Northern Hemisphere covered in snow & ice

At first glance it looks like a graphic from a Discovery Channel programme about a distant ice age. But this astonishing picture shows the world as it is today - with half the Northern Hemisphere covered with snow and ice.

Read the full article here:  http://www.dailymail.co.uk/news/article-1353073/Winter-storm-Map-shows-Northern-Hemisphere-covered-snow-ice.html

EXTRACT:

World of two halves! Map shows most of Northern Hemisphere is covered in snow and ice


It is the extent to which the line dips down over the Northern Hemisphere that is so remarkable about the image.


The image was released by the National Oceanic And Atmospheric Association (NOAA) on the day half of North America was in the grip of a severe winter storm.



view the PHOTO here.

January 3 - closest point to the sun, can you believe it?

 

Read all about it on:  http://www.bbc.co.uk/blogs/23degrees/2011/01/our_journey_begins_here_closes.html

Extract: 

Believe it or not, it's a very special day. Despite the freezing weather we are getting at the moment, the Earth is at its closest point to the sun it will get all year. It's called Perihelion which is Greek for "near to the sun", and right now the Earth is 5 million kilometres closer to the sun than it will be in July, when it's at its furthest point.



Perihelion highlights how fascinating the relationship is between the earth and its cosmic star. Who would have thought that at the point when we are closest to the sun, we would experience such freezing temperatures?

Perihelion is a result of the slightly strange shape of the Earth's orbit around the sun. It's not a perfect circle, it's an ellipse, and the sun isn't even in the centre, it's slightly off to one side. So at the moment we are just 147.1 million kilometres [91.4 million miles] from the sun.




You are probably thinking - if we are closer, then why aren't we warmer? Well, our journey around the sun is complex and there's another factor that shapes our climate that is more powerful than just how close we are to the sun. And that's the tilt of the planet. Earth doesn't sit upright; it's tilted over to one side at an angle of 23.5 degrees.


The tilt and the Earth's motion around the sun create the seasons.


In January the northern hemisphere is tilted away from the sun so the sunlight is spread more thinly over the northern half of the planet so we get our winter. Meanwhile the southern hemisphere which is now tilted towards the sun gets more sunlight and therefore enjoys summer. Gradually the Earth moves around the sun until July when the Northern hemisphere tilts towards the sun, when the reverse is true.

Now – in January – we are in midwinter, but the northern hemisphere is already starting its journey back towards the sun and over the next few months we will get more and more sunlight and slowly the Northern Hemisphere will rise from its slumber and move towards spring.




References: 
http://scienceblogs.com/
http://www.crh.noaa.gov/fsd/?n=season
http://plus.maths.org/content/comment/reply/2610
http://joseph-bartlo.net/articles/111897.htm
http://addins.kwwl.com/blogs/weather/archives/12492
http://redoubtreporter.wordpress.com/2010/03/24/reasons-for-the-seasons-%E2%80%94-distance-doesn%E2%80%99t-cause-changes-in-warmth-sunlight/
http://www.warren-wilson.edu/~physics/PhysPhotOfWeek/2008PPOW/20081219EarliestSunset/index.html
http://www.nightsky.ie/2010/01/
http://astrobob.areavoices.com/2010/09/20/jupiter-closest-to-earth-since-1963/
http://www.thesuntoday.org/sun-101/our-star-an-introduction-to-the-sun/