Friday, June 20, 2008
Although we have been enjoying summer heat for nearly a month... technically it won't we summer until 7:59 tonight! That is when the sun will ascend to its highest latitude (Tropic of Cancer, 23.5 degrees north latitude) on the celestial sphere making today the longest day of the year in the northern hemisphere while it will be the shortest in the southern hemisphere.
One of the common questions we get in the weather department is why today is the highest point for the sun yet our maximum temperatures do not occur until July/August typically?
The reason is something called the 'lag of the seasons' and it is the same reason why it is hotter in the mid-afternoon than at noon. We receive our maximum insolation (the time when the maxiumum solar energy is deposited during the day at a point on the surface of the Earth) at midday and on the first day of summer when the sun is the highest in the sky. Because the Earth, the atmosphere, and oceans store heat they release it at a slower pace than they stored it up. Thus it takes about a month for us to see our highest temperatures on average. The same happens with the first day of winter being in December, but us not seeing out coldest temperatures on average until January.
You can learn more about the 'Summer Solstice' by clicking here.
Have a great Summer!!
Posted by Chris Smith at 4:29 PM