All Physics Faculty Publications

Title

Ionospheric Plasma Bubble Climatology Over Brazil Based on 22Years (1977-1998) of 630 nm Airglow Observations

Document Type

Article

Journal/Book Title/Conference

Journal of Atmospheric and Solar-Terrestrial Physics

Volume

64

Issue

12-14

Publisher

Elsevier

Publication Date

9-2002

First Page

1517

Last Page

1524

DOI

10.1016/S1364-6826(02)00089-5

Abstract

The frequency of occurrence of the large-scale ionospheric plasma depletions, or plasma bubbles, over Cachoeira Paulista—CP (45°W, 33°S, 28°S dip), with solar activity, season, and geomagnetic activity, during the period of 1977–1998, is studied here based on 934 days of scanning photometers and imagers data of the atomic oxygen View the MathML source nocturnal airglow. The bubble occurrence for the entire period of study shows maximum rate of 86% in January and 11% in May. The seasonal pattern of the bubble occurrence shows up as broad a maximum and a minimum centered around summer and winter months, respectively. While during the high-solar activity the maximum extends from September to April, for the low-activity period it extends from October to March. The average sunspot number for the solar maximum (minimum) for the data of this work is 129.9 (33.1). Significant increase of bubble occurrence (by ∼80%) from low to high solar activity levels is found to occur in the present analysis only during the equinoctial months of March–April and September–October. The post-sunset plasma bubble occurrence over Cachoeira Paulista is found to decrease with increase of Kp that precedes the sunset by View the MathML source, suggesting the role of disturbance dynamo electric field to inhibit its development. Increase of Kp during sunset hours can increase the bubble occurrence as a possible effect of prompt penetration electric field. These results are presented and discussed in this paper.

Comments

Published by Elsevier in Journal of Atmospheric and Solar-Terrestrial Physics.

http://www.sciencedirect.com/science/article/pii/S1364682602000895

Publisher PDF is available for download through the link above.

http://www.sciencedirect.com/science/article/pii/S1364682602000895