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   

On the relationship between small atmospheric ions concentration and (1) smoke, (2) sulfur dioxide and (3) wind speed     

Dimitris A. Retalis 《Pure and Applied Geophysics》1977,115(3):575-581

In the present study the influence of smoke and sulfur dioxide concentrations and of wind velocity on the concentration of small positive and negative ions above Athens area (=37°58.3N, =23°43E,h=107 m) is examined.Between the above mentioned elements simple linear correlation and multiple linear correlation is attempted. This correlation is based on mean daily values of the elements, for the two-year period 1971–1972, for each month separately.From the above examination it has been ascertained that small ions concentration increases as smoke and/or sulfur dioxide concentration decreases. Also, small ions concentration increases as wind velocity increases.In addition, it was ascertained that sulfur dioxide contributes the least to the determination of the variance of small ions concentration, whilst the greatest contribution is made by smoke for the positive small ions or by wind velocity for the negative ones.  相似文献   

A spectrum of the acoustic-gravity waves associated with Auroral electro-jet     

E. O. Okeke 《Pure and Applied Geophysics》1977,115(3):593-606

This model concerns the analysis of Aurora initiated travelling pressure waves in an isothermal atmosphere. Electro-dynamic Lorentz Force associated with auroral electric current density during the periods of geomagnetic activity is invoked as a possible exciting source.The dispersion phenomena in auroral induced acoustic gravity modes in the earth's atmosphere are examined and various cut-off frequencies analysed.Finally, an attempt is made to obtain a far field representation of the forced oscillations by means of Green's Function technique. Therefrom, the spectral amplitudes of the ground-level oscillations are computed. Incorporating various scaling factors, it is deduced that these amplitude components are in reasonable agreement with the results of recent measurements.  相似文献