Science Lesson

Global Atmospheric Circulation

The sun’s energy does not fall evenly onto our spherical planet: some parts of the earth (a on image 1) are pointing directly at the sun, therefore the sun’s energy has less distance to travel to reach the surface and is focused over a small surface area; whereas other parts (b on image 1) point away from the sun, therefore the same amount of sunlight has further to travel (which allows more solar energy to be deflected back into space by particles in the atmosphere) and is spread over a larger region. The amount of solar energy an area gets over a period of time is known as insolation.

Have you seen the climate spiral?

Photo: The picture is actually an animation, showing global temperature change since 1850.SourceEd Hawkins, ClimateLabBook


Climate scientist, Ed Hawkins from the University of Reading has produced a revolutionary way to illustrate global warming over the past 160 years. Ed's graphic's has been retweeted more than 15,000 times, and now Jay Alder, from the USGS has stretched the the spiral out to model data out to 2100.

El Niño

The name El Niño, Spanish for ‘child’or ‘the Christ child’, was first used by fishermen along the coasts of Ecuador and Peru to refer to a warm ocean current that typically appears around Christmastime and lasts for several months. Fish are less abundant during these warm intervals, so fishermen often took a break to repair their equipment and spend time with their families.

Atlantic Meridional Overturning Circulation

Generalised model of thermohaline circulation, adapted from NASA.

The Atlantic Meridional Overturning Circulation (AMOC) is a system of currents in the Atlantic Ocean, including the Gulf Stream that circulates a vast amount of heat from the tropics towards the North Pole disseminating the cold, saline, dense waters towards the Tropics and even further south towards the South Pole. The figure above captures that in a generalised worldwide model of thermohaline (thermo- referring to temperature and –haline referring to salt content) circulation.

Aurora Borealis

The Aurora Borealis, also known as the Northern Lights, and Aurora Australis (Southern Lights) in the Southern Hemisphere, are a spectacular natural phenomenon. They light up a night sky, dancing around in fantastic colours. There are few places in the Northern Hemisphere where you can see them, but they can be elusive if you are really unlucky. Here we explain the science behind the Northern Lights and share few tips on how to maximise your chances of witnessing this wonderful spectacle.