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Acta meteorologica Sinica 1995年第1期9卷 69-77页

作者：罗哲贤 Nanjing institute of meteorology Nanjing 210044

This paper generalizes the contour dynamics for single ring vortices to that for multiple ring vortices,wherein sixsets of numerical computation are *** phenomenon of the counterclockwise loop of a moving vortex is clearly shown in the computational results and the asymmetric change with time of the vortex structure may serve as a pre-cursor for the ***,we also discuss the dependence of the motion direction of a vortex upon the degreeof its contour denseness,and the dependence of the westward component of vortex motion upon its *** results are fairly consistent with those of previous dynamical analyses and numerical experiments.

关键词： contour dynamics multiple ring vortex Coriolis force nonlinearity

The Interannual Variability of East Asian Winter Monsoon and Its Relation to the Summer Monsoon

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Advances in Atmospheric Sciences 2000年第1期17卷 48-60页

作者：陈文 Han-F.Graf 黄荣辉 institute of Atmospheric Physics Chinese Academy of Sciences China max-planck-institute of meteorology Hamburg Germany

Based on the NCEP/ NCAR reanalysis data the interannual variability of the East Asian winter mon-soon (EAWM) is studied with a newly defined EAWM intensity index. The marked features for a strong (weak) winter monsoon include strong (weak) northerly winds along coastal East Asia, cold (warm) East Asian continent and surrounding sea and warm (cold) ocean from the subtropical central Pacific to the trop-ical western Pacific, high (low) pressure in East Asian continent and low (high) pressure in the adjacent ocean and deep (weak) East Asian trough at 500 hPa. These interannual variations are shown to be closely connected to the SST anomaly in the tropical Pacific, both in the western and eastern Pacific. The results suggest that the strength of the EAWM is mainly influenced by the processes associated with the SST anom-aly over the tropical Pacific. The EAWM generally becomes weak when there is a positive SST anomaly in the tropical eastern Pacific (El Ni?o), and it becomes strong when there is a negative SST anomaly (La Ni?a). Moreover, the SST anomaly in the South China Sea is found to be closely related to the EAWM and may persist to the following summer. Both the circulation at 850 hPa and the rainfall in China confirm the connection between the EAWM and the following East Asian summer monsoon. The possible reason for the recent 1998 summer flood in China is briefly discussed too. Key words East Asian winter monsoon - Interannual variability - SST - Summer monsoon This study was supported by “ National Key Programme for Developing Basic Sciences” G1998040900 part 1, and by key project (KZ 952-S1-404) of Chinese Academy of Sciences.

关键词： East Asian winter monsoon Interannual variability SST Summer monsoon

Changes in Atlantic Thermohaline Circulation under Different Atmospheric CO_2 Scenarios in a Climate Model

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Journal of China University of Geosciences 2006年第4期17卷 326-331页

作者：牟林吴德星陈学恩 institute of Physical Oceanography Ocean University of China Qingdao 266003 China max-planck institute for meteorology Hamburg 20146 Germany

The changes in the thermohaline circulation （THC） because of the increased CO2 in the atmosphere play an important role in future climate regimes. In this article, a new climate model developed at the max-planck institute for meteorology is used to study the variation in THC strength, the changes of North Atlantic deep-water （NADW） formation, and the regional responses of the THC in the North Atlantic to increasing atmospheric CO2. From 2000 to 2100, under increased CO2 scenarios （B1, AIB, and A2）, the strength of THC decreases by 4 Sv （106 m^3/s）, 5.1 Sv, and 5.2 Sv, respectively, equivalent to a reduction of 20%, 25%, and 25.1% of the present THC strength. The analyses show that the oceanic deep convective activity significantly strengthens in the Greenland-leeland-Norway （GIN） Seas owing to saltier （denser） upper oceans, whereas weakens in the Labrador Sea and in the south of the Denmark Strait region （SDSR） because of surface warming and freshening due to global warming. The saltiness of the GIN Seas is mainly caused by the increase of the saline North Atlantic inflow through the Faro-Bank （FB） Channel. Under the scenario A1B, the deep-water formation rate in the North Atlantic decreases from 16.2 Sv to 12.9 Sv with increasing CO2.

关键词： thermohaline circulation (THC) greenhouse gases deepwater.

EVALUATION OF DAILY PRECIPITATION IN CHINA FROM ECMWF AND NCEP REANALYSES

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Chinese Journal of Oceanology and Limnology 2000年第1期18卷 35-41页

作者：崔茂常冯明练树民 institute of Oceanology Chinese Academy of Sciences Qingdao China max-planck institute for meteorology Germany

Correlation analysis, hidden period analysis and complex Morlet wavelet transform were used with daily rainfall in China from observation, ECMWF(European Centre for Medium Range Weather Forecast)and NCEP (National Center for Environmental Prediction) reanalyses to evaluate the validation of precipitation estimates. The results showed that Fisher’s test and wavelet analysis, specially the latter, are useful tools for statistical analysis of daily precipitation datasets. Daily rainfall data obtained from ECMWF reanalysis are obviously better than those from NCEP reanalysis in terms of long period daily mean, local correlation, variation amplitude, fluctuation pattern and frequency. Although there is still room for improvement, ECMWF reanalysis is the best available dataset with global coverage and daily variability. In both of the reanalyzed daily mean precipitation fields, the higher estimations of Sichuan Basin rainfall are most likely caused by the topography of the basin, where small scale mountains in the southeast could not be represented by the reanalysis grid points, the typhoon and summer monsoon rainbelt could reach this region.

关键词： daily precipitation ECMWF and NCEP reanalyses wavelet transform

Decreasing Trend in Global Land Monsoon Precipitation over the Past 50 Years Simulated by a Coupled Climate Model

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Advances in Atmospheric Sciences 2010年第2期27卷 285-292页

作者：李红梅周天军李超 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Graduate University of the Chinese Academy of Sciences International max planck Research School on Earth System Modeling max planck institute for meteorology

The authors examine the effects of external forcing agents such as greenhouse gases （GHGs） and aerosols, as well as solar variability and ozone, on global land monsoon precipitation by using a coupled climate model HadGEM1, which was developed by the Met Office Hadley Centre for Climate Research. The results indicate that HadGEM1 performs well in simulating the observed decreasing trend of global land monsoon precipitation over the past 50 years. This trend mainly occurred in the Northern Hemisphere and is significantly different from the trend of natural variability due to ocean-atmosphere-land interactions. The coherence between the simulation and the observations indicates that the specified external forcing agents, including GHGs and aerosols as well as solar variability and ozone, are important factors that have affected the decreasing trend of global land monsoon precipitation in the past 50 years.

关键词： monsoon precipitation decreasing trend coupled climate model external forcings

Analyses of the predicted changes of the global oceans under the increased greenhouse gases scenarios

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Chinese Science Bulletin 2006年第21期51卷 2651-2656页

作者： MU Lin WU Dexing CHEN Xue'en Jungclaus Physical Oceanography Laboratory Ocean University of ChinaQingdao 266003 China institute of Oceanography Hamburg University Hamburg 20146Germany max-planck institute for meteorology Hamburg 20146 Germany

A new climate model (ECHAM5/MPI-OM1) developed for the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC) at max-planck institute for meteorology is used to study the climate changes under the different increased CO2 scenarios (B1, A1B and A2). Based on the corresponding model results, the sea surface temperature and salinity structure, the variations of the thermohaline circulation (THC) and the changes of sea ice in the northern hemisphere are analyzed. It is concluded that from the year of 2000 to 2100, un- der the B1, A1B and A2 scenarios, the global mean sea surface temperatures (SST) would increase by 2.5℃, 3.5℃ and 4.0℃ respectively, especially in the region of the Arctic, the increase of SST would be even above 10.0℃; the maximal negative value of the variation of the fresh water flux is located in the sub- tropical oceans, while the precipitation in the eastern tropical Pacific increases. The strength of THC de- creases under the B1, A1B and A2 scenarios, and the reductions would be about 20%, 25% and 25.1% of the present THC strength respectively. In the north- ern hemisphere, the area of the sea ice cover would decrease by about 50% under the A1B scenario.

关键词：温室气体 THC 气候模型 IPCC

Dynamic Analogue Initialization for Ensemble Forecasting

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Advances in Atmospheric Sciences 2013年第5期30卷 1406-1420页

作者：李珊容新尧刘赟刘征宇 Klaus FRAEDRICH Department of Atmospheric and Oceanic Sciences School of Physics Peking University Chinese Academy of Meteorological Sciences Center for Climatic Research and Department of Atmospheric and Oceanic Sciences University of Wisconsin-Madison max planck institute for meteorology

This paper introduces a new approach for the initialization of ensemble numerical forecasting： Dynamic Analogue Initialization （DAI）. DAI assumes that the best model state trajectories for the past provide the initial conditions for the best forecasts in the future. As such, DAI performs the ensemble forecast using the best analogues from a full size ensemble. As a pilot study, the Lorenz63 and Lorenz96 models were used to test DAI＇s effectiveness independently. Results showed that DAI can improve the forecast significantly. Especially in lower-dimensional systems, DAI can reduce the forecast RMSE by ~50% compared to the Monte Carlo forecast （MC）. This improvement is because DAI is able to recognize the direction of the analysis error through the embedding process and therefore selects those good trajectories with reduced initial error. Meanwhile, a potential improvement of DAI is also proposed, and that is to find the optimal range of embedding time based on the error＇s growing speed.

关键词： initialization ensemble forecast analogue error growth

Study on Moist Potential Vorticity and Symmetric Instabilityduring a Heavy Rain Event Occurred inthe Jiang-Huai Valleys

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Advances in Atmospheric Sciences 1999年第2期16卷 314-321页

作者：寿绍文李耀辉 Nanjing institute of meteorology Nanjing

In the light of the theory on moist potential vorticity (MPV) investigation was undertaken of the 700 hPa vertical (horizontal) component MP1 (MPV2) for the heavy rain event occurring in July 5–6, 1991. Results show that the distribution features of the two components were closely related to the development of a mesoscale cyclone as a rainstorm-causing weather system in the lower troposphere in such a way that the ambient atmosphere of which MPV1 > 0 and MPV2 < 0 with |MPV1| ≥ |MPV2| favored the genesis of conditional symmetric instability (CSI) and that, as indicated by calculations, a CSI sector was really existent in the lower troposphere during the heavy rain happening and contributed greatly to its development.

关键词： Heavy rain Moist potential vorticity (MPV) Conditional symmetric instability

A STUDY ON THE PRECIPITATION CHARACTERISTICS OVER THE SOUTH CHINA SEA BEFORE AND AFTER THE MONSOON ONSET

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Journal of Tropical meteorology 2012年第1期18卷 1-10页

作者：李耀东宋明坤胡亮 institute of Aviation meteorology institute of meteorology PLA University of Science and Technology National Satellite meteorology Center CMA

This paper presents a study on the temporal and spatial variations of the precipitation over the area of the South China Sea (SCS) during the monsoon onset period. The data used are from the Tropical Rainfall Measuring Mission (TRMM) observations between April and June over the nine years from 1998 to 2006. This study focuses on the central and northern part of South China Sea (110-120°E, 10-20°N). Based on the observations, the 27th pentad is selected as the occurrence time of the SCS monsoon onset. The conclusions are as follows. (1) After the monsoon onset, the specific area, defined as the ratio of the number of pixels with certain type of precipitation to the number of total pixels, extends significantly for both convective and stratiform rain, with the latter having a larger magnitude. The specific rainfall, defined as the ratio of the amount of certain type of precipitation to the total amount of precipitation, decreases for convective rain and increases for stratiform rain. (2) Results also show significant increase in heavy rain and decrease in light rain after the monsoon onset. (3) Changes are also observed in the rainfall horizontal distributions over the SCS before and after the monsoon onset, manifested by the relocation of precipitation minima for both convective and stratiform rain. (4) After the monsoon onset, the variability in characteristics of precipitation vertical structure increases significantly, leading to more latent heat release and consequently deeper convection. Meanwhile, the bright-band altitude of stratiform precipitation is also elevated.

关键词： TRMM South China Sea monsoon onset precipitation

Conversion Characteristics between Barotropic and Baroclinic Circulations of the SAH in Its Seasonal Evolution

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Advances in Atmospheric Sciences 2000年第1期17卷 129-139页

作者：刘宣飞朱乾根郭品文 Nanjing institute of meteorology Nanjing

In the context of 1958–1997 NCEP/ NCAR re-analyses, the South Asia high (SAH) was divided into two components, barotropic and baroclinic, the former based on mass weighed vertical integration and the latter on the difference between the measured circulation and the barotropic component counterpart, whereupon the barotropic and baroclinic circulation conversion features were addressed of the research SAH during its seasonal variation. Evidence suggests that i) in summer (winter), the SAH is a thermal (dynamical) system, with dominant baroclinicity (barotropicity), either of the components accounting for approximately 70% of the total contribution; ii) as time progresses from winter to summer, accompanied by the barotropic SAH evolving into its baroclinic analog, the SAH is moving under the “ thermal guidance” of its baroclinic component circulation, suggesting that the component circulation precedes the system itself in variation; iii) the reversal happens when it goes from summer to winter, with the SAH displacement under the “ dynamic steering” of its barotropic component circulation. Key words SAH (South Asia high) - Barotropic circulation - Baroclinic circulation - Seasonal variation (1)This work is supported by the National Natural Sciences Foundation of China under Grant No.49735170.

关键词： SAH (South Asia high) Barotropic circulation Baroclinic circulation Seasonal variation