检索结果-南通市图书馆

High-frequency atmospheric variability over South China Sea as depicted by TRMM and QuikSCAT

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2011年第2期30卷 46-52页

作者： LI Weibiao WANG Dong xiao LEI Ting LIU Zijie LU0 Cong departmentofatmosphericsciences SunYat—SenUniversityGuangzhou510275China LED SouthChinaSeaInstituteofOceanologyChineseAcademyofSciencesGuangzhou510301China

By using the TRMM and QuikSCAT datathe characteristics of the 2–8 day high frequency atmospheric variability over the South China Sea are studied in this ***’s found that：（1） the 2–8 day high frequency signals are significant not only during the periods of the South China Sea Summer Monsoon （SCSSM）,but also after the retreat of the *** reaches its peak around July to August;（2） the 2–8 day high frequency signals exhibit strong intermittent features;（3） During El Nino years,the 2–8 day high frequency signals are active only in the periods of the *** La Nina years,the 2–8 day high frequency signals are obviously not only in periods of the SCSSM,but also after the retreat of the *** the SCSSM periods,the 2–8 day high frequency signals in El Nino years are much stronger than that in La Nina years;（4） During spring to early summer,most of 2–8 day signals propagate southward and eastward,during midsummer to autumn,however,most of 2–8-day signals propagate northward and westward;（5） The 2–8 day northward and westward propagation signals is probably related to the activities of high-frequency vortex over the SCS.

关键词： high-frequency atmospheric variability South China Sea TRMM QuikSCAT

A NUMERICAL STUDY ON A MULTI LAYER VEGETATION BOUNDARY-LAYER MODEL

在线全文

学校读者我要写书评

暂无评论

南京大学学报(自然科学) 1999年第6期 3-5页

作者： Zeng Xinmin Zhao Ming Su Bingkai Department of Atmospheric Sciences, Nanjing University, 210093,Nanjing,PRC) departmentofatmosphericsciences NanjingUniversity210093NanjingPRC

0　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔ’ｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｅｃｏｓｙｓｔｅｍｃａｎｇｒｅａｔｌｙｉｎｆｌｕｅｎｃｅｂｏｔｈｔｈｅｌｏｃａｌｃｌｉｍａｔｅａｎｄｔｈｅｇｅｎｅｒａｌｃｉｒｃｕｌａｔｉｏｎ.Ｏｎｔ... 详细信息

0　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔ’ｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｅｃｏｓｙｓｔｅｍｃａｎｇｒｅａｔｌｙｉｎｆｌｕｅｎｃｅｂｏｔｈｔｈｅｌｏｃａｌｃｌｉｍａｔｅａｎｄｔｈｅｇｅｎｅｒａｌｃｉｒｃｕｌａｔｉｏｎ.Ｏｎｔｈｅｎｕｍｅｒｉｃａｌｓｔｕｄｙｏ...

关键词： Numerical Model Boundary Layer Turbulence Vegetation Mixing Length

Typical severe dust storms in northern China during 1954—2002

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2003年第21期48卷 2366-2370页

作者： ZHOUZijiang ZHANGGuocai departmentofatmosphericsciences SchoolofPhysicsPekingUniversityBeijing100871China NationalMeteorologicalCenter Beijing100081China

Based on China抯 available daily observation data from 681 national meteorological stations from 1954 to 2002, a time series of typical severe dust storms in northern China is constructed in terms of the weather process, and the temporal and spatial distribution, and their evolution ten-dency is analyzed. The results indicate that there were 223 relatively typical severe dust storms in northern China from 1954 to 2002, among which the event on April 10—12, 1979 had the largest affected area. Closely associated with the geographical distribution of deserts, sandy lands and the tracks of strong cold air outbreaks, severe dust storms mainly occurred in the Tarim Basin, the eastern part of Northwest China and the northern part of North China. The season with the most frequent severe dust storms was spring, in which the frequency accounts for 82.5% in the whole year, while the least occurrence was in summer and autumn. Dur-ing the past 49 years, the highest frequency of severe dust storms occurred in the 1950s and the lowest was in the 1990s with a general descending tendency, but during 2000—2002 the occurrence was relatively increasing. On the average, the duration of severe dust storms was shortest in the 1990s, about 0.5—1 h shorter than that in the other 4 decades.

关键词：沙尘暴中国北方地区地理分布

Arctic Oscillation influence on daily temperature variance in winter over China

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2004年第6期49卷 637-642页

作者： GONGDaoyi WANGShaowu ZHUJinhong KeyLaboratoryofEnvironmentalChangeandNaturalDisaster.CollegeofResourcesScienceandTechnology.BeijingNormalUniversity.Beijing100875 China departmentofatmosphericsciences.SchoolofPhysics.PekingUniversity Beijing100871China

The relationship between the Arctic Oscillation (AO) and daily temperature variance of 150 Chinese stations are investigated in the present study for wintertime (1 No-vember through 31 March) in the period of 1954-2001. Re-sults show that the temperature variance significantly de-creases during the high AO years, and increases in low AO cases. A key factor connecting them is the Siberian High, particularly the high-frequency fluctuations of the High. Within the seasonal time scale, the frequency of low-temperature extremes (daily temperature anomaly below 2σ,σ is the standard deviation of daily temperature for a given winter and a given station) displays an odd relation to the variance: a larger (smaller) variance is found to be asso-ciated with smaller (greater) frequency o low-temperature events. That is due to the non-normal distribution of the temperatures, and also influenced by the hhases of AO. Dur-ing the last 50 years or so, AO experiences a significant increasing trend, meanwhile the variance of daily sea level pressure (SLP) in the central region of Siberian High has decreased at a rate of 10.7%/10 a. These result in a signifi-cant weakening of the daily temperature variance in China with a trend of 4.1%/10 a, and a significant increaswe in the intra-seasonal low-temperature extremes at a rate of 0.16d/10 a.

关键词：中国北极涛动日间温度变化冬季西伯利亚高气压海洋水位压力

Spiral rainband in a numeri-cally simulated tropical cyclone

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2005年第8期50卷 800-808页

作者： ZHUPeijun ZHENGYongguang WANGHongqing TAOZuyu DepartmentofEarthSciences CollegeofScienceZhejiangUniversityHangzhou310027China departmentofatmosphericsciences SchoolofPhysicsPekingUniversityBeijing100871China

Spiral rainband is a prominent structure of tropical cyclone. Though its forming mechanism, vortex Rossby wave theory, has been widely accepted in recent years, its internal structural features are still not well known. The spiral rainband in the severe tropical storm Kammuri (2002), which caused heavy rainfall in southeast China, is simulated using the mesoscale model MM5 (V3). Results show that the simulated spiral rainband propagates azimuthally at a speed close to that of vortex Rossby wave in theory, and is accom- panied with energy dispersion in the radial direction. The structural features of simulated spiral rainband are analyzed with the high-resolution model output including the full physical process. Positive vorticity, ascending motion, hori- zontal momentum and so on are highly concentrated in the spiral rainband. The convergent moisture of spiral rainband comes mostly from the planetary boundary layer under 1 km. Airflow from the outside of spiral rainband is convective instability, which can provide instability energy for convec- tion development. However, the atmospheric stratification in the inside of spiral rainband is neutral, implying that the instability energy has been released. There is a mesoscale strong wind band just near the spiral rainband in the outer side with a maximum wind speed exceeding 30 m/s, which results from the pressure force acceleration when the air flows into the spiral rainband along the gradient of pressure.

关键词：螺旋形雨带热带旋风数字模型罗斯比波

Three-dimensional hydrodynamic model of Xiamen waters

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2003年第2期22卷 151-170页

作者： WenShenghui CaiSong TangJunjian CaiQifu ThirdInstituteofOceanography StateOceanicAdministrationXiamen361005China departmentofatmosphericsciences PekingUniversityBeijing100871China SchoolofMathematicsandStatistics WuhanUneversityWuhan430072China

A semi-implicit and Eulerian - Lagrangian finite difference method for three-dimensionalshallow flow has been extended to a more complete system of equations incorporating second-moment turbulence closure model and transport equations of salinity and temperature. The simulation for flooding and drying of mudflats has been improved. The model is applied to Xiamen waters. Based on extensive survey data, water level elevation, temperature and salinity field along the eastern open boundary and at the Jiulong River inlets and runoffs are analyzed, specified and calibrated. The computed results show good agreement with the measured data, reproduce flooding, emergence of large and complex mudflat region.

关键词： Semi-implicit finite difference scheme Eulerian - Lagrangian approach three-dimensional shallow water flow Xiamen waters

THE TEMPORAL AND SPATIAL CHARACTERISTICS OF MOISTURE BUDGETS OVER ASIAN AND AUSTRALIAN MONSOON REGIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2002年第2期8卷 113-120页

作者：乔云亭罗会邦简茂球 departmentofatmosphericsciences ZhongshanUniversity

Apparent moisture sink and water vapor transport flux are calculated by using NCAR/NCEP reanalyzed daily data for water vapor and wind fields at various levels from 1980 to *** the aid of EOF analysis method,temporal and spatial characteristics of moisture budgets over Asian and Australian monsoon regions are *** results show that there is apparent seasonal transition of moistrue sink and water vapor transport between Asian monsoon region and Australian monsoon *** winter,the Asian monsoon region is a moisture source,in which three cross-equatorial water vapor transport channels in the 'continent bridge',at 80°E and 40°E～50° transport water vapor to the Australian monsoon region and southern Indian Ocean which are moistrue *** summer,Australian Monsoon region anmd southern Indian Ocean are moistrue sources and by the three cross-equatorial transport channels water vapor is transport to the Asian monsoon region which is a moisture *** spring and autumn,ITCZ is the main moisture sink and there is no apparent water vapor transport between Asian monsoon region and Australian monsoon region.

关键词： Asian-Australian monsoon region moisture budgets temporal and spatial characteristics

An estimation of ozone flux in a stratosphere-troposphere exchange event

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2004年第2期49卷 167-174页

作者： CUIHong ZHAOChunsheng QINYu ZHENGXiangdong ZHENGYongguang CHANChuenYu CHANLoYin departmentofatmosphericsciences SchoolofPhysicsPekingUniversityBeijing100871China ChineseAcademyofMeteorologicalSciences Beijing100081China DepartmentofCivilandStructuralEngineering TheHongKongPolytechnicUniversity.HungHomHongKongChina

A new method based on mass fluxes and observed ozone profiles was developed to estimate crosstropopause ozone flux. Using this method, we estimated the cross-tropopause ozone flux in a stratospheric-tropospheric exchange event that occurred over East Asia in March *** result revealed that the ozone flux across the tropopause in this event was an order of magnitude higher than the global and hemispheric average. Compared to the traditional method using a linear relationship between ozone mixing ratio and potential vorticity near the tropopause, the cross-tropopause ozone flux evaluated with ozonesonde data was somewhat higher, although the orders of the two values were the same.

关键词：臭氧同温层对流层东亚地区 STE

Localized 3D-structural features of dynamic-chemical processes of urban air pollution in Beijing winter

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2003年第8期48卷 819-825页

作者： XUXiangde DINGGuoan ZHOULi ZHENGXiangdong BIANLingen QIUJinheng YANGLiquan MAOJietai ChineseAcademyofMeteorologicalSciences Beijing100081China InstituteofAtmosphericPhysics ChineseAcademyofSciencesBeijing100029China departmentofatmosphericsciences PekingUniversityBeijing100871China

The Beijing City Air Pollution Observation Field Experiment (BECAPEX) is described with emphases on the 損oint-surface?research approach and composite analysis. The analysis results of measurements from four observation sites across the Beijing urban area from January to March indicate that the overall impact of urban emission sources in the heating season is significant, and the staggered impact of urban emission sources has different features at observation sites over different parts of Beijing in both heat-ing and non-heating seasons. The pollutants NOx, SO2 and CO in the urban boundary layer have the in-phase variation features over a large area. O3 concentrations at different sites have the same variation trend but its change is reversed phases with above pollutants. The pollutants over the urban area in heating and non-heating seasons also have the syn-chronous variation trend. The comprehensive sounding of BECAPEX indicates that pollutants and aerosol vertical profiles are closely correlated to the vertical structure of the large-scale inversion layer in the urban boundary layer over the urban area. The localized 3D-structural features of local urban polluting processes associated with the peripheral areas are discussed with a 損oint-surface?comprehensive sounding technique.

关键词：空气污染北京卫星遥感技术污染监测环境保护