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Simulation of 1991-2005 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, China meteorological administration, Guangzhou 510080, China 2 Guangdong Climate Center, Guangzhou 510080, China 3 Chinese Academy of meteorological Sciences, Beijing 100081, China 4.National Climate Center, China meteorological administration, Beijing 100081, China institute of Tropical and Marine meteorology China Meteorological Administration Guangzhou 510080 China Guangdong Climate Center Guangzhou 510080 China Chinese Academy of meteorological Sciences Beijing 100081 China National Climate Center China Meteorological Administration Beijing 100081 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 1991-2005 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, 2000, 2001, 2002 and 2004., 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 32 d, 3 d shorter than the observation. The index of Meiyu intensity is 2.4., 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

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. 22 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 4.4. times greater than during Interim period. The absolute value of temperature gradient is lower than 0.1℃ cm-1 for 30 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

Growth characteristics and response to climate change of Larix Miller tree-ring in China

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Science China Earth Sciences 2010年第6期53卷 871-879页

作者： SUN Yu1,4. WANG LiLi1,2,3, CHEN Jin5, DUAN JianPing1,4. SHAO XueMei1,2 & CHEN KeLong6 1 institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2 institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 3 institute of desert and meteorology, China meteorological {4., urumqi 830002. China 4.Graduate University of Chinese Academy of Sciences, Beijing 10004., China 5 institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 10004., China 6 School of Life and Geography Sciences, Qinghai Normal University, Xining 810008, China 1. institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China4. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China3. Institute of Desert and Meteorology China Meteorological Administration Urumqi 830002 China5. Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China6. School of Life and Geography Sciences Qinghai Normal University Xining 810008 China

As one of the earliest species used in dendrochronological studies, Larix responds sensitively to climate change. In this study, nine larch species and one variety from eleven sites were collected to study the growth characteristics of tree-ring width using dendrochronological methods. Ten residual tree-ring chronologies were developed to analyze their relationships with regional standardized anomaly series by Pearson’s correlation analysis. The results suggest that most of the chronologies had significantly positive correlations with the mean temperature and mean maximum temperature in May. The spring temperature evidently limited the radial growth of the larch species without precipitation control. The largest mean tree-ring width was found in Himalayan Larch in Jilong, whereas Master Larch in Si’er reflected the smallest mean value. Both species presented little climate information in this study. Chinese, Potanin, and Tibetan larches are significantly correlated with climate change, implying a huge potential for climate history reconstruction. The elevation of the sampling sites appears to be an important condition for tree-ring growth of larches responding to climate factors.

关键词： Larix Miller tree-ring climate change mean temperature in May

Reconstructing mean maximum temperature of growing season from the maximum density of the Schrenk Spruce in Yili,Xinjiang,China

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Chinese Science Bulletin 2009年第13期54卷 2300-2308页

To study the historical temperature variation in Yili of Xinjiang,the tree-ring chronologies of maximum density(MXD) and tree-ring width(TRW) were established with the Schrenk Spruce(Picea schrenkiana *** Mey) collected from six sites to analyze the characteristics and ability of response to climate *** results suggest that the MXD chronology of the Schrenk Spruce from different sampling sites responded to climate change well and were positively correlated with the mean maximum temperature and the mean temperature from April to August in the study *** mean maximum temperature anomaly from April to August,spanning the years from 184. to 2000,was reconstructed by three MXD chronologies which were selected by stepwise *** reconstructed function was stable and explained 56.2% of the *** reconstructed results indicated a cold span of 153 years in spring and summer from the beginning of the 1950s to the beginning of the 1970s in the Yili *** strongly increasing tendency was detected in the mean maximum temperature anomaly from April to August during this reconstructed period.

关键词：平均最高气温伊犁谷地最大密度云杉胡杨生长季节新疆树木年轮宽度

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 meteorological administration(CMA),Guangzhou 510080,China 2 institute of Urban meteorology,CMA,Beijing 100089,China 3 State Key Laboratory of Severe Weather,Chinese Academy of meteorological Sciences,Beijing 100081,China 1. institute of Tropical and Marine meteorology Chinese Meteorological Administration (CMA) Guangzhou 510080 China 3. State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China 2. institute of Urban meteorology CMA Beijing 100089 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

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, China meteorological administration, Beijing 100089, China 2. Mesoscale and Microscale meteorology Division, National Center for Atmospheric Research, Boulder, CO 80307-3000, 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 USA. Beijing meteorological Bureau Beijing 100089 China

In an effort to study the severe rainfall event of 4.5th July 2000 in Beijing (with 24. accumulated precipitation of 24. mm), we perform numerical simulations to investigate this event using the MM5v3.6 model. The model is initialized with the MM5/WRF 3DVAR analysis, which incorporates the ground-based GPS precipitable water vapor, automatic and conventional meteorological observations in its assimilation step. For 24.h accumulated precipitation forecast, the threat scores are 0.72, 0.76, 0.67 and 0.63, for thresholds of 1, 5, 10, and 20 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 3DVAR ground-based GPS numerical simulation.

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

An Examination of Boundary Layer Structure under the Influence of the Gap Winds in urumqi,China,during Air Pollution Episode in Winter

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An Examination of Boundary Layer Structure under the Influen...

An improvement on summer regional climate simulation over East China: Importance of data assimilation of soil moisture

强化科技基础推进气象现代化——第29届中国气象学会年会

作者： Xia Li institute of desert meteorology,urumqi,China meteorology administration,China LAGEO,institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing,China Mailing address:No.4.,Jianguo Road,urumqi,Xinjiang,China,830002.Xiangao Xia LAGEO,institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing,China Yu Xin Xinjiang Climatic Center,urumqi,China Yufen Ma institute of desert meteorology,urumqi,China meteorology administration,China Jing Yang Xinjiang meteorological Science and Technological Service Center Jinglin Li Xinjiang Information Center of Developing Agriculture Network,urumqi,China Xinghua Yang institute of desert meteorology,urumqi,China meteorology administration,China

Tethered-sonde measurements of atmospheric profiles were performed at Urumuqi,capital of the Xinjiang Uyghur Autonomous Region of China,from 29 December 2008 to 14.January *** data were used to examine the boundary layer structure during this severe air pollution *** evolution of local wind flow near urumqi was simulated using the fifth-generation Pennsylvania State University-NCAR Mesoscale Model(MM5).Measurements from Operational radiosonde data showed that a southeasterly elevated low-level jet often intruded upon urumqi through the middle Tianshan Mountain pass to the south of the *** tethered-sonde measurements showed that calm and northwesterly winds prevailed near the surface in urumqi,while the southeasterly winds of relatively higher speed were dominant above 00 *** temperature inversion and humidity inversion frequently occur during day and *** inversion intensity could sharply rise as the stronger elevated southeasterly gales(ESEGs) *** simulations showed that the winds near the surface around urumqi remained calm during nighttime and developed toward the mountains during *** cool air flow in the basin confronted the southeasterly winds from the pass in the lower layer,they formed a convergence line around urumqi city,which was not favor for dilution of air pollutants.

关键词： middle Tianshan Mountain pass gap wind elevated southeasterly gale (ESEG) tethered-sonde severe air pollution episodes

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Chinese Science Bulletin 2010年第9期55卷 867-873页

作者： HU YaMin1,2,3, DING YiHui4.& LIAO Fei2 1 institute of Tropical and Marine meteorology, China meteorological administration, Guangzhou 510080, China 2 Guangdong Climate Center, Guangzhou 510080, China 3 Chinese Academy of meteorological Sciences, Beijing 100081, China 4.National Climate Center, China meteorological administration, Beijing 100081, China

The Newtonian relaxation is used to assimilate data from the Second Global Soil Wetness Project (GSWP2) into the initial field for soil moisture in a regional climate model (i.e., BCC_RegCM 1.0, hereinafter called RegCM). The results show that different nudging parameters can improve the simulation of the air temperature and the precipitation to some extent in summertime season over East China. When the nudging intensity is 0.5 and nudging duration is 5 days, the result is desirable. Introducing the data assimilation of soil moisture into RegCM, the amelioration is not only in the spatial distribution pattern but also in the magnitude of the temperature and the precipitation. More specifically, the assimilation experiments have corrected the systematical cold bias of the air temperature and the precipitation on the low side, which is much closer to the observation compared with the control experiment. On the whole, the assimilation experiments shed light on the fact that the simulated bias in the original RegCM may be affected by the description of soil moisture in the land surface process. Therefore, the effect of soil moisture in RegCM should be paid more attention in the future.

关键词： soil moisture Newtonian relaxation data assimilation regional climate simulation