Inertial-Dissipation flux measurements over south Bay of Bengal during BOBMEX-Pilot experiment     

M. Venkataramana  K. Sengupta  G. S. Bhat  S. Ameenulla  J. V. S. Raju 《Journal of Earth System Science》2000,109(2):239-247

This paper describes measurement of air-sea parameters and estimation of sensible and latent heat fluxes by the “Inertial-Dissipation” technique over south Bay of Bengal. The data were collected on ORV Sagar Kanya during BOBMEX-Pilot cruise during the period 23rd October 1998 to 12th November 1998 over south Bay of Bengal. The fluxes are estimated using the data collected through fast response sensors namely Gill anemometer, Sonic anemometer and IR Hygrometer. In this paper the analyses carried out for two days, one relatively cloud free day on November 3rd and the other cloudy with rain on November 1st, are presented. Sea surface and air temperatures are higher on November 3rd than on November 1st. Sensible heat flux for both the days does not show any significant variation over the period of estimation, whereas latent heat flux is more for November 3rd than November 1st. An attempt is made to explain the variation of latent heat flux with a parameter called thermal stability on the vapor transfer from the water surface, which depends on wind speed and air to sea surface temperature difference.  相似文献   

The Chromospheric Network – (A) Network Evolution Viewed as a Diffusion Process     

Srikanth  R.  Singh  Jagdev  Raju  K.P. 《Solar physics》1999,187(1):1-9

Autocorrelation and cross-correlation techniques have been applied to obtain quantitative information about the dynamics of magnetic flux on the solar surface. The speed of network magnetic elements and the diffusion coefficient associated with their random motion is derived. The speed is found to be about 0.1 km s^–1, independent of activity level. However, the diffusion coefficient shows a strong activity dependence: it is about 370–500 km² s^–1in the quiet network and 135–210 km² s^–1in the enhanced network. It is found that the lifetime of the enhanced network relative to the quiet network is compatible with that suggested by a comparison of their respective diffusion coefficients. This supports the proposition that a diffusion-like dispersion of magnetic flux is the dominant factor in the large-scale, long-term evolution of the network.  相似文献   

A biogeochemical study of the Podili and Tirupati area of Andhra Pradesh, India     

K. S. Reddy  K. S. S. Prasad  A. N. Raju 《Environmental Geology》1999,37(4):313-316

 The fluoride content of dung, urine and milk of grazing animals, for example cow, she-buffalo, doe and ewe, was studied in the Podili area, India, (endemic fluorosis) and also in Tirupati (non-fluorosis) for the purpose of comparison. The data reveal that the fluoride content of the urine of animals is suitable for the preparation of biogeochemical atlases studying the environmental effect in relation to health. Received: 1 August 1997 · Accepted: 2 March 1998  相似文献   

The Effect of Mass Motions Inside the Coronal Loops on Emission Line Profiles     

Raju  K.P. 《Solar physics》1999,185(2):311-322

The observed green coronal emission line profiles have been often found to have multi-components. Further examinations reveal that the occurrence of multi-components in line profiles is related to the solar cycle variations as well as the activity of the coronal region. The spatial correspondence between the intense loops in active regions and strong multi-components in line profiles suggests that the presence of loops affects the line shapes. The emission line profiles have been found to be fitted well with single or multi-Gaussians with line-of-sight velocities up to 70 km s–1. A simple radiative transfer model of coronal emission line profiles is developed which shows that coronal loops with mass motions inside may give rise to multi-components in line profiles. The effects of loop parameters such as electron density, flow velocity and kinetic temperature and the line-of-sight variations are studied. It is found that line profiles strongly reflect the physical conditions inside the loop.  相似文献   

Advancements in hydrochemistry mapping: methods and application to groundwater arsenic and iron concentrations in Varanasi,Uttar Pradesh,India     

Ricardo?A.?OleaEmail author  N.?Janardhana?Raju  Juan?José?Egozcue  Vera?Pawlowsky-Glahn  Shubhra?Singh 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(1):241-259

The area east of Varanasi is one of numerous places along the watershed of the Ganges River with groundwater concentrations of arsenic surpassing the maximum value of 10 parts per billion (ppb) recommended by the World Health Organization in drinking water. Here we apply geostatistics and compositional data analysis for the mapping of arsenic and iron to help in understanding the conditions leading to the occurrence of elevated level of arsenic in groundwater. The methodology allows for displaying concentrations of arsenic and iron as maps consistent with the limited information from 95 water wells across an area of approximately 210 km²; visualization of the uncertainty associated with the sampling; and summary of the findings in the form of probability maps. For thousands of years, Varanasi has been on the erosional side in a meander of the river that is free of arsenic values above 10 ppb. Maps reveal two anomalies of high arsenic concentrations on the depositional side of the valley, which has started seeing urban development. The methodology using geostatistics combined with compositional data analysis is completely general, so this study could be used as a prototype for hydrochemistry mapping in other areas.  相似文献