Temperature and aerosol soundings in the middle atmosphere at different mid and high-latitude lidar stations during day and night

摘要

Lidars provide an important tool to measure temperature and minor constituents in the atmosphere up to -110 km altitude with high accuracy and temporal resolution. The Leibniz-Institute of Atmospheric Physics operates various lidars for the whole range between troposphere and lower thermosphere. The lidars are installed at Ktlhlungsborn, Germany (54°N, 12°E), at the ALOMAR site, Norway (69°N, 16°E), or in a mobile 20-foot container. Summertime soundings in polar regions as well as coverage of tides and gravity waves require measurements during full daylight. With a standard lidar the daylight background is several magnitudes larger than the signal in the mesosphere. Narrowband spectral filtering by etalons as well as spatial filtering by small fields of view (-50 urad) are realized instead. At this low FOV turbulence and jitter of the beam pointing affects the signal and have to be compensated. We describe the techniques applied at our lidars. Additionally we will discuss the influence of the etalon filter technique on calculated temperature profiles. The etalon transmission of the Doppler-broadened backscatter signal is temperature dependent and has to be taken into account to avoid systematic errors. Overall, narrow-band lidars provide temperature profiles in the whole range up to the lower thermosphere. We will present observations of temperatures profiles of the lower and middle atmosphere as well as noctilucent clouds (NLC). These quantities provide important insights into the dynamics of the middle atmosphere. Time-resolved and averaged profiles of observations at the different locations will be shown and the results from different latitudes compared.