Note the large-scale, ocean basin patterns:  clockwise loops in the northern hemisphere, counterclockwise loops in the south.  These loops are known as "gyres."  Also note that at very low latitudes all currents are warm, at very high latitudes all currents are cold, and at middle latitudes most continents have cold currents along their western boundaries and warm currents along their eastern boundaries in both northern and southern hemispheres.      Click here for an expandable, more detailed image.