Worldwide Measurements of Atmospheric CO2 and Other Trace Gas Species Using Commercial Airlines

Abstract

New automated observation systems for use in passenger aircraft to measure atmospheric carbon dioxide (CO 2 ) and other trace species have been developed and are described in this paper. The Continuous CO 2 Measuring Equipment (CME) is composed mainly of a nondispersive infrared analyzer, a datalogger, and two calibration cylinders for in situ CO 2 measurements. The Automatic Air Sampling Equipment (ASE), on the other hand, is designed for flask sampling; the instrument, connected to a metal bellows pump, is made up of a specially designed control board and can accommodate 12 flasks. The CME platform can be used to conduct high-frequency measurements of CO 2 for obtaining a detailed spatial observation over a wide area, while ASE, despite the limited flight frequency, can provide useful distributions not only of CO 2 but also various trace gas species, as well as their isotopic ratios. ASE and CME are installed on the racks in the forward cargo compartment of the aircraft and the air bypass intake is mounted on the airconditioning duct upstream of the recirculation fan. Both sets of sampling equipment are automatically controlled through input of relevant flight parameters from the aircraft data system. Their deployment in a Boeing 747-400 aircraft was approved by the aviation regulatory agencies in the United States and Japan through issuance of the supplemental type certificate (STC), while the approval for installation of CME in a Boeing 777-200ER was also obtained via STC. First measurement results of CO 2 variations obtained by CME and ASE deployed on Japan Airlines (JAL) aircraft are reported herein.

The global methane budget 2000–2012

“…Such observations can also be used to test remote-sensing measurement from space or from the surface and bring them on the same scale as the in situ surface measurements. Aircraft measurements have been undertaken in various regions either during campaigns (Wofsy, 2011;Beck et al, 2012;Chang et al, 2014;Paris et al, 2010) or in a recurrent mode using small aircrafts in the planetary boundary layer Umezawa et al, 2014;Gatti et al, 2014) and commercial aircrafts (Schuck et al, 2012;Brenninkmeijer et al, 2007;Umezawa et al, 2012Umezawa et al, , 2014Machida et al, 2008). Balloons can carry in situ instruments (e.g.…”

Bias corrections of GOSAT SWIR XCO<sub>2</sub> and XCH<sub>4</sub> with TCCON data and their evaluation using aircraft measurement data

“…In order to test for remaining biases in the GOSAT data after applying the empirical correction developed using TCCON data, we use aircraft profile data provided by the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) project (Machida et al, 2008), the NOAA Earth System Research Laboratory/Global Monitoring Division (ESRL/GMD; Xiong et al, 2008;Sweeney et al, 2015), the US Department of Energy (DOE; Biraud et al, 2013;Schmid et al, 2014), the National Institute for Environmental Studies (NIES; Machida et al, 2001), the Japan Meteorological Agency (JMA; Tsuboi et al, 2013), the HI-APER Pole-to-Pole Observations (HIPPO) project (Wofsy et al, 2011Kort et al, 2012;Santoni et al, 2014), and an aircraft measurement campaign by NIES and the Japan Aerospace Exploration Agency (JAXA) (Tanaka et al, 2012). To calculate aircraft-based XCO 2 and XCH 4 (as described in the next paragraph), we also used tower data from the Meteorological Research Institute (MRI) in Tsukuba (Inoue andMatsueda, 1996, 2001) and the NOAA ESRL/GMD tall tower network in Park Falls, WI and West Branch, IA .…”

A 4D-Var inversion system based on the icosahedral grid model (NICAM-TM 4D-Var v1.0) – Part 2: Optimization scheme and identical twin experiment of atmospheric CO<sub>2</sub> inversion

“…However, even with the perfect (non-biased) transport model and the ideal prior error variances, improvements in the prior flux estimate in some regions have been found to be limited due to the sparseness of the observations. Further improvements are expected by adding data from in situ continuous measurements and worldwide observations by aircraft (e.g., Machida et al, 2008) and satellites (e.g., Yoshida et al, 2013;Saitoh et al, 2016) in a future study. Appendix C: Pseudo-observation sites …”

“…For example, in situ continuous observation measurements are now regularly taken at background stations, as well as at tall towers to infer regional continental fluxes (e.g., Sasakawa et al, 2010;Andrews et al, 2014). Moreover, worldwide aircraft observation programs have started to collect observations on a regular basis (e.g., Machida et al, 2008;Sawa et al, 2015;Matsueda et al, 2015), along with satellite observations dedicated to measurements of GHGs (Yoshida et al, 2013;Saitoh et al, 2016). These numerous GHG observational data can be exploited to estimate surface fluxes on a much finer scale than a subcontinental scale.…”