Santoni, GregoryDaube, BruceKort, E. A.Jiménez, R.Park, SunyoungPittman, J. V.Gottlieb, ElaineXiang, BinZahniser, M. S.Nelson, D. D.McManus, J. B.Peischl, J.Ryerson, T. B.Holloway, J. S.Andrews, A. E.Sweeney, C.Hall, B.Hintsa, E. J.Moore, F. L.Elkins, J. W.Hurst, D. F.Stephens, B. B.Bent, J.Wofsy, Steven2017-03-132014Santoni, G. W., B. C. Daube, E. A. Kort, R. Jiménez, S. Park, J. V. Pittman, E. Gottlieb, et al. 2014. “Evaluation of the Airborne Quantum Cascade Laser Spectrometer (QCLS) Measurements of the Carbon and Greenhouse Gas Suite – CO2, CH4, N2O, and CO – During the CalNex and HIPPO Campaigns.” In Atmospheric Measurement Techniques 7, no. 6: 1509–1526. doi:10.5194/amt-7-1509-2014.1867-8548http://nrs.harvard.edu/urn-3:HUL.InstRepos:30761880We present an evaluation of aircraft observations of the carbon and greenhouse gases CO2, CH4, N2O, and CO using a direct-absorption pulsed quantum cascade laser spectrometer (QCLS) operated during the HIPPO and CalNex airborne experiments. The QCLS made continuous 1 Hz measurements with 1σ Allan precisions of 20, 0.5, 0.09, and 0.15 ppb for CO2, CH4, N2O, and CO, respectively, over > 500 flight hours on 79 research flights. The QCLS measurements are compared to two vacuum ultraviolet (VUV) CO instruments (CalNex and HIPPO), a cavity ring-down spectrometer (CRDS) measuring CO2 and CH4 (CalNex), two broadband non-dispersive infrared (NDIR) spectrometers measuring CO2 (HIPPO), two onboard gas chromatographs measuring a variety of chemical species including CH4, N2O, and CO (HIPPO), and various flask-based measurements of all four species. QCLS measurements are tied to NOAA and WMO standards using an in-flight calibration system, and mean differences when compared to NOAA CCG flask data over the 59 HIPPO research flights were 100, 1, 1, and 2 ppb for CO2, CH4, N2O, and CO, respectively. The details of the end-to-end calibration procedures and the data quality assurance and quality control (QA/QC) are presented. Specifically, we discuss our practices for the traceability of standards given uncertainties in calibration cylinders, isotopic and surface effects for the long-lived greenhouse gas tracers, interpolation techniques for in-flight calibrations, and the effects of instrument linearity on retrieved mole fractions.en-USJournal Article2015-08-04Santoni, G. W.; Daube, B. C.; Kort, E. A.; Jimenez, R.; Park, S.; Pittman, J. V.; Gottlieb, E.; Xiang, B.; Zahniser, M. S.; Nelson, D. D.; McManus, J. B.; Peischl, J.; Ryerson, T. B.; Holloway, J. S.; Andrews, A. E.; Sweeney, C.; Hall, B.; Hintsa, E. J.; Moore, F. L.; Elkins, J. W.; Hurst, D. F.; Stephens, B. B.; Bent, J.; Wofsy, S. C.2017-03-1310.5194/amt-7-1509-2014