HR: 09:15h
AN: SA51A-04    [Abstracts]
TI: New Estimates of Greenhouse Cooling in the Upper Atmosphere
AU: * Akmaev, R A
EM: Rashid.Akmaev@noaa.gov
AF: CIRES, U. Colorado, 216 UCB, Boulder, CO 80309-0216 United States
AB: Our understanding of the various mechanisms of long-term cooling in the mesosphere and lower thermosphere (MLT) and of their relative contributions is evolving as new data on relevant physical processes, atmospheric composition, and on the atmospheric response become available. For example, such an important parameter as the collisional excitation rate of CO₂ molecules by atomic oxygen has recently been reevaluated downward according to laboratory measurements. Estimates of atmospheric cooling over the recent decades will be revisited using, in particular, new CRISTA data on the MLT CO₂ densities and compared to forcings from middle-atmospheric composition changes such as the ozone depletion and water vapor increases. Possible implications for the overall energy balance in the MLT will also be briefly discussed.
DE: 0342 Middle atmosphere--energy deposition
DE: 0358 Thermosphere--energy deposition
DE: 1610 Atmosphere (0315, 0325)
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly