Estimation of duct-lifetimes for storm-time low latitude whistlers observed at Srinagar, India

• DOI: 10.1007/s12648-013-0274-8
• Publication Date: 2013-03-11T06:32:12Z
• Authors: K. K. Singh; S. A. Sheikh; A. K. Singh; F. Ahmad; Lalmani
• Keywords: 13. Climate action; 0103 physical sciences; 01 natural sciences

Whistler data recorded during 5-h period at our low latitude ground station Srinagar (geomag. lat. 24°10′N; L = 1.28) are used to determine lifetime of whistler ducts. On certain occasions, whistler occurrence rate at Srinagar is found to exhibit some periodicity. Power spectrum analysis of occurrence rate yields a dominant period of about 1 hour. It is suggested that this period is an indication of the duct-lifetimes at low L-values. Dispersion analysis of these whistlers has qualitatively confirmed the existence of separate ducts during the period of observation. Further the dispersion analysis shows that these whistlers have propagated in the magnetosphere along higher L-values (L = 2.10–4.12). Power spectrum analysis may not be applicable to the whistler data corresponding to high L-values because at high latitudes the occurrence rate of whistlers is very high. Moreover a large number of ducts might simultaneously contribute to the occurrence rate.