Origin of tropospheric NO x over subarctic eastern Canada in summer

The origin of NO{sub x} in the summertime troposphere over subarctic eastern Canada is investigated by photochemical modeling of aircraft and ground-based measurements from the Arctic Boundary Layer Expedition (ABLE 3B). It is found that decomposition of peroxyacetyl nitrate (PAN) can account for most of the NO{sub x} observed between the surface and 6.2 km altitude (aircraft ceiling). Forest fires represent the principal source of PAN in the region, implying the same origin for NO{sub x}. There is, however, evidence for an unidentified source of NO{sub x} in occasional air masses subsiding from the upper troposphere. Isoprene emissions from boreal forests maintain high NO{sub x} concentrations in the continental boundary layer over eastern Canada by scavenging OH and NO{sub 3}, thus slowing down conversion of NO{sub x} to HNO{sub 3}, both in the daytime and at night. This effect is partly compensated by the production of CH{sub 3}CO{sub 3} radicals during isoprene oxidation, which slows down the decomposition of PAN subsiding from the free troposphere. The peroxy radical concentrations estimated from concurrent measurements of NO and NO{sub 2} concentrations during ABLE 3B are consistent with values computed from our photochemical model below 4 km, but model values are low atmore » higher altitudes. The discrepancy may reflect either a missing radical source in the model or interferences in the NO{sub 2} measurement. 63 refs., 10 figs., 1 tab.« less

[1]  S. Wofsy,et al.  SUMMERTIME DISTRIBUTION OF PAN AND OTHER REACTIVE NITROGEN SPECIES IN THE NORTHERN HIGH-LATITUDE ATMOSPHERE OF EASTERN CANADA , 1994 .

[2]  D. Cahoon,et al.  A meteorological interpretation of the Arctic Boundary Layer Expedition (ABLE) 3B flight series , 1994 .

[3]  L. Heidt,et al.  Carbon trace gas fluxes along a successional gradient in the Hudson Bay lowland , 1994 .

[4]  D. Blake,et al.  Effects of biomass burning on summertime nonmethane hydrocarbon concentrations in the Canadian wetlands , 1994 .

[5]  S. Wofsy,et al.  Factors influencing atmospheric composition over subarctic North America during summer , 1994 .

[6]  G. W. Sachse,et al.  Summertime partitioning and budget of NOy compounds in the troposphere over Alaska and Canada: ABLE 3B , 1994 .

[7]  L. Barrie,et al.  Chemical composition of the atmospheric aerosol in the troposphere over the Hudson Bay lowlands and Quebec-Labrador regions of Canada , 1994 .

[8]  W. Grant,et al.  Ozone and aerosol distributions in the summertime troposphere over Canada , 1994 .

[9]  K. E. Moore,et al.  Growing season boundary layer climate and surface exchanges in a subarctic lichen woodland , 1994 .

[10]  P. Crutzen,et al.  Acetone in the atmosphere: Distribution, sources, and sinks , 1994 .

[11]  D. Blake,et al.  Summertime distribution and relations of reactive odd nitrogen species and NOy in the troposphere over Canada , 1994 .

[12]  D. Jacob,et al.  Reactive nitrogen oxides and ozone above a taiga woodland , 1994 .

[13]  L. O. Wade,et al.  A photostationary state analysis of the NO2-NO system based on airborne observations from the subtropical/tropical North and South Atlantic , 1993 .

[14]  D. Jacob,et al.  Simulation of summertime ozone over North America , 1993 .

[15]  P. Kasibhatla,et al.  Global NO x , HNO3, PAN, and NO y distributions from fossil fuel combustion emissions: A model study , 1993 .

[16]  Paul J. Crutzen,et al.  Reaction of N2O5 on tropospheric aerosols: Impact on the global distributions of NO x , O3, and OH , 1993 .

[17]  J. Seinfeld,et al.  Development and evaluation of a photooxidation mechanism for isoprene , 1992 .

[18]  D. Blake,et al.  Summertime tropospheric observations related to N x O y distributions and partitioning over Alaska: Arctic Boundary Layer Expedition 3A , 1992 .

[19]  P. Crutzen,et al.  Atmospheric measurements of peroxyacetyl nitrate and other organic nitrates at high latitudes: Possible sources and sinks , 1992 .

[20]  S. Wofsy,et al.  Measurements of NO(x) and NO(y) concentrations and fluxes over Arctic tundra , 1992 .

[21]  D. Jacob,et al.  Summertime photochemistry of the troposphere at high northern latitudes , 1992 .

[22]  Paul B. Kebabian,et al.  The Arctic Boundary Layer Expedition (ABLE 3A): July–August 1988 , 1992 .

[23]  S. Madronich,et al.  Observations of peroxyacetyl nitrate, peroxypropionyl nitrate, methyl nitrate and ozone during the Mauna Loa Observatory photochemistry experiment , 1992 .

[24]  S. Madronich,et al.  Actinometer and Eppley radiometer measurements of the NO2 photolysis rate coefficient during the Mauna Loa Observatory photochemistry experiment , 1992 .

[25]  Barry J. Huebert,et al.  A study of the photochemistry and ozone budget during the Mauna Loa Observatory Photochemistry Experiment , 1992 .

[26]  S. Madronich,et al.  Measurements and model simulations of the photostationary state during the Mauna Loa Observatory Photochemistry Experiment: Implications for radical concentrations and ozone production and loss rates , 1992 .

[27]  A. Thompson,et al.  The Oxidizing Capacity of the Earth's Atmosphere: Probable Past and Future Changes , 1992, Science.

[28]  D. Ehhalt,et al.  Sources and distribution of NO x in the upper troposphere at northern mid‐latitudes , 1992 .

[29]  P. Crutzen,et al.  The changing photochemistry of the troposphere , 1991 .

[30]  F. Fehsenfeld,et al.  Observations and modeling of the reactive nitrogen photochemistry at a rural site , 1991 .

[31]  S. Ghan,et al.  Tropospheric nitrogen: A three‐dimensional study of sources, distributions, and deposition , 1991 .

[32]  R. Atkinson,et al.  A product study of the gas-phase reaction of Isoprene with the OH radical in the presence of NOx , 1990 .

[33]  D. Jacob,et al.  Budgets of reactive nitrogen, hydrocarbons, and ozone over the Amazon forest during the wet season , 1990 .

[34]  B. Huebert,et al.  Peroxyacetyl nitrate measurements during CITE 2 - Atmospheric distribution and precursor relationships , 1990 .

[35]  S. Madronich,et al.  Observed and model-calculated NO2/NO ratios in tropospheric air sampled during the NASA GTE/CITE-2 field study , 1990 .

[36]  R. Atkinson,et al.  A product study of the gas-phase reaction of methacrolein with the OH radical in the presence of NOx , 1990 .

[37]  Jack G. Calvert,et al.  Permutation reactions of organic peroxy radicals in the troposphere , 1990 .

[38]  R. Atkinson,et al.  A Product Study of the Gas Phase Reaction of Methyl Vinyl Ketone with the OH Radical in the Presence of NOx. , 1990 .

[39]  R. Atkinson.  Gas-phase tropospheric chemistry of organic compounds: a review , 1990 .

[40]  R. Atkinson,et al.  A product study of the gas‐phase reaction of methyl vinyl ketone with the OH radical in the presence of NOx , 1989 .

[41]  Roger Atkinson,et al.  Evaluated kinetic and photochemical data for atmospheric chemistry: Volume III - gas phase reactions of inorganic halogens , 2006 .

[42]  E. Dlugokencky,et al.  Studies of nitrate radical reactions with some atmospheric organic compounds at low pressures , 1989 .

[43]  G. Sachse,et al.  An intercomparison of results from ferrous sulphate and photolytic converter techniques for measurements of NO x made during the NASA GTE/CITE 1 aircraft program , 1988 .

[44]  M. Mozurkewich,et al.  Reaction probability of N2O5 on aqueous aerosols , 1988 .

[45]  S. M. Aschmann,et al.  Rate constants for the gas-phase reactions of the nitrate radical with a series of organic compounds at 296 .+-. 2 K , 1988 .

[46]  D. Jacob,et al.  Photochemistry of biogenic emissions over the Amazon forest , 1988 .

[47]  D. Kley,et al.  Ozone Production in the Black Forest: Direct Measurements of RO2, NOx and Other Relevant Parameters , 1988 .

[48]  Stuart A. McKeen,et al.  Impact of natural hydrocarbons on hydroxyl and peroxy radicals at a remote site , 1987 .

[49]  I. Isaksen,et al.  Calculation of trends in the tropospheric concentration of O3, OH, CO, CH4 and NOx , 1987 .

[50]  H. Levy,et al.  Fate of US and Canadian combustion nitrogen emissions , 1987, Nature.

[51]  Sasha Madronich,et al.  Intercomparison of NO2 photodissociation and U.V. Radiometer Measurements , 1987 .

[52]  Alan C. Lloyd,et al.  A chemical mechanism for use in long‐range transport/acid deposition computer modeling , 1986 .

[53]  H. Singh,et al.  Global distribution of peroxyacetyl nitrate , 1986, Nature.

[54]  D. Fahey,et al.  Measurements of the NO x ‐O3 photostationary state at Niwot Ridge, Colorado , 1986 .

[55]  M. Molina,et al.  Chemical kinetics and photochemical data for use in stratospheric modeling , 1985 .

[56]  B. Heikes,et al.  Effects of heterogeneous processes on NO3, HONO, and HNO3 chemistry in the troposphere , 1983 .

[57]  S. Wofsy,et al.  Tropospheric chemistry: A global perspective , 1981 .

[58]  P. Hanst,et al.  Peroxyacetyl nitrate (PAN) in the unpolluted atmosphere: An important reservoir for nitrogen oxides , 1981 .

[59]  R. B. Harvey,et al.  Measurements of oxides of nitrogen and nitric acid in clean air , 1980 .

[60]  Paul J. Crutzen,et al.  The Role of NO and NO2 in the Chemistry of the Troposphere and Stratosphere , 1979 .

[61]  I. Tang,et al.  Aerosol growth studies — IV. Phase transformation of mixed salt aerosols in a moist atmosphere , 1978 .

[62]  Robert G. Lamb,et al.  Numerico-Empirical Analyses of Atmospheric Diffusion Theories , 1975 .