the measured
diurnal bi-modal pollen concentration patterns were
associated with a lull in the duration of upward motions,
especially evident in the duration fraction of strong ejection
events. Furthermore, diurnal patterns of the fraction of
pollen that reach high elevations, i.e. c(z/h = 2)/ch followed
the same trends as ejection duration fractions, indicating
the important effect of large coherent structures on pollen
dispersal