ESS228
Prof. Jin-Yi Yu
Why QBO?
q Kevin Waves accelerates westerly.
q Mixed Rossby-Gravity Wave accelerates easterly.
• The
vertically propagating equatorial Kelvin wave
and mixed Rossby-gravity waves provide the
zonal momentum source of QBO.
•The
eastward propagating Kelvin wave provides the
needed source of westerly momentum, and the
westward propagating mixed Rossby-gravity wave
provides easterly momentum.
•The
westerly Kelvin waves tend to be damped in westerly
shear zones, and the easterly mixed Rossby-gravity wave is damped in easterly
shear zones.