MMM SEMINAR NCAR
The
spacing of convective orographic rainbands
triggered by small-scale terrain
Recent observations indicate that
quasi-stationary rainbands may add strong variability
to precipitation distributions over mountainous terrain. While the mechanisms
behind the triggering of these bands have recently been identified, the spacing
between adjacent bands is an unresolved problem that requires deeper
investigation. In this study we examine this issue through idealized
simulations of moist flow over a topographic barrier and a linear model that
describes the transition from stable, topographically generated lee waves to
unstable moist convection within an orographic cap
cloud. This approach leads to a novel hypothesis for the spacing of orographic rainbands that links
the lee-wave oscillations that are generated upstream of an orographic
cap cloud to the scales of the convection that develops within it.
Refreshments
NCAR-Foothills Laboratory
Bldg 2 Auditorium, Rm. 1022