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Relationship between the Asian-Pacific oscillation and the tropical cyclone frequency in the western North Pacific

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Science china Earth sciences 2008年第3期51卷 380-385页

作者： ZHOU BoTao1, CUI Xuan2 & ZHAO Ping3 1 Laboratory for Climate Studies, National Climate Center, china meteorological Administration, beijing 100081, china 2 National meteorological Center, china meteorological Administration, beijing 100081, china 3 chinese academy of meteorological sciences, china meteorological Administration, beijing 100081, china 1. Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing 100081 China 2. National meteorological Center China Meteorological Administration Beijing 100081 China 3. chinese academy of meteorological sciences China Meteorological Administration Beijing 100081 China

The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of ob- served data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale at- mospheric general circulation changes underlying the linkage between APO and the WNP tropical cy- clone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable envi- ronment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.

关键词： Asian-Pacific oscillation western North Pacific tropical cyclone atmospheric circulation

An integrative estimation model of summer rainfall-band patterns in china

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Progress in Natural Science:Materials International 2007年第3期17卷 280-288页

作者： WEI Fengying (State Key Laboratory of Severe Weather, chinese academy of meteorological sciences, beijing 100081, china) State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

Three variation indices are defined to objectively and quantitatively represent fluctuations of three rainfall-band patterns in summers in china for the period from 1951 to 2005, and the variation features of these indices are analyzed on both of interdecadal and interannual scales. A new method is proposed to establish an integrative estimation model based on the analysis of rainfall-band indices, and the model is applied to air, ocean factors to estimate their roles on variations of three rainfall-band patterns on different time-scales. The tests of estimation effects show that the fluctuations of three rainfall-band patterns are composed of variations on both significant inter-decadal and interannual scales, of which the interannual variation is mainly influenced by the Elnino/Lanina events, the East Asia monsoon and the ridge locations of subtropical high pressures in western pacific, while the interdecadal variation is mainly controlled by the Pacific decadal oscillation and interdecadal oscillations of the Arctic oscillation, ENSO, Nino3 sea surface temperature and summer monsoon. The estimated results from the integrative estimation model of rainfall-band patterns suggest that the way of estimation first according to each time scale of both the interdecadal and interannual scales, then estimating with an integration, which is proposed in this paper, has an obvious improvement on that without separation of time scales.

关键词： rainfall-band pattern interannual variation interdecadal variation integration estimation model.

An integrated decision method for prediction of tropical cyclone movement by using genetic algorithm

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Science china Earth sciences 2005年第3期48卷 429-440页

作者： YANG Yuanqin1 & WANG Jizhi2 1. National meteorological Center, beijing 100081,china 2. chinese academy of meteorological sciences, beijing 100081, china 1. National meteorological Center 100081 Beijing China 2. chinese academy of meteorological sciences 100081 Beijing China

In this study an integrated decision method for the multi-prediction results of tropical cyclone movements by using genetic algorithm (GA) has been adopted. A genetic learning artifi- cial neural network (GLANN) as a learning mechanism for track prediction was developed through training with the huge samples of typhoon tracks from 1884 to 2002. The prediction of typhoon motion is to consider how to suit the dynamic change of environment, where typhoon passed through. The neural network structure is described by GA. A fitness function for choice of GA is given to approach the maximum of fitness (the minimum of the errors). Parallel comparing analyses for prediction abilities of unusual typhoon tracks in recent years by GLANN with multi-forecast methods were conducted. More types of cases were employed in the comparing analyses, which consist of the typhoon, Winnie, No.11, in 1997, characterized by a long life over the ocean and in the mainland with severe effect on china, the 10 unusual typhoon tracks in the 1990s, the tracks with landfall and affected action in 1998 and the typhoons born in the Northwestern Pacific and the South china Sea in 2000, including the 24—48 h forecast, etc. The results indicated that for prediction ability of typhoon tracks, specially for unusual typhoons, GA decision-making developed in this study is superior to the others.

关键词： genetic algorithm, integrated decision, prediction of tropical cyclone.

Numerical experiments for the impacts of temperature and precipitation variation on the growth and development of winter wheat

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Journal of Environmental sciences 1993年第2期5卷 194-200页

作者： Zhang YuAgrometeorological Research Center, chinese academy of meteorological sciences, beijing 100081, china Agrometeorological Research Center Chinese Academy of Meteorological Sciences Beijing 10081 China. China

The growth process of winter wheat was simulated by CERES-wheat model assuming the daily temperature increase -1, 0,1, 2℃ and daily precipitation increase -20, -10, -5, 0, 5, 10, and 20 percent, respectively. The case study site is Zhenjiang City of Jiangsu Province in the east china. Simulation results show that the impacts of temperature variation on winter wheat is stronger than that of precipitation. Climate warming would speed development rate and shorten phonological period. In general, the adverse effect of climate change on grain yield is greater than that of its beneficial effect, especially when the climate becoming cooler and dryer. The increase of temperature and decrease of precipitation would reduce the plant extractablc soil water content.

关键词： climate change winter wheat CERES-wheat model.

Interdecadal trend turning of global terrestrial temperature and precipitation during 1951-2002

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Progress in Natural Science:Materials International 2008年第11期18卷 1383-1393页

作者： Xiaohui Shi Xiangde Xu State Key Laboratory of Severe Weather,chinese academy of meteorological sciences,beijing 100081,china State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

A grid-by-grid counting of interdecadal trend turning(ITT)of annual mean surface air temperature(SAT)and total precipitation at 67,359 terrestrial grids in the period 1951-2002 is *** analysis of the last ITTs of SAT and total precipitation in the period,in the context of both occurrence time and linear trends after the breakpoint,indicates that a warming trend has become highly significant across most reagent of the world in the late 20th *** terrestrial grids have recorded an ITT of total precipitation in either the 1970s or 1980s,and 45.7% of the terrestrial grids in the study have seen a decreasing trend in total annual precipitation after the break- point,with the remaining 54.3% having experienced an increasing ***,global terrestrial regions have experienced either an increasingly warm and dry climate or an increasingly warm and wet *** analysis of ITT of regional mean SAT and total pre- cipitation in 22 regions shows that the Northern American continent has become increasingly warm and dry after the last interdecadal ***,the African continent has become increasingly warm and wet,with both Europe and most of Asia having the same *** South America and the West of Australia have experienced an opposite trend in climate,becoming increasingly cold and wet.

关键词： Global terrene Surface air temperature Precipitation Interdecadal trend turning

Simulated seasonal movement of precipitation zone in rainy season over china and its change on CO_2-doubling

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Journal of Environmental sciences 1993年第2期5卷 150-157页

作者： Cao Hongxingchinese academy of meteorological sciences, beijing 100081, china chinese academy of meteorological sciences Beijing 10081 China. China

In this paper, an investigation of simulated monthly precipitations from April to September is made. Though the precipitations are sometimes overestimated or underestimated, the geographical advance and recession of precipitation zones are well simulated by the UKMO global climate model with a simple mixed-layer ocean. Main characteristics of large-scale precipitation distribution are changed less on CO2-doubling, but the change is significant in some regions. The change in precipitation threatens us while the dry region is imposed by rainfall defect or the wet region by abundant rainfall induced by CO2-doubling.

关键词： greenhouse effect carbon dioxide change climate simulation.

Analysis of 1989/1990 main physical fields for air-sea coupled system in the tropical western Pacific

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Acta Oceanologica Sinica 1993年第1期12卷 93-105页

作者： Yao Huadong Jiang Dayong and Liu Yimin chinese academy of meteorological sciences, beijing 100081, china chinese academy of meteorological sciences Beijing 100081 China China

In this paper, the marine ship observation data sets in the seventh (October 16-December 4. 1989) and eighth (June 1-July 16, 1990) cruises of PRC -US tropical ocean and global atmosphere (TOGA) joint scientific investigation in the tropical western Pacific are used to analyze the elements such as sea surface temperature (SST), surface wind field, fluxes and net heat budget, which are important physical parameters of underlying earth's surface influencing the global mean circulation evolution on seasonal and interannual time scales. These diagnostic analyses are very beneficial to the understanding of the regional climate characteristics and the air-sea interaction mechanism, and the improving of surface flux parameterizations and regional or global climate model.

关键词： Analysis of 1989/1990 main physical fields for air-sea coupled system in the tropical western Pacific Nino

A comparative analysis on two solar proton events

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chinese Science Bulletin 2007年第1期52卷 47-51页

作者： LE GuiMing1,2,3,4, HAN YanBen2 & ZHANG YiJun3 1 Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, china meteorological Administration, beijing 100081, china 2 National Astronomical Observatories, chinese academy of sciences, beijing 100012, china 3 chinese academy of meteorological sciences, china meteorological Administration, beijing 100081, china 4 National Center for Space Weather, china meteorological Administration, beijing 100081, china Key Laboratory of Radiometric Calibration and Validation for EnvironmentalSatellites China Meteorological Administration Beijing 100081 China

This paper presents a comparative analysis on the two Solar Proton Events (SPE), which occurred on 14 July 2000 (Bastille Day) and 28 October 2003 (28OCT03) respectively. It is found that although the peak flux of the latter seemed to be greater than that of the former based on geostationary observations, the maximum intensities of the energetic protons (>10 MeV and 30 MeV) during the Bastille Day event were all higher than those of the 28OCT03 event according to the interplanetary observations. Further analysis indicated that the quantity of the seed particles, which could be accelerated to the energies exceeding 10 and 30 MeV by the Coronal Mass Ejection (CME)-driven shock on 14 July 2000, was far larger than that of the 28OCT03 event. In the Bastille Day case, when the CME approached to the height around 14 R⊙, the CME-driven shock would reach its maximum capacity in accelerating the solar en- ergetic protons (>100 MeV). In contrast, on 28 October 2003, when CME approached to the height about 58R⊙, the CME-driven shock reached its highest potential in accelerating the solar energetic protons of the same category. At this moment, the peak flux (>100 MeV) was about 155 pfu, which was much lower than 355 pfu measured on 14 July 2000. This demonstrated that in the Bastille Day event, the quantity of the seed particles, which could be accelerated to the energy beyond 100 MeV, was significantly larger than its counterpart in the 28OCT03 case. Therefore, the peak flux of an SPE event depends not only on the interplanetary intensity of the solar energetic particles, but also on the velocity of the associated CME-driven shock, and the quantity of the seed particles as well as on the interplanetary magnetic en- vironment. This paper also reveals that the magnetic sheath associated with ICME on 28 October 2003 captured a large number of solar energetic protons, including those having energy greater than 100 MeV.

关键词：太阳质子 CME 太阳耀斑太阳系

The least-square method in complex number domain

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Progress in Natural Science:Materials International 2006年第3期16卷 307-312页

作者： GU Xiangqian, KANG Hongwen and CAO Hongxing (State Key Laboratory of Severe Weather, chinese academy of meteorological sciences, beijing 100081, china) [a]State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing China

The classical least-square method was extended from the real number into the complex number domain, which is called the complex least-square method. The mathematical derivation and its applications show that the complex least-square method is different from one that the real number and the imaginary number are separately calculated with the classical least-square, by which the actual least-square estimation cannot be obtained in practice. Applications of this new method to an arbitrarily given series and to the precipitation in rainy season at 160 meteorological stations in china mainland show advantages of this method over other conventional statistical models.

关键词： complex least square Fourier transformation forecast in rainy season.