： Yu Shuqiu(State Key Laboratory on Severe Weather,chinese Academy of meteorological Sciences,beijing 100081,china) State Key Laboratory on Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

The large scale character of the interannual variation of precipitation and the urban effect on local annual precipitation anomaly are investigated in this paper based on the 1960-2000 annual precipitation observations at 20 stations in the beijing *** results show that:the annual precipitation in the beijing region possesses the large scale variation character with the linear trend of-1.197/10 yr,which corresponds to a total reduction of 27.82 mm in annual precipitation in the 41 years;the local annual precipitation anomalies(percent of the normal 1960-2000)show a positive center near the urban area,*** precipitation island(UpI),whose intensity increases with the linear trend of 0.6621%/10 yr,opposite to the interannual trend of large scale precipitation over the beijing region;changes in the UpI are also associated with the intensity of synoptic processes of precipitation,and when the synoptic processes are strong(wet years),the intensity of UpI strengthens,while the synoptic processes are weak(dry years),and the UpI disappears in the beijing region.

关键词： urban precipitation island effect interannual climate variation precipitation beijing atmospheric science

Effects of nuclear chimney on climate

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Journal of Environmental Sciences 1990年第4期2卷 111-116页

作者： Gao Suhua, Ding Yihui, pan Yaru and Zhang QingchenAcademy of meteorological Science State meteorological administration,beijing 100081,china

In this paper, according to the data from several single nuclear explosion experiments of an equivalent to magnitude of million tons, and combined with meteorological data, their effects on the regional climate nave b... 详细信息

关键词： nuclear chimney nuclear explosion temperature change.

Solar release time of solar energetic particles and associated acceleration source in corona

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chinese Science Bulletin 2008年第2期53卷 161-168页

作者： LE GuiMing1,2,3,4, TANG YuHua1 & HAN YanBen4 1 Department of Astronomy, Nanjing University, Nanjing 210093, china 2 Key Laboratory of radiometric Calibration and Validation for Environmental Satellites, china meteorological administration, beijing 100081, china 3 National center for Space Weather, china meteorological administration, beijing 100081, china 4 National Astronomical Observatories, chinese Academy of Sciences, beijing 100012, china Department of Astronomy Nanjing University Nanjing China Key Laboratory of radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration Beijing China National center for Space Weather China Meteorological Administration Beijing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

Solar energetic particles (SEps) are accelerated in corona at an early phase of solar energetic particle events (SEpE). The acceleration mechanism of SEps in corona can only be inferred from an analysis of multi-band observational data, as the observation of SEps is usually made around 1AU. In this context, people have investigated spectrums, charge state, solar release time (SrT), and multi-band data of SEpEs, in an attempt to judge the acceleration mechanism of SEps. The SrT computation of SEps is an important and commonly used approach to study the acceleration mechanism of SEps in corona. This paper reviews some important findings concerning the SrT computation of SEps, and analyzes different merits of each approach for such calculation, based on a range of SEpE case studies. This paper also analyzes and discusses both possible and actual acceleration mechanisms of a number of SEpEs, by calculating the SrT of the SEpEs. Finally, the paper summarizes the possible problems in studying an acceleration mechanism of SEpEs inferred from the SrT of SEp.

关键词：阳光释放时间加速度电晕太阳耀斑

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 meteorological administration, beijing 100081, china Department of Atmospheric Sciences Lanzhou University Lanzhou China Training center of chinese meteorological administration 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.

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, china 2 National Climate center, beijing 100081, china 3 Graduate University of chinese Academy of Sciences, beijing 100049, china chinese Academy of meteorological Sciences Beijing China National Climate center Beijing China Graduate University of chinese Academy of Sciences Beijing 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