Atomic hydrogen and atomic oxygen density in the mesopause region: Global and seasonal variations deduced from Solar Mesosphere Explorer near-infrared emissions

Journal Article · Thu Sep 20 00:00:00 EDT 1990 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JD095iD10p16457· OSTI ID:6101319

Thomas, R J ^[1]

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1. Univ. of Colorado, Boulder (USA)

Atomic oxygen and atomic hydrogen have been inferred from the hydroxyl airglow measurements on Solar Mesosphere Explorer (SME) spacecraft between 0.01 and 0.0013 mbar (80-93 km). This constitutes the first measurements of the seasonal and latitudinal variations of these atomic species, in the mesopause region. At night, atomic oxygen is directly proportional to the Meinel band emission of OH. During the day the emission is proportional to the product of ozone and hydrogen. Since daytime ozone is inferred from the O{sub 2} ({sup 1}{Delta}{sub g}) emission, daytime hydrogen can be inferred. Daytime atomic oxygen is then inferred from the measured hydrogen and ozone. At levels where atomic oxygen is found by both methods (at 0.0032-0.0013 mbar or 88-93 km) the day and night atomic oxygen display the same relative seasonal variations. Very large annual and semiannual changes are found in the atomic hydrogen density between 80 and 93 km. At 40{degree}N the summer-to-spring ratio of atomic hydrogen exceeds a factor of 4 at 0.01 mbar (80 km). Between 80 and 90 km the odd oxygen family is found to be almost entirely atomic oxygen. Its behavior is characterized by annual variations at 40{degree} north and south and semiannual changes at the equator; in both cases the changes are a doubling from minimum to maximum. At least part of the mid-latitude semiannual variation in ozone is found to be due to the product of two annually varying functions. The atomic oxygen is annual and maximizes in the winter while the ozone-oxygen partitioning, controlled mostly by temperature, maximizes in the summer due to temperature changes.

• OSTI ID: 6101319
• Journal Information: Journal of Geophysical Research; (USA), Vol. 95:D10; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HYDROGEN
ECOLOGICAL CONCENTRATION
MESOSPHERE
ATMOSPHERIC CHEMISTRY
OXYGEN
ANNUAL VARIATIONS
ATOMS
DENSITY
GLOBAL ASPECTS
HYDROXYL RADICALS
LATITUDE EFFECT
NEAR INFRARED RADIATION
OZONE
REMOTE SENSING
SEASONAL VARIATIONS
SPACE VEHICLES
CHEMISTRY
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELEMENTS
GEOGRAPHICAL VARIATIONS
INFRARED RADIATION
NONMETALS
PHYSICAL PROPERTIES
RADIATIONS
RADICALS
VARIATIONS
VEHICLES
540110*