Satellite observations of polar mesospheric clouds by the solar backscattered ultraviolet spectral radiometer: Evidence of a solar cycle dependence

Journal Article · Sun Jan 20 00:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JD02312· OSTI ID:5560861

Thomas, G E ^[1]; McPeters, R D ^[2]; Jensen, E J ^[3]

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1. Univ. of Colorado, Boulder (USA)
2. NASA Goddard Space Flight Center, Greenbelt, MD (USA)
3. NASA Ames Research Center, Moffett Field, CA (USA)

Measurements from space of the Earth's ultraviolet albedo are affected by scattering of sunlight from polar mesospheric clouds (PMC). The authors have examined 8 years of solar backscattered ultraviolet (SBUV) albedo data and find evidence of an annual occurrence of PMC in the summertime polar cap regions of both hemispheres. The authors have devised a cloud selection algorithm based upon the expected spectral properties of PMC scattering and show that the albedo residuals selected by this algorithm, at least above some threshold brightness, possess the basic properties of PMC with regard to their brightness levels, their seasonal characteristics, and latitude variation. Because of the uniform sampling of the polar caps, particularly in the southern hemisphere, it is possible to examine year-to-year variations in PMC activity. The authors find that a significant trend is present in the PMC occurrence frequency values over the period 1978 to 1986. The increase (up to a factor of 10 at some brightness levels) in the occurrence frequency from solar maximum to solar minimum conditions indicates an anticorrelation with solar activity, an effect that also appears to be present in noctilucent cloud sightings over the past several decades. The authors have identified two kinds of hemispherical asymmetries: the first, that PMC in the northern hemisphere is significantly brighter than in the south is consistent with previous results derived from Solar Mesosphere Explorer data; and the second, that the solar cycle response in the south is more pronounced than in the north. The authors show that if PMC scattering is not taken into account in the SBUV ozone retrieval algorithm, systematic errors of order 10% can occur in derived ozone concentration in the 40-50 km region of the summer polar cap.

• OSTI ID: 5560861
• Journal Information: Journal of Geophysical Research; (United States), Vol. 96:D1; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CLOUDS
CORRELATIONS
MESOSPHERE
POLAR REGIONS
SOLAR CYCLE
ALBEDO
ALGORITHMS
CALCULATION METHODS
DISSOCIATION
ECOLOGICAL CONCENTRATION
FLUCTUATIONS
FREQUENCY DEPENDENCE
LYMAN LINES
NORTHERN HEMISPHERE
OZONE
PHOTOCHEMICAL REACTIONS
RADIOMETRIC SURVEYS
SATELLITES
SCATTERING
SEASONAL VARIATIONS
SOLAR ACTIVITY
SOLAR FLUX
SOUTHERN HEMISPHERE
ULTRAVIOLET RADIATION
WATER VAPOR
CHEMICAL REACTIONS
EARTH ATMOSPHERE
EARTH PLANET
ELECTROMAGNETIC RADIATION
FLUIDS
GASES
GEOPHYSICAL SURVEYS
MATHEMATICAL LOGIC
PLANETS
RADIATIONS
SURVEYS
VAPORS
VARIATIONS
540110*