Evaluation of a new JMA aircraft flask sampling system and laboratory trace gas analysis system

Abstract

We established and evaluated a flask air sampling system on a cargo C-130H aircraft, as well as a trace gas measurement system for the flask samples, as part of a new operational monitoring program of the Japan Meteorological Agency (JMA). Air samples were collected during each flight, between Kanagawa Prefecture (near Tokyo) and Minamitorishima (an island located nearly 2000 km southeast of Tokyo), from the air-conditioning system on the aircraft. Prior to the operational employment of the sampling system, a quality assurance test of the sampled air was made by specially coordinated flights at a low altitude of 1000 ft over Minamitorishima and comparing the flask values with those obtained at the surface. Based on our storage tests, the flask samples remained nearly stable until analyses. The trace gas measurement system has, in addition to the nondispersive infrared (NDIR) and vacuum ultraviolet resonance fluorescence (VURF) analyzers, two laser-based analyzers using wavelength-scanned cavity ring-down spectroscopy (WS-CRDS) and off-axis integrated cavity output spectroscopy (ICOS). Laboratory tests of the laser-based analyzers for measuring flask samples indicated relatively high reproducibility with overall precisions of less than ±0.06 ppm for CO₂, ±0.68 ppb for CH₄, ±0.36 ppb for CO, and ±0.03 ppb for N₂O. Flask air sample measurements, conducted concurrently on different analyzers were compared. These comparisons showed a negligible bias in the averaged measurements between the laser-based measurement techniques and the other methods currently in use. We also estimated that there are no significant isotope effects for CH₄, CO and N₂O using standard gases with industrial isotopic compositions to calibrate the laser-based analyzers, but CO₂ was found to possess isotope effects larger than its analytical precision

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 .…”

“…Details of the aircraft and tower measurements are described in Inoue et al (2013) and Inoue et al (2014), except for the JMA aircraft and groundbased measurements. The JMA aircraft measurements are conducted by utilizing the cargo aircraft C-130H of the Japan Ministry of Defense (MOD) to collect flask air samples once a month during a regular flight between the mainland of Japan and Minamitorishima, an island located nearly 2000 km southeast of Tokyo (Tsuboi et al, 2013). In addition, the JMA routinely obtains ground-based measurements at a height of 20 m over Minamitorishima.…”

Seasonal Variations of CO₂, CH₄, N₂O and CO in the Mid-Troposphere over the Western North Pacific Observed Using a C-130H Cargo Aircraft

“…Since the technical details are given by Tsuboi et al (2013), a short description of the C-130H aircraft observation and its measurement system is provided here. The mid-tropospheric observation program is conducted by JMA in cooperation with the Japan Ministry of Defense for the aircraft operation and with the Meteorological Research Institute (MRI) for measurement techniques.…”

“…Since the mid of 2010, the Japan Meteorological Agency (JMA) has been conducting regular GHG observations in the mid-troposphere over the western North Pacific region by sampling air in flasks onboard a C-130H cargo aircraft (Tsuboi et al 2013). In this paper, we present seasonal variations of CO 2 , CH 4 , N 2 O, and carbon monoxide (CO) by analyzing measurements of the JMA aircraft observation.…”

Scale and stability of methane standard gas in JMA and comparison with MRI standard gas

“…These results indicate that the NOAA04 gravimetric scale is different from that of NMIJ, but the NMIJ and MRI/JMA scales are similar. The experimental uncertainties of the GC/FID analyses remain, so further and more accurate comparisons obtained by using a high-precision laser-based instrument (e.g., Tsuboi et al, 2013) are needed to validate the differences of the CH 4 standard gas scales.…”