Informatics Publishing Limited

A. K. Sharma ¹, D. P. Nade ¹, S. S. Nikte ¹, R. N. Ghodpage ², P. T. Patil ², M. V. Rokade ¹, R. S. Vhatkar ¹, S. Gurubaran ³

Affiliations
1 Earth and Space Science Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004, IN
2 Medium Frequency Radar, Indian Institute of Geomagnetism, Shivaji University Campus, Kolhapur 416 004, IN
3 Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410 218, IN

Abstract

This article describes the possibility of using the fast image analysis technique for qualitative and quantitative analysis of equatorial plasma bubble obtained using All-Sky imager (ASI) data. Automated image processing (generally) is useful for identification of equatorial plasma bubbles (EPBs) and its parameters. We have developed a fast (and efficient) analysis technique essential to study the data of images. The present work reports the results of a statistical study of the zonal plasma bubble velocities using nightglow OI 630.0 nm emission data, acquired by ASI (FOV 140°) at the low-latitude station Kolhapur (16.42°N, 74.2°E and 10.6°N dip lat.). Based on the observations of 15 nights made in January 2012, we have determined the velocity of EPB using our new method. The daily mean values of the EPB velocity match well with those of the earlier studies made at Kolhapur. We have found that, generally, the mean zonal drift velocities of the plasma bubbles tend to decrease with local time (after midnight). The most significant finding from this work is that the calculated velocities of plasma bubble using fast and scanning methods are nearly equal.

Keywords

All-Sky Imager, Equatorial Plasma Bubble, Nightglow Emissions, Zonal Drift Velocity.

Full Text

   

R. N. Ghodpage ¹, A. Taori ², P. T. Patil ¹, Devendraa Siingh ³, S. Gurubaran ⁴, A. K. Sharma ⁵

Affiliations
1 Medium Frequency Radar, Indian Institute of Geomagnetism, Shivaji University Campus, Kolhapur 416 004, IN
2 Atmospheric Research Laboratory, Gadanki 517 112, IN
3 Indian Institute of Tropical Meteorology, Pune 411 008, IN
4 Indian Institute of Geomagnetism, Navi Mumbai 410 218, IN
5 Department of Physics, Shivaji University, Kolhapur 416 004, IN

Abstract

The photometric measurements of mesospheric OH and O(¹S) emission, carried out from Kolhapur (16.8°N, 74.2°E), Maharashtra during January-April 2005 are used to study the wave characteristics. The nocturnal variability reveals the dominant long-period wave signatures with significant amplitudes of embedded short-period waves. We carry out a sensitivity study on the vertical wavelength (VW) derived with the help of Krassovsky parameters (η = |η|e^iΦ) of the OH data, which reveals VW to vary from 38.9 to 110.2 km. This was compared with the VW estimates using the phase difference of the simultaneously observed waves in both OH and O(¹S) emission intensities. Results reveal that in the absence of attitudinally resolved measurements, the VW estimated using Krassovsky method can be used.

Keywords

Airglow, Atmospheric Gravity Waves, Lower Thermosphere, Mesosphere, Vertical Wavelength.

Full Text