The Antarctic Circumpolar Current is the only ocean current which extends around the globe. It is located between about 50-60 S and passes through Drake Passage south of South America into the Atlantic Ocean, then continuous via the gap between Antarctica and South Africa into the southern Indian Ocean and finally ventures into the South Pacific Ocean via the gap between Antarctica and Australia. For the purpose of this exercise, we assume here that the water flows on average with a speed of V=0.5 m s-1. Question 1: How long does it take for a water parcel to travel around the globe at this latitude (mid-point S)? Question 2: If there were no continental boundaries near the Equator, how long would it take to travel around the world along the Equator? Pathway to solution: Firstly, we need to calculate the length of the pathway to then secondly, calculate the time required. Thus calculate the length of the pathway or circumference U of a circle at mid-point between 50-60 S from the following formula with Earth's radius R = 6,370, = midpoint S, and r = R x cos being the radius at a particular latitude. The circumference of a circle follows then from the following: U = 2 r U = 2 x x R x cos