On the conception ‘Fair weather condition’ in atmospheric electricity     

Sven Israelsson 《Pure and Applied Geophysics》1978,116(1):149-158

Measurements of atmospheric electrical and meteorological parameters during different meteorological conditions indicate that the use of the conception Fair weather condition in atmospheric electricity is discussable. Fair weather contains a very broad stability range, from very unstable to strong stable stability of the atmosphere. For turbulent fluctuations of the electric parameters (the most local variations) the variations are determined by the micrometeorological processes for all stability conditions.These fluctuations represent frequencies greater than one period per four minutes. For lower frequencies (less local variations), however, the stability dependency increases. During stable conditions the electric field and vertical current density were nearly wholly influenced by the charges and their transfer in the nearest layer. During near-neutral and unstable conditions the electrical parameters were influenced by more separated sources. Measurements of how well Ohm's law was fulfilled also indicate the difficulties by using the conception fair weather. The measurements also indicate the importance of taking the convection current density into consideration in studies of the electric charge transfer in the atmosphere.In the more large scale of variations measurements of the electric field by radiosoundings show that 88% of the ionospheric potential is derived from the troposphere, where the meteorological processes are of fundamental character for the atmospheric electrical phenomena. The relatively great stability of the diurnal variation of the large scale or global electric field is also valid for the meteorological processes in this scale of variations.  相似文献   

Intercomparison of New Zealand filter ozonometer and Dobson spectrophotometer total ozone measurements     

H. Müller  R. Reiter 《Pure and Applied Geophysics》1980,118(2):847-857

A commercial version of the prototype New Zealand narrowband interference filter instrument has been run at Garmisch-Partenkirchen since autumn 1977. The vicinity of the Dobson stations Hohenpeissenberg and Arosa permitted a check of the filter instrument's utility, reliability and long-term stability in total ozone measurement by (i) station to station-or short-range intercomparisons of daily means and (ii) a several days' direct intercomparison at Arosa in spring 1978.The regression analysis with the Hohenpeissenberg data-covering the five month autumn-winter 1977/78 period with highly variable ozone-shows that the filter instrument's direct-sun modeX _AD total ozone values were systematically too low by a conversion factor of 0.93. The excellent proportionality between the instruments is indicated by the standard deviation of only 1,3%. The (–7.0±1.3%) bias perfectly agrees with the result reported byBasher [1] for a similar, yet direct, intercomparison.During the direct Arosa intercomparison the filter instrument also tracked down short-time variations in a remarkable, though biased, parallelism with the Dobson instruments, and theX _AD daily means fit well into the prognostic relationship derived from the preceding autumn-winter short-range intercomparison.A creeping deterioration of the characteristics of the 305.5 nm double filter then prevented any furtherX _AD total ozone intercomparison. No final decision is possible whether this behaviour after a half year's run is typical or just an unusual exception. The otherwise excellent long-term stability is demonstrated by the comparison of theX _CD daily means with the HohenpeissenbergX _AD data for a 1 1/2 year's period (autumn 1977–spring 1979), resulting in the same bias relationship as for theX _AD total ozone measurements.  相似文献   

Measurement of lower-stratospheric aerosol by a balloon-borne photometer     

Y. Kondo  M. Takagi 《Pure and Applied Geophysics》1980,118(2):858-866

Height distribution of the stratospheric aerosol extinction coefficient was measured in the altitude range 10 to 20 km by a balloon-borne multi-color sunphotometer in May 1978. It is demonstrated that detailed structures of the distribution of stratospheric aerosol can be remotely measured by the solar occultation method as well as by lidar andin situ particle counter observations. In the aerosol layer appearing at 18 km altitude the extinction coefficient at 800–1000 nm wavelength reached to 3×10^–7 m^–1, which was reasonable compared with lidar observations. Wavelength dependence of the aerosol optical depth was crudely estimated to be proportional to ^–1.5.  相似文献   

The characteristics of rain electricity in Nigeria. I — Magnitudes and variations     

A. I. I. Ette  E. O. Oladiran 《Pure and Applied Geophysics》1980,118(2):753-764

The characteristics of rain and point charges based on routine measurements extending over four rainy seasons are presented. An average rain current density of (1.0±0.1)×10^–10 A m^–2 and charge per unit volume of rain water of (0.43±0.02)×10^–4 C m^–3 for the locality are obtained, which are compared with data obtained elsewhere by other workers. The point-discharge current measurements lead to a revised estimate of (0.86±0.08)×10^–9 A m^–2 for the average point discharge current below storm clouds.  相似文献   

Equations of kinetic and available potential energy evolution in wave-number frequency space     

S. K. Kao 《Pure and Applied Geophysics》1980,118(2):867-879

The equations of kinetic and available potential energy for the analysis of the growth and decay of atmospheric waves in wave-number-frequency space are derived. The effects of linear and nonlinear interactions of waves in the velocity and temperature fields, the conversions between the available potential and kinetic energies, and the Reynolds and molecular stresses on wave growth and decay are discussed.  相似文献   

Global distribution of gaseous mercury in the troposphere     

W. Seiler  C. Eberling  F. Slemr 《Pure and Applied Geophysics》1980,118(2):964-974

Atmospheric mercury concentrations were measured during a nautical expedition on the Atlantic Ocean between Hamburg (54°N, 10°E) and Santo Domingo (20°N, 67°W). In addition, samples were taken during flights on a commerical aircraft in the upper and middle troposphere between 60°N and 55°S, mostly over the Pacific Ocean. The data obtained in the lower troposphere over the Northern Atlantic show considerable variation in the Hg concentrations, with values ranging between 1 and 11 ng/m³; the average concentration was found to be 2.8 ng/m³. The upper tropospheric data show an interhemispheric difference with average values of 1.45 ng/m³ and 1.08 ng/m³ in the Northern and Southern Hemisphere, respectively. This suggests that mercury production occurs predominantly over the continents both by natural and anthropogenic processes. The mercury content in aerosols was found to be 0.3 ng/m³, or one-tenth of the atmospheric concentration. The data indicate a mean residence time of mercury in the atmosphere of a few months to one year.  相似文献   

Spatial and Temporal Characteristics of Horizontal Rolls and Cells in the Atmospheric Boundary Layer Based on Radar and in Situ Observations     

F. Lohou  A. Druilhet  B. Campistron 《Boundary-Layer Meteorology》1998,89(3):407-444

This paper is the second of a series devoted to the observation and analysis of coherent structures in the cloudy Atmospheric Boundary Layer (ABL) such as horizontal rolls or thermal cells. In the first paper, the TRAC (Turbulence Radar Aircraft Cells) experiment which is the observational support of this investigation based on coupled radar-aircraft measurements, was presented along with an overview of the main results of this campaign held in June 1993 in France. Here the analysis is focused on the spatial characteristics (length-scale, orientation ... ) of the coherent structures, their temporal evolution and vertical distribution deduced from the radar reflectivity fields acquired in clear air at several levels for five different ABLs. For that, an original and efficient image processing method able to extract the major mode of the organisation was developed. These characteristics are examined in relation to the dynamic and thermodynamic state of the ABL using mean and turbulent information as observed by the in-situ aircraft. These experimental results are the basis of a future Large Eddy Simulation modeling of an organised ABL which is in progress and will be the concern of the third paper in the series.  相似文献   

大气密度方程   总被引：4，自引：0，他引：4  

张学文 《气象学报》1998,56(3):377-382

通过一个思想实验把大气密度的时空分布函数与一个概率分布函数联系了起来,又利用最大熵原理导出了一个新的全球大气的方程,即大气密度方程。文章给出了它的通解并指出等温大气的压力高度公式是它的一个特解。对这个新的理论思路,新的方程和它的应用潜力作了初步讨论。  相似文献   

大气重力信号的理论计算及其检测   总被引：22，自引：6，他引：16       下载免费PDF全文

孙和平  罗少聪 《地球物理学报》1998,41(5):634-641

基于标准大气定律和大气圆柱体分布模型,本文引进了大气重力格林函数,用离散格积方法求得了大气对重力场观测的影响,对台站高程、周围地形和地表温度变化等因素的影响问题进行了讨论．结果说明台站近区气压变化是大气重力信号的主要贡献者,考虑大气质量负荷引起的弹性地球形变效应后,对距台站0．5°的区域积分获得的大气重力导纳值为-0．3603μGal／hPa,占全球大气变化引起的总信号的90％以上,这一理论模型结果与超导重力仪实测结果相吻合,并能较有效地用于消除重力观测中的气压干扰成分．  相似文献   

Mean bulk densities of samples of dry atmospheric aerosol particles: A summary of measured data     

Gottfried Hänel  Jürg Thudium 《Pure and Applied Geophysics》1977,115(4):799-803

Mean bulk densities of various samples of dry atmospheric aerosol particles sampled at different sites and during different seasons and weather situations range between 1.8 and more than 3 gm cm³.  相似文献