EAS212 Lecture Notes - Lecture 10: Pressure-Gradient Force, Geostrophic Current, Ekman Transport

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS212
• Professor: Juliana Marson

Document Summary

Mean flow x ekman transport: unlike ekman motion, pressure gradient transfer occurs at all depths where a pressure gradient may be found, this means that the mean flow in deeper layers may oppose the. 90 to the right (left) of the pressure gradient in the nh (sh) (note that in reality flows are never perfectly geostrophic as friction and other effects come into play) Geostrophic flow: geostrophic current ideally flows parallel to the isobars. Water-covered earth: the ekman transport is based on the large scale atmospheric circulation, this leads to bands of convergence and divergence, convergence ~ 30 , divergence ~ eq. , 60 : this then generates large- scale geostrophic currents that would flow around the. Circumpolar current: gyres: closed circulation loops within the ocean, sub-tropical: gyres which flow clockwise (anti-cyclonic) in the. Northern hemisphere: sub-polar: gyres flowing counterclockwise (cyclonic) in the. Northern hemisphere: gyre direction reversed in southern hemisphere.