On Fri, Jan 04, 2013 at 08:53:09PM +1100, Andrew McGlashan wrote:
And whilst today is hot, you might expect that, we are as close [in distance] to the Sun as we'll be for the whole year.
you do realise that aphelion/perihelion has negligible affect on Earth's temperature, right? That the slightly elliptical orbit of the earth around the sun is NOT the cause of seasons? perhaps not...your understanding of science in general and climate science in particular seems deeply flawed. the following relevant excerpt from the Bad Astronomy blog may help you understand: http://www.slate.com/blogs/bad_astronomy/2013/01/02/perihelion_earth_is_clos... [...] The Earth orbits the Sun in an ellipse, not a circle. This fact wasn't discovered until the early 1600s, when astronomer Johannes Kepler published the first two of his three laws of planetary motion. Until that time, for thousands of years previously, everyone thought the planets orbited the Sun moved along perfectly circular paths. But orbit in an ellipse we do, which means sometimes we're closer to the Sun, and sometimes farther. For the Earth, the difference isn't all that much: about 5 million km (3 million miles) separate closest and farthest distance from the Sun - very roughly 147 - 152 million km (91 - 94 million miles). It's a change of only about 3%, which to the eye would make it look pretty much like a perfect circle. In fact, I used Wolfram Alpha to draw a circle and an ellipse with the same shape as Earth's orbit. Can you see the difference? [...] Some people think that the distance to the Sun is the reason we have seasons. But as you can see, this difference is so small it hardly has any affect at all. There's some, but it's small. We're a little bit cooler on average when we're farther away, but the tilt of the Earth's axis is a far bigger influence on temperature than our distance from the Sun. Note that we reach perihelion in January, in the dead of winter for the Northern Hemisphere! That's the opposite of what you would expect if distance to the Sun alone were the cause of the seasons. craig -- craig sanders <cas@taz.net.au>