edu.ucar.opensky::articles:10590 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T13:33:04.966000 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7mw2hn5 Patterns of CO₂ and radiocarbon across high northern latitudes during International Polar Year 2008 2011-07-16T00:00:00Z publication https://n2t.org/ark:/85065/d7mw2hn5 https://doi.org/10.1029/2011JD015643 Vay, S. author Choi, Y. author Vadrevu, K. author Blake, D. author Tyler, Stanley C. author Wisthaler, Armin author Hecobian, A. author Kondo, Y. author Diskin, G. author Sachse, G. author Woo, J. author Weinheimer, Andrew author Burkhart, J. author Stohl, A. author Wennberg, P. author UCAR/NCAR - Library publisher High-resolution in situ CO₂ measurements were conducted aboard the NASA DC-8 aircraft during the ARCTAS/POLARCAT field campaign, a component of the wider 2007–2008 International Polar Year activities. Data were recorded during large-scale surveys spanning the North American sub-Arctic to the North Pole from 0.04 to 12 km altitude in spring and summer of 2008. Influences on the observed CO₂ concentrations were investigated using coincident CO, black carbon, CH₃CN, HCN, O₃, C2Cl4, and Δ¹ ⁴CO₂ data, and the FLEXPART model. In spring, the CO₂ spatial distribution from 55°N to 90°N was largely determined by the long-range transport of air masses laden with Asian anthropogenic pollution intermingled with Eurasian fire emissions evidenced by the greater variability in the mid-to-upper troposphere. At the receptor site, the enhancement ratios of CO₂ to CO in pollution plumes ranged from 27 to 80 ppmv ppmv-1 with the highest anthropogenic content registered in plumes sampled poleward of 80°N. In summer, the CO₂ signal largely reflected emissions from lightning-ignited wildfires within the boreal forests of northern Saskatchewan juxtaposed with uptake by the terrestrial biosphere. Measurements within fresh fire plumes yielded CO₂ to CO emission ratios of 4 to 16 ppmv ppmv-1 and a mean CO₂ emission factor of 1698 ± 280 g kg-1 dry matter. From the ¹ ⁴C in CO₂ content of 48 whole air samples, mean spring (46.6 ± 4.4‰) and summer (51.5 ± 5‰) Δ¹ ⁴CO₂ values indicate a 5‰ seasonal difference. Although the northern midlatitudes were identified as the emissions source regions for the majority of the spring samples, depleted Δ¹ ⁴CO₂ values were observed in <1% of the data set. Rather, ARCTAS Δ¹ ⁴CO₂ observations (54%) revealed predominately a pattern of positive disequilibrium (1-7‰) with respect to background regardless of season owing to both heterotrophic respiration and fire-induced combustion of biomass. Anomalously enriched Δ¹ ⁴CO₂ values (101-262‰) measured in emissions from Lake Athabasca and Eurasian fires speak to biomass burning as an increasingly important contributor to the mass excess in Δ¹ ⁴CO₂ observations in a warming Arctic, representing an additional source of uncertainty in the quantification of fossil fuel CO₂. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2011 American Geophysical Union. None eng geoscientificInformation