01:460:120 Lecture 11: Lecture 11 - ocean circulation
Document Summary
Key concepts: ocean circulation is driven by wind and by differences in water density, ocean currents, along with winds, distribute tropical heat worldwide. Surface currents are driven by the winds: mostly of the surface wind energy is concentrated in the trade winds and westerlies. Some wind energy is transferred to water by friction: moving water s deflected into circular patterns - gyres - by the coriolis effect and blockage by continents. Surface currents also redistribute heat: global sea surface temperature. The flow around a gyre is not symmetrical; it is different on the eastern and western boundaries due to. Coriolis: the westward shift of the "hill" is because the coriolis effect is strongest near the poles and diminishes toward the equator. Flow would by symmetrical of coriolis affect did not vary. In reality, water flowing eastward at high latitudes (red) turns sooner, "short-circuiting" the gyre. Water flowing westward near equator (green) tends not to turn until encountering a blocking continent.