Greenhouse gas analysis of air samples collected onboard the CARIBIC passenger aircraft

Abstract

Abstract. CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) is a long-term atmospheric measurement program based on the use of a comprehensive scientific instrument package aboard a commercial passenger aircraft. In addition to realtime measurements, whole air sampling is performed regularly at cruising altitudes in the tropical middle troposphere and the extra-tropical UT/LS region. Air samples are analyzed for greenhouse gases, NMHCs, halocarbons, and trace gas isotopic composition. The routinely performed greenhouse gas analysis comprises gas chromatography measurements of CO 2 , CH 4 , N 2 O and SF 6 .The air sampling procedure, the GC system and its performance are described. Comparisons with similar systems employed in other laboratories and a comparison with results from a CO 2 in-situ analyzer that is also part of the CARIBIC instrumentation are shown. In addition, the time series of CO 2 , obtained from the collection of 684 samples at latitudes between 30 • N and 56 • N on 21 round trips out of Germany to different destinations in Asia between November 2005 and October 2008, is presented. A time shift in the seasonal cycle of about one month was observed between the upper troposphere and the tropopause region. For two sets of return flights from Germany to the Philippines the relationship between the four greenhouse gases is briefly discussed.

Comparison between CARIBIC Aerosol Samples Analysed by Accelerator-Based Methods and Optical Particle Counter Measurements

“…The CARIBIC system comprises an instrumented container that is connected to a multiple probe inlet system for trace gases and aerosol that is permanently mounted on the belly of a Lufthansa Airbus A340-600. Concentrations of CO, O 3 , NO / NO y , VOCs, gaseous and condensed water are determined, and air samples collected are analysed for greenhouse gases, hydro and halo carbons (Brenninkmeijer et al, 2007;Schuck et al, 2009;Oram et al, 2012). Aerosol particle number concentration measurements down to a diameter of 4 nm are undertaken with three condensation particle counters (CPC, TSI model 7610; Hermann et al, 2003), and for the particle size distribution in the diameter range ∼ 130-∼ 1000 nm a 16-channel OPC (RION, KS-93) is used (Rauthe-Schöch et al, 2012).…”

Carbon monoxide measurements onboard the CARIBIC passenger aircraft using UV resonance fluorescence

“…Holloway et al, 2000), because the air at altitudes between 9 and 12 km is dry. The typical mixing ratios of water vapor at the altitudes are 10-100 ppmv, with very rare and short episodes reaching 1000 ppmv (Schuck et al, 2009). According to Gerbig et al (1999), such low humidity does not influence the signal.…”

AirCore-HR: a high-resolution column sampling to enhance the vertical description of CH<sub>4</sub> and CO<sub>2</sub>

“…Several aircraft missions contribute vertical information with regular measurements along commercial airlines such as the CONTRAIL project (Machida et al, 2008) and the CARIBIC project (Schuck et al, 2009). Other, less regular aircraft campaigns are also dedicated to study GHG at a local scale (Zhang et al, 2014;Chen et al, 2010;Karion et al, 2013;Crevoisier et al, 2006Crevoisier et al, , 2010Sweeney et al, 2015) or from pole to pole such as the HIPPO project (Wofsy, 2011).…”