MAST382 Lecture 12: Class notes 10/6 Circulation II
18 Oct 2016
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Document Summary
Water is moved toward center of gyre. Sea surface mount dev at the center of the gyre. Center of each subtropical gyre is called a subtropical convergence. Each gyre is modified in shape and location by the configuration of each ocean"s coastlines. Western boundary currents are narrower, faster, deeper and warmer than eastern boundary currents. Western boundary currents are intensified bc the strength of the coriolis effect varies w lat. No coriolis effect at equator so currents can flow directly east to west or west to east. Currents are complicated bc southern hemisphere winds extend over equator. Divergences are areas of upwelling where biological primary productivity is high bc of the supply of nutrients from below. Convergences area areas of downwelling where productivity is poor. Upwelling and downwelling can occur when winds blow parallel to the coast and cause ekman transport of the surface layer offshore or onshore. Independent of and more variable than the adjacent ocean gyre currents.
