Open AccessOxalic acid in clear and cloudy atmospheres: Analysis of data from International Consortium for Atmospheric Research on Transport and Transformation 2004
Author(s) -
Sorooshian Armin,
Varutbangkul Varuntida,
Brechtel Fred J.,
Ervens Barbara,
Feingold Graham,
Bahreini Roya,
Murphy Shane M.,
Holloway John S.,
Atlas Elliot L.,
Buzorius Gintas,
Jonsson Haflidi,
Flagan Richard C.,
Seinfeld John H.
Publication year - 2006
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jd006880
Subject(s) - oxalic acid , plume , oxalate , aerosol , environmental science , atmospheric sciences , meteorology , chemistry , physics , inorganic chemistry
Oxalic acid is often the leading contributor to the total dicarboxylic acid mass in ambient organic aerosol particles. During the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field campaign, nine inorganic ions (including SO 4 2− ) and five organic acid ions (including oxalate) were measured on board the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter research aircraft by a particle‐into‐liquid sampler (PILS) during flights over Ohio and surrounding areas. Five local atmospheric conditions were studied: (1) cloud‐free air, (2) power plant plume in cloud‐free air with precipitation from scattered clouds overhead, (3) power plant plume in cloud‐free air, (4) power plant plume in cloud, and (5) clouds uninfluenced by local pollution sources. The aircraft sampled from two inlets: a counterflow virtual impactor (CVI) to isolate droplet residuals in clouds and a second inlet for sampling total aerosol. A strong correlation was observed between oxalate and SO 4 2− when sampling through both inlets in clouds. Predictions from a chemical cloud parcel model considering the aqueous‐phase production of dicarboxylic acids and SO 4 2− show good agreement for the relative magnitude of SO 4 2− and oxalate growth for two scenarios: power plant plume in clouds and clouds uninfluenced by local pollution sources. The relative contributions of the two aqueous‐phase routes responsible for oxalic acid formation were examined; the oxidation of glyoxylic acid was predicted to dominate over the decay of longer‐chain dicarboxylic acids. Clear evidence is presented for aqueous‐phase oxalic acid production as the primary mechanism for oxalic acid formation in ambient aerosols.