A satellite image shows a train of lenticular clouds extending about downwind of a…
PHYSICS · Multi-part · Fermi University Physics · Fluids & Continuum Physics · Waves, acoustics and compressible flow · Convection, rotation and geophysical flows
Signal Speeds in Fluids, Ch Internal gravity waves in a stratified fluid
Problem
A satellite image shows a train of lenticular clouds extending about 45km downwind of a coastal mountain range. Over this stretch the wind is roughly uniform at U=12ms−1, and the buoyancy frequency of the air is N=1.5×10−2s−1.
((a)) Estimate the shortest horizontal wavelength a lee wave can have and still propagate upward rather than decay with height.
((b)) Taking the observed cloud spacing to be of this order, estimate the number of distinct cloud bands expected in the 45km train.