Open AccessChemical data assimilation estimates of continental U.S. ozone and nitrogen budgets during the Intercontinental Chemical Transport Experiment–North America
Author(s) -
Pierce Robert B.,
Schaack Todd,
AlSaadi Jassim A.,
Fairlie T. Duncan,
Kittaka Chieko,
Lingenfelser Gretchen,
Natarajan Murali,
Olson Jennifer,
Soja Amber,
Zapotocny Tom,
Lenzen Allen,
Stobie James,
Johnson Donald,
Avery Melody A.,
Sachse Glen W.,
Thompson Anne,
Cohen Ron,
Dibb Jack E.,
Crawford Jim,
Rault Didier,
Martin Randall,
Szykman Jim,
Fishman Jack
Publication year - 2007
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 - 10.1029/2006jd007722
Subject(s) - stratosphere , ozone , environmental science , tropopause , troposphere , atmospheric sciences , tropospheric ozone , chemical transport model , ozone layer , climatology , data assimilation , meteorology , geology , geography
Global ozone analyses, based on assimilation of stratospheric profile and ozone column measurements, and NOy predictions from the Real‐time Air Quality Modeling System (RAQMS) are used to estimate the ozone and NOy budget over the continental United States during the July–August 2004 Intercontinental Chemical Transport Experiment–North America (INTEX‐A). Comparison with aircraft, satellite, surface, and ozonesonde measurements collected during INTEX‐A show that RAQMS captures the main features of the global and continental U.S. distribution of tropospheric ozone, carbon monoxide, and NOy with reasonable fidelity. Assimilation of stratospheric profile and column ozone measurements is shown to have a positive impact on the RAQMS upper tropospheric/lower stratosphere ozone analyses, particularly during the period when SAGE III limb scattering measurements were available. Eulerian ozone and NOy budgets during INTEX‐A show that the majority of the continental U.S. export occurs in the upper troposphere/lower stratosphere poleward of the tropopause break, a consequence of convergence of tropospheric and stratospheric air in this region. Continental U.S. photochemically produced ozone was found to be a minor component of the total ozone export, which was dominated by stratospheric ozone during INTEX‐A. The unusually low photochemical ozone export is attributed to anomalously cold surface temperatures during the latter half of the INTEX‐A mission, which resulted in net ozone loss during the first 2 weeks of August. Eulerian NOy budgets are shown to be very consistent with previously published estimates. The NOy export efficiency was estimated to be 24%, with NOx + PAN accounting for 54% of the total NOy export during INTEX‐A.