Open AccessFlow and pollution transport during Wagerup 2006: a case study
Author(s) -
Retallack Charles,
Calhoun Ron,
Fernando H. J. S.,
Rayner Ken,
Stuart Anthony,
Sutton John,
Hibberd Mark F.
Publication year - 2010
Publication title -
meteorological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 59
eISSN - 1469-8080
pISSN - 1350-4827
DOI - 10.1002/met.161
Subject(s) - escarpment , stratification (seeds) , environmental science , richardson number , atmospheric sciences , geology , boundary layer , meteorology , turbulence , geomorphology , mechanics , geography , physics , seed dormancy , botany , germination , dormancy , biology
As part of a broader field campaign dubbed Wagerup 2006, a case study was carried out to determine the overnight pollution transport mechanisms and flow characteristics near Wagerup, Western Australia. The ambient conditions were characterized by stable stratification with little synoptic influence in the lower boundary layer. An elevated jet intrusion originating on a nearby escarpment slope was found to induce sufficient mixing causing elevated pollution plumes to reach ground level. Onset of mixing was accurately predicted by non‐linear critical Richardson number estimates obtained in previous laboratory work. The increase in ground level temperatures brought about by shear induced mixing later prompted a sea‐breeze like gravity current that was completely blocked by the escarpment and as a result pollutants were trapped against the escarpment slope. A notable side effect of the topographic blocking was the subsequent steady 360° rotation of ground level winds within an area of influence described by the Rossby deformation radius. Copyright © 2009 Royal Meteorological Society