[magicalist]

That's what I thought at first as well (the animation shows going in one direction and then rising and moving in the opposite, after all), though it seemed really optimistic that you could have enough control from different layers of wind to stay around one spot. Layers of wind move in different directions, but not often diametrically opposed (at least not near to each other vertically), and overall winds in the stratosphere move largely west to east. It seems more likely that you could do some steering with the different layers, but not anything approaching staying still. More like change your latitude very slowly. IANAMeteorologist, though.

Check out the "how loon works" video, it seems to back that up (the source article quotes it as well): http://www.google.com/loon/how/ at around 2:55

from the transcript:

> "Now we have some ability to steer in general, however, in the stratosphere, most of the time the winds actually flow from west to east. Because the winds generally circulate this way, we typically will have bands of our balloons that will be around the world at different latitudes. So if the balloons are circling around the bottom half of the world, eventually the balloon that's over South Africa will pass over South America."