Why is the Northern Hemisphere Colder Than the Southern?

[jimmydasaint]

This is a brief question exposing my lack of knolwedge on this issue. However, on average, I am considering that most of Northern Europe (including e.g. Sweden, Norway and Scotland) is colder than Southern Europe closer to the Equator. However, why is it that Australia, New Guinea and New Zealand are considered hot countries when they are close to the South Pole?

 

I would love to know the answer.

Edited August 27, 2012 by jimmydasaint

[swansont]

Australia has the Tropic of Capricorn and 30º latitude lines running through it, making its location the equivalent of Northern Africa, not Europe. New Zealand is well north of the Antarctic circle — around 45º — so comparing it to Sweden/Norway (or even Scotland) is not a fair comparison. New Guinea is entirely tropical, almost touching the equator. Southern Europe doesn't extend past 30º — it's closer to 40º.

http://www.lib.utexas.edu/maps/world_maps/world_pol495.jpg

 

In short, your north vs south comparisons are off.

[dimreepr]

The truth of the matter is the opposite; the northern hemisphere Temperature exceeds the southern by an average of approximately 2 degrees C.

 

http://itg1.meteor.wisc.edu/wxwise/AckermanKnox/chap14/climate_spatial_scales.html

 

http://cdiac.esd.ornl.gov/trends/temp/jonescru/graphics/glnhsh.png

[jimmydasaint]

Australia has the Tropic of Capricorn and 30º latitude lines running through it, making its location the equivalent of Northern Africa, not Europe. New Zealand is well north of the Antarctic circle around 45º so comparing it to Sweden/Norway (or even Scotland) is not a fair comparison. New Guinea is entirely tropical, almost touching the equator. Southern Europe doesn't extend past 30º it's closer to 40º.

http://www.lib.utexas.edu/maps/world_maps/world_pol495.jpg

 

In short, your north vs south comparisons are off.

 

Very interesting. Yes, I can see that I made unfair comparisons for the countries that I chose. So it was only a perception then! What about the hemispheres by themselves? I should choose different countries at the same latitude from the equator to make a reasonably fair comparison.

 

What about Mongolia, Kazakhstan, Ukraine and France compared to Southern Argentina, Southern Autralia and New Zealand? Would that be an acceptable comparison about North and South?

 

The truth of the matter is the opposite; the northern hemisphere Temperature exceeds the southern by an average of approximately 2 degrees C.

 

http://itg1.meteor.wisc.edu/wxwise/AckermanKnox/chap14/climate_spatial_scales.html

 

I see that the reports talked about average temperatures over both hemispheres at a large scale which misses out climatic differences in a single country and that is OK. However, it is a surprising result for me because I would not have expected people to flock to Northern hemispheres from the likes of Africa for warm holidays but it tends to be the case for people in Britain to go south when they want warmer climes. I suppose I am being excessively insular.

 

http://cdiac.esd.ornl.gov/trends/temp/jonescru/graphics/glnhsh.png

Edited August 27, 2012 by jimmydasaint

[swansont]

Very interesting. Yes, I can see that I made unfair comparisons for the countries that I chose. So it was only a perception then! What about the hemispheres by themselves? I should choose different countries at the same latitude from the equator to make a reasonably fair comparison.

 

What about Mongolia, Kazakhstan, Ukraine and France compared to Southern Argentina, Southern Autralia and New Zealand? Would that be an acceptable comparison about North and South?

Once you compare equal latitudes, the matters affecting climate will be important — the presence of water and ocean currents, or lack thereof, and mountain ranges, to name a few factors.

[dimreepr]

I see that the reports talked about average temperatures over both hemispheres at a large scale which misses out climatic differences in a single country and that is OK. However, it is a surprising result for me because I would not have expected people to flock to Northern hemispheres from the likes of Africa for warm holidays but it tends to be the case for people in Britain to go south when they want warmer climes. I suppose I am being excessively insular.

 

As swansont points out, there is no real way to compare. Local topography is important and affects the weather in many ways, Britain being a prime example, without the large coastline (not to mention the north Atlantic currents) the temperatures, both winter and summer, would be much more extreme and thus negate the need for the citizenry to travel for their sunshine and skiing holidays.

 

http://www.weatheronline.co.uk/reports/wxfacts/North-Atlantic-Drift-Gulf-Stream.htm

 

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

[jimmydasaint]

Nice links dimreepr. Need to read through them now. Will get back to you.

 

I read through both links with interest, although I just quickly scanned the wiki article because it was quite lengthy.

 

From what I can tell, there are specific factors which affect climate. Add to these for clarification guys:

 

1) Latitude (as it increases, temperature decreases);

2) Large bodies of water (can affect overall temperatures of land nearby);

3) Windward (wet) or leeward (drier) parts of a slope;

4) Elevation ( higher means colder);

5) Ocean Currents, e.g. the thermohaline circulation you referred to above which bring warmth to the Northern Atlantic Ocean.

 

The combinations lead to differences in temperature from region to region of the same country, as well as between countries. Therefore, the OP was just speculation and is not backed up with evidence.

Edited August 27, 2012 by jimmydasaint