Multi-year comparisons of ground-based and space-borne Fourier transform spectrometers in the high Arctic between 2006 and 2013

Abstract

Abstract. This paper presents 8 years (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013) of measurements obtained from Fourier transform spectrometers (FTSs) in the high Arctic at the Polar Environment Atmospheric Research Laboratory (PEARL; 80.05 • N, 86.42 • W). These measurements were taken as part of the Canadian Arctic ACE (Atmospheric Chemistry Experiment) validation campaigns that have been carried out since 2004 during the polar sunrise period (from mid-February to mid-April). Each spring, two ground-based FTSs were used to measure total and partial columns of HF, O 3 , and trace gases that impact O 3 depletion, namely, HCl and HNO 3 . Additionally, some tropospheric greenhouse gases and pollutant species were measured, namely CH 4 , N 2 O, CO, and C 2 H 6 . During the same time period, the satellite-based ACE-FTS made measurements near Eureka and provided profiles of the same trace gases. Comparisons have been carried out between the measurements from the Portable Atmospheric Research Interferometric Spectrometer for the InfraRed (PARIS-IR) and the co-located high-resolution Bruker 125HR FTS, as well as with the latest version of the ACE-FTS retrievals (v3.5). The total column comparison between the two colocated ground-based FTSs, PARIS-IR and Bruker 125HR, found very good agreement for most of these species (except HF), with differences well below the estimated uncertainties (≤ 6 %) and with high correlations (R ≥ 0.8). Partial columns have been used for the ground-based to space-borne comparison, with coincident measurements selected based on time, distance, and scaled potential vorticity (sPV). The comparisons of the ground-based measurements with ACE-FTS show good agreement in the partial columns for most species within 6 % (except for C 2 H 6 and PARIS-IR HF), which is consistent with the total retrieval uncertainty of the ground-based instruments. The correlation coefficients (R) of the partial column comparisons for all eight species range from approximately 0.75 to 0.95. The comparisons show no notable increases of the mean differences over these 8 years, indicating the consistency of these datasets and suggesting that the space-borne ACE-FTS measurements have been stable over this period. In addition, changes in the amounts of these trace gases during springtime between 2006 and 2013 are presented and discussed. Increased O 3 (0.9 % yr −1 ), HCl (1.7 % yr −1 ), HF (3.8 % yr −1 ), CH 4 (0.5 % yr −1 ), and C 2 H 6 (2.3 % yr −1

Retrievals of tropospheric ozone profiles from the synergism of AIRS and OMI: methodology and validation

“…The 950-1150 cm −1 spectral region includes high-density absorption features of the ozone υ3 band (the strongest fundamental band) and minor absorption from interfering species. The υ3 band has been exploited in the tropospheric O 3 soundings by a suite of TIR satellite-borne, nadir-viewing instruments, including AIRS (Susskind et al, 2003(Susskind et al, , 2014Wei et al, 2010), Cross-track Infrared Sounder (CrIS) (Gambacorta et al, 2013), and IASI (Boynard et al, 2009(Boynard et al, , 2016Dufour et al, 2012;Oetjen et al, 2014Oetjen et al, , 2016, as well as the solar occultation satellite-borne (Bernath et al, 2005;Bernath, 2017), balloon-borne (Toon, 1991;Fu et al, 2007a), and ground-based (Hannigan et al, 2011) FTSs that quantify the stratospheric ozone layer and the species playing an essential role in the stratospheric ozone chemistry (Fu et al, 2007b(Fu et al, , 2009(Fu et al, , 2011Sung et al, 2007;Wunch et al, 2007;Allen, 2009;Boone, 2013;Nassar, 2013;Griffin et al, 2017). The spectral resolution of TES (resolving power (RP): 10 500) is significantly higher than the existing TIR, including AIRS (RP: 1200), CrIS (RP: 816), and IASI (RP: 5250).…”

Comparison of ground-based and satellite measurements of water vapour vertical profiles over Ellesmere Island, Nunavut

“…As a result, measurements taken at PEARL have contributed to many validation studies, e.g. of ACE (Griffin et al, 2017), Measurement of Pollution in the Troposphere (MOPITT; Buchholz et al, 2017), Orbiting Carbon Obeservatory-2 (OCO-2;Wunch et al, 2017), and Optical Spectrograph and InfraRed Imaging System (OSIRIS; Adams et al, 2012).…”

“…MUSICA uses the existing NDACC FTIR spectrometer observations to produce precise and accurate measurement of water vapour isotopologues. This process applies an optimal-estimation technique based on Rodgers (2000) and the PROFITT retrieval code of Hase et al (2004) using a combination of strong and weak absorption features on a logarithmic scale. The accuracy of the MUSICA water vapour profiles is about 10 % (Schneider et al, 2016).…”

Authors' reply to Reviewer 1

“…As a result, measurements taken at PEARL have contributed to many validation studies, e.g. of ACE (Griffin et al, 2017), Measurement of Pollution in the Troposphere (MOPITT; Buchholz et al, 2017), Orbiting Carbon Obeservatory-2 (OCO-2;Wunch et al, 2017), and Optical Spectrograph and InfraRed Imaging System (OSIRIS; Adams et al, 2012).…”

“…MUSICA uses the existing NDACC FTIR spectrometer observations to produce precise and accurate measurement of water vapour isotopologues. This process applies an optimal-estimation technique based on Rodgers (2000) and the PROFITT retrieval code of Hase et al (2004) using a combination of strong and weak absorption features on a logarithmic scale. The accuracy of the MUSICA water vapour profiles is about 10 % (Schneider et al, 2016).…”