A better theory on the Cooler Climate

As I’ve blogged about in the past, this year has been unseasonably cooler. (it seems) Instead of blaming the condition on lack of sunspots, it could potentially be because Earth is at Aphelion. (or maybe it’s the two combined.) Aphelion is when Earth is furthest away from the Sun; Perihelion is when Earth is closest. Unless you’re a second grader, you probably know that this is not what causes the seasons. That is caused by the precession of the Earth – or Earth’s wobble. The hemispheres receive more or less warmth from the sun because they tilt and the light becomes dispersed over those regions (or concentrated when it tilts towards the Sun at the opposing hemisphere).

So if the Earth is at its closest to the Sun, it must not have a perfectly circular orbit, right?  Correct. It makes an ellipse around the sun with the closest distance at 148 million Km and the furthest at 152 Km. Which makes us at the 152 Km presently. If the Apelion lands on winter and Perihelion lands on summer we would have an extra hot winter, and an extra hot summer. However it will supposedly be several thousand years before the two will actually co-incide. For now we have summer co-inciding with the apelion. Which would, as common logic suggests, give us a cooler summer. But this is by no means exact science.

Supposedly the difference between aphelion and perihelion is  only 5% sunlight. Which can be big if one were to calculate the difference in power received in each region.  But I’m simplifying things.

Of course, if the Earth is never the same distance from the sun, how did they come up with an Astronomical Unit(AU)? Well they simply took an average, which turns out to be 149,597,870,691 ± 30m or roughly just 150 million KM. (wikipedia)

Sources:

http://blogs.discovermagazine.com/badastronomy/2008/07/04/does-the-sun-look-smaller-to-you/

http://en.wikipedia.org/wiki/Astronomical_unit