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Summary A study of the wavelength exponent of aerosol scattering in the Ångström relation for extinction by aerosol has been made from the ground-based measurments of direct solar radiation using Ångström pyrheliometer with and without Schott filters. It has been observed that in India, mainly for the middle part of the year this exponent is zero or even negative which means that the aerosol scattering is nearly neutral which is in marked contrast with the condition prevailing in middle latitudes. It is evident from the -values that the aerosol size distribution in India is far different from that prevailing in middle latitudes. At four representative stations in India, the values of the wavelength exponent and the atmospheric turbidity coefficient have been determined using the method introduced byÅngström [1,2]) and are discussed here.  相似文献   
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Summary Frequency, magnitude and energy of Indian earthquakes with magnitude greater than 5 has been studied. The Indian regions can be divided into three main seismically active regions, viz. 1. Delhi and Himalayan region, 2. Assam region and 3. Koyana region which includes southwest India. The relations between frequency-magnitude and energy-magnitude of earthquakes are shown in Fig. 3 and 4 respectively. Further a relationship, logN=p+q logE type has been established for frequency and energy of Indian earthquakes and the values of constantsp andq have been determined for all the three seismic regions. The results thus obtained are good and satisfactory.  相似文献   
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Summary Vertical time-section charts for temperature and dew-point anomalies have been plotted. The temperature anomaly decreasing upwards give convection according to Byers and Braham [1]2). The coincidence of temperature anomalies with central minimum and of dew-point anomalies with central maximum, or of upward decreasing trend in temperature anomalies and upward increasing trend in dewpoint anomalies, correspond to the convection associated with greater moisture influx, thus representing the case of a thunderstorm. The mentioned anomalies have been found to occur in such a way that cells with central maximum are followed by those with central minimum, and vice versa. Thus simultaneous occurrences of upward decreasing anomalies in temperature, i.e. occurrence of cells with central minimum of temperature, and upward increasing anomalies in dew-point, i.e. occurrence of cells with central maximum, can be observed at any station, hence the occurrences of thunderstorms at that station can be predicted. Moreover, the two kinds of anomalies can give the idea (along with that of convection, of coming of the synoptic situation having dry air aloft and moist air below, which is the ideal condition) for the occurrence of a hailstorm (Fawbush andMiller [2]).  相似文献   
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Summary In the present paper an attempt has been made to interpret irregular vertical magnetic anomalies due to magnetite ore in the form of inclined thin veins, pods or lenses striking neither north nor east. A chart has been prepared for varying percentage of magnetite ore using arbitrary values of susceptibility contrast for Singhbhum and Palamau districts (Bihar), which would be helpful while interpreting magnetic anomalies to be found in these areas. Depth to width ratio against parameter c as well as two theoretical curves have also been presented. Further two field profiles are being matched with theoretical curves. The depths and widths of thin veins have been calculated using simple rules. An overall checking of these quantities is possible by curve-matching process.  相似文献   
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Summary The best fit curves for upper air mean dry-bulb and dew-point temperatures over Gauhati airport (26°05N, 91°43E, 49 metres a.m.s.l.), for the month of April, have been calculated with the equation,x=A+By+Cy 2,y being the log value in mb of the isobaric level under consideration andx, the mean dry-bulb or dew-point temperature as the case may be, at the isobaric level under consideration. The values of constantsA, B andC for morning dry-bulb and dew-point curves come to be –29.54559, –93.65766 and +37.35048 and –118.84791, –31.15503 and +25.63585 respectively and values of these constants for evening curves come to be –35.86214, –94.15694 and +38.61870 and –127.55970, –29.97192 and +26.36538 respectively. These best fit curves help in finding out mean desired temperatures at any isobaric level in forecasting of thunderstorms and hailstorms, at a station, by dry-bulb and dew-point temperature anomaly technique propsed earlier by the authors.  相似文献   
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