Das Projekt "Erforschung der arktischen Stratosphaere unter Verwendung von ALOMAR" wird vom Umweltbundesamt gefördert und von Universität Bonn, Physikalisches Institut durchgeführt. There can be no doubt today of the fundamental importance of a better understanding of phenomena which lead to the depletion of the protective stratospheric ozone layer. It is now widley recognized that the ozone depletion occurs mainly in the very cold polar vortex (temperature below 190 k) where the conditions of formation of PSCs are reached and the heterogeneous reactions which lead ot the destruction of ozone are possible. The alomar (arctic lidar observatory for middle atmosphere research) observatory is a large research facility under construction at andoya (69 Grad N, 16 Grad E) in norther norway. Research groups form france, germany, norway, UK and the use cooperate to provide the state of the art lidar equipments to study the arctic middle atmosphere (temperature, wind, aerosols, ozone and sodium). The participants to this proposal are associated to the core instrument, a powerful rayleigh/mie raman lidar able to measure simultaneously the vertical profiles of molecular density, temperature, horizontal wind and particulates backscattering at 2 wavelengths and 2 polarizations. This proposal covers the implentation, the exploitation and the data analysis of the rayleigh/mie/raman part of alomar for 1994-95. Our objectives in alomar may be divided in 4 categories. 1) Process studies: Characterization of the different types of PSCs and study of their formation and disparition in relation of other parameters (temperature, gravity waves). 2) Climatological studies: Start of the acouisition of a climatologic data base for lower arctic stratosphere (temperature, aerosols and PSCs). 3) Participation to specific campaigns for the study of polar ozone (sesame in winter 1994-95). 4) Validation of satellite measurements.
Das Projekt "Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR): Entwicklung von Instrumenten zur Messung von Aerosol, Wolkenpartikeln, Temperaturstruktur und Thermodynamik in der polaren Stratosphaere" wird vom Umweltbundesamt gefördert und von Universität Bonn, Physikalisches Institut durchgeführt. The scientific and technical aims of the EC-ALOMAR project will be achieved by using multi-channel detection, ranging in wavelength from the ultraviolet via the visible to the infrared part of the spectrum, a) for aerosol and cloud particle detection and characterization, b) for Doppler wind, and c) various temperature measurements. These measurements will be based on and use the following techniques: a) For aerosol and cloud particle observations a combination of three independent schemes: a1) Observation of N2 vibrational Raman scatter for the measurement of air density profiles, unbiased by the presence of aerosols; a2) Comparison of Rayleigh vs Mie scatter at widely different wavelengths to characterize the aerosol and cloud particle size distributions; a3) Polarization studies of the Rayleigh scatter for separation of spherical from non-spherical particles. b) The 3 components of the wind vector will be determined from measurements, of the Doppler shift of the backscattered Cabannes line using high resolution Fabry-Perot interferometers. c) For temperature measurements three different techniques will be applied and will give altitude-overlapping data: C1) Integration of measured air density profile; C2) Two-channel measurement of the N2 + O2 rotational Raman scatter; c3) Measurement of the Doppler width of the Cabannes line using high resolution Fabry-Perot interferometers.