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Variations of Winter Precipitation over Southeastern China in Association with the North Atlantic Oscillation

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Journal of meteorological Research 2017年第3期31卷 476-489页

作者： Maoyuan LOU Chao LI Shifeng HAO Juan LIU zhejiang provincial meteorological Observatory zhejiang Institute of meteorological Sciences zhejiang meteorological Service Center

The synoptic-scale winter precipitation variations over southeastem China （22°-32°N, 105°-125°E） and their asso- ciation with the North Atlantic Oscillation （NAO） during 1951-2007 are investigated in this paper. The variability of wintertime precipitation is characterized by meridional displacement of its maximum center. Two precipitation re- gimes, with maximum centers located over the Yangtze and Pearl River basins, are identified via cluster analysis. Time-lagged analyses suggest that the two precipitation regimes are connected with the decaying phases of positive NAO （NAO＋） events of different amplitudes. A strong （medium） NAO＋ event is defined as one when the maximum amplitude of the NAO index exceeds 1.0 （in the range of 0.7-1.0） for at least 4 consecutive days and drops to less than 0.3 within 7 days following the peak index. After the peak of a strong NAO＋, southerly winds expand north- ward to the Yangtze River （about 30°N）, a northeast-southwest-tilted trough migrates to east of Lake Baikal, and cold air intrudes into central eastern China; thus, precipitation is strengthened over the Yangtze River basin where warm and cold air masses converge. In comparison, during the decaying phase of medium NAO＋ events, the south- erly winds are relatively weak, and precipitation tends to be enhanced at lower latitudes （around 25°N）. Further ana- lysis indicates that downstream Rossby-wave propagation may account for the latitudinal expansion of the southerly wind anomalies over the eastern coastal area of China during the decaying phase of NAO＋ events of different strengths.

关键词： precipitation regime North Atlantic Oscillation (NA0) cluster analysis westerly jet stream

A Numerical Study of the Severe Heavy Rainfall Associated with Typhoon Haitang (2005)

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Acta meteorologica Sinica 2008年第2期22卷 224-238页

作者：余贞寿倪东鸿高守亭闵锦忠任鸿翔 Wenzhou meteorological bureau Jiangsu Key Laboratory of meteorological Disaster NUIST Institute of Atmosphelic Physics Chinese Academy of Sciences zhejiang provincial meteorological bureau

Typhoons landing in the central and north of Fujian Province often seriously impact zhejiang Province. Much attention has been given to exceptionally torrential rain in the South/North Yandang mountainous regions in the southeast of zhejiang Province associated with typhoon-landing. Typhoon Haitang （2005） is a typical case of such a category, which landed in Huangqi Town of Lianjiang County in Fujian Province, and meanwhile greatly impacted Southeast zhejiang. A numerical simulation has been performed with the PSU/NCAR non-hydrostatic model MM5V3 to study the torrential rain associated with Typhoon Haitang. The comparison of simulated and observed rainfalls shows that the MM5V3 was able to well simulate not only the intensity but also the locations of severe heavy rain of Typhoon Haitang, especially the locations of the south/north heavy rain center areas in the South/North Yandang mountainous regions. Meanwhile, the diagnostic analysis has been also carried out for better understanding of the severe heavy rain mechanism by using the model output data of high resolution. The diagnostic analysis indicates that the westward tilt of the axis of vorticity from lower layer to upper layer over the south heavy rain center area and the coupled structure of convergence in the lower layer and divergence in the upper level over the north heavy rain center area, were both propitious to stronger upward motion in the layers between the mid and upper atmosphere, and the secondary circulation induced by the vertical shear of the ambient winds further strengthened the upward motion in the heavy rain areas. After Haitang passed through Taiwan Island into the Taiwan Strait, the water vapor east of Taiwan Island was continuously transferred by typhoon circulation towards South Wenzhou, leading to the torrential rainfall in the South Yandang mountainous region south of Wenzhou. Subsequently~ Haitang moved northwards, the water vapor belt east of Taiwan Island slowly advanced northwards,

关键词： typhoon torrential rain vertical shear unstable stratification effect of terrain

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Journal of Tropical Meteorology 2012年第3期18卷 322-331页

作者：钟元潘劲松朱红陈卫锋陈世春梁明珠 zhejiang meteorological Research Institute zhejiang meteorological Observatory Huzhou meteorological bureau

A quantitative scheme is put forward in our work of forecasting the storm rainfall of typhoons for specific *** the initial parameters,weather situations and physical quantities as well as numerical weather prediction products,the scheme constructs multivariate,objective and similarity criteria for environmental factors for the time between the current and forthcoming moment within the domain of *** defining a non-linear similarity index,this work presents a comprehensive assessment of the similarity between historical samples of typhoons and those being forecast in terms of continuous dynamic states under the multivariate criteria in order to identify similar *** historical rainfall records of the similar samples are used to run weighted summarization of the similarity index to determine site-specific and quantitative forecasts of future typhoon *** resembling the typhoon being forecast are selected by defining a non-linear similarity index composed of multiple *** tests have demonstrated that this scheme has positive prediction skill.

关键词： weather forecast forecasting methods typhoon storm precipitation site-specific and quantitative forecast similarity

Spatial Distribution and Temporal Variation of the Winter Wheat Late Frost Disaster in Henan,China

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Acta meteorologica Sinica 2011年第2期25卷 249-259页

作者：张雪芬郑有飞王春乙陈怀亮任振和邹春辉 Nanjing University of Information Science & Technology meteorological Observation Centre of CMA Hainan provincial meteorological bureau Henan provincial meteorological bureau Chinese Academy of meteorological Sciences

The winter wheat late frost disaster（WFD） occurs mainly in the Yellow and Huaihe River area,of which Henan Province covers the most *** is the major area of wheat production in China,but it is severely hit by the *** this study,we construct a WFD index based on the minimum temperature and the winter wheat development period（WDP）.The WFD degrees and days at 30 agrometeorological stations in Henan Province during the period of 1981-2004 are *** the large-scale temporal variation analysis of WFD,the 24-yr WDP observation series is relatively short,so it is expanded by using the relation between the turning green date of winter wheat and the 5-day running mean temperature and that between the stem elongation phase and the effective cumulative temperature above a critical value of 2.5 ℃.The WFD data are also expanded for the last 50 years and are analyzed by using the empirical orthogonal function（EOF） and the Morlet wavelet *** in the spatial distribution and temporal variation of WFD are *** results show that the frequency of WFD is generally high,exceeding 40% in parts of Henan,and exhibits a rising trend in the period of *** variation trend of WFD degrees is similar to that of WFD days,and the areas with higher WFD degrees coincide the areas with more WFD ***,the WFD degree has a greater impact on the winter wheat yield than the WFD *** areas with high WFD degrees lie in the southeast and southwest of Henan,and the areas with low WFD degrees lie in the south of the Huaihe River and parts of western *** variations of the first and second EOF modes of the WFD degree display 16-and quasi-22-yr periodicities,*** areas of high（low） WFD frequency are distributed in the northern Henan and the southwest border of Henan（the northeast Henan and the middle part of southwest Henan）.The temporal variation of the first（second） EOF mode of WFD days exhibits a periodicity（periodicities

关键词： late frost disaster frost index EOF analysis Morlet wavelet analysis

NUMERICAL STUDY OF COLD AIR IMPACT ON RAINFALL REINFORCEMENT ASSOCIATED WITH TROPICAL CYCLONE TALIM(2005):*** OF DIFFERENT COLD AIR INTENSITY

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Journal of Tropical Meteorology 2013年第1期19卷 87-96页

作者：董美莹陈联寿李英程正泉郑沛群 zhejiang Institute of meteorological Sciences State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Guangdong provincial meteorological Observatory zhejiang provincial meteorological Observatory

In 2005,significant rainfall reinforcement and severe disaster was induced by tropical cyclone(TC) Talim after it made landfall on the east of *** analyses show that it has relationship with cold air *** investigating the impact of cold air intensity,we make use of Weather Research and Forecasting(WRF) model,the synthesizer of NCEP/NCAR reanalysis data and Japan regional spectral model data,to carry out numerical *** show that rainfall reinforcement occurs in all *** intensity of cold air can modify the rainfall distribution and intensity *** the rainfall center,the increment maximum of rainfall is twice as large as that of the *** cold air intrusion may result in the strongest rainfall *** cold air intensity can lead to different motion of low-level convergence lines and *** is a good relationship between the rainfall region and the eastern part of the *** one hand,strong cold air weakens the TC intensity by its intrusion into the TC center and results in weak convergence and a convergent zone and a rain band shifted *** the other hand,weak cold air reduces the convergence and moves the convergent zone and rain band *** cold air intrusion maintains strong low-level convergence and high-level divergence,keeping strong upward motion over certain ***,the rain band begins to stagnate and rainfall reinforces abruptly therein.

关键词： numerical study cold air tropical cyclone rainfall reinforcement

Typhoon Vortex Self-Organization in a Baroclinic Environment

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Acta meteorologica Sinica 2009年第5期23卷 539-549页

作者：滕代高罗哲贤余晖李春虎代刊 zhejiang meteorological Observatory Key Laboratory of meteorological Disaters NUIST Laboratory of Typhoon Forecast Technique Shanghai Typhoon Institute of CMA Shandong provincial meteorological bureau National meteorological Center

Self-organization of typhoon vortex in a baroclinic environment is studied based on eight numerical experiments with the fifth-generation Pennsylvania State University/National Center for Atmospheric Research （PSU/NCAR） Mesoscale Model （MM5）. The results show that, when there are only two 400-km-away mesoscale axisymmetric vortices with a radius of 500 km in the initial field, the two vortices move away from each other during co-rotating till the distance between them greater than a critical distance named co-rotating critical distance. Then, they stop co-rotating. The situation is changed when a small vortex with a radius of 80 kin is introduced in between the two vortices in the initial field, with the two initially separated vortices approaching each other during their co-rotation, and finally self-organizing into a typhoon-like vortex consisting of an inner core and spiral bands. This result supports both Zhou Xiuji＇s view in 1994 and the studies in the barotropic framework concerning the interactions between the same and different scales of vortices. Six other experiments are carried out to study the effects of the initial vortex parameters, including the initial position of the small-scale vortex, the distance and intensity of the initially axisymmetric binary mesoscale vortices. It is found that the distance between the initial axisymmetrie mesoscale vortices is the most important parameter that influences the self-organizing process of the final typhoon-like vortex. This conclusion is similar to that obtained from barotropical model experiments.

关键词： self-organization small-scale vortex mesoscale vortex typhoon vortex three-dimensional vortex

Advances in Ecological Applications of Fengyun Satellite Data

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Journal of meteorological Research 2021年第5期35卷 743-758页

作者： Xiuzhen HAN Hao GAO Jun YANG Yachun LI Weicheng GENG National Satellite meteorological Center China Meteorological AdministrationBeijing 100081 Jiangsu Climate Center Jiangsu Provincial Meteorological BureauNanjing 210008

In recent years,the remote sensing based on meteorological satellite observations has become an important tool for assessing global ecological *** the early 2000,Fengyun(FY)satellite data have been widely used to derive the key parameters of ecological environment in *** integrated earth-observation system has been developed in China through using FY satellite data,including retrievals the key ecological parameters as well as to constructions of long-term data records of vegetation index,land surface temperature,net primary production,vegetation health index,and so *** progress has thus been made in the application and service for prevention of air pollution,management and control of ecological redline,ecological monitoring for the Belt and Road Initiative,and assessment of ecological environment for human *** order to monitor the ecological parameters in real time and with a full dynamic coverage,it is necessary to improve the technology in application of ecological remote sensing from meteorological satellites,and further enhance the ecological meteorological service.

关键词： Fengyun satellite ecological environment remote sensing assessing and monitoring operational service

IMPROVEMENT OF NUMERICAL SIMULATION OF TYPHOON RANANIM (0414) BY USING DOPPLER RADAR DATA

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Journal of Tropical Meteorology 2008年第2期14卷 89-92页

作者：余贞寿钟建锋赵放冀春晓 Wenzhou meteorological bureau meteorological Science Research Institute of zhejiang Province

Typhoon Rananim （0414） has been simulated by using the non-hydrostatic Advanced Regional Prediction System （ARPS） from Center of Analysis and Prediction of Storms （CAPS）. The prediction of Rananim has generally been improved with ARPS using the new generation CINRAD Doppler radar data. Numerical experiments with or without using the radar data have shown that model initial fields with the assimilated radar radial velocity data in ARPS can change the wind field at the middle and high levels of the troposphere; fine characteristics of the tropical cyclone （TC） are introduced into the initial wind, the x component of wind speed south of the TC is increased and so is the y component west of it. They lead to improved forecasting of TC tracks for the time after landfall. The field of water vapor mixing ratio, temperature, cloud water mixing ratio and rainwater mixing ratio have also been improved by using radar refiectivity data. The model＇s initial response to the introduction of hydrometeors has been increased. It is shown that horizontal model resolution has a significant impact on intensity forecasts, by greatly improving the forecasting of TC rainfall, and heavy rainstorm of the TC specially, as well as its distribution and variation with time.

关键词： radar data ARPS numerical simulation typhoons heavy rain

ANALYSIS OF RAINSTORMS ASSOCIATED WITH SIMILAR TRACK TROPICAL CYCLONES HAITANG (0505) AND BILIS (0604)

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Journal of Tropical Meteorology 2009年第1期15卷 111-115页

作者：余贞寿陈宣淼倪东鸿冀春晓谢海华 Wenzhou meteorological bureau Yueqin meteorological bureau Key Laboratory of meteorological Disaster of Ministry of Education NUIST zhejiang Institute of meteorological Sciences

It is generally thought that the influence of comparable track typhoons is approximately similar, but in fact their wind and especially their rainstorm distribution are often very different. Therefore, a contrastive analysis of rainstorms by tropical cyclones (TCs) Haitang (0505) and Bilis (0604), which are of a similar track, is designed to help understand the mechanism of the TC rainstorm and to improve forecasting skills. The daily rainfall of TC Haitang (0505) and Bilis (0604) is diagnosed and compared. The result indicates that these two TCs have similar precipitation distribution before landfall but different precipitation characteristics after landfall. Using NCEP/GFS analysis data, the synoptic situation is analyzed; water vapor transportation is discussed regarding the calculated water vapor flux and divergence. The results show that the heavy rainfall in the zhejiang and Fujian Provinces associated with Haitang (0505) and Bilis (0604) before landfall results from a peripheral easterly wind, a combination of the tropical cyclone and the terrain. After landfall and moving far inland of the storm, the precipitation of Haitang is caused by water vapor convergence carried by its own circulation; it is much weaker than that in the coastal area. One of the important contributing factors to heavy rainstorms in southeast zhejiang is a southeast jet stream, which is maintained over the southeast coast. In contrast, the South China Sea monsoon circulation transports large amounts of water vapor into Bilis – when a water-vapor transport belt south of the tropical cyclone significantly strengthens – which strengthens the transport. Then, it causes water vapor flux to converge on the south side of Bilis and diverge on the north side. Precipitation is much stronger on the south side than that on the north side. After Bilis travels far inland, the cold air guided by a north trough travels into the TC and remarkably enhances precipitation. In summary, combining vertical wi

关键词： weather forecast tropical cyclones typhoon rainstorms similar tracks water vapor flux vertical wind shear