caa a22 4500 445367431 CHVBK 20180317142935.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00484-010-0361-x doi (NATIONALLICENCE)springer-10.1007/s00484-010-0361-x On the causes of variability in amounts of airborne grass pollen in Melbourne, Australia [Elektronische Daten] [Julian de Morton, John Bye, Alexandre Pezza, Edward Newbigin] In Melbourne, Australia, airborne grass pollen is the predominant cause of hay fever (seasonal rhinitis) during late spring and early summer, with levels of airborne grass pollen also influencing hospital admissions for asthma. In order to improve predictions of conditions that are potentially hazardous to susceptible individuals, we have sought to better understand the causes of diurnal, intra-seasonal and inter-seasonal variability of atmospheric grass pollen concentrations (APC) by analysing grass pollen count data for Melbourne for 16 grass pollen seasons from 1991 to 2008 (except 1994 and 1995). Some of notable features identified in this analysis were that on days when either extreme (>100 pollen grains m−3) or high (50-100 pollen grains m−3) levels of grass pollen were recorded the winds were of continental origin. In contrast, on days with a low (<20 pollen grains m-3) concentration of grass pollen, winds were of maritime origin. On extreme and high grass pollen days, a peak in APC occurred on average around 1730hours, probably due to a reduction in surface boundary layer turbulence. The sum of daily APC for each grass pollen season was highly correlated (r = 0.79) with spring rainfall in Melbourne for that year, with about 60% of a declining linear trend across the study period being attributable to a reduction of meat cattle and sheep (and hence grazing land) in rural areas around Melbourne. Finally, all of the ten extreme pollen events (3days or more with APC > 100 pollen grains m−3) during the study period were characterised by an average downward vertical wind anomaly in the surface boundary layer over Melbourne. Together these findings form a basis for a fine resolution atmospheric general circulation model for grass pollen in Melbourne's air that can be used to predict daily (and hourly) APC. This information will be useful to those sectors of Melbourne's population that suffer from allergic problems. ISB, 2010 Pollen nationallicence Allergies nationallicence Asthma nationallicence Rainfall nationallicence Anticyclone nationallicence Hayfever nationallicence de Morton Julian School of Earth Sciences, University of Melbourne, 3010, Melbourne, Victoria, Australia aut Bye John School of Earth Sciences, University of Melbourne, 3010, Melbourne, Victoria, Australia aut Pezza Alexandre School of Earth Sciences, University of Melbourne, 3010, Melbourne, Victoria, Australia aut Newbigin Edward School of Botany, University of Melbourne, 3010, Melbourne, Victoria, Australia aut International Journal of Biometeorology Springer-Verlag 55/4(2011-07-01), 613-622 0020-7128 55:4<613 2011 55 484 https://doi.org/10.1007/s00484-010-0361-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00484-010-0361-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- de Morton Julian School of Earth Sciences, University of Melbourne, 3010, Melbourne, Victoria, Australia aut NATIONALLICENCE 700 1- Bye John School of Earth Sciences, University of Melbourne, 3010, Melbourne, Victoria, Australia aut NATIONALLICENCE 700 1- Pezza Alexandre School of Earth Sciences, University of Melbourne, 3010, Melbourne, Victoria, Australia aut NATIONALLICENCE 700 1- Newbigin Edward School of Botany, University of Melbourne, 3010, Melbourne, Victoria, Australia aut NATIONALLICENCE 773 0- International Journal of Biometeorology Springer-Verlag 55/4(2011-07-01), 613-622 0020-7128 55:4<613 2011 55 484 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer