Five years of CO, HCN, C 2 H 6 , C 2 H 2 , CH 3 OH, HCOOH and H 2 CO total columns measured in the Canadian high Arctic

• Published in: Atmospheric Measurement Techniques
• Main Authors: C. Viatte, K. Strong, K. A. Walker, J. R. Drummond
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2014
• Subjects: Environmental engineering; TA170-171; Earthwork. Foundations; TA715-787; Arctic; Canada; Eureka; Nunavut
• Online Access: https://doi.org/10.5194/amt-7-1547-2014; https://doaj.org/article/6f50706322894a828452dc72f705358a

We present a five-year time series of seven tropospheric species measured using a ground-based Fourier transform infrared (FTIR) spectrometer at the Polar Environment Atmospheric Research Laboratory (PEARL; Eureka, Nunavut, Canada; 80°05' N, 86°42' W) from 2007 to 2011. Total columns and temporal variabilities of carbon monoxide (CO), hydrogen cyanide (HCN) and ethane (C 2 H 6 ) as well as the first derived total columns at Eureka of acetylene (C 2 H 2 ), methanol (CH 3 OH), formic acid (HCOOH) and formaldehyde (H 2 CO) are investigated, providing a new data set in the sparsely sampled high latitudes. Total columns are obtained using the SFIT2 retrieval algorithm based on the optimal estimation method. The microwindows as well as the a priori profiles and variabilities are selected to optimize the information content of the retrievals, and error analyses are performed for all seven species. Our retrievals show good sensitivities in the troposphere. The seasonal amplitudes of the time series, ranging from 34 to 104%, are captured while using a single a priori profile for each species. The time series of the CO, C 2 H 6 and C 2 H 2 total columns at PEARL exhibit strong seasonal cycles with maxima in winter and minima in summer, in opposite phase to the HCN, CH 3 OH, HCOOH and H 2 CO time series. These cycles result from the relative contributions of the photochemistry, oxidation and transport as well as biogenic and biomass burning emissions. Comparisons of the FTIR partial columns with coincident satellite measurements by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) show good agreement. The correlation coefficients and the slopes range from 0.56 to 0.97 and 0.50 to 3.35, respectively, for the seven target species. Our new data set is compared to previous measurements found in the literature to assess atmospheric budgets of these tropospheric species in the high Arctic. The CO and C 2 H 6 concentrations are consistent with negative trends observed over the Northern Hemisphere, ...