Open AccessMean and gravity wave structures and variability in the Mars upper atmosphere inferred from Mars Global Surveyor and Mars Odyssey aerobraking densities
Author(s) -
Fritts David C.,
Wang Ling,
Tolson Robert H.
Publication year - 2006
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006ja011897
Subject(s) - mars exploration program , atmosphere (unit) , latitude , atmosphere of mars , longitude , geology , atmospheric sciences , amplitude , gravity wave , altitude (triangle) , scale height , forcing (mathematics) , geophysics , geodesy , astrobiology , gravitational wave , physics , meteorology , astronomy , martian , geometry , mathematics , quantum mechanics
We have used density measurements obtained during aerobraking (AB) on Mars Global Surveyor and Mars Odyssey to examine mean densities and the characteristics and variability of gravity waves (GWs) in the upper atmosphere of Mars. Mean densities exhibit variability with latitude and season and in response to variable forcing and filtering from below. These data also reveal significant variability of GWs, both spatially and temporally. In general, GW amplitudes increase, while apparent horizontal scales remain the same, with increasing altitude. The dominant spatial scales at the lower AB altitudes are typically ∼20–200 km and density fluctuations vary from ∼5 to 50%, though even larger values are occasionally observed. GW amplitudes also vary significantly with season, being generally larger in winter and at middle and high latitudes, and apparently reflecting mean source and filtering conditions. Amplitudes also appear to vary with longitude and time and may provide clues to variability of, and interactions with, larger‐scale motions.