edu.ucar.opensky::articles:22208 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-25T15:48:13.161394 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7g73hqn https://doi.org/10.13140/RG.2.1.2504.2806 https Related CreativeWork #1 Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation Number 18 Atmospheric oxidation in the presence of clouds during the Deep Convective Clouds and Chemistry (DC3) study 2018-10-10T00:00:00Z publication https://n2t.org/ark:/85065/d7g73hqn https://doi.org/10.5194/acp-18-14493-2018 Brune, W. H. author Ren, X. author Zhang, L. author Mao, J. author Miller, D. O. author Anderson, B. E. author Blake, D. R. author Cohen, R. C. author Diskin, G. S. author Hall, Samuel R. author Hanisco, T. F. author Huey, L. G. author Nault, B. A. author Peischl, J. author Pollack, I. author Ryerson, T. B. author Shingler, T. author Sorooshian, A. author Ullmann, Kirk author Wisthaler, A. author Wooldridge, P. J. author UCAR/NCAR - Library publisher Deep convective clouds are critically important to the distribution of atmospheric constituents throughout the troposphere but are difficult environments to study. The Deep Convective Clouds and Chemistry (DC3) study in 2012 provided the environment, platforms, and instrumentation to test oxidation chemistry around deep convective clouds and their impacts downwind. Measurements on the NASA DC-8 air-craft included those of the radicals hydroxyl (OH) and hydroperoxyl (HO2), OH reactivity, and more than 100 other chemical species and atmospheric properties. OH, HO2, and OH reactivity were compared to photochemical models, some with and some without simplified heterogeneous chemistry, to test the understanding of atmospheric oxidation as encoded in the model. In general, the agreement between the observed and modeled OH, HO2, and OH reactivity was within the combined uncertainties for the model without heterogeneous chemistry and the model including heterogeneous chemistry with small OH and HO2 uptake consistent with laboratory studies. This agreement is generally independent of the altitude, ozone photolysis rate, nitric oxide and ozone abundances, modeled OH reactivity, and aerosol and ice surface area. For a sunrise to midday flight downwind of a nighttime mesoscale convective system, the observed ozone increase is consistent with the calculated ozone production rate. Even with some observed-to-modeled discrepancies, these results provide evidence that a current measurement constrained photochemical model can simulate observed atmospheric oxidation processes to within combined uncertainties, even around convective clouds. For this DC3 study, reduction in the combined uncertainties would be needed to confidently unmask errors or omissions in the model chemical mechanism. 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 2018 Author(s). This work is licensed under a Creative Commons Attribution 4.0 International license. None eng geoscientificInformation