Rayleigh lidar observations of temperature over Tsukuba: Winter thermal structure and comparison studies

Abstract

Routine lidar observations are in progress at the National Institute for Environmental Studies (NIES), Tsukuba, Japan (36°N, 140°E), providing vertical profiles of ozone and temperature in the stratosphere and lower mesosphere. The present study focuses the winter thermal structure over Tsukuba and validation/comparison of the lidar derived temperature profiles. Atmospheric temperatures for the altitude region 30-75 km are determined from the neutral density profiles. 33 temperature observations recorded during the winter months of 1995 and 1996 are used in the study. Winter thermal structure is characterized with its variability with an observed stratopause temperature of about 260 K. Although evidence of minor stratospheric warming is seen on some days, there appears to be no direct linkage with major mid winter warmings at the poles. Temperature profiles show evidence of mesospheric temperature inversion layers. For the purpose of validation/comparison of the lidar temperature profiles, other datasets based on rocketsondes, National Meteorological Center (NMC) analyses, Solar Mesosphere Explorer (SME) spacecraft measurements, and CIRA 86 have been used. Encouraging agreements between the lidar and rocket profiles are evident, which confirms the potential of lidar technique for deriving the absolute temperatures in the atmosphere. Climatological comparisons also reveal satisfactory agreement between the lidar and other datasets.