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Comparison of the global air-sea freshwater exchange evaluated from independent datasets

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Progress in Natural Science:Materials International 2003年第8期 68-73页

作者： ZHOU Tianjun(State key Laboratory of Numerical modeling for {2. sciences and geophysical fluid dynamics (LASG), institute of atmospheric physics, chinese academy of sciences, Beijing 10002., china) State key Laboratory of Numerical modeling for {2. sciences and geophysical fluid dynamics LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The implied air-sea freshwater flux is examined in two reanalysis datasets provided respectively by European Center forMedium-range Weather Forecasts and National Center for Environmental Prediction. Not only for annual mean state but also for seasonalvariation, two reanalyses agree qualitatively well with each other, and both can reproduce reasonably the global distribution of E-P (i. *** minus Precipitation). In the view of quantitative comparison, however, remarkable difference has been found on regionalscales, especially over the middle and lower latitudes, with some local disagreement exceeding 100 cm/yr. One important difference be-tween current and previous evaluation is the new found net evaporation over the high latitude North Atlantic, which is demonstrated to re-sult from the transient disturbances during boreal winter.

关键词： air-sea freshwater exchange reanalysis datasets.

用格子Boltzmann模型模拟垂直平板间的热对流

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物理学报 2004年第3期53卷 671-675页

作者：赵颖季仲贞冯涛中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室

引入一个新的能量分布函数 ,利用该能量分布函数与粒子速度分布函数耦合来求解一个热流场 .因而 ,这一能量分布函数与粒子速度分布函数和Boltzmann方程构成了一个新的格子Boltzmann模型 .这一模型满足质量、动量和能量守恒的准则 .用该... 详细信息

引入一个新的能量分布函数 ,利用该能量分布函数与粒子速度分布函数耦合来求解一个热流场 .因而 ,这一能量分布函数与粒子速度分布函数和Boltzmann方程构成了一个新的格子Boltzmann模型 .这一模型满足质量、动量和能量守恒的准则 .用该模型对垂直平板间的狭缝热对流进行了数值模拟 ,数值结果表明 ,在Prandtl数为 1,Grashof数在 1 3× 10 2.— 1× 10 6 之间时 ,流场将出现多个旋涡结构的流型 .

关键词：能量分布函数热对流 Boltzmann方程粒子速度分布函数能量守恒动量守恒质量守恒热力学

Development of the universal and simplified soil model coupling heat and water transport

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Science china Earth sciences 2008年第1期51卷 88-102页

作者： LI Qian1,2.& SUN ShuFen1 1 State key Laboratory of Numerical modeling for {2. sciences and geophysical fluid dynamics, institute of atmospheric physics, chinese academy of sciences, Beijing 10002., china 2.Graduate University of the chinese academy of sciences, Beijing 100049, china State key Laboratory of Numerical modeling for {2. sciences and geophysical fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of the chinese academy of sciences Beijing 100049 State key Laboratory of Numerical modeling for {2. sciences and geophysical fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

It is very important to develop a universal soil model with higher simplicity and more accuracy, which can be widely applied to very general cases such as wet or dry soil, frozen or unfrozen soil and homogeneous or heterogeneous soil. Firstly in this study, based on analysis of both magnitude order and the numerical simulation results, the universal and simplified soil model (USSM) coupling heat and mass transport processes is developed. Secondly, in order to avoid the greater uncertainty caused by the phase change term in numerical iteration process for the model solution obtaining, new version of the universal simplified soil model (NUSSM) is further derived through variables transformation, and accordingly a more efficient numerical scheme for the new version is designed well. The simulation results from the NUSSM agree with the results from more complicated and accurate soil model very well, also reasonably reproduce the observed data under widely real conditions. The new version model, because of its simplicity, will match for the development of land surface model.

关键词： universal and simplified soil model coupled heat and mass transport processes frozen soil arid soil heterogeneous soil

Spring Arctic Sea Ice as an Indicator of Eurasian Summer and North American Rainfall

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Spring Arctic Sea Ice as an Indicator of Eurasian Summer and...

UNIFICATION AND APPLICATIONS OF MODERN OCEANIC/atmospheric DATA ASSIMILATION ALGORITHMS

第2.届中国气象学会年会

作者： MirongSong Jiping liu State key Laboratory of Numerical {2. for atmospheric sciences and geophysical fluid dynamics,institute of atmospheric physics,chinese {{12. of sciences,Beijing,10002.,{12.

Associations between spring Arctic sea ice concentrations（SIC） and 1) Eurasian and 2. North American summer rainfall are examined using singular value *** show that a reduced SIC in the north Atlantic and Pacific sectors of the Arctic and an enhanced SIC in much of the central Arctic Basin and Beaufort Sea are accompanied by 1) dry conditions over northern and eastern Europe,Mongolia,and northern and central china,and wet conditions over much of Siberia,western and southern Europe,and Middle East,and 2. dry conditions over the western United States,the northern Great Plains,the Midwest,westernmost Canada,and central and eastern Greenland,and wet conditions over the southern United States,Alaska,northern Canada,and western *** circulation anomalies associated with the SIC variability show wave train structures,which are quite persistent from spring to summer and responsible for the identified covariability between the spring Arctic SIC and 1) Eurasian and 2. North American summer *** relationships suggest a potential long‐term outlook for the 1) Eurasian and 2. North American summer rainfall as the decline of the spring sea ice in the north Atlantic and Pacific sectors of the Arctic is expected to continue associated with greenhouse warming.

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Journal of Hydrodynamics 2004年第5期16卷 501-517页

作者： QIAOFang-li ZHANGShao-qing YUANYe-li instituteofOceanography ChineseAcademyofSciencesQingdao266071China geophysicalfluid{2.Laboratory PrincetonUniversityPrincetonNJ08542USA keyLaboratoryofMarineScienceandNumericalmodeling TheFirstInstituteofOceanographyStateOceanicAdministrationQingdao266061China

The key mathematics and applications of various modern atmospheric/oceanicdata assimilation methods including Optimal Interpolation (OI), 4-dimensional variational approach(4D-Var) and filters were systematically reviewed and classified. Based on the data assimilationphilosophy, i. e. , using model {2. to extract the observational information, the commoncharacter of the problem, such as the probabilistic nature of the evolution of theatmospheric/oceanic system, noisy and irregularly spaced observations, and the advantages anddisadvantages of these data assimilation algorithms, were discussed. In the filtering framework, allmodern data assimilation algorithms were unified: OI/3D-Var is a stationary filter, 4D-Var is alinear (Kalman) filter and an ensemble of Kalman filters is able to construct a nonlinear *** nonlinear filter such as the Ensemble Kalman Filter (EN-KF), Ensemble Adjustment Kalman Filter(EAKF) and Ensemble Transformation Kalman Filter (ETKF) can, to some extent, account for thenon-Gaussian information of the prior distribution from the model. The flow-dependent covarianceestimated by an ensemble filter may be introduced to OI and 4D-Var to improve these traditionalalgorithms. In practice, the performance of algorithms may depend on the specific numerical modeland the choice of algorithm may depend on the specific problem. However, the unification ofalgorithms allows us to establish a unified test system to evaluate these algorithms, which providesmore insights into data assimilation philosophies and helps improve data assimilation techniques.

关键词： data assimilation oceanic/atmospheric system filtering optimalinterpolation (OI) 4-dimensional variational(4D-Var) approach

ENVIRONMENTAL AND TOPOGRAPHIC INFLUENCES ON atmospheric INTERNAL SHIP WAVES

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Journal of Hydrodynamics 2008年第4期20卷 440-447页

作者： ZANG Zeng-liang PAN Xiao-bin ZHANG Ming Department of Martial Meteorology Institute of Meteorology PLA University of Science and TechnologyNanjing 211101 China State key Laboratory of atmospheric {2. and geophysical fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

A theoretical model was used to investigate the influences of environmental and topographic parameters on the atmospheric three-layer internal ship waves. The results show that both the wavelength and the wedge angle decrease with an increase in the Scorer parameter, and the rate of changes in the wavelength and wedge angle are also alike. The results also show that the wedge angle decreases with an increase in the width of mountain, but the wavelength varies little with it. It is suggested that the wedge angle is determined by the ratio of the wavelength to the scale of the mountain. Besides, numerical sensitivity experiments were performed to test the former numerical experiments. The simulated results are consistent with the analytical results.

关键词： Scorer parameter topographic parameter atmospheric internal ship waves numerical simulation

Perturbed solution of sea-air oscillator for the El Nino/ La Nina-Southern Oscillation mechanism

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Acta Oceanologica Sinica 2009年第3期28卷 1-4页

作者： ZHOU Xianchun LIN Yihua WANG Hui MO Jiaqi College of Electronic and Information Engineering Nanjing University of information Science and Technology Nanjing 210044 China Division of Computational Science E-Institutes of Shanghai Universities at SJTU Shanghai 200240 China State key Laboratory of Numerical modeling for {2. sciences and geophysical fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China National Marine Environmental Forecastins Center Beijing 100081 China Department of Mathematics Anhui Normal University Wuhu 241000 China

A class of coupled system of the E1 Nino/La Nina-Southern Oscillation （ENSO） mechanism is studied. Using the perturbed theory, the asymptotic expansions of the solution for ENSO model are obtained and the asymptotic... 详细信息

关键词： nonlinear perturbation theory E1 Nino/La Nina-Southern Oscillation model

Statistical characteristics of the double ridges of subtropical high in the Northern Hemisphere

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Science Bulletin 2005年第20期 82-87页

作者： ZHAN Ruifen1,2.3, LI Jianping1 & HE Jinhai2. 1. State key Laboratory of Numerical modeling for {2. Sci- ences and geophysical fluid dynamics (LASG), institute of Atmos- pheric physics, chinese academy of sciences, Beijing 10002., china 2. Department of {2. sciences, institute of Meteorology, Nan- jing University of Information Science and Technology, Nanjing 2.0044, china 3. Graduate School of the chinese academy of sciences, Beijing 100039, china

The generality and some climatological charac- teristics of the double ridge systems of subtropical high (SH) are investigated statistically by using the daily NCEP/NCAR reanalysis data from 1958 to 1998. The results show that the SH double-ridge event is a common phenomenon in the Northern Hemisphere, with the distinct seasonal and re- gional features, that is, the majority of SH double-ridge geneses concentrate over the eastern North India Ocean- western North Pacific as well as the central North Pacific in the period from mid-July to mid-September. Especially over the western North Pacific subtropics, the SH double-ridge events are extremely active. It is found that the life cycle of most double-ridge events of western Pacific subtropical high (WPSH) is shorter but some still last longer. The WPSH dou- ble-ridge events occur most frequently from July to Septem- ber, while there is a paucity of occurrences during Novem- ber-March. Also, it is shown that the WPSH double-ridge events have a strong interannual variation with a certain periodicity which possesses a remarkably abrupt change in the mid-1970s. Additionally, the relationship between the WPSH double ridges and the meridional movement of WPSH is discussed.

关键词： subtropical high double ridges statistical characteristics meridional movement.

Influences of Typhoon Chanchu on the 2.06 South china Sea summer monsoon onset

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Influences of Typhoon Chanchu on the 2006 South China Sea su...