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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, {2. 2.National meteorological Center, china meteorological administration, Beijing 100081, {2. 3.Chinese Academy of meteorological Sciences, china meteorological administration, Beijing 100081, {2. Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing China National meteorological Center China Meteorological Administration Beijing China Chinese Academy of meteorological Sciences China Meteorological Administration Beijing 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

Numerical simulation of topography effects on the “00.7” severe rainfall in Beijing

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Progress in Natural Science:Materials International 2005年第9期15卷 818-826页

作者： ZHANG Chaolin1**, JI Chongping1, KUO Yinghwa2. FAN Shuiyong1, XUAN Chunyi3.and CHEN Min1(1. Institute of Urban meteorology,{2., Beijing 100089, china 2. Mesoscale and Microscale meteorology Division, National Center for Atmospheric Research, Boulder, CO 803.7-3.00, USA 3. Beijing meteorological Bureau, Beijing 100089, china) Institute of Urban meteorology China Meteorological Administration Beijing 100089 China Mesoscale and Microscale meteorology Division National Center for Atmospheric Research Boulder CO 80307-3000 United States Beijing meteorological Bureau Beijing 100089 China

In an effort to study the severe rainfall event of 4—5th July 2.00 in Beijing (with 2.h accumulated precipitation of 2.0 mm), we perform numerical simulations to investigate this event using the MM5v3.6 model. The model is initialized with the MM5/WRF 3.VAR analysis, which incorporates the ground-based GPS precipitable water vapor, automatic and conventional {2. observations in its assimilation step. For 2. h accumulated precipitation forecast, the threat scores are 0.72. 0.76, 0.67 and 0.63. for thresholds of 1, 5, 10, and 2. mm, respectively. Holding other factors unchanged, sensitivity experiments were conducted with different topographic resolutions of 110, 50 and 3.7 km to investigate the topographic effects on precipitation over the Beijing area. In these sensitivity experiments, we attempt to preserve the realistic orographic distribution in the model topography under the condition of keeping the dynamic-thermodynamic consistency of the initial model atmosphere to the extent possible. Results indicate that the unique topographic distribution and variations in the Beijing area play an important role in determining the location, distribution and intensity of heavy precipitation.

关键词： topography heavy rainfall 3.VAR ground-based GPS numerical simulation.

Possible mechanism of the effect of convection over Asian-Australian “land bridge” on the East Asian summer monsoon onset

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Science china Earth Sciences 2006年第11期49卷 1223-1232页

作者： HE Jinhai1, WEN Min2. DING Yihui3.& ZHANG Renhe2.1. Jiangsu Key Laboratory of meteorological Disaster (KLME), Nanjing Institute of {2., Nanjing University of Informa- tion Science and Technology, Nanjing 2.0044, china 2. State Key Laboratory of Severe Weather (LaSW), Chinese Academy of meteorological Sciences, Beijing 100081, china 3. National Climate Center, Chinese meteorological administration, Beijing 100081, china Jiangsu Key Laboratory of meteorological Disaster (KLME) Nanjing Institute of Meteorology Nanjing University of Information Science and Technology Nanjing China State Key Laboratory of Severe Weather (LaSW) Chinese Academy of Meteorological Sciences Beijing China National Climate Center Chinese Meteorological Administration Beijing China

The Asian-Australian “land bridge” is an area with the most vigorous convection in Asian monsoon region in boreal spring, where the onset and march of convection are well associated with the onset of East Asian summer monsoon. The convection occurs over Indo-china Peninsula as early as mid-April, which exerts critical impact on the evolution of monsoon circulation. Before mid-April there are primarily sensible heatings to the atmosphere over Indo-china Peninsula and Indian Peninsula, so the apparent heating ratios over them decrease with height. However, after mid-April it changes into latent heating over Indo-china Peninsula due to the onset of convection, and the apparent heating ratio increases with height in mid- and lower troposphere. The vertical distribution of heating ratio and its differences between Indo-china Peninsula and Indian Peninsula are the key factors leading to the splitting of boreal subtropical high belt over the Bay of Bengal. Such mechanism is strongly supported by the fact that the evolution of the vertical heating ratio gradient above Indo-china Peninsula leads that of 850 hPa vorticity over the Bay of Bengal. Convections over Indo-china Peninsula and its surrounding areas further increase after the splitting. Since then, there is a positive feedback lying among the convective heating, the eastward retreat of the subtropical high and the march of monsoon, which is a possible mechanism of the advance of summer monsoon and convection from Indo-china Peninsula to South china Sea.

关键词： Asian-Australian 'land bridge', tropical convection, Indo-china Peninsula, the splitting of boreal subtropical high belt, East Asian summer monsoon onset.

Simulation of 1991-2.05 Meiyu seasons in the Yangtze-Huaihe region using BCC_RegCM 1.0

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Chinese Science Bulletin 2010年第11期55卷 1077-1083页

作者： HU YaMin1,2.3. DING YiHui4 1 Institute of Tropical and Marine meteorology,{2., Guangzhou 510080, china 2.Guangdong Climate Center, Guangzhou 510080, china 3.Chinese Academy of meteorological Sciences, Beijing 100081, china 4 National Climate Center,{2., Beijing 100081, china Institute of Tropical and Marine meteorology China Meteorological Administration Guangzhou China Guangdong Climate Center Guangzhou China Chinese Academy of meteorological Sciences Beijing China National Climate Center China Meteorological Administration Beijing China

By using BCC_RegCM 1.0 (RegCM for short) from Beijing Climate Center (BCC), china meteorological administration (CMA), the Meiyu season characters over the Yangtze-Huaihe region during 1991-2.05 are simulated. The major conclusions of this study may be summarized as the following: (1) RegCM can reproduce the interannual variation and the spatial distribution of the summertime precipitation and temperature in the Yangtze-Huaihe region. (2. By use of a generalized Meiyu criterion and in accordance with model-calculated precipitation and temperature, the Meiyu onset and ending date have been determined. Compared with the observation, RegCM can simulate the interannual variation of the Yangtze-Huaihe Meiyu with preferable capability for most of the normal Meiyu years (such as 1995, 1997, 2.00, 2.01, 2.02.and 2.04), especially for the rich Meiyu years of 1996, 1998 and 1999. (3. In terms of the average simulation for the recent 15 years, the timings of onset and ending of Meiyu occur on June 1 and July 13. respectively, which are earlier than the climatological observation. For duration, Meiyu persists for 3. d, 3.d shorter than the observation. The index of Meiyu intensity is 2.45, while the climatological one is 3.00. Therefore, RegCM is capable of simulating the climatological Meiyu duration and intensity, while the capability of simulating the onset and ending date of Meiyu still needs to be improved.

关键词：梅雨季节模拟计算长江气候观测发病时间强度指数中国气象局空间分布

Urban effects and summer thunderstorms in a tropical cyclone affected situation over Guangzhou city

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Science china Earth Sciences 2007年第12期50卷 1867-1876页

作者： MENG WeiGuang1,3.YAN JingHua1 & HU HaiBo2.1 Institute of Tropical and Marine meteorology,Chinese {2. administration(CMA),Guangzhou 510080,{3. 2.Institute of Urban meteorology,CMA,Beijing 100089,{3. 3.State Key Laboratory of Severe Weather,Chinese Academy of {2. Sciences,Beijing 100081,{3. Institute of Tropical and Marine meteorology Chinese Meteorological Administration (CMA) Guangzhou China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing China Institute of Urban meteorology CMA Beijing China

With data mainly from Guangzhou mesonet Automatic Weather Stations(AWS),Guangzhou Doppler Radar and satellite TBB data,characteristics and evolution of the urban heat island(UHI) over Guang-zhou City were analyzed in a tropical cyclone affected situation for early August *** particular,two thunderstorms occurring during this period respectively at the night of 4 August and in the afternoon of 7 August were investigated to study the relationships between the development of thunderstorms and the *** showed that two thunderstorms were associated with the UHI *** induced local air convergence and initiated the thunderstorm *** cases showed a general agreement in time and space for the locations of maximum UHI,convergence,convection,and *** was found to be more favorable to developing in time periods and locations with stronger intensity of *** also showed that,due to the urban effects,both thunderstorms got strengthened when moving over Guangzhou City,with maximum radar echoes observed right over the urban area and precipitation located within the *** these features reveal that two thunderstorms were urban-induced storms.

关键词： summer thunderstorms, urban heat islands (UHI), urban effects, tropical cyclone

Climate instability in the Yili region, Xinjiang during the last glaciation

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Chinese Science Bulletin 2000年第17期45卷 1604-1609页

作者： YE Wei, DONG Guangrong, YUAN Yujiang & MA Yingjie1. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, urumqi 83.011, {2. 2. Department of Geography, Zhejiang Normal University, Jinhua 3.1004, {2. 3. Institute of {3. Research, Chinese Academy of Sciences, Lanzhou 73.000, {2. 4. Xinjiang Institute of meteorological Research, urumqi 83.002. china Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi China Department of Geography Zhejiang Normal University Jinhua China Institute of desert Research Chinese Academy of Sciences Lanzhou China Xinjiang Institute of meteorological Research Urumqi China

The climate is influenced by westerlies year in year out and the aeolian loess is widespread in the Yili region, the Xinjiang Uygur Autonomous Region. Through the study of the loess section with a thickness of 2..5 m, much useful information about climatic change in this region during the last glaciation was gotten. Grain size analysis of loess samples in the section showed that the climatic change in the Yili region was of instability during the last glaciation and similar to those of the North Atlantic Ocean and Greenland. In correspondence with the Heinrich events, the percentage of the size fraction of loess with grain size less than 10 μm decreased in cold stadials in the Yili region. This result suggests that the westerly wind be strengthened during the cold periods. Compared with the stadials, the content of the loess with grain size less than 10 μm was increased in interstadials, which indicated that the strength of the westerly wind was weakened. It is obvious that the climate was instable

关键词： Yili region last glaciation climate instability.

Persistent anomalous flows over the subtropical western Pacific insummer

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Chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1 and JI Liren\+2.1. National meteorological Centre, china meteorological administration, Beijing 100081, {2. 2. LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100080, {2. National meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western Pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLR anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WPA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

Variations of Snow Temperature and their Influence on Snow Cover Physical Parameters in the Western Tianshan Mountains,china

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Journal of Mountain Science 2011年第6期8卷 827-837页

作者： CHEN Xia WEI WenShou LIU MingZhe GU GuangQin Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Hebei Key Laboratory for meteorology and Eco-environmen Shijiazhuang 050021 China HeBei Climate Center Shijiazhuang 050021 China Institute of desert meteorology China Meteorological Administration Urumqi 830011 China Tianshan Station for Snow-cover and Avalanche Research Chinese Academy of Sciences Urumqi 830011 China

This article discussed about snow temperature variations and their impact on snow cover parameters. Automatic temperature recorders were used to sample at lo-minute intervals at the Tianshan Station for Snow-cover and Avalanche Research, Chinese snow temperature Academy of Sciences. lo-layer and the snow cover parameters were measured by the snow property analyzer （Snow Fork） in its Stable period, Interim period and Snow melting period. Results indicate that the amplitude of the diurnal fluctuation in the temperature during Snow melting period is 1.62.times greater than that during Stable period. Time up to the peak temperature at the snow surface lags behind the peak solar radiation by more than 2.5 hours, and lags behind the peak atmospheric temperature by more than 0.2.hours during all three periods. The optimal fitted function of snow temperature profile becomes more complicated from Stable period to Snow melting period. 2. h temperature profiles in Stable period are the optimal fitted by cubic polynomial equation. In Interim period and Snow melting period, temperature profiles are optimal fitted by exponential equation between sunset and sunrise, and by Fourier function when solar radiation is strong. The vertical gradient in the snow temperature reaches its maximum value at the snow surface for three periods. The peak of this maximum value occurs during Stableperiod, and is 4.46 times greater than during Interim period. The absolute value of temperature gradient is lower than 0.1℃ cm-1 for 3. cm beneath snow surface. Snow temperature and temperature gradient in Stable period-Interim period indirectly cause increase （decrease） of snow density mainly by increasing （decreasing） permittivity. While it dramatically increases its water content to change its permittivity and snow density in Snow melting period.

关键词： Snow temperature Vertical temperaturegradient Optimal fitting function Snow density Western Tianshan Mountains china

Global analysis theory of climate system and its applications

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Chinese Science Bulletin 2003年第10期48卷 1034-1039页

作者： LI Jianping1,2.& CHOU Jifan2.3.1. LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 10002., china 2. Department of Atmospheric Sciences, Lanzhou University, Lanzhou 73.000, china 3. Training Center for china meteorological administration, Beijing 100081, china LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Department of Atmospheric Sciences Lanzhou University Lanzhou 730000 China Training Center for china meteorological administration Beijing 100081 China

The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

关键词：整体分析理论气侯体系应用不定性计算法则气侯科学数字模型