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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 830011, china 2. Department of Geography, Zhejiang Normal University, Jinhua 321004, china 3. Institute of desert Research, Chinese Academy of Sciences, Lanzhou 730000, china 4. Xinjiang Institute of meteorological Research, urumqi 830002. 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 21.5 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.

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 4.46 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

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 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

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

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 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 1991-2005 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 2.45, 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

Climatic change and urbanization effect in china

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Journal of Environmental Sciences 1993年第1期5卷 23-29页

作者： Zhao Zongci Academy of meteorological Science, State meteorological administration, Beijing 100081, china Academy of meteorological Science State Meteorological Administration Beijing 100081 China. China

Climatic change and urbanization effect in china during the last 39 years were investigated. It is found that a warming of about 0.23℃ for the annual temperature has been noticed from 1951 to 1989. The warmings of about 0.78 ℃ in winter and 0.34 3℃ in spring have been shown. It is also presented that a cooling of about -0.27℃ in summer has been indicated. The bigger cities are warmer than smaller cities in china. The dried trends in the annual precipitation during the last 39 years were presented. The precipitation decreased obviously in summer all over china. The bigger cities were drier than smaller cities.

关键词： climatic change urbanization effect global warming.

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...

Predictor-based error correction method in short-term climate prediction

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.46,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

来源： cnki会议评论

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Progress in Natural Science:Materials International 2008年第1期18卷 129-135页

作者： Hongli Ren Laboratory for Climate Studies,National Climate Center,china meteorological administration,Beijing 100081,china Laboratory for Climate Studies National Climate Center China Meteorological Administration Beijing 100081 China

In terms of the basic idea of combining dynamical and statistical methods in short-term climate prediction,a new prediction method of predictor-based error correction(PREC)is put forward in order to effectively use statistical experiences in dynamical ***- yses show that the PREC can reasonably utilize the significant correlations between predictors and model prediction errors and correct prediction errors by establishing statistical prediction ***,the PREC is further applied to the cross-validation experiments of dynamical seasonal prediction on the operational atmosphere-ocean coupled general circulation model of china meteorological Admin- istration/National Climate Center by selecting the sea surface temperature index in Ninflo3 region as the physical predictor that represents the prevailing ENSO-cycle mode of interannual variability in climate *** is shown from the prediction results of summer mean circulation and total precipitation that the PREC can improve predictive skills to some *** the PREC provides a new approach for improving short-term climate prediction.

关键词： Short-term climate prediction Seasonal prediction Predictor Error correction

Sensitivity experiments and assessment of climatic changes in china induced by greenhouse effect

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Journal of Environmental Sciences 1990年第4期2卷 73-84页

作者： Zhao Zongci and Ding YihuiAcademy of meteorological Science,State meteorological administration,Beijing 100081,china

Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in china .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2-5℃ in summer in china as simulated by the GCMs induced by doubling CO2 have been found. There are getting drier or wetter regions in china due to doubled CO2 as simulated by most of models. Comparing the simulated results with the observed data in china, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.

关键词： greenhouse effect climatic changes global warming.