HR: 08:45h
AN: SA51A-02    [Abstracts]
TI: Multi-Decadal Variations in the Brightness of Polar Mesospheric Clouds
AU: * Shettle, E P
EM: shettle@nrl.navy.mil
AF: Naval Research Laboratory, Code 7227, Remote Sensing Division, Washington, DC 20375-5315 United States
AU: DeLand, M T
EM: matthew_deland@ssaihq.com
AF: SSAI, Suite 400 10210 Greenbelt Rd. , Lanham, MD 20706 United States
AU: Thomas, G E
EM: Gary.Thomas@lasp.colorado.edu
AF: University of Colorado, LASP Campus Box 392, Boulder, CO 80309-0392 United States
AU: Olivero, J J
EM: oliveroj@erau.edu
AF: Embry-Riddle Aeronautical University, Dept. of Physical Sciences, Daytona Beach, FL 32114 United States
AB: The Solar Backscatter Ultraviolet (SBUV and SBUV/2) instruments on the NOAA polar-orbiting meteorological satellites have measured the properties of Polar Mesospheric Clouds (PMC) continuously since 1978. Over much of this time period there have been two (and occasionally three) SBUV/2 instruments making measurements simultaneously, allowing us to combine data from the multiple instruments to study long-term PMC behavior. The seasonally averaged PMC albedo measured by each of the SBUV instruments at a wavelength of 252 nm provides a measure of the PMCs brightness. These PMC albedos show a clear anti-correlation with the solar activity as measured by the solar Lyman-  flux. After removing this dependence on the solar activity, there is a statistically significant long-term increase in the PMC albedo in both Northern and Southern Hemispheres. The variations over the past 27 years have been examined as a function of latitude, with the results indicating that the largest changes occur at the lowest latitudes.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0360 Transmission and scattering of radiation
DE: 1610 Atmosphere (0315, 0325)
DE: 1640 Remote sensing
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly