HR: 08:00h
AN: SA51C-01 INVITED     [Abstracts]
TI: Lidar observations of vertical fluxes of heat, momentum and Na in the mesopause region
AU: * Liu, A Z
EM: liuzr@uiuc.edu
AF: University of Illinois at Urbana-Champaign, 1308 W Main St., Urbana, IL 61801 United States
AU: Gardner, C S
EM: cgardner@uillinois.edu
AF: University of Illinois at Urbana-Champaign, 1308 W Main St., Urbana, IL 61801 United States
AB: Lidar observations of wind, temperature, and Na density profiles between 85 and 100 km, conducted at the Starfire Optical Range (SOR), NM, and Maui, HI are used to characterize the vertical fluxes of heat, Na, and horizontal momentum and their relationships to atmospheric stabilities and gravity wave activity in this region. The annual mean heat flux has a downward maximum between 85 and 90 km, corresponding to region of low static stability. At SOR, the vertical heat and Na fluxes exhibit strong 6-month oscillations with maximum downward fluxes during winter and summer. The wind and temperature variances exhibit strong 6-month oscillations with maxima during the summer and winter that are about 3 times larger than the spring and fall minima. The downward heat flux exceeds -3 K m/s in mid-winter and is nearly zero during the spring and fall equinoxes. This creates a strong cooling in the mesopause region in excess of 50 K/day. The annual mean momentum fluxes are not large, but exhibit strong seasonal variations, which are related to the horizontal winds. Two-thirds of the time the horizontal momentum flux is directed against the mean wind field. The mean wind acceleration due to momentum flux convergence exceeds 100 m/s/day. The Na flux can be related to the heat flux based on gravity wave dissipation theory. This provides a method to estimate other constituent fluxes by gravity waves from the heat flux measurement.
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 0342 Middle atmosphere: energy deposition (3334)
DE: 3304 Atmospheric electricity
DE: 3360 Remote sensing
DE: 3384 Acoustic-gravity waves
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005