Time filter

Source Type

Gokani S.A.,Indian Institute of Geomagnetism Navi Mumbai India | Singh R.,Dr Ks Krishnan Geomagnetic Research Laboratory Indian Institute Of Geomagnetism Allahabad India | Cohen M.B.,Georgia Institute of Technology | Kumar S.,University of The South Pacific | And 3 more authors.
Journal of Geophysical Research A: Space Physics | Year: 2015

We present analysis of more than 2000 lightning-generated whistlers recorded at a low-latitude station, located at Allahabad (geographic latitude, 25.40°N; geographic longitude, 81.93°E; L=1.081), India, during December 2010 to November 2011. The main focus of this work is on the correlation between observed low-latitude whistlers and lightning activity detected by the World-Wide Lightning Location Network near the conjugate point (geography 9.87°S, 83.59°E) of Allahabad. Whistler occurrence is higher in the postmidnight period as compared to the premidnight period. Whistlers were observed in the daytime only on 2days that too before 8:30 LT (morning). Seasonally, occurrence is maximum during winter months, which is due to more lightning activity in the conjugate region and favorable ionospheric conditions. About 63% of whistlers were correlated with lightning strokes in the vicinity of the conjugate point within spatial extent of 1000km (conjugate area). Most (about 53%) whistlers were found to be associated with lightning strokes that were offset to the southeast of the conjugate point. The results indicate that an energy range of 7.5-17.5kJ of lightning strokes generate most of whistlers at this station. The L shell calculations show that propagation paths of the observed whistlers were embedded in the topside ionosphere. Based on these results we suggest a possibility of ducted mode of propagation even for such very low latitude whistlers. ©2015. American Geophysical Union.

Loading Dr Ks Krishnan Geomagnetic Research Laboratory Indian Institute Of Geomagnetism Allahabad India collaborators
Loading Dr Ks Krishnan Geomagnetic Research Laboratory Indian Institute Of Geomagnetism Allahabad India collaborators