For a better understanding of the state of the Earth-Atmosphere system, it is necessary to obtain systematic data from the atmosphere, in particular the free troposphere and lower stratosphere. This is the main objective of CARIBIC - Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrumentation Container, an automated air chemistry measurement container (2.4/1.6/1.5m) deployed in the forward cargo bay of a Boeing 767-ER of LTU Int. Airways (Duesseldorf, GER). Long-distance measurement flights are made from Germany to the Indian Ocean, southern Africa, and the Carribean. The inlet system is mounted underneath the container, ~10m from the bow of the aircraft. The instrumentation (~800kg) comprises two O3 monitors (a fast 10Hz chemiluminescence sensor calibrated against a conventional UV absorption monitor), a gas chromatograph for CO, three condensation particle counters, a 14 sample aerosol impactor for elemental/chemical analysis, and a 12 canister air sampler for lab. analysis of CO2, CH4, CO, N2O, SF6, ~40 halocarbons, ~15 hydrocarbons and the isotope composition 13C/12C, 14C/12C, and 18O/16O of CO and CO2.
Main research topics are:
a) To diagnose physical and chemical links between upper troposphere and lowermost stratosphere. Most air traffic takes place here and in situ observations are required in this complex boundary layer area.
b) To quantify the frequency and impact of vertical transport (e.g. convection) from the ground to the upper troposphere. In particular in the tropics can polluted surface air be transported rapidly to high altitudes.
c) To accumulate a comprehensive data set of trace gas variations. As we take air samples that are analyzed in the laboratory, very precise measurements for the greenhouse gases can be made. Up to date, such data were only available for ground based stations, where pollution is a problem and the data are often not representative for large parts of the atmosphere.