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Woodcock, Deardorff , Grossman Soaring gulls, the convective boundary layer and its similarity hypothesis David Fitzjarrald Atmospheric Sciences Research Center University at Albany, SUNY Albany, New York, US of A dfitzjarrald@albany.edu April 17, 2014 Miller’s air-sea interaction class.
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Woodcock, Deardorff, Grossman Soaring gulls, the convective boundary layer and its similarity hypothesis David Fitzjarrald Atmospheric Sciences Research Center University at Albany, SUNY Albany, New York, US of A dfitzjarrald@albany.edu April 17, 2014 Miller’s air-sea interaction class.
Laboratory Bénard convection Woodcock’s idealizations…. “Langmuir lines”—know to seaweed-watching Woodcock
We did not learn about the structure of the convective boundary layer only after computer simulations were available! Habits of convection in laboratory flows Whitehead, 1978
Woodcock, 1940 How the herring gulls soared Not soaring U (m/s) Linear soaring Circular soaring T(ocean) – T(air)
Woodcock, 1942 U (m/s) T(ocean) – T(air)
Woodcock, 1975 T(ocean) – T(air)
Digression about similarity hypotheses in boundary layer meteorology
•the atmospheric convective boundary layer--w*: Ultimately, the thermals "know" more about a capping inversion lid than they do about the distance to the surface. Then the situation is somewhat like convection between two plates. So we perform the similarity analysis using as our fundamental observables zi, (g/Θr)H. What you get is a convective velocity w*. This is known as the mixed layer similarity hypothesis
Willis and Deardorff, 1974 Convection chamber--water Heat flux zi
LES simulations of the CBL, Schmidt & Schumann, 1989
Deardorff, 1982. Modeling—the first ‘large-eddy’ published simulation…. T(ocean) – T(air)
5. Professional Affiliations, Honors or Awards 1971 - Editorial Award, American Meteorological Society 1972 - Publications Award, National Center for Atmospheric Research 1973 - Elected a Fellow of the American Meteorological Society 1974 - Second Half-Century Award American Meteorological Society 1978 - Rossby Research Medal, American Meteorological Society. 1986 - Was elected a Fellow of the American Association for the Advancement of Science James Deardorff, we are finally get to where he already was in 1970….. JD lost interest in meteorology…
Roll circulations in the ABL. Spectra
Cartoon from Roland Stull Benard convection.
Hazards of taking measurements in the Rolls Hodograph from convergentzone Hodograph from center zone 1-km The OLE winds Station A 3 U 2 - 5 km 2 The Mean Wind Z/ 1 Station B V Mean Flow Hodograph RABrown 2004
Dopper radar investigations of rolls. Weckworth et al 1999