Civil Aircraft for the regular investigation of the atmosphere based on an instrumented container: The new CARIBIC system

摘要

An airfreight container with automated instruments for measurement ofatmospheric gases and trace compounds was operated on a monthly basisonboard a Boeing 767-300 ER of LTU International Airways duringlong-distance flights from 1997 to 2002 (CARIBIC, Civil Aircraft for RegularInvestigation of the Atmosphere Based on an Instrument Container,href="http://www.caribic-atmospheric.com">http://www.caribic-atmospheric.com). Subsequently a more advanced system hasbeen developed, using a larger capacity container with additional equipmentand an improved inlet system. CARIBIC phase #2 was implemented on a newlong-range aircraft type Airbus A340-600 of the Lufthansa German Airlines(Star Alliance) in December 2004, creating a powerful flying observatory.The instrument package comprises detectors for the measurement of O₃,total and gaseous H₂O, NO and NO_y, CO, CO₂, O₂, Hg, andnumber concentrations of sub-micrometer particles (>4 nm, >12 nm, and>18 nm diameter). Furthermore, an optical particle counter (OPC) and aproton transfer mass spectrometer (PTR-MS) are incorporated. Aerosol samplesare collected for analysis of elemental composition and particle morphologyafter flight. Air samples are taken in glass containers for laboratoryanalyses of hydrocarbons, halocarbons and greenhouse gases (includingisotopic composition of CO₂) in several laboratories. Absorption tubescollect oxygenated volatile organic compounds. Three differential opticalabsorption spectrometers (DOAS) with their telescopes mounted in the inletsystem measure atmospheric trace gases such as BrO, HONO, and NO₂. Avideo camera mounted in the inlet provides information about clouds alongthe flight track. The flying observatory, its equipment and examples ofmeasurement results are reported.