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In-Situ Environmental Measurements Needed for Future Mars MissionsExisting measurements and modeling studies indicate that the climate and general circulation of the thin, predominately CO2 Martian atmosphere are characterized by large-amplitude variations with a wide range of spatial and temporal scales. Remote sensing observations from Earth-based telescopes and the Mariner 9, Viking, Phobos, and Mars Global Surveyor (MGS) orbiters show that the prevailing climate includes large-scale seasonal variations in surface and atmospheric temperatures (140 to 300 K), dust optical depth (0.15 to 1), and water vapor (10 to 100 precipitable microns). These observations also provided the first evidence for episodic regional and global dust storms that produce even larger perturbations in the atmospheric thermal structure and general circulation. In-situ measurements by the Viking and Mars Pathfinder Landers reinforced these conclusions, documenting changes in the atmospheric pressure on diurnal (5%) and seasonal (>20%) time scales, as well as large diurnal variations in the near-surface temperature (40 to 70 K), wind velocity (0 to 35 m/s), and dust optical depth (0.3 to 6). These in-situ measurements also reveal phenomena with temporal and spatial scales that cannot be resolved from orbit, including rapid changes in near-surface temperatures (+/- 10 K in 10 seconds), large near-surface vertical temperature gradients (+/- 15 K/meter), diurnally-varying slope winds, and dust devils . Modeling studies indicate that these changes are forced primarily by diurnal and seasonal variations in solar insolation, but they also include contributions from atmospheric thermal tides, baroclinic waves (fronts), Kelvin waves, slope winds, and monsoonal flows from the polar caps.
Document ID
20010023087
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
Authors
Crisp, D.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Wilson, G. R.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Murphy, J. R.
(New Mexico State Univ. United States)
Banfield, D.
(Cornell Univ. United States)
Barnes, J. R.
(Oregon State Univ. United States)
Farrell, W. M.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Haberle, R. M.
(NASA Ames Research Center Moffett Field, CA United States)
Magalhaes, J.
(NASA Ames Research Center Moffett Field, CA United States)
Paige, D. A.
(California Univ. Los Angeles, CA United States)
Tillman, J. E.
(Washington Univ. United States)
Date Acquired
August 20, 2013
Publication Date
July 1, 2000
Publication Information
Publication: Concepts and Approaches for Mars Exploration
Issue: Part 1
Subject Category
Lunar And Planetary Science And Exploration
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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