Disturbed O/N 2 Ratios and their Transport to Middle and Low Latitudes
2011; American Geophysical Union; Linguagem: Inglês
10.1029/181gm20
ISSN2328-8779
Autores Tópico(s)Solar and Space Plasma Dynamics
ResumoThe neutral atmospheric composition responds dramatically to geomagnetic storms. Much progress toward understanding the response came from in situ measurements on board the Atmospheric Explorer and Dynamics Explorer 2 satellites. These observations also provided significant databases for the Mass Spectrometer Incoherent Scatter empirical model. Strong evidence was found for upwelling of molecular species at high latitudes and downwelling at lower latitudes. Early authors connected these composition changes to ionospheric effects, including both positive and negative phases of geomagnetic storms. Models have confirmed some of their conclusions, but up until recently, the data have not yet been good enough to completely define the mechanisms of the drivers or evolution of the composition. Global imaging capabilities evolved from Dynamics Explorer 1 through the Polar and IMAGE satellites. However, the Global Ultraviolet Imager (GUVI) spectroscopic imager on the TIMED satellite has provided a revolutionary view of composition changes and their relationship to ionospheric storms. Even so, we still do not have much of the right data in the right places and the right times to unravel the combined effects of composition, winds, and electric fields on the ionosphere. In this short review, we explain what is known about disturbed O/N 2 ratios during storms and discuss how changes can occur at regions remote from the high latitude forcing. We also discuss their relationship with neutral winds and their effects on NmF 2 . Finally, we discuss outstanding problems and required measurements for addressing them.
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