Mean winds, tides and gravity waves in the upper middle atmosphere during ALOHA-90

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL01226· OSTI ID:5518464

Vincent, R A; Lesicar, D ^[1]

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1. Univ. of Adelaide (Australia)

Wind measurements made with a partial reflection radar located on Christmas Island (2{degree}N, 157{degree}W) are used to describe the dynamical state of the equatorial mesopause region during ALOHA-90. Time mean westward (easterly) winds prevailed at most heights, and reached their maximum values of about {minus}60 ms{sup {minus}1} near 85 km, but the mean meridional motions were weak. Strong oscillations due to the 24, 12, and 8 hr atmospheric tides were also observed in both wind components. The inferred vertical wavelengths were large, even for the diurnal tide. On the nights of 22 and 25 March, when airborne lidar observations were made in the vicinity of Christmas Island, the prevailing and tidal winds combined to produce especially strong westward winds ({minus}100 ms{sup {minus}1}). Gravity wave activity was also high during March/April, especially for short period waves, although considerable day-to-day variability was noted.

• OSTI ID: 5518464
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:7; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
ATMOSPHERIC CIRCULATION
COMPARATIVE EVALUATIONS
EARTH ATMOSPHERE
EQUATOR
EVALUATION
GRAVITY WAVES
MEASURING INSTRUMENTS
MESOSPHERE
OPTICAL RADAR
OSCILLATIONS
RADAR
RANGE FINDERS
WAVELENGTHS
WIND