Observations of noctilucent clouds and temperature structure from 1-105 km by co-located lidars at 54°N

摘要

At the mid-latitude location of Kuehlungsborn (54°N, 12°E) a resonance lidar and a Rayleigh-Mie-Raman (RMR) lidar are operated to observe e.g. the occurrence and particle properties of Noctilucent Clouds (NLC) and to measure continuous temperature profiles from the troposphere to the lower thermosphere. For the temperature profiles the two lidars (RMR lidar and potassium lidar) and three different measurement methods (rotational Raman, Rayleigh/vib. Raman, Doppler resonance) are combined. The profiles are obtained continuously between 1 and 105 km with a temporal and vertical resolution of at least 15 min and 1 km, respectively. Temperature fluctuations due to gravity waves and tides with amplitudes of up to ±20 K are observed. In summer during the cold phases of waves the temperature above 80 km drops occasionally below the frostpoint temperature. However, the mean temperature below 83 km is a few Kelvin above the frost point and only for about two weeks in summer the air becomes continuously supersaturated between 85 and 90 km. Therefore, the existence of NLC ice particles above our site is only allowed in the cold phases of waves. We will present lidar-observations of NLC and temperatures below and above the NLC layer showing the coupling of the NLC to supersaturated air in the mesopause region.