HR: 0800h
AN: SA31A-1117    [Abstracts]
TI: Lidar-derived, long-term trends and variability in the mid-latitude middle atmosphere
AU: * Wynn, T A
EM: troywynn@hotmail.com
AF: Utah State University, Center for Atmospheric and Space Sciences, 4405 Old Main Hill, Logan, UT 84322-4405 United States
AU: Herron, J P
EM: joshua.herron@usu.edu
AF: Utah State University, Center for Atmospheric and Space Sciences, 4405 Old Main Hill, Logan, UT 84322-4405 United States
AU: Wickwar, V B
EM: vincent.wickwar@usu.edu
AF: Utah State University, Center for Atmospheric and Space Sciences, 4405 Old Main Hill, Logan, UT 84322-4405 United States
AB: The USU Rayleigh Lidar (41.74$\deg$N 111.81$\deg$W) data set spans more than ten years, containing 593 nightly profiles from September 1993 to the present. A least-squares method was used to fit a model to the data to determine a linear trend, the amplitude and phase of the annual and semiannual variations, and solar cycle effects. A large cooling trend of about 1K/year was observed at 80 km, while there was no statistically significant trend below 65 km. The annual variation closely matched the MSISe90 model in magnitude and phase, while the semiannual variation is close in magnitude only. A residual resampling technique was used to determine the error bars for the amplitudes and phase angles. An 80-day, smoothed, MgII index was used for the solar proxy. It gave better results than the F10.7 index. The solar-cycle effect from 68 to 72 km was -5.32 K/Cycle, which was statistically significant at the 95$%$ level. No other statistically significant solar-cycle effect was found.
DE: 3360 Remote sensing
DE: 1610 Atmosphere (0315, 0325)
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0350 Pressure, density, and temperature
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting