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1.
Boundary-Layer Meteorology - The vertical eddy diffusion coefficient (K z) for five smoke plumes entrapped in a stable marine layer is estimated from the published LANDSAT imagery data sets of... 相似文献
2.
Summary Utilising two years data collected at two tropical coastal stations, Madras (13°04N, 80°15E) and Waltair (17°42N, 83°18E) and for one tropical continental station, Nagpur (21°09N, 79°07E), the authors have re-evaluated the constants ofBrunt's regression equation. Analyses of the observations for Waltair and Nagpur show good correlation coefficients (r) between the values of the effective emissivity of the atmosphere (the effective emissivity is the ratio of incoming long-wave sky radiation at the surfaceR
s
, to black body radiation T
4) and the square root values of surface vapour pressuree (mb). The value ofr for Waltair from radiometer observations is 0.98. It is also determined for Waltair and Nagpur from Ångström compensation pyrgeometer observations as 0.83 and 0.91 respectively. A low correlation co-efficient 0.56 is obtained for Madras. It might be due to higher surface vapour pressure values at Madras than at Waltair and Nagpur. The applicability of the reduced regression equations are examined for different years for the different stations. The agreement between the computed values with the new regression equations and the observed long-wave sky radiation at the surface seems to be quite good. 相似文献
3.
Pure and Applied Geophysics - The relationship between (Q) total solar radiation, as measured by a solarimeter, and hours of bright sunshine (n), as measured by a Campbell-Stokes recorder, has been... 相似文献
4.
Summary The study of heat exchanges or temperature changes in the surface layers of the soil are important in agricultural science at tropical latitudes. The quantity, thermal diffusivity largely determines the temperature change produced in any layer of the soil when heat is conducted there from an adjacent layer. Therefore, the authors have determined the thermal diffusivity of the soil from range and lag methods suggested byJohnson andDavies [15]2) andCoutis [7] respectively. The values of diffusivity cbtained from these methods agree well with each other. The effect of soil moisture on diffusivity has been studied. The diffusivity increases with the increase of moisture in the surface layers of the scil. The ratio of ranges of soil temperature at different depths is found to be approximately constant which is in agreement with the theory of heat flow into the soils. The results of diffusivity obtained from these methods agree well with those results of past workers. The mean value of the thermal diffusivity of red sandy soil at the experimental site of Waltair is found to be 6.336×10–3 cm2/sec. 相似文献
5.
Summary The present paper contains studies of the nocturnal radiation at some Indian Stations (Madras, Waltair, Nagpur, New Delhi and Poona) with the help of the Ångström compensation Pyrgeometer. The technique of measurement is also described briefly. A study of the mean monthly variation of sky radiation during clear as well as all nights has been discussed. A comparitive study of mean monthly values of sky and other nocturnal radiation components at these stations is also presented.
Ångström, [4]2) expressed the dependence of sky radiationS—on water vapour pressuree (mm of mercury) at the earth's surface and air temperatureT (degrees absolute), near the instrument to be given byS=T
4 (0.75–0.32×10–0.069e
) cal/cm2/min. According to this semi-empirical relationship, the calculated values of sky radiation for clear nights are smaller than the observed values of sky radiation at all the above stations. It is for this reason the authors obtained a new formula with different constants using nine years observed data at all the stations. To investigate the value of the constant, the mean annual observations presented for nine years from clear skies were analysed for correlations betweenB (black body radiation) versesS (sky radiation),N (net radiation) andE (absolute error) and obtained a good correlation co-efficients 0.90, 1 and 0.98 respectively. The new suggested formula isS=T
4 (0.88–0.32×10–0.069e
) cal/cm2/min, 267° A<T<313° A. It is also verified using with observed data of different years of the stations. The agreement between the computed values with the new formula of sky radiation and observed sky radiation is found to be good. 相似文献
6.
Y. Viswanadham 《Boundary-Layer Meteorology》1979,17(4):537-544
Values of Richardson number (Ri) and the wind profile curvature () in the atmospheric surface layer are evaluated from experimental data. The relationship between Ri and shows some scatter, but gives agreement with the theoretical relation derived by Businger et al. (1971). 相似文献
7.
V. V. S. S. Sarma M. S. Krishna R. Viswanadham G. D. Rao V. D. Rao B. Sridevi B. S. K. Kumar V. R. Prasad Ch. V. Subbaiah T. Acharyya D. Bandopadhyay 《Journal of Oceanography》2013,69(1):45-55
A study on biogeochemical cycling in the west coastal Bay of Bengal was undertaken during the peak discharge period to understand the influence of enhanced stratification and primary production on the possible intensification of the oxygen minimum zone (OMZ). Our study reveals that oxygen concentrations were below the detection limits in the northwestern (NW) coastal Bay of Bengal between 100 and 500 m associated with strong stratification and high phytoplankton biomass. Such low oxygen concentrations have never been reported so far from the coastal Bay of Bengal. Despite the existence of an environment conducive to denitrification in the coastal Bay of Bengal, accumulation of neither secondary nitrite nor nitrous oxide (N2O) was observed. The absence of denitrification was reported to be caused by faster scavenging of organic matter and low bacterial respiration rates; in contrast, our results suggest that neither of these factors are potential reasons for the absence of denitrification in the coastal Bay of Bengal. 相似文献
8.
—An attempt has been made to study the atmospheric surface layer characteristics such as Richardson number (Ri). Monin-Obukhov length scale (L), friction velocity (U * ?), friction temperature (θ *?), roughness length (Z 0?), turbulent kinetic energy (TKE), ratio of eddy conductivity to eddy diffusivity (K m ?/K h ?) over a semi-moist convective regime. Data which were collected at Varanasi (25°18′N, 83°E) as part of the experiment known as MONTBLEX-90 (Monsoon Trough Boundary Layer Experiment) during the summer monsoon season was used in the present study. The variation of the above parameters with stability has been discussed. The differences within the surface layer are also pointed out. Some broad features are found to coincide with that of Businger et al. (1971). The heterogeneity and the anisotropic turbulence typical of monsoon tropical atmosphere are shown to be responsible for the deviations noticed within the surface layer. 相似文献
9.
Summary In this paper the dispersal capacity of the atmosphere has been determined over North India by studying spatial variations of inversions, isothermals, lapse conditions, mixing heights and ventilation coefficients. Seasonal variations of these parameters have also been studied. The western part of North India is best for good dispersal of pollutants while the eastern part is poor at all time of year.With 9 Figures 相似文献
10.
Monthly mean afternoon (maximum) and early morning (minimum) mixing heights have been calculated for the winter, pre-monsoon, monsoon and post-monsoon seasons for eleven stations in India, with the assumption of a dry adiabatic lapse rate in the mixing layer. The morning mixing heights have been calculated by adding +5 °C to the surface minimum temperature except for the monsoon season for which a value of +3 °C has been utilized to account for the urban heat island effect. The spatial variation of mean maximum mixing heights over India has also been studied by isopleth analysis. The morning and afternoon ventilation coefficients have been calculated for the eleven stations under consideration. The spatial distribution of afternoon ventilation coefficients has also been studied. The optimum siting industries to minimize our pollution has been discussed. 相似文献