An observationally constrained evaluation of the oxidative capacity in the tropical western Pacific troposphere

• Autores: Nicely, Julia M.; Anderson, Daniel C.; Canty, Timothy P.; Salawitch, Ross J.; Wolfe, Glenn M.; Apel, Eric C.; Steve, R. Arnold; Atlas, Elliot L.; Blake, Nicola J.; Bresch, James F.; Campos, Teresa L.; Dickerson, Russell R.; Duncan, Bryan; Emmons, Louisa K.; Mathew, Evans J.; Fernandez, Rafael Pedro; Flemming, Johannes; Hall, Samuel R.; Hanisco, Thomas F.; Honomichl, Shawn B.; Hornbrook, Rebecca S.; Huijnen, Vincent; Lisa, Kaser; Kinnison, Douglas E.; Lamarque, Jean Francois; Mao, Jinqqiu; Monks, Sarah A.; Montzka, Denise D.; Pan, Laura L.; Riemer, Daniel D.; Saiz López, Alfonso; Steenrod, Stephen D.; Stell, Meghan H.; Tilmes, Simone; Turquety, Solene; Ullmann, Kirk; Weinheimer, Andrew J.
• Año de publicación: 2016
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Tropospheric OH; CONTRAST; HOLW Structures; Tropical Western Pacific
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Hydroxyl radical (OH) is the main daytime oxidant in the troposphere and determines the atmospheric lifetimes of many compounds. We use aircraft measurements of O3, H2O, NO, and other species from the Convective Transport of Active Species in the Tropics (CONTRAST) field campaign, which occurred in the tropical western Pacific (TWP) during January-February 2014, to constrain a photochemical box model and estimate concentrations of OH throughout the troposphere. We find that tropospheric column OH (OHCOL) inferred from CONTRAST observations is 12 to 40% higher than found in chemical transport models (CTMs), including CAM-chem-SD run with 2014 meteorology as well as eight models that participated in POLMIP (2008 meteorology). Part of this discrepancy is due to a clear-sky sampling bias that affects CONTRAST observations; accounting for this bias and also for a small difference in chemical mechanism results in our empirically based value of OHCOL being 0 to 20% larger than found within global models. While these global models simulate observed O3 reasonably well, they underestimate NOx (NO +NO2) by a factor of 2, resulting in OHCOL ~30% lower than box model simulations constrained by observed NO. Underestimations by CTMs of observed CH3CHO throughout the troposphere and of HCHO in the upper troposphere further contribute to differences between our constrained estimates of OH and those calculated by CTMs. Finally, our calculations do not support the prior suggestion of the existence of a tropospheric OH minimum in the TWP, because during January-February 2014 observed levels of O3 and NO were considerably larger than previously reported values in the TWP.
Fil: Nicely, Julia M.. University of Maryland. Department of Atmospheric and Oceanic Science; Estados Unidos
Fil: Anderson, Daniel C.. University of Maryland. Department of Atmospheric and Oceanic Science; Estados Unidos
Fil: Canty, Timothy P.. University of Maryland. Department of Atmospheric and Oceanic Science; Estados Unidos
Fil: Salawitch, Ross J.. University of Maryland. Department of Atmospheric and Oceanic Science; Estados Unidos
Fil: Wolfe, Glenn M.. University of Maryland; Estados Unidos
Fil: Apel, Eric C.. National Center for Atmospheric Research; Estados Unidos
Fil: Steve, R. Arnold. University of Leeds; Reino Unido
Fil: Atlas, Elliot L.. University of Miami; Estados Unidos
Fil: Blake, Nicola J.. University of California; Estados Unidos
Fil: Bresch, James F.. University of Maryland; Estados Unidos
Fil: Campos, Teresa L.. University of Maryland; Estados Unidos
Fil: Dickerson, Russell R.. University of Maryland; Estados Unidos
Fil: Duncan, Bryan. University of Maryland; Estados Unidos
Fil: Emmons, Louisa K.. National Center for Atmospheric Research; Estados Unidos
Fil: Mathew, Evans J.. University of York; Reino Unido
Fil: Fernandez, Rafael Pedro. Universidad Tecnologica Nacional. Secretaria de Ciencia Tecnologia y Posgrado.; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Dinosaurios.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina
Fil: Flemming, Johannes. European Centre for Medium-Range Weather Forecasts; Estados Unidos
Fil: Hall, Samuel R.. National Center for Atmospheric Research; Estados Unidos
Fil: Hanisco, Thomas F.. Atmospheric Chemistry and Dynamics Laboratory; Estados Unidos
Fil: Honomichl, Shawn B.. National Center for Atmospheric Research; Estados Unidos
Fil: Hornbrook, Rebecca S.. National Center for Atmospheric Research; Estados Unidos
Fil: Huijnen, Vincent. Royal Netherlands Meteorological Institute; Países Bajos
Fil: Lisa, Kaser. National Center for Atmospheric Research; Estados Unidos
Fil: Kinnison, Douglas E.. National Center for Atmospheric Research; Estados Unidos
Fil: Lamarque, Jean Francois. National Center for Atmospheric Research; Estados Unidos
Fil: Mao, Jinqqiu. University of Princeton; Estados Unidos
Fil: Monks, Sarah A.. State University of Colorado at Boulder; Estados Unidos
Fil: Montzka, Denise D.. National Center for Atmospheric Research; Estados Unidos
Fil: Pan, Laura L.. National Center for Atmospheric Research; Estados Unidos
Fil: Riemer, Daniel D.. University of Miami; Estados Unidos
Fil: Saiz López, Alfonso. Institute of Physical Chemistry Rocasolano; España
Fil: Steenrod, Stephen D.. Universities Space Research Association; Estados Unidos
Fil: Stell, Meghan H.. University of Denver.; Estados Unidos
Fil: Tilmes, Simone. National Center for Atmospheric Research; Estados Unidos
Fil: Turquety, Solene. Sorbonne University; Francia
Fil: Ullmann, Kirk. National Center for Atmospheric Research; Estados Unidos
Fil: Weinheimer, Andrew J.. National Center for Atmospheric Research; Estados Unidos