Mean winds and momemtum fluxes over Jicamarca, Peru, during June and August 1987

Journal Article · Tue Dec 15 00:00:00 EST 1992 · Journal of the Atmospheric Sciences; (United States)

DOI:https://doi.org/10.1175/1520-0469(1992)049<2372:MWAMFO>2.0.CO;2· OSTI ID:6721223

Hitchman, M H; Bywaters, K W ^[1]; Fritts, D C ^[2]; Coy, L ^[3]; Kudeki, E; Surucu, F ^[4]

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1. Univ. of Wisconsin, Madison (United States)
2. Univ. of Colorado, Boulder (United States)
3. Saint Louis Univ., MO (United States)
4. Univ. of Illinois, Champaign (United States)

Data from the mesophere-stratosphere-troposphere (MST) radar at Jicamarca, Peru, together with other available data, are used to diagnose the mean structure of winds and gravity-wave momentum fluxes from the surface to 90 km during two ten-day campaigns in June and August of 1987. In the stratosphere a layer of maximum eastward flow associated with the quasi-biennial oscillation (QBO) was seen to strengthen and descend rapidly from June to August, overlying persitent westward flow. A layer of enhanced signal return, suggestive of a turbulent layer, was observed just above the descending QBO eastward maximum. Notable zonal asymmetries were present during this transition and the local meridional circulation departed form zonal-mean QBO theory. A substantial northeastward momentum flux was found below 25 km, which may be related to topographic gravity waves excited by southeastward flow across the Andes. In the lower mesosphere a relatively weak second mesopause semiannual oxcillation is confirmed. Gravity-wave zonal and meridional momentum fluxes usually opposed the flow, yielding body forces of [approximately]10-100 ms[sup [minus]1] day [sup [minus]1]. In both the lower stratosphere and mesosphere, body forces were comparable in magnitude to inferred Coriolis torques. 52 refs., 9 figs.

• OSTI ID: 6721223
• Journal Information: Journal of the Atmospheric Sciences; (United States), Vol. 49:24; ISSN 0022-4928
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
MESOSPHERE
ATMOSPHERIC CIRCULATION
RADAR
DIAGNOSTIC USES
STRATOSPHERE
TROPOSPHERE
WIND
STRUCTURAL MODELS
ANDES
ANNUAL VARIATIONS
COMPILED DATA
CORIOLIS FORCE
GRAVITY WAVES
PERU
TURBULENT FLOW
DATA
DEVELOPING COUNTRIES
EARTH ATMOSPHERE
FLUID FLOW
INFORMATION
LATIN AMERICA
MEASURING INSTRUMENTS
MOUNTAINS
NUMERICAL DATA
RANGE FINDERS
SOUTH AMERICA
USES
VARIATIONS
540110*