Peroxy radical behavior during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign as measured aboard the NASA P-3B aircraft

[1] Peroxy radical concentrations were measured aboard the NASA P-3B aircraft during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign in the spring of 2001 and varied in ways that depended on radical production rates and reactive nitrogen concentrations. Measurements of HO2 ,H O2 +R O2, and OH during this study allowed calculation of radical ratios, examination of functional relationships of these ratios on controlling variables, and comparison with numerical model estimations. Radical production terms show changes in relative contributions at low, middle, and high total production rates that are understandable in terms of systematic variations in the controlling components (trace gas concentrations and photolysis rate coefficients). Ozone tendency calculations indicate net ozone production in the western Pacific basin because the concentrations of critical precursor trace gases (e.g., NOx, hydrocarbons) are highest there. The dependence of ozone tendency follows the concentration of NO systematically. Peroxy radical levels on the two aircraft (HO2 +R O2 on the P-3B and HO2 on the DC-8) during two relatively short prescribed intercomparison periods were in good agreement in one instance and poorer in another given reasonable assumptions about the apportioning of radicals between HO2 and RO2. Recommended changes to CH2O photolysis quantum yields, HO2 self reaction, and O( 1 D) quenching kinetics lead to small changes (<5%) in calculated peroxy radical levels for TRACE-P conditions. There is evidence from this campaign that peroxy radicals are lost by interaction with aerosols and cloud droplets. INDEX TERMS: 0317 Atmospheric Composition and Structure: Chemical kinetic and photochemical properties; 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; 0368 Atmospheric Composition and Structure: Troposphere—constituent transport and chemistry; KEYWORDS: photochemistry, peroxy radicals, ozone

[1]  R. Lueb,et al.  A fast‐GC/MS system to measure C2 to C4 carbonyls and methanol aboard aircraft , 2003 .

[2]  A. Weinheimer,et al.  Summary of measurement intercomparisons during TRACE-P , 2003 .

[3]  D. Blake,et al.  Highlights of OH, H2SO4, and methane sulfonic acid measurements made aboard the NASA P‐3B during Transport and Chemical Evolution over the Pacific , 2003 .

[4]  John C. Gille,et al.  Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft mission: Design, execution, and first results , 2003 .

[5]  D. Jacob,et al.  In situ measurements of HCN and CH3CN over the Pacific Ocean: Sources, sinks, and budgets , 2003 .

[6]  D. Tanner,et al.  Chemical ionization mass spectrometer instrument for the measurement of tropospheric HO2 and RO2. , 2003, Analytical chemistry.

[7]  M. Zondlo,et al.  Peroxy radical observations using chemical ionization mass spectrometry during TOPSE , 2003 .

[8]  D. Blake,et al.  Steady state free radical budgets and ozone photochemistry during TOPSE , 2003 .

[9]  Paul S. Monks,et al.  Potential for photochemical ozone formation in the troposphere over the North Atlantic as derived from aircraft observations during ACSOE , 2002 .

[10]  H. Akimoto,et al.  Photochemical ozone production at a subtropical island of Okinawa, Japan: Implications from simultaneous observations of HO2 radical and NOx , 2002 .

[11]  A. Ravishankara,et al.  Redetermination of the rate coefficient for the reaction of O(1D) with N2 , 2002 .

[12]  J. Thornton,et al.  Ozone production rates as a function of NOx abundances and HOx production rates in the Nashville urban plume , 2002 .

[13]  K. Jucks,et al.  Kinetics of HO2 + HO2 → H2O2 + O2: Implications for Stratospheric H2O2 , 2002 .

[14]  K. Jucks,et al.  Kinetics of HO_2 + HO_2 → H_2O_2 + O_2: Implications for Stratospheric H_2O_2 , 2002 .

[15]  B. Lamb,et al.  Loss of isoprene and sources of nighttime OH radicals at a rural site in the United States: Results from photochemical models , 2002 .

[16]  Paul S. Monks,et al.  A Seasonal Comparison of the Ozone Photochemistry in Clean and Polluted Air Masses at Mace Head, Ireland , 2002 .

[17]  M. Molina,et al.  Measurement of Radical Quantum Yields from Formaldehyde Photolysis between 269 and 339 nm , 2002 .

[18]  S. Vay,et al.  OH and HO2 in the tropical Pacific: Results from PEM‐Tropics B , 2001 .

[19]  D. Blake,et al.  Marine latitude/altitude OH distributions: Comparison of Pacific Ocean observations with models , 2001 .

[20]  D. Blake,et al.  Seasonal differences in the photochemistry of the South Pacific: A comparison of observations and model results from PEM-Tropics A and B , 2001 .

[21]  H. Akimoto,et al.  Behavior of OH and HO2 radicals during the Observations at a Remote Island of Okinawa (ORION99) field campaign: 1. Observation using a laser‐induced fluorescence instrument , 2001 .

[22]  P. Shepson,et al.  Nighttime observations of anomalously high levels of hydroxyl radicals above a deciduous forest canopy , 2001 .

[23]  James Lee,et al.  OH and HO2 measurements in a forested region of north-western Greece , 2001 .

[24]  M. J. Elrod,et al.  Direct kinetics study of the temperature dependence of the CH2O branching channel for the CH3O2 + HO2 reaction , 2001 .

[25]  John P. Burrows,et al.  Peroxy radical and related trace gas measurements in the boundary layer above the Atlantic Ocean , 2001 .

[26]  R. Cohen,et al.  Comparing atmospheric [HO2]/[OH] to modeled [HO2]/[OH]: Identifying discrepancies with reaction rates , 2001 .

[27]  M. J. Elrod,et al.  JCK ( Wiley ) RIGHT BATCH short standard long Direct Kinetics Study of the Temperature Dependence of the CH 2 O Branching Channel for the CH 3 O 2 HO 2 Reaction , 2001 .

[28]  Bruce E. Anderson,et al.  Observations of HO x and its relationship with NO x in the upper troposphere during SONEX , 2000 .

[29]  Yutaka Kondo,et al.  Photochemistry of HO x in the upper troposphere at northern midlatitudes , 2000 .

[30]  D. Covert,et al.  Hygroscopic properties of aerosol particles in the north-eastern Atlantic during ACE-2 , 2000 .

[31]  P. Monks,et al.  On the relationship of HO2 + RO2 with j(O1 D) during the Free Tropospheric Experiment (FREETEX '96) at the Jungfraujoch Observatory(3580 m above sea level) in the Swiss Alps , 1999 .

[32]  Bruce E. Anderson,et al.  OH and HO2 chemistry in the North Atlantic free troposphere , 1999 .

[33]  D. Blake,et al.  Assessment of upper tropospheric HOx sources over the tropical Pacific based on NASA GTE/PEM data: Net effect on HOx and other photochemical parameters , 1999 .

[34]  A. Weinheimer,et al.  Airborne in‐situ OH and HO2 observations in the cloud‐free troposphere and lower stratosphere during SUCCESS , 1998 .

[35]  Webster,et al.  Hydrogen radicals, nitrogen radicals, and the production of O3 in the upper troposphere , 1998, Science.

[36]  D. Blake,et al.  Implications of large scale shifts in tropospheric NO x levels in the remote tropical Pacific , 1997 .

[37]  Rick D. Saylor,et al.  An estimate of the potential significance of heterogeneous loss to aerosols as an additional sink for hydroperoxy radicals in the troposphere , 1997 .

[38]  W. Stockwell,et al.  The influence of aqueous-phase chemical reactions on ozone formation in polluted and nonpolluted clouds , 1997 .

[39]  Alan Fried,et al.  HO2/OH and RO2/HO2 ratios during the Tropospheric OH Photochemistry Experiment: Measurement and theory , 1997 .

[40]  D. Tanner,et al.  Peroxy radical concentrations measured and calculated from trace gas measurements in the Mauna Loa Observatory Photochemistry Experiment 2 , 1996 .

[41]  Jack G. Calvert,et al.  Measurements and steady state calculations of OH concentrations at Mauna Loa Observatory , 1996 .

[42]  Z. Li,et al.  Aerosol dynamics in the equatorial Pacific marine boundary layer: Microphysics, diurnal cycles and entrainment , 1996 .

[43]  S. Rowland,et al.  Assessment of ozone photochemistry in the western North Pacific as inferred from PEM‐West A observations during the fall 1991 , 1996 .

[44]  W. Brune,et al.  Measuring OH and HO2 in the Troposphere by Laser-Induced Fluorescence at Low Pressure , 1995 .

[45]  D. R. Hanson,et al.  Measurement of hydroxyl and hydroperoxy radical uptake coefficients on water and sulfuric acid surfaces , 1992 .

[46]  P. Mcmurry,et al.  Mass Accommodation Coefficient for HO 2 Radicals on Aqueous Particles , 1987 .

[47]  S. Schwartz.  Gas‐ and aqueous‐phase chemistry of HO2 in liquid water clouds , 1984 .