Sorry - just realised I am really behind with the posts for our ocean unit. We spent week three looking at ocean currents and how they distribute warm water around the globe.
They started by sprinkling flour on the surface of a bowl of water - when you gently blow up the middle of the bowl you can see the Coriolis effect
We decided to see if we could create a better version of this by using food colouring - red for the southern hemisphere and blue for the northern - the idea being that we would see the 'warmer' water mix with the 'colder' water and the overall temperature (colour) of the water would change.
Sadly this just proved a flop : (
Our colouring just sank to the bottom of the water but at least it led to a good discussion on deep ocean currents.
Not to be deterred we tried again but this time with glitter sprinkled on the surface of the water,
this not only showed the Coriolis effect beautifully but also allowed us to see how the warmer water from the equator changes the temperature (aka colour) of the colder northern waters - yay for glitter : )