Intercomparison of UV-visible measurements of ozone and NO<sub>2</sub> during the Canadian Arctic ACE validation campaigns: 2004–2006

Abstract

Abstract. The first three Canadian Arctic ACE validation campaigns were held during polar sunrise at Eureka, Nunavut, Canada (80 • N, 86 • W) from 2004 to 2006 in support of validation of the ACE (Atmospheric Chemistry Experiment) satellite mission. Three or four zenith-sky viewing UV-visible spectrometers have taken part in each of the three campaigns. The differential slant column densities and vertical column densities of ozone and NO 2 from these instruments have been compared following the methods of the UV-visible Working Group of the NDACC (Network for Detection of Atmospheric Composition Change). The instruments are found to partially agree within the required accuracies for both species, although both the vertical and slant column densities are more scattered than required. This might be expected given the spatial and temporal variability of the Arctic stratosphere in spring. The vertical column densities are also compared to integrated total columns from ozonesondes and integrated partial columns from the ACE-FTS (ACE-Fourier Transform Spectrometer) and ACE-MAESTRO (ACE-Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) instruments on board ACE. For both species, the columns Correspondence to: A. Fraser (amery@atmosp.physics.utoronto.ca) from the ground-based instruments and the ozonesondes are found to generally agree within their combined error bars. The ACE-FTS ozone partial columns and the ground-based total columns agree within 4.5%, averaged over the three campaigns. The ACE-MAESTRO ozone partial columns are generally smaller than those of the ground-based instruments, by an average of 9.9%, and are smaller than the ACE-FTS columns by an average of 14.4%. The ACE-FTS NO 2 partial columns are an average of 13.4% smaller than the total columns from the ground-based instruments, as expected. The ACE-MAESTRO NO 2 partial columns are larger than the total columns of the ground-based instruments by an average of 2.5% and are larger than the partial columns of the ACE-FTS by an average of 15.5%.

Validation of ACE and OSIRIS ozone and NO<sub>2</sub> measurements using ground-based instruments at 80° N

“…Fraser et al (2008) found a mean relative difference of +5.5 % to +22.5 % between ACE-FTS v2.2 and ACE-MAESTRO v1.2 ozone 16-44 km partial columns from 2004-2006, which is larger than the +2.7 % mean relative difference found in this study. Dupuy et al (2009) compared profiles from ACE-FTS v2.2, ACE-MAESTRO v1.2, and OSIRIS SaskMART v2.1 data.…”

“…This was the maximum altitude range for which the majority of OSIRIS, ACE-FTS, and ACE-MAESTRO profiles within 500 km of PEARL had available data. Ozonesonde data from the nearest day were added to the satellite profiles from 0-14 km, in a similar approach to Fraser et al (2008). The resulting satellite-plussonde profile was smoothed from 12-16 km using a moving average filter in order to avoid discontinuities where the two profiles joined.…”

“…Measurements taken at PEARL have been included in numerous validation studies (e.g. Batchelor et al, 2010;Dupuy et al, 2009;Fraser et al, 2008;Fu et al, 2007Fu et al, , 2011Kerzenmacher et al, 2005;Sica et al, 2008;Sung et al, 2007). PEARL ( Kerzenmacher et al, 2005).…”

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

“…ACE-FTS started routine measurements in February 2004, followed quickly by the first of the Canadian Arctic ACE validation campaigns which continue to this day. These campaigns (e.g., Kerzenmacher et al, 2005;Fraser et al, 2008;Batchelor et al, 2010;Fu et al, 2011;Adams et al, 2012) comprise groundbased measurements during the polar sunrise period (from the end of February to early April) at the Polar Environment Atmospheric Research Laboratory (PEARL) near Eureka, Nunavut (Fogal et al, 2013), at approximately 80 • N, 86 • W. Two ground-based Fourier transform spectrometers (FTSs), the Portable Atmospheric Research Interferometric Spectrometer for the InfraRed (PARIS-IR), and the highresolution Bruker 125HR FTS are part of these campaigns. Here, these datasets are used to compare multiple trace gas species to the space-borne ACE-FTS v3.5 retrievals between 2006.…”

The spring 2011 final stratospheric warming above Eureka: anomalous dynamics and chemistry

“…Ozone and NO 2 columns were measured above PEARL by two UV-visible DOAS instruments: the PEARL and University of Toronto ground-based spectrometers (GBSs) (Fraser et al, 2009 (Kerzenmacher et al, 2005;Fraser et al, 2008). The GBSs are part of the Network for the Detection of Atmospheric Composition Change (NDACC) and their Eureka ozone and NO 2 datasets are described in detail by Adams et al (2012a).…”