Regensburg 2007 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 16: Atmosphärische Spurengase und Aerosole: Instrumentelles

UP 16.5: Vortrag

Dienstag, 27. März 2007, 17:15–17:30, H48

The new Compact Cloud and Aerosol LIDAR ’ComCAL’: First results of aerosol measurements at midlatitudes and the tropics — •Franz Immler, Raffael Maurer, and Otto Schrems — Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Deutschland

We have designed a Compact Cloud and Aerosol Lidar (ComCAL) to detect particles in the entire troposphere with a vertical resolution of 7.5 m and a temporal resolution of 1 min. The system measures the returns of a pulsed Nd:YAG-laser emitting vertically into the atmosphere at the wavelengths 355 nm, 532 nm, and 1064 nm. Beside the elastic backscatter and the depolarisation, the inelastic backscatter between 380 nm and 450 nm can be detected by means of a grating UV/Vis spectrometer and a multi-anode photomultiplier. This set-up allows the detection of aerosol extinction, water vapor profiles and fluorescence of organic aerosol. The new ComCAL system has undergone its crucial test aboard the research vessel Polarstern in October 2005 during a cruise from Bremerhaven to Capetown. Furthermore, it was operated at a midlatitude coastal site (Bremerhaven, 53.5^∘N;8.5^∘E) throughout spring and summer of 2006, and at the tropical station in Paramaribo/Suriname (5.8^∘N, 55.2^∘W) during the local dry season in September and October 2006. In Paramaribo the aerosol in the boundary layer can be classified by two main types: a marine type with low optical depth, depolarization and no detectable fluorescence on the one hand and a polluted type with high optical depth, no depolarisation but significant fluorescence on the other hand.