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291.
Faraday rotation angle records of VHP (137.35 MHz) signals from ATS-3 received at São José dos Campos (Magnetic dip-23.7°) exhibit nighttime fluctuations during equinoctial and summer months. These fluctuations have periodicities ranging from several seconds to about an hour. We investigate the relationship between these fluctuations and the F-layer irregularities. 相似文献
292.
Bianchi Type III massive string cosmological model for perfect fluid distribution in the presence of magnetic field, is investigated. It is assumed that the universe is filled with barotropic perfect fluid. We have attempted to investigate Bianchi Type III string cosmological model incorporating perfect fluid with magnetic field. To get the deterministic model in terms of cosmic time, we have assumed that the expansion (θ) in the model is proportional to the shear. We have also assumed that F 12 is the only non-vanishing component of electromagnetic field tensor F ij . The behaviour of the model in presence and absence of magnetic field together with singularities in these models are also discussed. 相似文献
293.
294.
This research develops a one-parameter model of saturated source area dynamics and the spatial distribution of soil moisture. The single required parameter is the maximum soil moisture deficit within the catchment. The concept behind the development of the model comes from the fact that the complexity of topographically-driven runoff generation can be reduced through the use of geomorphological scaling relations. The scaling formulation allows the prediction of the dynamics of saturated source areas as a function of basin-wide soil moisture state. This model offers a number of potential advantages. Firstly, the model parameter is independent of topographic index distribution and its associated scale effects. Secondly, it may be possible to measure this single parameter using field measurements or perhaps remote sensing, which gives the model significant potential for application in ungauged basins. Finally, the fact that this parameter is a physical characteristic of the basin, estimation of this parameter avoids regionalization and parameter transferability problems. The model is tested using rainfall–runoff data from the 10.4 ha experimental catchment known as Tarrawara in Australia, the 37 km2 Town Creek catchment in U.S.A., and the 620 km2 Balaphi and the 850 km2 Likhu sub-catchments of the Koshi river in Nepal. In sub-catchments of Koshi river, the simulation results compare favorably against the calibrated TOPMODEL both in terms of direct runoff and the spatial distribution of soil moisture state. In the Tarrawara and Town Brook catchments, simulation results compare favorably against observed storm runoff using all observed data, without calibration. 相似文献
295.
Some inhomogeneous viscous fluid cosmological models in the presence of an electromagnetic field for cylindrical symmetry are obtained. To get a determinate solution, it is assumed that the coefficient of shear viscosity is proportional to the rate of expansion. The paper also discusses the behaviour of the model when viscosity is absent and comments on some other physical properties. 相似文献
296.
297.
298.
Bianchi Type-V bulk viscous fluid string dust cosmological model in General Relativity is investigated. It has been shown
that if coefficient of bulk viscosity (ζ) is inversely proportional to the expansion (θ) in the model then string cosmological
model for Bianchi Type-V space-time is possible. In absence of bulk viscosity (ζ), i.e. when ζ → 0, then there is no string
cosmological model for Bianchi Type-V space-time. The physical and geometrical aspects of the model are also discussed. 相似文献
299.
M. B. Potdar S. A. Sharma V. Y. Parikh P. C. S. Devara P. E. Raj Y. K. Tiwari R. S. Maheskumar K. K. Dani S. K. Saha S. M. Sonbawne Y. Jaya Rao G. Pandithurai 《Journal of Earth System Science》2004,113(1):103-116
With the launch of the German Aerospace Agency's (DLR) Modular Opto-electronic Scanner (MOS) sensor on board the Indian Remote
Sensing satellite (IRS-P3) launched by the Indian Space Research Organization (ISRO) in March 1996, 13 channel multi-spectral
data in the range of 408 to 1010 nm at high radiometric resolution, precision, and with narrow spectral bands have been available
for a variety of land, atmospheric and oceanic studies. We found that these data are best for validation of radiative transfer
model and the corresponding code developed by one of the authors at Space Applications Centre, and called ATMRAD (abbreviated
for ATMospheric RADiation). Once this model/code is validated, it can be used for retrieving information on tropospheric aerosols
over ocean or land. This paper deals with two clear objectives, viz.,
The data validation procedure essentially involves
The results show that the model performance is satisfactory and a relationship between the spectral parameters of MOS radiances
and aerosol optical thickness can be established. In this communication, we present the details of the experiments conducted,
database, validation of the ATMRAD model and development of the relationship between AOT and MOS radiance. 相似文献
1 | Validation of ATMRAD model/code using MOS data and synchronously measured atmospheric data, and if found performing well, then to |
2 | derive relationship between MOS radiances and Aerosol Optical Thickness (AOT). |
– | •near-synchronous measurements of columnar aerosol optical thickness and altitude profiles of aerosol concentration using ground-based multi-filter solar radiometers and Argon-ion Lidar, respectively and |
– | •computation of the top-of-the-atmosphere (TOA) radiances from a low reflecting target (near clear water reservoir in the present study) using the ATMRAD model. |
300.
An inhomogeneous cylindrically symmetric cosmological model for stiff perfect fluid distribution with electromagnetic field is obtained.F
12 is the non-vanishing component of electromagnetic field tensor. The metric potentials are functions ofx andt both. The behaviour of the electromagnetic field tensor together with geometrical and physical aspects of the model are also examined. 相似文献