Articles | Volume 26, issue 7
https://doi.org/10.5194/angeo-26-1865-2008
https://doi.org/10.5194/angeo-26-1865-2008
09 Jul 2008
 | 09 Jul 2008

Seasonal variation of low-latitude E-region plasma irregularities studied using Gadanki radar and ionosonde

D. V. Phanikumar, A. K. Patra, C. V. Devasia, and G. Yellaiah

Abstract. In this paper, we present seasonal variation of E region field-aligned irregularities (FAIs) observed using the Gadanki radar and compare them with the seasonal variation of Es observed from a nearby location SHAR. During daytime, FAIs occur maximum in summer and throughout the day, as compared to other seasons. During nighttime, FAIs occur equally in both summer and winter, and relatively less in equinoxes. Seasonal variations of Es (i.e. ftEs and fbEs) show that the daytime activity is maximum in summer and the nighttime activity is maximum in equinoxes. No relation is found between FAIs occurrence/SNR and ftEs/fbEs. FAIs occurrence, however, is found to be related well with (ftEs−fbEs). This aspect is discussed in the light of the present understanding of the mid-latitude Es-FAIs relationship. The seasonal variations of FAIs observed at Gadanki are compared in detail with those of Piura, which show a significant difference in the daytime observations. The observed difference has been discussed considering the factors governing the generation of FAIs.

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