Auroral effects on midlatitude semidiurnal tides

Journal Article · Fri Mar 01 00:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/90GL02586· OSTI ID:5941471

Fesen, C G ^[1]; Richmond, A D; Roble, R G ^[2]

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1. Dartmouth Coll., Hanover, NH (United States)
2. National Center for Atmospheric Research, Boulder, CO (United States)

The effect of auroral activity on mid-latitude semidiurnal tides was investigated using simulations from the NCAR Thermosphere/Ionosphere General Circulation Model (TIGCM). Model runs were made for solar cycle minimum equinox conditions for four levels of geomagnetic activity parameterized by the total hemispheric power index and the cross polar cap potential drop. Simulations at 42.5{degree}N (gg) predicted that the upper thermosphere semidiurnal winds and temperatures generally increase with increasing geomagnetic activity, while the lower thermosphere fields were relatively insensitive to the level of auroral forcing in the model. The modeled semidiurnal mid-latitude tidal response was determined by the magnitude and phasing of the waves generated by in situ solar forcing and the auroral momentum and energy sources, in conjunction with those propagating up from the lower atmosphere. The predicted sensitivity of the model tides to the level of geomagnetic activity may contribute to the observed tidal variability at mid latitudes. Successful modeling of observations will require careful specification of the high-latitude energy and momentum sources.

• OSTI ID: 5941471
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 18:3; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
THERMOSPHERE
GRAVITY WAVES
AURORAE
COMPUTERIZED SIMULATION
GENERAL CIRCULATION MODELS
MAGNETIC STORMS
POLAR REGIONS
SOLAR CYCLE
VARIATIONS
WAVE PROPAGATION
EARTH ATMOSPHERE
MATHEMATICAL MODELS
SIMULATION
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)