Dr. David Fitzjarrald
Jungle Research Group
Atmospheric Sciences Research Center
University at Albany, SUNY
| Decaying
convective turbulence in early evening sets initial conditions for stable
boundary layer development. Mixing continues in the convective boundary
layer for a time following the end of positive sensible heat flux. The
subsequent growth of the stable surface and boundary layers often depends
strongly on local topography and land cover. As the night progresses,
other influences vex our attempts to understand turbulent exchange using
textbook truths. Complications include the growth nocturnal jets and associated
intermittent mixing events. Boundary layer meteorologists owe a debt to
the ecologists studying CO2 exchange--now these thorny issues must be
addressed rather than sidestepped if the ecosystem respiration flux (nocturnal
CO2 exchange) is to be estimated properly. The presentation will focus
on observations obtained in the Hudson valley last year during the Hudson
Valley Ambient Meteorology Study (HVAMS), but this will be complemented
by illustrative examples from field studies by our group Brazil, Namibia
and Canada. |