edu.ucar.opensky::articles:6271 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T15:23:11.061559 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7474b1w Total observed organic carbon (TOOC) in the atmosphere: A synthesis of North American observations 2008-04-08T00:00:00Z publication https://n2t.org/ark:/85065/d7474b1w https://doi.org/10.5194/acp-8-2007-2008 Heald, C. author Goldstein, A. author Allan, J. author Aiken, A. author Apel, Eric C. author Atlas, Elliot author Baker, A. author Bates, T. author Beyersdorf, A. author Blake, D. author Campos, Teresa author Coe, H. author Crounse, J. author DeCarlo, P. author De Gouw, J. author Dunlea, E. author Flocke, Frank M. author Fried, Alan author Goldan, P. author Griffin, R. author Herndon, S. author Holloway, J. author Holzinger, R. author Jimenez, J. author Junkermann, W. author Kuster, W. author Lewis, A. author Meinardi, S. author Millet, D. author Onasch, T. author Polidori, A. author Quinn, P. author Riemer, D. author Roberts, J. author Salcedo, D. author Sive, B. author Swanson, A. author Talbot, R. author Warneke, C. author Weber, R. author Weibring, Petter author Wennberg, P. author Worsnop, D. author Wittig, A. author Zhang, R. author Zheng, J. author Zheng, Wengang author UCAR/NCAR - Library publisher Measurements of organic carbon compounds in both the gas and particle phases made upwind, over and downwind of North America are synthesized to examine the total observed organic carbon (TOOC) in the atmosphere over this region. These include measurements made aboard the NOAA WP-3 and BAe-146 aircraft, the NOAA research vessel Ronald H. Brown, and at the Thompson Farm and Chebogue Point surface sites during the summer 2004 ICARTT campaign. Both winter and summer 2002 measurements during the Pittsburgh Air Quality Study are also included. Lastly, the spring 2002 observations at Trinidad Head, CA, surface measurements made in March 2006 in Mexico City and coincidentally aboard the C-130 aircraft during the MILAGRO campaign and later during the IMPEX campaign off the northwestern United States are incorporated. Concentrations of TOOC in these datasets span more than two orders of magnitude. The daytime mean TOOC ranges from 4.0 to 456 μgC m⁻³ from the cleanest site (Trinidad Head) to the most polluted (Mexico City). Organic aerosol makes up 3-17% of this mean TOOC, with highest fractions reported over the northeastern United States, where organic aerosol can comprise up to 50% of TOOC. Carbon monoxide concentrations explain 46 to 86% of the variability in TOOC, with highest TOOC/CO slopes in regions with fresh anthropogenic influence, where we also expect the highest degree of mass closure for TOOC. Correlation with isoprene, formaldehyde, methyl vinyl ketone and methacrolein also indicates that biogenic activity contributes substantially to the variability of TOOC, yet these tracers of biogenic oxidation sources do not explain the variability in organic aerosol observed over North America. We highlight the critical need to develop measurement techniques to routinely detect total gas phase VOCs, and to deploy comprehensive suites of TOOC instruments in diverse environments to quantify the ambient evolution of organic carbon from source to sink. 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 Authors 2008. This work is distributed under the Creative Commons Attribution 3.0 License None eng geoscientificInformation