HR: 13:40h
AN: A53E-01    [Abstracts]
TI: Long-term temperature observations from the troposphere to upper mesosphere over Mauna Loa, HI (19.5N, 155.6W) and Table Mountain, CA (34.4N, 117.7W) by JPL Lidars and nearby Radiosondes
AU: * Li, T
EM: taoli@tmf.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, Table Mountain Facility, PO Box 367, Wrightwood, CA 92397-0367, United States
AU: Leblanc, T
EM: leblanc@tmf.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, Table Mountain Facility, PO Box 367, Wrightwood, CA 92397-0367, United States
AU: McDermid, S
EM: mcdermid@tmf.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, Table Mountain Facility, PO Box 367, Wrightwood, CA 92397-0367, United States
AU: Wu, D L
EM: Dong.L.Wu@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AB: The JPL Rayleigh lidars at Mauna Loa Observatory (MLO), HI (19.5N, 155.6W) and Table Mountain Observatory (TMO), CA (34.4N, 117.7W) have been operated for the regular nighttime data acquisition of temperature since 1994 and 1989 respectively. Using the monthly mean temperature vertical profiles observed by the JPL lidars (35- 85km) and nearby radiosondes (5-30km), and with the linear regression analysis, we are able to extract the temperature trend, solar cycle, El Nino South Oscillation (ENSO), and Quasi-Biennial Oscillation (QBO) signals from the troposphere to upper mesosphere over MLO and TMO. The temperature trends show different behaviors at two sites, minor trend at MLO, but more negative trend at TMO. The solar cycle responses in temperature are generally positive above the middle stratosphere at both sites, but negative response at MLO and positive at TMO below. During the El Nino events, the warmer temperatures in the troposphere and upper mesosphere, and the colder temperatures in the stratosphere and lower mesosphere were observed at MLO and almost visa verse at TMO. The significant QBO oscillations were observed in the stratosphere with amplitudes of ~2-3K and with clearer downward phase progression at MLO than that at TMO. The mesospheric QBO near 75-85km is clearly present at both sites with amplitude of ~2K and with longer vertical wavelength than that in stratosphere. In addition, we calculated the GW variances using lidar temperature profiles with 30min and 1km resolutions in the upper stratosphere (38-50km) and lower mesosphere (50-62km), and nearby radiosondes in the lower stratosphere (18-30km). The monthly mean GW variances clearly show an annual oscillation with a maximum in the winter and minimum in the summer. The QBO signature could be clearly seen in the lower stratosphere. In the upper stratosphere, a longer period oscillation (~5-6 years) with maxima in 2000-2001 and 2006 was revealed to synchronize with the solar maximum and minimum. No clear signature of GW activity in the lower mesosphere could be associated to that in the upper stratosphere, suggesting that part of gravity waves may either dissipated or reflected when crossing the stratopause region.
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3360 Remote sensing
DE: 3384 Acoustic-gravity waves
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting