edu.ucar.opensky::articles:21163 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T02:21:29.186448 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7b85bqf Formaldehyde in the Tropical Western Pacific: Chemical sources and sinks, convective transport, and representation in CAM-Chem and the CCMI models 2017-10-26T00:00:00Z publication https://n2t.org/ark:/85065/d7b85bqf https://doi.org/10.1002/2016JD026121 Anderson, D. C. author Nicely, J. M. author Wolfe, G. M. author Hanisco, T. F. author Salawitch, R. J. author Canty, T. P. author Dickerson, R. R. author Apel, Eric C. author Baidar, S. author Bannan, T. J. author Blake, N. J. author Chen, D. author Dix, B. author Fernandez, R. P. author Hall, Samuel R. author Hornbrook, Rebecca author Gregory Huey, L. author Josse, B. author Jöckel, P. author Kinnison, Douglas E. author Koenig, T. K. author Le Breton, M. author Marécal, V. author Morgenstern, O. author Oman, L. D. author Pan, Laura L. author Percival, C. author Plummer, D. author Revell, L. E. author Rozanov, E. author Saiz-Lopez, A. author Stenke, A. author Sudo, K. author Tilmes, Simone author Ullmann, Kirk author Volkamer, R. author Weinheimer, Andrew author Zeng, G. author UCAR/NCAR - Library publisher Formaldehyde (HCHO) directly affects the atmospheric oxidative capacity through its effects on HOx. In remote marine environments, such as the tropical western Pacific (TWP), it is particularly important to understand the processes controlling the abundance of HCHO because model output from these regions is used to correct satellite retrievals of HCHO. Here we have used observations from the Convective Transport of Active Species in the Tropics (CONTRAST) field campaign, conducted during January and February 2014, to evaluate our understanding of the processes controlling the distribution of HCHO in the TWP as well as its representation in chemical transport/climate models. Observed HCHO mixing ratios varied from ~500 parts per trillion by volume (pptv) near the surface to ~75 pptv in the upper troposphere. Recent convective transport of near surface HCHO and its precursors, acetaldehyde and possibly methyl hydroperoxide, increased upper tropospheric HCHO mixing ratios by ~33% (22 pptv); this air contained roughly 60% less NO than more aged air. Output from the CAM-Chem chemistry transport model (2014 meteorology) as well as nine chemistry climate models from the Chemistry-Climate Model Initiative (free-running meteorology) are found to uniformly underestimate HCHO columns derived from in situ observations by between 4 and 50%. This underestimate of HCHO likely results from a near factor of two underestimate of NO in most models, which strongly suggests errors in NOx emissions inventories and/or in the model chemical mechanisms. Likewise, the lack of oceanic acetaldehyde emissions and potential errors in the model acetaldehyde chemistry lead to additional underestimates in modeled HCHO of up to 75 pptv (~15%) in the lower troposphere. 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 2017 American Geophysical Union. None eng geoscientificInformation