检索结果-南通市图书馆

维普期刊数据库

UNIFICATION AND APPLICATIONS OF MODERN OCEANIC/atmospheric DATA ASSIMILATION ALGORITHMS

在线全文

学校读者我要写书评

暂无评论

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 keylaboratoryofMarineScienceand{2.{2. 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

维普期刊数据库

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

在线全文

学校读者我要写书评

暂无评论

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

第2.届中国气象学会年会

作者： MirongSong Jiping Liu State key {2. of {2. modeling for atmospheric sciences and geophysical fluid dynamics,institute of atmospheric physics,chinese academy of sciences,{12.,10002.,China

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.

关键词：

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

在线全文

cnki会议

学校读者我要写书评

暂无评论

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

“2.10年北京气象学会中青年优秀论文评选”学术研讨会

作者： Jiangyu Mao and Guoxiong Wu 1 State key {2. of {2. modeling for atmospheric sciences and geophysical fluid dynamics(LASG),institute of atmospheric physics,chinese academy of sciences,{12.,China.

This study reveals some unique features associated with the impact of Typhoon Chanchu on the South China Sea(SCS) summer monsoon(SCSSM) onset in *** Typhoon Chanchu entering the SCS in mid-May, southwesterlies were induced over the SCS and its upstream region due to a thermally forced Rossby wave response,leading to a reversal of low-level winds and a positive meridional temperature gradient(MTG) in the upper troposphere over the *** Chanchu thus acted as an immediate trigger for the SCSSM onset,and the onset date was suggested to occur in the third pentad of *** the typhoon landed in the coast of southern China,it still contributed to the establishment of the SCSSM due to warming the air column over the northern SCS,resulting in a persistent positive MTG with the ridge surface tilting northward.

关键词：

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

在线全文

cnki会议

学校读者我要写书评

暂无评论

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 {2. of {2. modeling for atmospheric 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

维普期刊数据库

modeling of Dust Flux to Oceans from Asian Continent

在线全文

学校读者我要写书评

暂无评论

Modeling of Dust Flux to Oceans from Asian Continent

第三届中日韩气象学术会议

作者： Shen Yanbo~(1,2. Shi Guangyu~2.(1.laboratory for Climate Studies,National Climate Center,Center for Wind and Solar Energy Resources Assessment,China Meteorological Administration,beijing,100081 2.S{2. key laboratory of numerical modeling for atmospheric sciences and geophysical fluid dynamics(LASG),{12.,chinese academy sciences,beijing,10002.)

＜正＞Plenty of dust aerosols are blown into atmosphere during the frequent Asian dust *** aerosols have not only direct and indirect climate effects through radiative processes,but also have important influences on the oceanic environment. As dust aerosols carrying nutriments like Fe fall into ocean,they will facilitate oceanic primary *** change in oceanic primary productivities will then cause the change in the flux ofradiatively active gases between ocean and atmosphere and result in the climate change *** the studying of these profound items, estimation of dust flux into oceans is an important *** this report,two schemes and relative observation data are combined to study the dust deposition flux and amount into seas near China from Asian continent during the spring of 2.06.

关键词： Dust aerosol chinese Seas Deposition Flux numerical simulation Aerosol Optical Depth

A Further Investigation on Tropical Indian Ocean Dipole Index

在线全文

cnki会议

学校读者我要写书评

暂无评论

A Further Investigation on Tropical Indian Ocean Dipole Inde...

第三届中日韩气象学术会议

作者： Tan Yanke~1 Du Zhencai~2.Li Chongyin~(1 3) 1 Lab for Applied Geophysics institute of Meteorology PLA University of Science and Technology Nanjing 2.1101 2.Graduate University of {2. beijing 100049 3 State key laboratory of numerical modeling for atmospheric sciences and geophysical {12. dynamics institute of atmospheric physics {2. beijing 10002.

＜正＞The Indian Ocean Dipole（IOD）mode,which is also known as the Indian Ocean Zonal mode,is characterized by an east-west dipole pattern in sea surface temperature （SST）*** SST anomalies are found to be closely associated with changes in surface *** anomalous winds related to IOD raise（deepen）the thermocline in the east（west）that gives rise to a subsurface ***,data analyses revealed that the SST anomalies in the eastern tropical Indian Ocean（TIO）,together with the temperature anomalies above 50m and below 150m in situ,are positively related to the western *** temperature anomalies in subsurface from 50- 150m in the eastern TIO are negatively related to the analogue in the western *** a consequence,the subsurface dipole pattern is much stronger than the mode in the *** fact,the primary modes of SST anomalies are composed by the monopole pattern and *** former with basin wide same sign,are reacts of SST in TIO to ENSO at interannual time scale and to the global warming by the surface thermal fluxes between air and *** latter are dominated by the ocean-atmosphere dynamic *** such a way a new index of IOD are revised in terms of SST anomalies with monopole *** revised index gives a similar structure in surface to the pattern in subsurface,i.e.,the eastern pole exists in the southeast TIO, and the western pole is consisted of two centers off equatorial Indian *** structure implies that the western anomalies are possible Rossby-like response to the eastern *** composite of extreme IOD events shows that the evolutions are rather a local seesaw style oscillation than *** work is supported by China National Natural Science Foundation under grant 40405010.

关键词： air-sea interaction Indian Ocean Dipole anomalous temperature pattern

The relationship between middle stratiform clouds and large scale circulation over eastern China

在线全文

cnki会议

学校读者我要写书评

暂无评论

The relationship between middle stratiform clouds and large ...

中国气象学会2.06年年会“气候变化及其机理和模拟”分会场

作者： Yunying Li1,2.and Hong Gu2. State key {2. of {2. modeling for atmospheric sciences and geophysical fluid dynamics (LASG), institute of atmospheric physics, chinese academy of sciences, {12., China. 2.institute of Meteorology, PLA University of Science and Technology, Nanjing,China.

Eastern China is the globally unique land region with lots of middle stratiform clouds in cold seasons. The distribution of this specific stratiform cloud is determined by three main factors, viz, rel

关键词：

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

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science Bulletin 2005年第20期 82-87页

作者： ZHAN Ruifen1,2.3, LI Jianping1 & HE Jinhai2. 1. State key {2. of {2. modeling for atmospheric Sci- ences and geophysical fluid dynamics (LASG), institute of Atmos- pheric physics, chinese academy of sciences, {12., China 2. Department of atmospheric 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.

Simulation of sea surface temperature changes in the Middle Pliocene warm period and comparison with reconstructions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2011年第9期56卷 892-901页

作者： YAN Qing1,2., ZHANG ZhongShi3,1*, WANG HuiJun1,4, JIANG DaBang1,4,5 & ZHENG WeiPeng6 1 Nansen-Zhu International Research Centre, institute of atmospheric physics, chinese academy of sciences, {2., China 2.Graduate University of chinese academy of sciences, beijing 100049, China 3 Bjerknes Centre for Climate Research, UniResearch, Bergen N-5007, Norway 4 Climate Change Research Center, chinese academy of sciences, {2., China 5 key laboratory of Regional Climate-Environment Research for Temperate East Asia, chinese academy of sciences, {2., China 6 National key laboratory of numerical modeling for atmospheric sciences and geophysical fluid dynamics, institute of atmospheric physics, chinese academy of sciences, {2., China Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of chinese academy of sciences Beijing 100049 China Bjerknes Centre for Climate Research UniResearch Bergen N-5007 Norway Climate Change Research Center Chinese Academy of Sciences Beijing 100029 China key laboratory of Regional Climate-Environment Research for Temperate East Asia Chinese Academy of Sciences Beijing 100029 China National key laboratory of {2. {2. for atmospheric sciences and geophysical fluid dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The Middle Pliocene (ca 3.12.2.97 Ma) is a recent warm period in the Earth’s history. In many respects, the warmth of the Middle Pliocene is similar to the probable warm situation of the late 2.st century predicted by climate models. Understanding the Middle Pliocene climate is important in predicting the future climate with global warming. Here, we used the latest reconstructions for the Middle Pliocene—Pliocene Research Interpretation and Synoptic Mapping (PRISM) version 3—to simulate the Middle Pliocene climate with a fully coupled model Fast Ocean Atmosphere Model. From comparison of the results of simulations with reconstructions, we considered two important scientific topics of Middle Pliocene climate modeling: extreme warming in the subpolar North Atlantic and a permanent El Ni?o in the tropical Pacific. Our simulations illustrate that the global annual mean sea surface temperature (SST) in the Middle Pliocene was about 2.3°C higher than that in the pre-industrial era. The warming was stronger at midand high latitudes than at low latitudes. The simulated SST changes agree with SST reconstructions in PRISM3 data, especially for the North Atlantic, North Pacific and west coast of South America. However, there were still discrepancies between the simulation of the SST and reconstructions for the subpolar North Atlantic and tropical Pacific. In the case of the Atlantic, the weakened meridional overturning circulation in the simulation did not support the reconstruction of the extremely warm condition in the subpolar North Atlantic. In the case of the tropical Pacific, the whole ocean warmed, especially the eastern tropical Pacific, which did not support the permanent El Ni?o suggested by the reconstruction. From evaluation of the modeling and reconstruction, we suggest that the above discrepancies were due to uncertainties in reconstructions, difficulties in paleoclimate modeling and deficiencies of climate models. The discrepancies should be reduced through cons

关键词： Middle Pliocene sea surface temperature permanent El Ni?o numerical modeling extreme warming