CARIBIC - Civil aircraft for global measurement of trace gases and aerosols in the tropopause region

The deployment of measurement equipment in passenger aircraft for the obser vation of atmospheric trace constituents is described. The package of autom ated instruments that is installed in a one-ton-capacity aircraft freight c ontainer positioned in the forward cargo bay of a Boeing 767 ER can registe r a vast amount of atmospheric data during regular long-distance flights. T he air inlet system that is mounted on the fuselage directly below the cont ainer comprises an aerosol inlet, a separate inlet for trace-gas sampling, and an air exhaust. All instruments, the central computer, and power supply are mounted in aviation-approved racks that slide into the reinforced cont ainer. The current instrument package comprises a fast-response chemilumine scence sensor and a conventional UV absorption detector for O-3; a gas chro matograph for CO; two condensation nuclei counters for particles larger tha n 5 and 12 nm; and a 12-canister large-capacity whole air sampler for labor atory trace-gas analysis and isotopic analysis of CO2, CO, CH4, and N2O. Fi rst measurement results of the operational Civil Aircraft for Remote Sensin g and In Situ Measurements in Troposphere and Lower Stratosphere Based on t he Instrumentation Container Concept (CARIBIC) container are reported.