The seasonal variation of water vapor and ozone in the upper mesosphere: Implications for vertical transport and ozone photochemistry

Journal Article · Sat Jan 20 04:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JD095iD01p00883· OSTI ID:5078523

Bevilacqua, R M; Summers, M E ^[1]; Strobel, D F ^[2]; Olivero, J J ^[3]; Allen, M ^[4]

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1. Naval Research Lab., Washington, DC (United States)
2. Johns Hopkins Univ., Baltimore, MD (United States)
3. Pennsylvania State Univ., University Park (United States)
4. California Inst. of Tech., Pasadena (United States)

Ground-based microwave techniques have supplied the only long-term measurements of water vapor in the mesosphere. The authors review the entire current data base, which consists of measurements obtained in three separate experiments over an 8-year period. The data from all three experiments indicate that the water vapor seasonal variation at mid-latitudes in the upper mesosphere is dominated by an annual component with low mixing ratios in winter and high mixing ratios in summer. This suggests that the vertical distribution of water vapor in the upper mesosphere (up to 80 km) is controlled by advective rather than diffusive processes. This consistent with the low mesospheric K{sub zz} values ({approx} 10{sup 5} cm{sup 2}/s) deduced from the vertical gradient of the microwave water vapor measurements by Strobel et al. (1987). However, it is difficult to reconcile the predominantly annual water vapor variation with the semiannual variation in ozone at 78 km observed by the Solar Mesosphere Explorer. The authors perform a series of one-dimensional photochemical/vertical transport model calculations which verify that (within the context of the hydrogen/oxygen chemistry considered in the model), the seasonal variation of water vapor cannot be the mechanism for the semiannual ozone variation. This variation is either a manifestation of some heretofore unknown ozone photochemical mechanism, or it could be driven by a seasonal variation in the vertical transport of atomic oxygen from the thermosphere. One possible vertical transport scenario for producing the semiannual ozone variation (while retaining the annual water vapor variation) is described.

• OSTI ID: 5078523
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:D1; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ATMOSPHERIC CHEMISTRY
CHEMICAL REACTIONS
CHEMISTRY
DATA ANALYSIS
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
ELECTROMAGNETIC RADIATION
FLUIDS
GASES
GENERAL CIRCULATION MODELS
MATHEMATICAL MODELS
MESOSPHERE
MICROWAVE RADIATION
MIXING
ONE-DIMENSIONAL CALCULATIONS
OZONE
PHOTOCHEMICAL REACTIONS
RADIATIONS
SEASONAL VARIATIONS
VAPORS
VARIATIONS
WATER VAPOR