Far ultraviolet equatorial aurora during geomagnetic storms as observed by the Low-Resolution Airglow and Aurora Spectrograph
| Autor: | Kenneth F. Dymond, Scott A. Budzien, Andrew W. Stephan, Robert P. McCoy, Supriya Chakrabarti, Stefan E. Thonnard |
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| Rok vydání: | 2001 |
| Předmět: |
Atmospheric Science
Soil Science Astrophysics Aquatic Science Oceanography Atmospheric sciences Physics::Geophysics Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Emission spectrum Physics::Atmospheric and Oceanic Physics Astrophysics::Galaxy Astrophysics Ring current Earth-Surface Processes Water Science and Technology Geomagnetic storm Physics Ecology Energetic neutral atom Airglow Paleontology Forestry Geophysics Earth's magnetic field Space and Planetary Science Physics::Space Physics Astrophysics::Earth and Planetary Astrophysics Ionosphere Thermosphere |
| Zdroj: | Journal of Geophysical Research: Space Physics. 106:30323-30330 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/2001ja001103 |
| Popis: | We report the detection of storm time enhancements in the low-latitude far ultraviolet airglow as observed by the Low-Resolution Airglow and Aurora Spectrograph on the Advanced Research and Global Observation Satellite. The enhancements are present in several of the dayside and nightside emission lines, including the prominent 1304- and 1356-A lines of atomic oxygen as well as the N2 Lyman-Birge-Hopfield bands near 1465 and 1495 A. Time histories of the average low-latitude intensities of all emissions show a correlation with geomagnetic activity, as measured by the Dst index. Comparisons between the prestorm and storm time latitude profiles indicate that the emission increases are confined to magnetic latitudes < 20°. We have used the ratio of 1356 A/1495 A as a measure of O/N2 composition changes at these low latitudes. Although this ratio shows composition changes during the storm, no change in the ratio is observed during the peak in the emission. On the basis of the emission morphology, we conclude that these emission enhancements are most likely the result of energetic neutral atoms, which are created in the ring current and collisionally excite ambient atomic oxygen and molecular nitrogen in the low-altitude, low-latitude ionosphere and thermosphere. |
| Databáze: | OpenAIRE |
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