Diurnal variation of atmospheric Maxwell current over the low-latitude continental station, Tirunelveli, India (8.7°N, 77.8°E)

Abstract

Observations of atmospheric Maxwell current from the low-latitude continental station, Tirunelveli (8.7 • N, 77.8• E), over a period of 8 years are presented in this study. The horizontal long-wire antenna is used as a sensor for picking up charges from the atmosphere. The objectives of the present work have been to understand the antenna system in response to different meteorological conditions and on fairweather days. We define a fairweather day as a day when there is no snowfall/rainfall at the measuring site, when there are high clouds less than 3 octas throughout the day, and when the wind speed is less than 10 m s −1 . A sunrise effect is observed in the measured Maxwell current during fairweather days in all seasons. The measured current exhibits an increase that commences about 30 min before sunrise and lasts for nearly 1.5 h. The sunrise effect is found to be inhibited on days when there is pre-dawn convection and during the presence of rain, haze, or cloud cover. Barring the sunrise effect, the rest of the variations on fairweather day appear to follow a trend typical of the Carnegie curve. On clear cloudless conditions, reasonably good data are obtained during equinox and winter months but not in summer when strong winds associated with the onset of the southwest monsoon make the measurement of Maxwell current difficult and limited data are available.

Measurement of atmospheric air-earth current density from a tropical station using improvised Wilson’s plate antenna

“…Pollution is low, and scanty rainfall in this region enables a large number of atmospheric electricity measurements to be made, including the vertical electric field using a horizontal passive wire antenna, Wilson's plate antenna for conduction current, and the Maxwell current density using a long wire antenna. The results of these studies have been reported earlier (Panneerselvam et al, 2007).…”

Investigation of the Influence of Galactic Cosmic Rays on Clouds and Climate in Antarctica

“…The atmospheric electricity measuring instrumentations used are long wire antenna, passive antenna and electric field mill, which are similar to the standard ones used (e.g., Ruhnke, 1969;Willett and Bailey, 1983;Tammet et al, 1996;Harrison, 1997). Instruments are calibrated at the highly sophisticated electronic laboratories in India and described in Dhanorkar and Kamra (1997), Deshpande and Kamra (2001) and Panneerselvam et al (2007a). An Automated Weather Station (AWS) is operated at Maitri for monitoring meteorological parameters.…”

Atmospheric electric parameters and micrometeorological processes during the solar eclipse on 15 January 2010

“…The sum of all these current components is described as the Maxwell current. The current components have been successfully measured in recent years to study atmospheric electrical parameters at the Tirunelveli site [e.g., Panneerselvam et al ., , ; Anil Kumar et al ., ].…”