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Annual precipitation fields secular variation over global land areas for 1948—2000

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Chinese Science Bulletin 2003年第3期48卷 281-286页

作者： SHI Neng & CHEN Luweng Department of Atmospheric Sciences, nanjing institute of meteorology, nanjing 2..044, china Department of Atmospheric Sciences Nanjing Institute of Meteorology Nanjing 210044 China

The secular variation over the global land an-nual precipitation (GLAP) fields for 1948—2000 is investi-gated. Evidence suggests that the GLAP abruptly reduced around 1978 and experienced a decrease of 0.54 mm/a, on average. Fuzzy clustering is used to group the annual pre-cipitation over commonly-used 36 latitudes belts into six belts for examining its secular variation. The results show that, except northern high-latitudes (60°—90°N) where it is slightly increased, the precipitation is decreased, especially in 35°N—35°S, and the diminution is the maximum of 0.98 mm/a at tropics. Moreover, identification of 1948—2000 flood/drought years on a global basis is made, showing no-ticeable interdecadal variations. During the years of warm (cold) events the precipitation decreases (increases) by 15.4 mm (14.4 mm) per year, on average. It can be assumed that global warming and frequent ENSO occurrences from the end of the 1970s maybe serve as the root cause of the dimi-nution.

关键词：全球降水长期变化年降水 ENSO 陆地 1948-2000年

Zonal propagation of kinetic energy and convection in the South china Sea and Indian monsoon regions in boreal summer

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Science china Earth Sciences 2004年第12期47卷 1076-1084页

作者： CHEN Longxun 1 ,GAO Hui 2 ,HE Jinhai 2 ,TAO Shiyan 3 & JIN Zuhui 3 1.Chinese Academy of Meteorological Sciences,Beijing 100081,china 2..anjing institute of meteorology,nanjing 2..044,china 3.institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,china Chinese Academy of Meteorological Sciences Beijing China nanjing institute of meteorology Nanjing China Chinese Academy of Sciences Institute of Atmospheric Physics Beijing China

Zonal propagation of kinetic energy (KE) and convection in the South china Sea (SCS) and Indian summer monsoon areas are examined in present study. Results suggest that the SCS and Indian summer monsoon prevailed regions (5 —15°N) are dominated by the southwesterly wind, however, the disturbances of KE at 850 hPa and convection are observed mainly coming from the western Pacific Ocean (140—150°E), after passing through the SCS, and westward propagated into the Bay of Bengal (90—100°E). In the Indian summer monsoon domain, where the disturbances of KE are found mainly coming from the Arabian Sea (AS) and eastward propagated into the Bay of Bengal. Therefore, the SCS and the Indian summer mon- soon are quite different in zonal propagation of KE and convection. The SCS summer monsoon is mainly affected by the KE and convection coming from the tropical western Pacific. The Indian summer monsoon, however, can be partly influenced by the AS and the SCS summer monsoon. The analysis also suggests that the interaction region between the SCS and the Indian summer monsoon is around 90—95°E, rather than 105°E as proposed by earlier studies.

关键词： zonal propagation of KE and convection, East Asian monsoon, Indian monsoon.

APPLICATION　OF　MILES－HOWARD　THEOREM　TO　STUDY　THE　INSTABILITY　OF　ATMOSPHERIC　GRAVITY　WAVES　ON　A　HETEROGENEOUS　ORTHOGONAL　SHEAR　FLOW

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Journal of Hydrodynamics 1996年第3期8卷 17-24页

作者： Sun Li-tan (Air Force institute of meteorology, nanjing 211101, P. R. china) Air Force Inst of meteorology Nanjing China

The instability of heterogenous orthogonal shear flow with free surface boundary condition is investigated in this paper, and the distribution law of frequency on the complex coordinated plane is also given. The result shows that the existence of free surface make it more difficult to satisfy the sufficient condition for instability and further more the complex frequency is limited in a semi-ellipse inside the Howard Semi-circle,with its maximum axis coinciding on the diameter of Howard Semi-circle, while the minimum axis depending upon the wave number, free surface condition, flow shear and the angle between the shear vector and the wave number vector.

关键词： stratified flow shear flow instability

Estimation of annual actual evapotranspiration from nonsaturated land surfaces with conventional meteorological data

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Science china Earth Sciences 2004年第3期47卷 239-246页

作者： QIU Xinfa1, ZENG Yan2, MIAO Qilong1 & YU Qiang2 1. Department of Geography, nanjing institute of meteorology, nanjing 2..044, china 2. institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, china Department of Geography Nanjing Institute of Meteorology Nanjing 210044 China Inst. of Geogr. Sci./Nat. Rsrc. Res. Chinese Academy of Sciences Beijing 100101 China

Views diverge greatly on the relationship between actual evapotranspiration (AE) and potential evapotranspiration (PE). Penman showed that AE is determined in intensity by PE and changes proportionally as a function of PE. In contrast, Bouchet indicated that AE deter-mines PE and varies inversely with PE. Based on nearly 30 years data from 432 weather stations and 512 hydrological stations in china, the two different theories, Penman抯 assumption and Bouchet抯 complementary relationship between AE and PE, were tested on nine river basins. With data integration technique, the complementary relationship between AE and PE was dis-played entirely. A general model to estimate the actual evapotranspiration from nonsaturated surfaces by routine meteorological observations has been established on the basis of thorough analysis of the concept of PE. The results show that the calculations are all in error control of <10%, except for a few years over the Yellow River Basin.

关键词： complementary relationship of evapotranspiration, potential evapotranspiration, actual evapotranspiration.

Possible effect of climate changes on the coastal zone of the Yangtze River Delta

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Journal of Geographical Sciences 1998年第1期8卷 42-51页

作者： Miao Qilong nanjing institute of meteorology, nanjing 2..044, china

A coastal historical evolution of the Yangtze River Delta was discussed in this paper on the basis of the historical data of the coastal zone and an estimation was made for the future change of the coast The emphasis was put on the future climate change that will have influence on the sea wall, coastal navigation and freshwater resources in the Delta It was also pointed out that the global warming and precipitation increase in the Yangtze River Valley may exert more impact on the zone In addition, some measures describing how to adapt to the climate change and reduce its impact were put forward

关键词： climate change greenhouse effect sea surface rising the Yangtze River Delta coastal zone

EXPLICIT SIMULATION ON THE TRACK AND INTENSITY OF TROPICAL CYCLONE WINNIE (1997)

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Journal of Hydrodynamics 2006年第6期18卷 736-741页

作者： ZHONG Zhong ZHANG Jirl-shan institute of meteorology PLA University of Science and Technology Nanjing 211101 China nanjing Hydraulic Research institute Nanjing 210029 China

An explicit simulation of the tropical cyclone Winnie （1997） was conducted by use of a triply-nested 3-D nonhydrostatic mesoscale model MM5, before and after its landfall. The simulated results show that the model can well reproduce the track of Winnie （1997） with a BOGUS storm-like vortex inserted in the large-scale first-guess field at the initial model time. The mean track error in a 6 h interval is 54.5 km, which is much less than that obtained with the operational prediction. Comparisons between simulation and observation near the landfall place show that the main temporal variation features of sea level pressure and surface wind speed can also be successfully captured. The characteristics of the eyewall, the spiral cloud band and the corresponding precipitation were disclosed, and the applications of the model outputs were also discussed.

关键词： tropical cyclone simulation track intensity,eyewall spiral cloud band storm surge

GENERALIZED VARIATIONAL OPTI MAZATION ANALYSIS FOR2-D FLOW FIELD

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Journal of Hydrodynamics 2005年第4期17卷 459-465页

作者： HUANG Si-xun XU Ding-hua LAN Wei-ren TENG Jia-jun institute of meteorology PLA University of Science and Technology Nanjing 211101 China LMSWE Nanjing University Nanjing 210093 China LMSWE Nanjing University Nanjing 210093 China East china Technology institute Fuzhou 344000 China institute of meteorology PLA University of Science and Technology Nanjing 211101 China

The Variational Optimization Analysis Method （VOAM） for 2-D flow field suggested by Sasaki was reviewed first. It is known that the VOAM can he used efficiently in most cases. However, in the cases where there are high frequency noises in 2-D flow field, it appears to be inefficient. In the present paper, based on Sasaki＇s VOAM, a Generalized Variational Optimization Analysis Method （GVOAM） was proposed with regularization ideas, which could deal well with flow fields containing high frequency noises. A numerical test shows that observational data can be both variationally optimized and filtered, and therefore the GVOAM is an efficient method.

关键词： variational optimization analysis regularization methods generalized variational optimization analysis

A SEMI-CIRCLE THEOREM FOR UNSTABLE PERTURBATION IN TROPICAL CYCLONE-SCALE VORTICLES

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Journal of Hydrodynamics 2009年第4期21卷 473-481页

作者： HUANG Hong ZHANG Ming XU Ming institute of meteorology PLA University of Science and Technology Nanjing 211101 China Shanghai Typhoon institute China Meteorological Administration Shanghai 200030 China Laboratory of Typhoon Forecast Technique/CMA Shanghai 200030 China

In this paper, we discusses the spectrum distribution of baroclinic disturbances in tropical cyclone-scale vortices with the assumption that the basic flow does not vary with height. The semi-circle theorem for the unstable perturbation is obtained and the upper bound of growth rate can be estimated. The upper bound of instability growth rate increases with the increase of the maximum basic-state tangential wind speed, angular speed, inertial parameter, absolute vorticity, radial gradient of absolute vorticity and static stability. The upper bound of instability growth rate is greater for vortices of larger horizontal scale and smaller vertical scale and lower wave-number disturbances.

关键词： tropical cyclone-scale vortex spiral bands instability semi-circle theorem

Influence of interannual variability of Antarctic oscillation on mei-yu along the Yangtze and Huaihe River valley and its importance to prediction

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Chinese Science Bulletin 2003年第S2期48卷 61-67页

作者： GAO Hui~(1,2), XUE Feng~1 WANG Huijun~1 1. institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, china 2. Department of Atmospheric Sciences, nanjing institute of meteorology, nanjing 2..044. china Chinese Acad Sci Inst Atmospher Phys Beijing 100029 Peoples R China nanjing Inst Meteorol Dept Atmospher Sci Nanjing 210044 Peoples R China

Both correlation analysis and case study indi-cate that Antarctic oscillation (AAO) is closely related withsummer rainfall in eastern china. When AAO is stronger inboreal spring, especially in May, there is more mei-yu rain-fall in summer with a longer period along the Yangtze andHuaihe River valley. In contrast, there is less rainfall with ashorter period corresponding to a weaker AAO. Besides, ananomalous AAO changes the position and intensity of severalcirculation systems, which are important to summer rainfallalong the Yangtze and Huaihe River valley. Furthermore, theAntarctic sea ice is negatively correlated with the intensity ofAAO with a 6-month leading time. The result in this studyprovides a new method for the prediction of mei-yu.

关键词： Antarctic oscillation interannual variability mei-yu Antarctic sea ice.