A seasonal study of foF2 data of two Pakistani Ionospheric Stations viz : Karachi and Islamabad for the period from March 1982 to February 1983 shows that the percentage occurrence of the fore – noon & post – noon bite – outs traveling from a higher latitude to a lower one is maximum in winter and minimum in Summer. A reversed seasonal trend is observed for the bite – outs which traveled from lower to higher latitudes. The propagation of fore – noon and post – noon bite – outs from higher to lower latitudes and vice versa gives a clue that the possibility of their production by E x B drift may be ruled out and that a plausible cause of the bite – outs may be meridional wind (equatorward / poleward winds). |
Abstracts 
