443
4. Summary and conclusions
For the first time a comprehensive study of different conditions affecting the Izaiia
baseline station has been performed using back-trajectories to characterize the air masses
arriving at the Observatory. The trajectory model has been shown to be very suitable in
describing the flow climatology of Izaiia.
Seven categories were established to classify the trajectories. Five-day trajectory
starting outside a 2000-km radius circle defined long-range transport. The North Atlantic
Ocean sector was the most frequent origin of air masses, confirming the suitability of the
Observatory to measure clean background conditions and to represent the North Atlantic
area in the BAPMoN network. The trade-wind inversion further isolates the Izaiia
Observatory from local pollution and lowers the probability of arrival of polluted European
air masses at the station. A high year-to-year persistence of sector frequency distribution
was observed.
Acknowledgements- We wish to thank to: the Climate Monitoring and Diagnostic Laboratory (CMDL) of
NOAA at Boulder, CO, for their full support and specially to 1. Harris who computed the air-mass trajectories;
H. Alonso, J. De la Cruz, A. Diaz, F. Martin, E. Hernandez, F. Valero, and B. Albarran for his valuable
contribution in the preparation of this manuscript; Prof Nacere Hayek (University of La Laguna) for his
invitation to the "Mathematics of Models in Climatology and Environment" Nato ASI.
References
Bergametti G., Gomes L., Coude-Gaussen G., Rognon P. and Le Coustumer M. N. (1989) African dust over
Canary Island: source region identification and transport pattern for some summer situations. J. Geophys.
Res. 94, 14,855-14,864.
Bodhaine B. A., Harris J. M., Ogren J. A. and Hofmann D. J. (1992) Aerosol optical properties at MaunaLoa
Observatory long-range transport from Kuwait Geophys. Res. Lett., 19 (6), 581-584.
Carlsson T. M. and Prospero 1. M. (1972) The large-scale movement of Saharan air outbreaks over the
Northern Equatorial Atlantic. J. Apple. Met. 11,283-297.
Coude-Gaussen G., Rognon P., Bergametti G., Gomes L., Strauss B., Gros J. M. and Le Coustumer M. N.
(1987) Saharan dust on Fuerteventura Island (Canaries): chemical and mineralogical characteristics. air
masses trajectories and probable sources. J. Geophys. Res. 92. 9753-9771.
Dlugokencky E. J., Harris J. M., Chung Y. S., Tan P. P. and Fung I. (1993) The relationship between the
methane seasonal cycle and regional sources and sinks at Tae-ahn Peninsula, Korea. Atmos. Environ .• 27 A
(14) 2115-2120.
Dubief J. (1979) Review of the North African climate with particular emphasis on the production of aeolian
dust in the Sahel zone and in the Sahara. In Saharan Dust: Mobilization. Transpon. Deposition (edited by
Morales C.), pp. 27-48. Workshop held in Gothenburg, Sweden, 25-28 April 1977. John Wiley, New
York.
Friedmann I., Smith G. I., Gleason J. D., Warden A., and Harris 1. M. (1992) Stable Isotope composition of
precipitation in southeastern California. J. Geophys. Res. 97, D5, 5795-5812.
Haagenson P. L. and Sperry P. D. (1989) A relationship of isentropic back trajectories with observed wind
direction and synoptic type in the North Atlantic. J. Apple. Met. 28, 25-42.
Halter B. C. and Harris J. M. (1983) On the variability of atmospheric carbon dioxide concentration at
Barrow, Alaska, during winter. J. Geophys. Res. 88 (C 11 ),. 6858-6862.
4. Summary and conclusions
For the first time a comprehensive study of different conditions affecting the Izaiia
baseline station has been performed using back-trajectories to characterize the air masses
arriving at the Observatory. The trajectory model has been shown to be very suitable in
describing the flow climatology of Izaiia.
Seven categories were established to classify the trajectories. Five-day trajectory
starting outside a 2000-km radius circle defined long-range transport. The North Atlantic
Ocean sector was the most frequent origin of air masses, confirming the suitability of the
Observatory to measure clean background conditions and to represent the North Atlantic
area in the BAPMoN network. The trade-wind inversion further isolates the Izaiia
Observatory from local pollution and lowers the probability of arrival of polluted European
air masses at the station. A high year-to-year persistence of sector frequency distribution
was observed.
Acknowledgements- We wish to thank to: the Climate Monitoring and Diagnostic Laboratory (CMDL) of
NOAA at Boulder, CO, for their full support and specially to 1. Harris who computed the air-mass trajectories;
H. Alonso, J. De la Cruz, A. Diaz, F. Martin, E. Hernandez, F. Valero, and B. Albarran for his valuable
contribution in the preparation of this manuscript; Prof Nacere Hayek (University of La Laguna) for his
invitation to the "Mathematics of Models in Climatology and Environment" Nato ASI.
References
Bergametti G., Gomes L., Coude-Gaussen G., Rognon P. and Le Coustumer M. N. (1989) African dust over
Canary Island: source region identification and transport pattern for some summer situations. J. Geophys.
Res. 94, 14,855-14,864.
Bodhaine B. A., Harris J. M., Ogren J. A. and Hofmann D. J. (1992) Aerosol optical properties at MaunaLoa
Observatory long-range transport from Kuwait Geophys. Res. Lett., 19 (6), 581-584.
Carlsson T. M. and Prospero 1. M. (1972) The large-scale movement of Saharan air outbreaks over the
Northern Equatorial Atlantic. J. Apple. Met. 11,283-297.
Coude-Gaussen G., Rognon P., Bergametti G., Gomes L., Strauss B., Gros J. M. and Le Coustumer M. N.
(1987) Saharan dust on Fuerteventura Island (Canaries): chemical and mineralogical characteristics. air
masses trajectories and probable sources. J. Geophys. Res. 92. 9753-9771.
Dlugokencky E. J., Harris J. M., Chung Y. S., Tan P. P. and Fung I. (1993) The relationship between the
methane seasonal cycle and regional sources and sinks at Tae-ahn Peninsula, Korea. Atmos. Environ .• 27 A
(14) 2115-2120.
Dubief J. (1979) Review of the North African climate with particular emphasis on the production of aeolian
dust in the Sahel zone and in the Sahara. In Saharan Dust: Mobilization. Transpon. Deposition (edited by
Morales C.), pp. 27-48. Workshop held in Gothenburg, Sweden, 25-28 April 1977. John Wiley, New
York.
Friedmann I., Smith G. I., Gleason J. D., Warden A., and Harris 1. M. (1992) Stable Isotope composition of
precipitation in southeastern California. J. Geophys. Res. 97, D5, 5795-5812.
Haagenson P. L. and Sperry P. D. (1989) A relationship of isentropic back trajectories with observed wind
direction and synoptic type in the North Atlantic. J. Apple. Met. 28, 25-42.
Halter B. C. and Harris J. M. (1983) On the variability of atmospheric carbon dioxide concentration at
Barrow, Alaska, during winter. J. Geophys. Res. 88 (C 11 ),. 6858-6862.