Skjøth, C. and Smith, Matthew and Brandt, J. and Emberlin, Jean (2009) Are the Birch Trees in Southern England a Source of Betula Pollen for North London? International Journal of Biometeorology, 51 (1). pp. 75-86. ISSN 0020-7128 (Print) 1432-1254 (Online)Full text not available from this repository.
Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts (n=60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200–0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.
|Uncontrolled Keywords:||aerobiology, back-trajectory analysis, birch pollen allergy, United Kingdom|
|Subjects:||G Geography. Anthropology. Recreation > GE Environmental Sciences|
|Divisions:||Research Centres > National Pollen and Aerobiology Research Unit|
|Depositing User:||Matthew Smith|
|Date Deposited:||10 Dec 2008 12:14|
|Last Modified:||22 Jul 2013 11:19|
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