Long-range transport of ozone and related pollutants over the North Atlantic in spring and summer

• Main Authors: Penkett, S. A., Evans, M. J., Reeves, C. E., Law, Kathy S., Monks, P. S., Bauguitte, S. J. B., Pyle, J. A., Green, T. J., Bandy, B. J., Mills, G., Cardenas, L. M., Barjat, H., Kley, D., Schmitgen, S., Kent, J. M., Dewey, K., Methven, J.
• Other Authors: University of East Anglia Norwich (UEA), University of Cambridge UK (CAM), Department of Chemistry Leicester, University of Leicester, Meteorological Research Flight, Bldg Y46, Kernforschungsanlage, Institut für Chemie (ICH 2), University of Reading (UOR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; North Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-00301372; https://hal.archives-ouvertes.fr/hal-00301372/document; https://hal.archives-ouvertes.fr/hal-00301372/file/acpd-4-4407-2004.pdf

International audience This paper presents strong experimental evidence for a major perturbation in ozone concentrations over large parts of the North Atlantic Ocean from the surface to 8 km associated with continental pollutants. The evidence was gathered in the course of 7 flights by the UK Meteorological Office C-130 aircraft based on the Azores, and 4 ferry flights between the UK to the Azores in spring and summer 1997 as a component of the NERC-funded ACSOE project. The total latitude range covered was approximately 55°N?25°N, and the longitude range was approximately 0° to 40°W. Many profiles were made between the sea surface and altitudes up to 9 km to survey the composition of the marine atmosphere. The C-130 aircraft was comprehensively equipped to measure many chemical and physical parameters along with standard meteorological instrumentation. Thus it was able to measure ozone and speciated NO y , along with tracers including water vapour, carbon monoxide and condensation nuclei, in near real time. The overall "picture" of the troposphere over large parts of the North Atlantic is of layers of pollution from the continents of different ages interspersed with layers of air uplifted from the marine boundary layer. The lowest ozone concentrations were recorded in the marine boundary layer where there is evidence for extensive ozone destruction in summer. Flights were made to penetrate the outflow of hurricane Erica, to determine the southerly extent of polluted air in summer, to examine the impact of frontal systems on the composition of remote marine air, and to trace long-range pollution from the west coast of the USA interspersed with air with a stratospheric origin. In one of the spring flights it is possible that a plume of polluted air with high ozone and NO y , and with an origin in southeast Asia, was intercepted off the coast of Portugal. The concentrations of NO x , in this plume were sufficient for ozone formation to be continuing along its track from west to east. The instrument to measure NO ...