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A. Yacob 《Pure and Applied Geophysics》1973,111(1):2319-2323
Summary Using the monthly mean diurnal inequalities of Colaba horizontal force for each of the 24 local hours given by Moos, the amplitudes of the sine and cosine terms of the annual and semiannual components and their mean errors were obtained by the application of the least-squares method and solution of simultaneous equations. The annual-component amplitude is largest for 13 hours and the epoch of maximum for most of the sunlit hours is in May. The semiannual component attains large amplitude during the forenoon hours, while its epoch of maximum shows considerable variation. A discontinuity is observed around 18 hours in the trend of change in amplitude and phase of both components, suggesting the effect of partial ring currents. 相似文献
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Examination of the night-time geomagnetic horizontal field component at Alibag for international quiet-days of solar minimum epochs, show effects of galactic X-ray ionization as depressions in the field approximately corresponding to transit times of individual sources. 相似文献
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Summary Secular variations inH at four Indian observatories near the regional focus of maximum horizontal intensity show that a reversal of the increasing trend occurred from about, 1965. Broad agreement in the secular trends is seen with some differences in detail. The changes observed at the observatories do not appear to be due to positional shift of the focus. The differences in the trends are attributable to secondary induced current effects in the earth's upper mantle or crust. An apparent long-period variation of 110 years is shown to be part of a much longer period trend. 相似文献
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Ethiopia and the Eastern Nile Basin 总被引：1，自引：0，他引：1
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Spatial and temporal variation of groundwater recharge in shallow aquifer in the Thepkasattri of Phuket,Thailand 
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下载免费PDF全文 Whether groundwater resources can be sustainably utilized is largely determined and characterized by hydrogeological parameters.Estimating the groundwater recharge is one of the essential parameters for managing water resources and protecting water resources from contamination.This study researched the spatial and temporal variation of groundwater recharge in the Thepkasattri sub-district through integrating chloride mass balance(CMB)and water table fluctuation(WTF)methods.The chloride content of representative rainfall and groundwater samples was analyzed.Besides,WTF method was adopted from groundwater level data from 2012 to 2015.According to the CMB method,the mean recharge was estimated to be 1172 mm per year,accounting for 47%of the annual rainfall.Moreover,the estimated recharge from the WTF method took 26%of annual rainfall in 2015.The recharge was underestimated according to the WTF method,because of the uncertainty in specific yield estimates and the number of representative wells in the study area.Moreover,the correlation between rainfall and water table fluctuation data indicated the positive linear relationship between two parameters.The spatial recharge prediction indicated that recharge was higher(1200-1400 mm/yr)in the eastern and western catchment,while that in the central floodplains was between 800 mm/yr and 1100 mm/yr.In addition,low recharge value between 450 mm/yr and 800 mm/yr was observed in the south-west part of Thepkasattri.The spatial variation of recharge partly reflects the influences of land use and land cover of the study area. 相似文献
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Summary The external field due to plasma within the magnetosphere has been computed as a function ofA
p, which is a measure of solar wind velocity, for very quiet to slightly disturbed conditions using mean daily horizontal intensity from 1932 to 1968 at Alibag. The intensity, corrected for secular change and reduced to a common epoch, showed initially a small increase withA
p followed by a steady depression with further increase in the index. ForA
p7.5, which is representative of conditions over the 33-hour interval during which data relating to low-energy protons were acquired and used byHoffman andBracken [4]2) to compute current distributions, the decrease, computed here from surface data, is 6 . This is in goodagreement with the southward directed field of the quiet-time proton belt 9±5 obtained byHoffman andBracken. 相似文献
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