Aircraft and ground-based measurements of hydroperoxides during the 2006 MILAGRO field campaign L. J. Nunnermacker1, J. B. Weinstein-Lloyd2, B. Hillery2, B. Giebel3, L. I. Kleinman1, S. R. Springston1, P. H. Daum1, J. Gaffney4, N. Marley4, and G. Huey5 1Brookhaven National Laboratory Atmospheric Sciences Division Upton, NY 11973, USA 2Chemistry/Physics Department State, University of New York, Old Westbury, NY, USA 3Rosenstiel School of Marine and Atmospheric Science, Division of Marine and Atmospheric Chemistry, University of Miami, Miami, FL, USA 4University of Arkansas, Department of Chemistry, Little Rock, AR, USA 5Georgia Institute of Technology School of Earth and Atmospheric Sciences, Atlanta, GA, USA
Abstract. Mixing ratios of hydrogen peroxide and hydroxymethyl hydroperoxide were
determined aboard the US Department of Energy G-1 Research Aircraft during
the March, 2006 MILAGRO field campaign in Mexico. Ground measurements of
total hydroperoxide were made at Tecámac University, about 35 km NW of
Mexico City. In the air and on the ground, peroxide mixing ratios near the
source region were generally near 1 ppbv. Strong southerly flow resulted in
transport of pollutants from Mexico City to two downwind surface sites on
several flight days. On these days, it was observed that peroxide
concentrations slightly decreased as the G-1 flew progressively downwind.
This observation is consistent with low or negative net peroxide production
rates calculated for the source region and is due to the very high NOx concentrations in the
Mexico City plateau. However, relatively high values
of peroxide were observed at takeoff and landing near Veracruz, a site with
much higher humidity and lower NOx concentrations.
Citation: Nunnermacker, L. J., Weinstein-Lloyd, J. B., Hillery, B., Giebel, B., Kleinman, L. I., Springston, S. R., Daum, P. H., Gaffney, J., Marley, N., and Huey, G.: Aircraft and ground-based measurements of hydroperoxides during the 2006 MILAGRO field campaign, Atmos. Chem. Phys., 8, 7619-7636, doi:10.5194/acp-8-7619-2008, 2008.