Cálculo da velocidade de crescimento vertical das bolhas de plasma ionosférico observado pelo imageamento do airglow OI 630,0 nm.

Abstract

This work aimed to objective calculate the speed of plasma bubbles's vertical growth at Sao Joao do Cariri (7.4°S, 36.5 0 W, 12.25°S de dip latitude) for the period September to November 2005. For this, we used the optical technique of airglow Ol 630.0 nm. The Ol 630.0 nm is a red light from the atomic oxygen thermosphere at an altitude around 250 km whose intensity is directly proportional to the electron density (concentration of electrons). Because the ionosphere plasma bubbles are regions where the electron density is greatly reduced as compared to its neighborhood, the intensity of the Ol 630.0 nm airglow also decreases in these regions. Thus, observing the intensity of the Ol 630.0 nm airglow can check the occurrence of ionospheric bubbles. The intensity of the Ol 630.0 nm airglow can be observed by digital monochrome images. Two applications were developed in the computer programming language IDL 6.2, one to process the digital images and the other to calculate the speed of vertical growth of plasma bubbles with greater precision. The images analyzed in this work were recorded by an instrument called all-sky imager operating in Sao Joao do Cariri. The general conclusions of this study were the following: 1) the vertical growth velocity of plasma bubbles showed a high variation the time interval observed each night, thereby having a high value on its standard deviation (between 15 and 43 m/s), 2) the intensity of the vertical growth rate of the bubbles is relatively higher during the period of high solar activity, 3) observed that there is a strong correlation between the magnitude of the pre-reversal vertical drift layer F, later afternoon, and the intensity of the vertical growth velocity of plasma bubbles.