Seasonal variations of the high-latitude F region for

Journal Article · Fri Jan 01 04:00:00 EST 1982 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA087iA01p00187· OSTI ID:5169067

Sojka, J J; Schunk, R W; Raitt, W J

We combined a plasma convection model with an inosphere-atmospheric composition model in order to study the seasonal variations of the high-latitude F region for strong convection. Our numerical study produced time-dependent, three-dimensional, ion density distributions for the ions NO/sup +/, O/sub 2/ /sup +/, N/sub 2/ /sup +/, O/sup +/, N/sup +/, and He/sup +/. We covered the high-latitude ionosphere above 42 /sup 0/N magnetic latitude and at altitudes between 160 and 800 km for a time period of one complete day. From our study we found the following: (1) For strong convection, the high-altitude ionosphere exhibits a significant UT variation both during winter and summer. (2) In general, the electron density is lower in winter than in summer. However, at certain universal times the electron density in the dayside polar cap is larger in winter than in summer owing to the effect of the mid-latitude 'winter anomaly' in combination with strong antisunward convection. (3) In both summer and winter, the major region of low electron density is associated with the main or mid-latitudde trough. The trough is deeper and its local time extend is much greater in winter than in summer. (4) Typically, the electron density exhibits a much larger variation with altitude in winter than in summer. (5) The ion composition and molecular/atomic ion transition altitude are highly UT dependent in both summer and winter. (6) The ion composition also displays a significant seasonal variation. However, at a given location the seasonal variation can be opposite at different universal times. (7) High-speed convection cells should display a marked seasonal variation, with a much larger concentration of molecular ions near the F region peak in summer than in winter.

• Research Organization: Center for Atmospheric and Space Sciences, Utah State University, Logan, Utah 84322
• OSTI ID: 5169067
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 87:A1; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED PARTICLES
CONVECTION
DISTRIBUTION FUNCTIONS
EARTH ATMOSPHERE
F REGION
FUNCTIONS
HELIUM IONS
ION DENSITY
IONOSPHERE
IONS
NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PLANETARY IONOSPHERES
PLASMA WAVES
SEASONAL VARIATIONS
VARIATIONS