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1.
珠三角地区前后汛期强对流过程物理量指数对比分析及阈值选取 总被引：4，自引：1，他引：3
珠江三角洲（简称珠三角）地区前汛期强对流是由锋面系统引起,后汛期强对流则多由热力系统引起。利用2004—2006年探空资料计算的物理量,选取与强对流天气相关性好的大气温湿类（整层比湿积分IQ）、层结稳定度类（K指数）、动力类（潜在下冲气流指数MDPI）、热力动力综合类（瑞士第一雷暴指数SWISS00）作为指示因子,通过对各指数的分布特征进行对比分析,分别得到珠三角地区前、后汛期的物理量指数的阈值,为进一步做好珠三角地区未来12小时强对流预报服务。 相似文献
2.
珠三角地区前汛期强对流潜势预报方法研究 总被引：3，自引：0，他引：3
利用2004—2006年前汛期探空资料计算的物理量,选取与强对流天气相关性好的大气温湿类(整层比湿积分IntegralQ)、层结稳定度类(K指数)、动力类(潜在下冲气流指数MDPI)、热力动力综合类(瑞士第一雷暴指数SWISS00)作为预报因子,通过对各指数的空间分布特征和数值进行二值Logistic回归分析,得到各指数的参数估算值,建立强对流诊断预报方程,得到前汛期强对流潜势预报因子P,从而制作珠江三角洲(以下简称珠三角)地区未来12小时出现强对流天气的潜势预报。并用此法回报2003—2006年3—6月前汛期的强对流天气。结果表明,P值大于0.9的准确率可达77.5%,P值小于0.5出现强天气的概率仅为3.8%。由于资料有限,对2007年3—4月发生的7次强对流的经验检验效果不明显,但P值小于0.5时不发生强对流的经验检验效果明显。此法对珠三角地区的短时强降水和雷雨大风等强对流天气的临近监测预警有较好的指示意义。 相似文献
3.
利用2003-2012年的地面填图和探空资料,统计常用对流参数满足指定阈值条件时广西6个探空站出现雷暴天气的概率（简称＂雷暴概率＂）。统计结果表明：整层比湿积分（IQ）、K指数（KI）和抬升指数（LI）与雷暴概率有显著的线性关系,当IQ、KI增大,或LI减小时,雷暴概率增大。对流有效位能（CAPE）在0-200J·kg-1之间增长时雷暴概率迅速增大,但超过200J·kg-1后雷暴概率增大不明显。根据统计结果,选取IQ、KI和LI作为预报因子,CAPE作为消空因子,定义了一个适用于广西雷暴天气的经验预报指标。用2013年资料做试报检验,结果表明该指标对6小时内的雷暴天气有较好的预报能力。 相似文献
4.
为了提高巴彦淖尔市冰雹天气的预报预警能力,利用探空资料分别计算了对流有效位能、K指数、沙氏指数、抬升指数、强天气威胁指数和总指数等物理参数,并且对巴彦淖尔市的冰雹、雷暴和稳定降水进行分类分析,结合统计学方法分析各物理参数与冰雹预报之间的相互联系,归纳出适合于巴彦淖尔市冰雹潜势预报的探空指标。结果表明:探空资料反演的众多物理量中,CAPE值和强天气威胁指数对冰雹的预报意义不大,K指数、沙氏指数、抬升指数和总指数对冰雹、雷暴和稳定性降水的区分有很好的指示意义。对巴彦淖尔市不同天气过程中的物理量分析发现,K指数在34℃以上时,发生强冰雹的可能性较大;沙氏指数在-2℃以下时,较大可能性发生强冰雹;抬升指数在-1.5℃以下时,发生强冰雹的可能性较大;总指数在50℃以上时,发生强冰雹和中冰雹的可能性较大。 相似文献
5.
利用伊犁河谷2010～2018年6～8月68个短时强降水天气过程样本,采用箱线图的形式讨论产生短时强降水的关键环境参数的阈值,并对短时强降水天气过程的关键环境参数月特征进行了讨论,最后对2019所夏季的短时强降水天气过程进行检验。结果表明：(1)K指数、修正K指数、瑞士第二雷暴指数、对流凝结高度、Teffer指数、大风指数、对流温度、对流凝结高度处温度、总指数、整层比湿积分与产生降水的相关系数达到0.30以上,对降水有较好的指示意义,其中整层比湿积分的相关系数最高,达到0.465。(2)17个物理量参数涵盖75%以上降水天气过程的阈值在无降水天气过程中的概率,Charbr修正K指数(ChTTK)指示意义最好,概率只有16.8%,而干暖盖指数(Ls)、特征层高度中的对流凝结高度到50%以上,对出现降水的指示性较差。最终选取Charbr修正K指数、K指数、mK指数、Teffer指数、瑞士第二雷暴指数、整层比湿积分这6个关键环境参数。(3)6个环境参数的阈值落在降水天气过程的概率都小于25%,瑞士第二雷暴指数指示意义最好,仅为10.7%。(４)6月份的mK指数、K指数、Charba修正K指数的阈值分别为32、38和36℃；7月份的mK指数、K指数、Charba修正K指数的阈值分别为31、37和35℃；8月份的mK指数、K指数、Charba修正K指数的阈值分别为32、38和37℃。6、7、8月份Teffer指数产生短时强降水的阈值,分别为43、47和43℃。瑞士第二雷暴指数(SWISS12)6、7、8月份的阈值分别为3.4、4.3、3.6。整层比湿积分6、7、8月的阈值,分别为2320 g.kg-1,2390 g.kg-1、2392 g.kg-1。(5)对2019年6-8月的降水天气过程及短时强降水天气过程进行检验评估,降水预报正确的样本为43个,漏报为41个,空报7个。准确率为(Ts)47.3%。短时强降水样本的检验,漏报率6、7、8三个月都为50%,空报率7月份最高,为71.4%,而8月份没有空报。准确率(Ts)是8月份最高(50%),6月份次之(33.3%),7月份最低(20%)。 相似文献
6.
利用2009—2015年江淮夏季雷暴大风观测资料和NCEP再分析资料,按整层可降水量将雷暴大风环境划分为干、湿两种环境,结果发现湿环境雷暴大风日约占总雷暴大风日数的86%。基于物理量参数和Logistic回归方法构建了江淮夏季干、湿环境下区域雷暴大风的潜势预报模型。西南区、东南区和北区湿环境雷暴大风的最显著预报因子分别是冰雹指数(CS)、K指数和沙氏指数(SI)。干环境雷暴大风的最显著预报因子是总指数(TT)。相对于大风指数(WINDEX),综合考虑热力学作用和高空水平动量信息的新大风指数(GUSTEX)对江淮干、湿环境雷暴大风的预报指示意义更好。通过历史样本回报确立了预报模型的概率阈值,并利用2016年独立样本试预报检验证明Logistic模型预报效果良好。 相似文献
7.
青藏高原的大范围热力、动力作用,致使高原地区空气不稳定,也导致高原夏季雷暴活动非常频繁,成为北半球同纬度地带雷暴数最多的地区。利用2004—2009年常规地面观测资料和探空资料,对拉萨地区夏季夜间雷暴的时间分布特征和背景场特征的分析结果显示:1)拉萨地区的雷暴主要集中在14:00—23:00,其中17:00—20:00雷暴次数最多,超过总雷暴次数的60%。2)从20时整层大气特性上看,20:00—02:00时(次日)发生雷暴时,整层大气的湿度、假相当位温(θse)比不发生雷暴时的大,在400 h Pa层差别最明显;两者的温度差异并不明显。分析抬升凝结高度(LCL)、400 h Pa的θse、修正的KI、SI指数和300 h Pa到400 h Pa的平均垂直风切变(MS)对雷暴的指示作用,结果显示:1)各指数都能较好地区分雷暴日与非雷暴日。2)各指数的TSS预报评分由高到低依次为:400 h Pa的θse352.1 K,TSS评分为0.401;修正的KI15.7℃,TSS评分为0.373;修正的SI3.20℃,TSS评分为0.288;LCL441.4 h Pa,TSS评分为0.276;MS1.87 m·s-1·km-1,TSS评分为0.201。400 h Pa的θse和修正的KI指数对拉萨夜间雷暴具有较好的指示意义。与稳定度有关的参数比与风切变有关的参数的指示意义好。 相似文献
8.
利用呼伦贝尔市CIMISS系统实况资料,统计分析了2010—2021年5—9月东北冷涡背景下的强对流天气时空分布及物理量参数特征。结果表明：(1)5月雷暴大风次数最多,6月冰雹次数最多,6—8月是短时强降水集中发生期,尤以8月次数最多。(2)强对流天气主要出现在12:00—20:00,其中短时强降水每个时次均有发生,但雷暴大风与冰雹天气在21:00—次日08:00基本没有发生过。(3)大兴安岭西部雷暴大风站次较多;大兴安岭东北部、岭上及岭西北的冰雹站次较多;短时强降水与强对流天气空间分布特征较为一致,均是大兴安岭岭上南段与岭东的站次较多。(4)雷暴大风天气的风速多以17.2～20.7 m·s-1为主;短时强降水量级为20.0～29.9 mm的站次占总站次的74.3%;持续时间小于5 min冰雹居多,直径小于5 mm冰雹的站次占总站次的49.1%。(5)短时强降水850 hPa的比湿、水汽通量、水汽通量散度的物理量参数均值均大于冰雹、雷暴大风;短时强降水K指数均值大于冰雹、雷暴大风,T850-T500均值大于26℃,短时强... 相似文献
9.
利用2016—2021年ECWMF集合预报资料、浙江自动站实况资料等，计算浙江短时强降水、雷暴大风和冰雹等强对流天气相关物理量的极端天气预报指数（EFI：Extreme Forecast Index），分析EFI分布特征，并构建了分类强对流预报模型。结果表明：强对流天气与物理量的EFI有密切联系，发生短时强降水时，对流有效位能、整层可降水量、850 hPa与500 hPa温差和位温差的EFI较大，而垂直风切变的EFI为负值，因而较小的垂直风切变更有利于出现极端降水；发生雷暴大风和冰雹时，对流有效位能、850 hPa与500 hPa温差和位温差以及850 hPa温度露点差的EFI较大，700 hPa露点温度的EFI为负值，与上层干冷下层暖湿的有利层结条件有关。利用支持向量机多分类方法，将强对流天气相关物理量的EFI作为特征值开展训练，构建的预报模型对于非局地强对流天气有较好的预报效果，其中短时强降水的误判率明显低于雷暴大风。 相似文献
10.
利用广东省清远地区2011、2012和2014年6—8月地闪定位资料将每天发生的雷暴情况进行分级,并结合对应的探空资料,计算对流有效位能、沙氏指数、K指数等反映大气稳定性或能量关系的参数,分析其在发生时间和强度不同的雷暴发生前的分布情况。结果表明,沙氏指数、抬升指数、K指数、全总指数、强天气威胁指数和对流有效位能与雷暴强度有一定的相关性,而对流抑制能量、粗理查森数与雷暴强度间没有发现较好的相关性。广东地区雷暴发生前沙氏指数小于0℃,抬升指数小于-2℃,K指数大于30℃,对流有效位能大于500J/kg,更容易产生中强雷暴。广东地区的K指数高于青藏高原地区20℃左右,对流有效位能的平均值高于青藏高原及陕甘宁地区约300J/kg,其余参数分布特点与部分地区相似,进一步反映了广东地区雷暴特征的特殊性,加深了对广东地区雷暴特征的认识。 相似文献
11.
Summary From a study of five cases of pronounced fronts in the upper troposphere, it is concluded that the waterspout model offers the most satisfactory solution to the problem of connecting frontal boundaries and tropopauses. Composite cross sections of temperature, potential temperature, normal wind component and potential vorticity are presented for the five cases. On the basis of the potential vorticity measurements it is suggested that the most likely explanation for the formation of the high-level front is a folding of the tropopause.
With 11 Figures
Contribution No. 37, Department of Meteorology and Climatology. —The research reported in this article has been supported by the Geophysical Research Directorate, Air Force Cambridge Research Center, under Contract No. AF 19 (604)-1811. 相似文献
Zusammenfassung Auf Grund einer Untersuchung von fünf Fällen ausgesprochener Fronten in der höheren Troposphäre wird der Schluß gezogen, daß die Wasserhosen-Vorstellung am besten den Zusammenhang zwischen Fronten und Tropopausen darstellt. Kombinierte Querschnitte von Temperatur, potentieller Temperatur, normaler Windkomponente und potentieller Vorticity werden für die fünf Fälle vorgelegt. Auf Grund der Bestimmungen der potentiellen Vorticity wird dargelegt, daß die wahrscheinlichste Erklärung für die Entstehung einer Front in der Höhe in der Annahme einer Faltung der Tropopause besteht.
Résumé En se fondant sur cinq cas de fronts très nets de la haute troposphère, les auteurs concluent que le schéma de trombe constitue la meilleure solution pour représenter la liaison entre zones frontales et tropopause. Ils donnent des profils combinés de température, de température potentielle, de composantes normales du vent et de vorticity potentielle pour les cinq cas. Ils montrent à l'aide de mesures de la vorticity potentielle que l'explication la plus probable de la formation d'un front en altitude consiste à admettre un plissement de la tropopause.
With 11 Figures
Contribution No. 37, Department of Meteorology and Climatology. —The research reported in this article has been supported by the Geophysical Research Directorate, Air Force Cambridge Research Center, under Contract No. AF 19 (604)-1811. 相似文献
12.
《Dynamics of Atmospheres and Oceans》1999,29(2-4):365-395
We present definitive observational evidence that the startling change of the Eastern Mediterranean deep circulation observed in winter 1995 and documented by [Roether, W., Manca, B.B., Klein, B., Bregant, D., Georgopoulos, D., Beitzel, V., Kovacevich, V., Luchetta, A., 1996. Recent changes in the Eastern Mediterranean deep water. Science 271, 333–335.] actually started before October 1991. This change involved not only the deep water mass pathways but also the origin and pathways of the water mass spreading in the intermediate layer. We carry out the first unified analysis of the POEMBC-O91 data set, which shows that, differently from the previous decade of the 80s, the Cretan/Aegean Sea was in 1991 the `driving' engine of the intermediate, transitional and deep layer circulations, with Cretan Intermediate Water (CIW), transitional water and Cretan Deep Water (CDW) spreading out from the Cretan Sea into the basin interior. The most important new results are: (a) the Levantine Intermediate Water (LIW) formed inside or at the periphery of the Rhodes gyre is blocked in its traditional westbound route on its density horizons σθ=29.05 and 29.10 kg/m3 by a three-lobe strong anticyclonic structure in the Southern Levantine, which induces a substantial LIW recirculation in the Levantine basin itself; (b) the CIW exiting from the Western Cretan Arc Straits spreads into the Ionian interior on the σθ=29.05–29.10 kg/m3 isopycnal surfaces, thus replacing the LIW confined in the Levantine basin. A branch of CIW flows eastward in the Cretan passage and is entrained by the Ierapetra anticyclone to flow again into the Cretan Sea through the Eastern Cretan Arc Straits; (c) on the horizons σθ=29.15 and 29.18 kg/m3 a transitional water mass of Cretan origin, denser than CIW, and CDW are observed to spread out massively from the Cretan Arc Straits both into the Ionian and Levantine interiors. These isopycnal surfaces rise to much shallower depths in 1991 than in 1987, increasing the salt content of the intermediate, transitional and deep layers. This leads to a massive salt increase in the Ionian below 1200 m, clearly related to lateral advection of the new denser waters of Cretan/Aegean origin, thus contradicting the hypothesis of a vertical salt redistribution proposed by Roether et al. 相似文献
13.
Hydrogen peroxide (H2O2) and organic hydroperoxides (ROOH) were measured on board of theRV Polarstern during its cruise across the Atlantic Ocean from 20 October to 12 November 1990 (54° N to 51° S latitude) by the enzyme fluorometric method. The H2O2 mixing ratio varied from below the detection limit of about 0.12 ppbv up to 3.89 ppbv, showing a latitudinal dependence with generally higher values around the equator and decreasing values poleward. The shape of the latitudinal H2O2 distribution agrees well with an analytical steady state expression for H2O2 using the measured H2O and O3 distribution and a wind dependent H2O2 deposition rate. The ROOH mixing ratio varied from below the detection limit of about 0.08 ppbv up to 1.25 ppbv with qualitatively the same latitudinal dependence as H2O2. The observed ratio ROOH/(ROOH + H2O2) varied between 0.17 and 0.98 showing higher values at the lowest H2O2 mixing ratios at high latitudes. The measured H2O2 mixing ratio shows a significant diurnal variation with a maximum around 14:00 local time, explicable by a superposition of the photochemical H2O2 production with a constant H2O2 deposition rate. Four independent estimations of the average effective H2O2 deposition rate inferred from the H2O2 decrease in the night, from the midday H2O2 production deficit (as derived from comparison with a photochemical model and from the daily ozone loss), and from the offset in the latitudinal H2O2 distribution, were consistent. An episode of maximum H2O2 concentration suggests the possibility of its formation in clouds. 相似文献
14.
P. Ya. Tishchenko V. B. Lobanov T. A. Gulenko A. P. Nedashkovskii O. S. Popov S. G. Sagalaev P. P. Tishchenko R. V. Chichkin 《Russian Meteorology and Hydrology》2012,37(11-12):775-782
During the hydrological survey from November 4 to 9, 2009, the underway measurements of pH, temperature, and salinity of the surface water in the Peter the Great Bay were carried out using the cell without the liquid junction in the running system. Using the measurement data, the partial pressure of carbon dioxide (pCO2) was computed which was below its atmospheric value and varied from 290 to 360μatm. Thus, during the period under study, the surface water of the bay forms the runoff for the atmospheric carbon dioxide. The minimum values of pCO2 are associated with the warm stream entering the bay from the southwestern part of the open sea. The maximum values of pCO2 are associated with the local upwelling of bottom waters. It is suggested that the horizontal convection caused by the nonuniform cooling of coastal water in the autumn forms the revealed mesoscale dynamic structures. 相似文献
15.
We present the power spectra of wind velocity and the cospectra of momentum and heat fluxes observed for different wind directions
over flat terrain and a large valley on the Loess Plateau. The power spectra of longitudinal (u) and lateral (v) wind speeds satisfy the −5/3 power law in the inertial subrange, but do not vary as observed in previous studies within
the low frequency range. The u spectrum measured at 32 m height for flow from the valley shows a power deficit at intermediate frequencies, while the v spectrum at 32 m downwind of the valley reaches another peak in the low frequency range at the same frequency as the u spectrum. The corresponding peak wavelength is consistent with the observed length scale of the convective outer layer at
the site. The v spectrum for flat terrain shows a spectral gap at mid frequencies while obeying inner layer scaling in its inertial subrange,
suggesting two sources of turbulence in the surface layer. All the spectra and cospectra from the valley direction show a
height dependency over the three levels. 相似文献
16.
Hiroyuki Enomoto 《Climatic change》1991,18(1):67-87
This paper summarizes the long-term fluctuations of snow accumulation in the Antarctic and analyzes its correlation with the sea level pressure (SLP) in the middle latitude (40°–50° S) of the Southern Hemisphere. Stratigraphic data which were compiled from studies on ice cores and snow-pits at eight stations in the Antarctic were used in the present study. It was found that the data concerning fluctuations in snow accumulation for East Antarctica showed correlations, whereas no such correlation was observed for the data from West Antarctica.This study shows possible relationships between snow accumulation in the Antarctic and SLP in the middle latitudes. The fluctuations of accumulation at South Pole, Dome C, Wilkes and South Ice Point show correlations with SLP over a large area in the 40°–50° S latitudinal zone. For the long-term fluctuations of SLP in the 40°–50 ° S latitudinal zone, a zonal fluctuation with wave number zero structure and a longitudinal variation of SLP anomalies due to their out-of-phase-fluctuation between the Pacific and the Indian Oceans were observed. The temporal scales for these fluctuations were found to be in the order of 20–30 years and 40–60 years, respectively. The influences of these two modes on the behaviour of snow accumulation in the Antarctic is also discussed.Now at Kitami Institute of Technology, Kitami, Hokkaido, Japan. 相似文献
17.
During a cruise of RV Polarstern over the Atlantic in September/October 1988, C2–C4 hydrocarbons were measured in surface sea water. The ship passed through three different ocean regions divided by divergences at 8° N and 3° S. Hydrocarbon concentrations differed considerably in these regions. The highest values were obtained for ethene with mean concentrations of 246 pMol/l between 35° N and 8° N, 165 pMol/l between 8° N and 3° S, and 63 pMol/l between 3° S and 30° S. Low values were found for i- and n-butane and acetylene between 32 pMol/l and 1 pMol/l. The alkene concentrations were in general higher than the concentrations of their saturated homologs. Concentrations decreased with increasing carbon numbers. The various alkenes were well correlated with one another as were the various alkanes. Oceanic emission rates of the light hydrocarbons were calculated from their sea water concentrations using an ocean atmosphere exchange model. The averaged fluxes ranged from about 108 molec cm-2 s-1 for the alkenes and ethane to less than 107 molec cm-2 s-1 for the C4 alkanes. Acetylene emissions were below 3×106 molec cm-2 s-1. Based upon these rates budget estimates of NMHC in the ocean surface layer were made with a simple model considering production and destruction processes in the water. The emissions to the atmosphere appear to be the dominant loss process between 35° N and 8° N, whereas destruction in the water seems to be dominant in the latitude ranges 8° N-3° S and 3° S-30° S. 相似文献
18.
Brianna Craft 《Climate Policy》2018,18(9):1203-1209
The Paris Agreement establishes a global goal on adaptation which will be assessed through the global stocktake, the first attempt by the international climate change regime to measure collective progress on adaptation. This policy analysis identifies four main challenges to designing a meaningful assessment. These are: designing a system that can aggregate results; managing the dual mandate of reviewing collective progress and informing the enhancement of national level actions; methodological challenges in adaptation; and political challenges around measurement. We propose a mixed-methods approach to addressing these challenges, combining short-term needs for reporting with longer-term aims of enhancing national adaptation actions.
Key policy insights
Broad domains of adaptation activity could be identified within each of the objectives of the adaptation goal and progress could be measured and aggregated through simple scorecards.
The goal should have both process and outcome indicators as well as some narrative linking activities to outcomes over time.
Reporting could be a compilation of national data using qualitative and quantitative sources, aligning with the global stocktake’s aim of enhancing national actions over time and reducing immediate reporting burdens.
There would be a complementary role at least in the short term for an expert assessment of priority areas.
19.
P. J. Fraser M. A. K. Khalil R. A. Rasmussen L. P. Steele 《Journal of Atmospheric Chemistry》1984,1(2):125-135
Results of more than 800 new measurements of methane (CH4) concentrations in the Southern Hemisphere troposphere (34–41° S, 130–150° E) are reported. These were obtained between September 1980 and March 1983 from the surface at Cape Grim, Tasmania, through the middle (3.5–5.5 km) to the upper troposphere (7–10 km). The concentration of CH4 increased throughout the entire troposphere over the measurement period, adding further support to the view that CH4 concentrations are currently increasing on a global scale. For data averaged vertically through the troposphere the rate of increase found was 20 ppbv/yr or 1.3%/yr at December 1981. In the surface CH4 data a seasonal cycle with a peak to peak amplitude of approximately 28 ppbv is seen, with the minimum concentration occurring in March and the maximum in September–October. A cycle with the same phase as that seen at the surface, but with a significantly decreased amplitude, is apparent in the mid troposphere but no cycle is detected in the upper tropospheric data. The phase and amplitude of the cycle are qualitatively in agreement with the concept that the major sink for methane is oxidation by hydroxyl radicals. Also presented is evidence of a positive vertical gradient in methane, with a suggestion that the magnitude of this gradient has changed over the period of measurements. 相似文献
20.
Abraham H. Oort 《Meteorology and Atmospheric Physics》1964,14(2):131-148
Summary In this study the horizontal component of the meridional circulation at the 100, 50 and 30 mb levels in the stratosphere is computed for the IGY period July 1957 through June 1958. Radiosonde data from approximately 240 stations, well distributed over the northern hemisphere, are used in the analysis of the north-south component of the wind. Values of the mean meridional circulation for the four seasons are presented at every 5° latitude from the equator to 80°N.In the annual average at 100 mb an apparent three cell pattern is obseered, consisting of a region of strong poleward motion north of 55°N, equatorward motion from 15° to 55°N and weak poleward motion from 0° to 15°N. In the annual averages at 50 and 30 mb poleward motions appear only at high latitudes and diminsih in strength with height. Equatorward motions dominate at 30 mb. A maximum value of the mean meridional circulation of +60 cm sec–1 is found at 100 mb at 70°N.
With 6 Figures
The research reported in this paper has been made possible through the support of the Atomic Energy Commission and of the Geophysics Research Directorate of the U.S. Air Force under contracts No. At (30-2) 2241 and 19(604)-5223. 相似文献
Zusammenfassung In dieser Untersuchung ist für die 100-, 50- und 30 mb-Niveaus die horizontale Komponente der meridionalen Zirkulation in der Stratosphäre im internationalen geophysikalischen Jahr (Juli 1957 bis Juni 1958) berechnet worden. Es werden dabei Radiosonden-Daten von etwa 240 Stationen, die über die nördliche Hemisphäre gut verteilt sind, für die Analyse der Nord-Süd-Windkomponente verwendet. Für jeden fünften Breitengrad vom Äquator bis 80°N werden Werte der durchschnittlichen Meridionalkomponente der Zirkulation für die vier Jahreszeiten mitgeteilt.Im Jahresdurchschnitt zeigt sich im 100 mb-Niveau eine Verteilung der Meridionalkomponente, die anscheinend einem aus drei Zellen bestehenden Zirkulationssystem entspricht, wobei nördlich von 55°N eine starke polwärts gerichtete Bewegung, zwischen 15° und 55°N eine Strömung gegen den Äquator und zwischen 0° und 15°N wieder eine schwache polwärts gerichtete Strömung besteht. In den Jahresdurchschnittswerten aus den Niveaus der 50- und 30 mb-Flächen sind polwärts gerichtete Strömungskomponenten nur in hohen geographischen Breiten festzustellen, die mit zunehmender Höhe an Stärke abnehmen. Im Niveau von 30 mb herrscht eine zum Äquator hin gerichtete Meridionalkomponente der Strömung vor. Ein Maximalwert der durchschnittlichen meridionalen Zirkulation von +60 cm sec–1 wurde in der 100 mb-Höhenlage bei 70°N festgestellt.
Résumé Dans cette étude, la composante horizontale de la circulation méridionale dans la stratosphère aux niveaux de 100, 50 et 30mb est calculée pour la période de Juillet 1957au Juin 1958 pour l'Année Géophysique Internationale. Les données de radiosondage d'environ 240 stations bien réparties sur l'hémisphère du nord sont employées dans l'analyse de la composante nord-sud du vent. Les valeurs de la circulation moyenne méridionale des quatre saisons sont présententées pour tous les 5° de latitude de l'équateur jusqu'à 80°N.En moyenne d'un an, on peut apparemment observer, à 100mb, une distribution en trois cellules consistant d'une région de mouvement fort vers le pôle au nord de 55°N, d'un mouvement vers l'équateur de 15° à 55°N et d'un mouvement faible vers le pôle de 0° à 15° N. A 50 et 30 mb en moyenne d'un an des mouvements vers le pôle apparaissent seulement dans les hautes altitudes et ils diminuent en force suivant la hauteur. Dans le niveau de 30 mb, c'est un mouvement vers l'équateur qui domine. Use valeur maxima de la circulation méridionale moyenne de +60 cm·sec–1 a été constatée à 100 mb à 70°N.
With 6 Figures
The research reported in this paper has been made possible through the support of the Atomic Energy Commission and of the Geophysics Research Directorate of the U.S. Air Force under contracts No. At (30-2) 2241 and 19(604)-5223. 相似文献