HR: 1330h
AN: A32B-0147    [PDF]
TI: Tropopause Height and Temperature Measurements by Using a Rayleigh Lidar
AU: Chen, W
EM: weinai@earth.sinica.edu.tw
AF: National Central University, Department of Physics, Chung-Li, 32054 Taiwan
AU: * Nee, J
EM: jbnee@phy.ncu.edu.tw
AF: National Central University, Department of Physics, Chung-Li, 32054 Taiwan
AB: The radiosonde measurements have been traditionally used in measuring the atmospheric temperature, height, humidity, etc. in the 0-30 km height range. Radiosonde may be limited by its spatial and temporal resolution. Inter-comparison of radiosonde with other instrument such as lidar should be useful. In this study, a Rayleigh lidar has been setup to measure temperature profile for the lower atmosphere in the 10-25 km range. The technique is limited by the presence of aerosols, which can interfere with the molecular scattering properties. However, the recent low aerosol abundance in the stratosphere allows Rayleigh temperature measurement extends down to upper troposphere. Lidar measurement implemented by an inversion algorithm has been developed to derive the atmospheric temperature profiles. The agreement with radiosonde data is excellent. Based on the measurements of the cold point tropopause, we find lidar temperature is cool by 0.8 K compared with the radiosonde measurements. The lidar tropopause height is about 450 meters more than the radiosonde. This difference should result from the intrinsic limit of radiosondes in determining the atmospheric height and locating the coldest temperature during its flight. The 10 year radionsonde measurements in 1990-2000 reveal the local tropopause (25 N, 121 E) has been changing steadily. The cold point tropopause has been rising for about 190 meters and temperature lowered by 1.5 K.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0350 Pressure, density, and temperature
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting