In-situ Measurements of Tropospheric Hydroxyl Radicals by Folded Long-Path Laser Absorption During the Field Campaign POPCORN   总被引：1，自引：0，他引：1  

Uwe Brandenburger  Theo Brauers  Hans-Peter Dorn  Martin Hausmann  Dieter H. Ehhalt 《Journal of Atmospheric Chemistry》1998,31(1-2):181-204

Absolutely calibrated in-situ measurements of tropospheric hydroxyl radicals, formaldehyde, sulfur dioxide, and naphthalene (C10H8) were performed by long-path laser absorption spectroscopy during the field campaign POPCORN. The absorption light path was folded into an open optical multiple reflection cell with a mirror separation of 38.5 m. Using a light path length of 1848 m and an integration time of 200 s, the average 1-detection limits of OH, HCHO, SO2 and C10H8 during POPCORN were 8.7 · 105 cm–3, 8.3 · 109 cm–3, 2.4 · 109 cm–3, 1.5 · 108 cm–3, respectively. In total, 392 identifications of OH in air spectra were made in a rural environment between August 5 and August 23, 1994. We present and discuss OH absorption spectra and diurnal OH concentration profiles of three days which are representative for measurements under different pollution conditions during POPCORN. The observed maximum and median OH radical concentrations are 1.3 · 107 OH/cm3 and 4.0 · 106 OH/cm3, respectively. The measured diurnal variation of the OH concentration shows a good correlation with the primary formation reaction of OH radicals which is the photolysis of ambient ozone. Deviations from this correlation in the morning and evening hours, when the OH concentration is higher than expected from the ozone photolysis, demonstrate the importance of other photochemical HOx production pathways during POPCORN.  相似文献   

NUMERICAL STUDY ON FUNCTIONS AFFECTING TROPICAL CYCLONE STRUCTURE AND MOTION^*          下载免费PDF全文

Chen Lianshou  Luo Zhexian 《Acta Meteorologica Sinica》1998,12(4):504-512

By using a beta-plane quasigeostrophic barotropic model,four numerical experiments with integration time more than five days are performed.Results show that the vorticity advection term and beta term are two basic factors significantly affecting tropical cyclone structure and motion.  相似文献   

NUMERICAL STUDY ON THE EFFECTS OF SEA SURFACE TEMPERATURE ON TROPICAL CYCLONE INTENSITY-PART I:NUMERICAL EXPERIMENT OF THE TROPICAL CYCLONE INTENSITY RELATED TO SST ^*     

Duan Yihong  Qin Zenghao  Gu dianfeng  Li Yongping 《Acta Meteorologica Sinica》1998,12(2):142-148

In the context of a model of tropical cyclone intensity based on an improved meso-scale atmospheric model, numerical simulation is performed of the track and intensity variation of tropical cyclones(TC) arising from sea surface temperature(SST) variation over a specified sea region. Evidence suggests that the model is capable of modeling quite welt the track and intensity of TC:SST variation leads to an abrupt change in the cyclone intensity:the response of the cyclone to the abrupt SST change lasts 8-12 h.  相似文献   

西太平洋副热带高压中期变化的数值试验 Ⅱ.热带西太平洋热源的作用     

巩远发  纪立人 《热带气象学报》1998,14(3):201-207

用一个全球谱模式作数值试验,研究了１９７９年６月中蟾一次西太平洋副热带高压西伸北进的中期天气过程中热带西太平洋地区理想热源的作用。结果表明：理想热源的作用大约在４天以后可以影响我国东部的副热带高压和中高纬度的环流;理想热源在热带洋面上产生的扰动首先沿副高南边的东风气流向西北方向传播,到中纬西风带后分为两支,一支继续向西北方向传播,另一支转向东北偏东方向传播,两支扰动的共同作用导致副热带高压和西风带  相似文献   

A NUMERICAL EXPERIMENTAL STUDY OF TROPICAL CYCLONE CROSSING SUBTROPICAL HIGH   总被引：1，自引：0，他引：1  

杨美川  朱永褆 《热带气象学报(英文版)》1998,4(1):65-71

The barotropic primitive equations model is used in a numerical study of a tropical cyclone crossing the Subtropical high. It is revealed that apart from its own characteristics, sensitive factors having immediate effects on the motion of the tropical cyclone also include its radial distance from the center of the subtropical high, the variation in latitudinal location and intensity. A complex mechanism for nonlinear interactions among the tropical,subtropical high and β effect is also shown in the experiment, and expected to serve for the diagnosis and prediction of abnormal motion.  相似文献   

高原地形对四川盆地西部突发性暴雨影响的数值试验   总被引：14，自引：2，他引：12  

郁淑华  滕家谟  何光碧 《大气科学》1998,22(3):379-383

用η模式对1995年8月24日四川盆地西部一次突发性暴雨进行了数值模拟和地形减半、无地形数值试验。由对数值模拟与试验的结果分析得出:（1）青藏高原地形有利于高原东麓暴雨区的扩大与强度加大。（2）高原地形对其以北的天气系统南伸和以南的天气系统北扩有阻碍作用。（3）高原地形可影响高原附近以东地区的物理特征场分布,从而影响暴雨区的位置与强度。  相似文献   

震源物理实验室“八五”技术改造     

李世愚 《国际地震动态》1998,(2):1-5

由国家地震局地球物理研究所承担的“ＭＴＳ－１００Ｔ伺服试验机改造”课题,对震源物理实验室进行了实验系统改造。该文简要介绍了该课题所完成的主要工作及其应用情况,包括：ＭＴＳ－１００Ｔ伺服试验机控制系统、１６通道高速数据采集系统、激光散斑图干涉仪。  相似文献   

Fault Geometry and Departure of Precursors From the Epicenter   总被引：3，自引：0，他引：3  

Ma Jin  Liu Liqiang  and Ma ShengliInstitute of Geology  SSB  Beijing  China 《中国地震研究》1998,(1)

Different tectonic elements may play different roles and their deformation styles and types of anomalies are also different in the process of deformation.Such differences may be the cause of the phenomena of the departure from the region with obvious anomalies from the coming epicenter,which are called "departure of precursors from epicenter." From some new experimental and numerical modeling results,five types of deformation elements are identified according to their roles in the process of deformation in a region.They are the brake(or locked),slip,yield,sensitive,and valve elements.Spatial distribution of different elements,especially sensitive and slip elements,are discussed by taking the bend fault,extension,compression,and complex en-echelon faults as examples.These elements with different roles may overlap each other in some cases or be separated in other cases.It is obvious that for different fault geometry,the spatial layout of these elements is different and thus the position and style of possi  相似文献   

VEBEX: Vegetation and surface energy balance experiment for the tropics     

Sethu Raman  Devdutta S. Niyogi  A. Prabhu  S. Ameenullah  S. T. Nagaraj  Udai Kumar  S. Jayanna 《Journal of Earth System Science》1998,107(1):97-105

Surface features such as soil moisture and vegetation have a profound impact on the surface energy balance and the atmospheric boundary layer. To quantify this effect for a tropical location, a detailed field experiment, VEBEX, was designed and successfully executed in a tropical site at Bangalore, India. VEBEX was a joint experiment between the North Carolina State University, Indian Institute of Science (IISc), and the University of Agricultural Science (UAS) at Bangalore, India. Continuous surface meteorological measurements were taken over an entire crop period (pre-sowing to post-harvest). During different stages of the plant growth, intensive observations of surface turbulence, and measurements of physiological and soil moisture measurements were also conducted. The results obtained provide an insight into the unusually strong variability for the tropics. Interpretation of the observations and an overview of the analysis procedure and future research initiatives are also presented.  相似文献   

本溪郑家潜水含水层二维水动力弥散试验及其结果分析   总被引：4，自引：0，他引：4  

吴耀国  田春声 《水文地质工程地质》1998,25(1):32-35

以本溪郑家潜水含水层的弥散试验为例,对多孔介质饱水二维水动力弥散进行研究,得到弥散机理的两点新认识。  相似文献