A Weather forum. Weather Banter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » Weather Banter forum » Weather Related Newsgroups » uk.sci.weather (UK Weather)
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

uk.sci.weather (UK Weather) (uk.sci.weather) For the discussion of daily weather events, chiefly affecting the UK and adjacent parts of Europe, both past and predicted. The discussion is open to all, but contributions on a practical scientific level are encouraged.

Arctic and Antarctic Sea Ice: The last 35 years



 
 
LinkBack Thread Tools Display Modes
  #1  
Old September 25th 13, 05:28 AM posted to uk.sci.weather
external usenet poster
 
Posts: 253
Default Arctic and Antarctic Sea Ice: The last 35 years

Hi

(You can find graphs on my blog: http://xmetman.wordpress.com/2013/09...last-35-years/)

I have graphed just about every kind of data related to climate and meteorology over the last eighteen months, but for some reason I've never got round to looking for a data set of sea ice extent, and with all the hoo-ha at the moment concerning that and climate change, I thought I would investigate what was going on by downloading the sea ice data made freely available from the National Snow and Ice Data Center in Boulder (thank God for America and its attitude to free data).

Method

Quite a simple parsing of CSV text file, made slightly tricky because the data for the first year or so was not daily but every other day, and the data for the the latest year was in a separate file. I combined both the Arctic data and the Antarctic data into one class to keep everything tidy. The nearly 11,000 lines of data in each file were parsed in less than 0.1 of a second. I plotted two graphs one showing an area chart with the daily values of sea ice extent in 10^6 square kilometres along with a trend line using all the data points. The second graph, a bar chart, displays the change in extent of sea ice in the last 365 days, red indicates less ice (warmer), blue indicates more ice (colder).

Results

The Arctic graphs were how I expected them to look, with a steady decline in sea ice from around 12.5^6 to 10.5^6 square kilometres in the last 35 years a reduction of approximately 16%. I knew that this year Arctic sea ice had been more stubborn to shift by watching the SYNOP observations from northern Canada and Greenland (see this blog). What did surprise me is even though they has been a steady decline in sea ice how volatile the change from season to season is.

The Antarctic graphs were a little surprising too, I did know that there had been a slight increase in sea ice there, and this was borne out by the area chart and the trend line showing a change from around 11.3^6 to 12.0^6 square kilometres, an increase of Antarctic sea ice of approximately 6% in 35 years. The other surprising thing was that for some reason I thought the Antarctic had a great deal more sea ice than the Arctic!

To do

Iíll try and link in this sea ice data set with global surface temperatures and maybe try and find an overlay the projections for future sea ice extent. Let me know if you spot any errors

Bruce.
  #2  
Old September 25th 13, 06:23 AM posted to uk.sci.weather
external usenet poster
 
Posts: 8,164
Default Arctic and Antarctic Sea Ice: The last 35 years

On Wednesday, September 25, 2013 5:28:10 AM UTC+1, exmetman wrote:
Hi



(You can find graphs on my blog: http://xmetman.wordpress.com/2013/09...last-35-years/)



I have graphed just about every kind of data related to climate and meteorology over the last eighteen months, but for some reason I've never got round to looking for a data set of sea ice extent, and with all the hoo-ha at the moment concerning that and climate change, I thought I would investigate what was going on by downloading the sea ice data made freely available from the National Snow and Ice Data Center in Boulder (thank God for America and its attitude to free data).



Method



Quite a simple parsing of CSV text file, made slightly tricky because the data for the first year or so was not daily but every other day, and the data for the the latest year was in a separate file. I combined both the Arctic data and the Antarctic data into one class to keep everything tidy. The nearly 11,000 lines of data in each file were parsed in less than 0.1 of a second. I plotted two graphs one showing an area chart with the daily values of sea ice extent in 10^6 square kilometres along with a trend line using all the data points. The second graph, a bar chart, displays the change in extent of sea ice in the last 365 days, red indicates less ice (warmer), blue indicates more ice (colder).



Results



The Arctic graphs were how I expected them to look, with a steady decline in sea ice from around 12.5^6 to 10.5^6 square kilometres in the last 35 years a reduction of approximately 16%. I knew that this year Arctic sea ice had been more stubborn to shift by watching the SYNOP observations from northern Canada and Greenland (see this blog). What did surprise me is even though they has been a steady decline in sea ice how volatile the change from season to season is.



The Antarctic graphs were a little surprising too, I did know that there had been a slight increase in sea ice there, and this was borne out by the area chart and the trend line showing a change from around 11.3^6 to 12.0^6 square kilometres, an increase of Antarctic sea ice of approximately 6% in 35 years. The other surprising thing was that for some reason I thought the Antarctic had a great deal more sea ice than the Arctic!



To do



Iíll try and link in this sea ice data set with global surface temperatures and maybe try and find an overlay the projections for future sea ice extent. Let me know if you spot any errors



Bruce.


You could just have gone to "Cryosphere Today" Bruce, though you obviously enjoy manipulating the data.
  #3  
Old September 25th 13, 10:42 AM posted to uk.sci.weather
external usenet poster
 
Posts: 627
Default Arctic and Antarctic Sea Ice: The last 35 years

"exmetman" wrote in message
...

Results

The Arctic graphs were how I expected them to look, with a steady decline in
sea ice from around 12.5^6 to 10.5^6 square kilometres in the last 35 years
a reduction of approximately 16%. I knew that this year Arctic sea ice had
been more stubborn to shift by watching the SYNOP observations from northern
Canada and Greenland (see this blog). What did surprise me is even though
they has been a steady decline in sea ice how volatile the change from
season to season is.

The Antarctic graphs were a little surprising too, I did know that there had
been a slight increase in sea ice there, and this was borne out by the area
chart and the trend line showing a change from around 11.3^6 to 12.0^6
square kilometres, an increase of Antarctic sea ice of approximately 6% in
35 years. The other surprising thing was that for some reason I thought the
Antarctic had a great deal more sea ice than the Arctic!

================================================== ==========

I think you may be missing a point about changes to sea ice. In the Northern
Hemisphere the trend in winter ice is much less than the annual average and
the trend in summer ice is much greater. See:
http://arctic.atmos.uiuc.edu/cryosph....1900-2010.png

I suspect the opposite is the case in the Southern Hemisphere.

The reason that the extent of the winter Arctic sea ice has remained fairly
constant is that there is a positive feedback controlling it. The more sea
ice there is, the colder the air can get and the further the sea ice can
spread out. So after a big summer melt when the winter ice reforms
it does so slowly, bet when it catches up then it spreads out to the same
area as before.

This has, IMHO, led scientists into a misleading complacency regarding
the loss od Arctic sea ice. They have concentrated on the annual trend,
roughly half the summer trend, and not realised that the summer ice loss is
more important because the strength of a chain is in its weakest link.

Cheers, Alastair.



  #4  
Old September 25th 13, 11:05 AM posted to uk.sci.weather
external usenet poster
 
Posts: 676
Default Arctic and Antarctic Sea Ice: The last 35 years

On 25/09/2013 05:28, exmetman wrote:
Hi

(You can find graphs on my blog: http://xmetman.wordpress.com/2013/09...last-35-years/)

I have graphed just about every kind of data related to climate and meteorology over the last eighteen months, but for some reason I've never got round to looking for a data set of sea ice extent, and with all the hoo-ha at the moment concerning that and climate change, I thought I would investigate what was going on by downloading the sea ice data made freely available from the National Snow and Ice Data Center in Boulder (thank God for America and its attitude to free data).

Method

Quite a simple parsing of CSV text file, made slightly tricky because the data for the first year or so was not daily but every other day, and the data for the the latest year was in a separate file. I combined both the Arctic data and the Antarctic data into one class to keep everything tidy. The nearly 11,000 lines of data in each file were parsed in less than 0.1 of a second. I plotted two graphs one showing an area chart with the daily values of sea ice extent in 10^6 square kilometres along with a trend line using all the data points. The second graph, a bar chart, displays the change in extent of sea ice in the last 365 days, red indicates less ice (warmer), blue indicates more ice (colder).

Results

The Arctic graphs were how I expected them to look, with a steady decline in sea ice from around 12.5^6 to 10.5^6 square kilometres in the last 35 years a reduction of approximately 16%. I knew that this year Arctic sea ice had been more stubborn to shift by watching the SYNOP observations from northern Canada and Greenland (see this blog). What did surprise me is even though they has been a steady decline in sea ice how volatile the change from season to season is.

The Antarctic graphs were a little surprising too, I did know that there had been a slight increase in sea ice there, and this was borne out by the area chart and the trend line showing a change from around 11.3^6 to 12.0^6 square kilometres, an increase of Antarctic sea ice of approximately 6% in 35 years. The other surprising thing was that for some reason I thought the Antarctic had a great deal more sea ice than the Arctic!

To do

Iíll try and link in this sea ice data set with global surface temperatures and maybe try and find an overlay the projections for future sea ice extent. Let me know if you spot any errors

Bruce.


What we lose on the arctic, we gain on the antarctic. Swings and
roundabouts.
  #5  
Old September 25th 13, 11:52 AM posted to uk.sci.weather
external usenet poster
 
Posts: 3,567
Default Arctic and Antarctic Sea Ice: The last 35 years

On Wed, 25 Sep 2013 11:05:36 +0100
Joe Egginton wrote:

On 25/09/2013 05:28, exmetman wrote:


Results

The Arctic graphs were how I expected them to look, with a steady
decline in sea ice from around 12.5^6 to 10.5^6 square kilometres
in the last 35 years a reduction of approximately 16%. I knew that
this year Arctic sea ice had been more stubborn to shift by
watching the SYNOP observations from northern Canada and Greenland
(see this blog). What did surprise me is even though they has been
a steady decline in sea ice how volatile the change from season to
season is.

The Antarctic graphs were a little surprising too, I did know that
there had been a slight increase in sea ice there, and this was
borne out by the area chart and the trend line showing a change
from around 11.3^6 to 12.0^6 square kilometres, an increase of
Antarctic sea ice of approximately 6% in 35 years. The other
surprising thing was that for some reason I thought the Antarctic
had a great deal more sea ice than the Arctic!



What we lose on the arctic, we gain on the antarctic. Swings and
roundabouts.


So, according to your maths, 2.0^6 = 0.7^6.

Apart from dodgy maths, you are also ignoring the fact that there is
also a net loss of ice in the Antarctic when the land ice is included.
Ice is being lost in both locations.


--
Graham P Davis, Bracknell, Berks.
'In wine there is wisdom, in beer there is freedom, in water there is
bacteria.' - Benjamin Franklin
  #6  
Old September 25th 13, 06:07 PM posted to uk.sci.weather
external usenet poster
 
Posts: 2,279
Default Arctic and Antarctic Sea Ice: The last 35 years

On Wednesday, 25 September 2013 06:23:27 UTC+1, Dawlish wrote:
On Wednesday, September 25, 2013 5:28:10 AM UTC+1, exmetman wrote:

Hi








(You can find graphs on my blog: http://xmetman.wordpress.com/2013/09...last-35-years/)








I have graphed just about every kind of data related to climate and meteorology over the last eighteen months, but for some reason I've never got round to looking for a data set of sea ice extent, and with all the hoo-ha at the moment concerning that and climate change, I thought I would investigate what was going on by downloading the sea ice data made freely available from the National Snow and Ice Data Center in Boulder (thank God for America and its attitude to free data).








Method








Quite a simple parsing of CSV text file, made slightly tricky because the data for the first year or so was not daily but every other day, and the data for the the latest year was in a separate file. I combined both the Arctic data and the Antarctic data into one class to keep everything tidy. The nearly 11,000 lines of data in each file were parsed in less than 0.1 of a second. I plotted two graphs one showing an area chart with the daily values of sea ice extent in 10^6 square kilometres along with a trend line using all the data points. The second graph, a bar chart, displays the change in extent of sea ice in the last 365 days, red indicates less ice (warmer), blue indicates more ice (colder).








Results








The Arctic graphs were how I expected them to look, with a steady decline in sea ice from around 12.5^6 to 10.5^6 square kilometres in the last 35 years a reduction of approximately 16%. I knew that this year Arctic sea ice had been more stubborn to shift by watching the SYNOP observations from northern Canada and Greenland (see this blog). What did surprise me is even though they has been a steady decline in sea ice how volatile the change from season to season is.








The Antarctic graphs were a little surprising too, I did know that there had been a slight increase in sea ice there, and this was borne out by the area chart and the trend line showing a change from around 11.3^6 to 12.0^6 square kilometres, an increase of Antarctic sea ice of approximately 6% in 35 years. The other surprising thing was that for some reason I thought the Antarctic had a great deal more sea ice than the Arctic!








To do








Iíll try and link in this sea ice data set with global surface temperatures and maybe try and find an overlay the projections for future sea ice extent. Let me know if you spot any errors








Bruce.




You could just have gone to "Cryosphere Today" Bruce, though you obviously enjoy manipulating the data.


so Cryosphere me a river or graph.
  #7  
Old September 25th 13, 08:40 PM posted to uk.sci.weather
external usenet poster
 
Posts: 1,184
Default Arctic and Antarctic Sea Ice: The last 35 years

On 25/09/13 11:52, Graham P Davis wrote:
On Wed, 25 Sep 2013 11:05:36 +0100
Joe wrote:

On 25/09/2013 05:28, exmetman wrote:


Results

The Arctic graphs were how I expected them to look, with a steady
decline in sea ice from around 12.5^6 to 10.5^6 square kilometres
in the last 35 years a reduction of approximately 16%. I knew that
this year Arctic sea ice had been more stubborn to shift by
watching the SYNOP observations from northern Canada and Greenland
(see this blog). What did surprise me is even though they has been
a steady decline in sea ice how volatile the change from season to
season is.

The Antarctic graphs were a little surprising too, I did know that
there had been a slight increase in sea ice there, and this was
borne out by the area chart and the trend line showing a change
from around 11.3^6 to 12.0^6 square kilometres, an increase of
Antarctic sea ice of approximately 6% in 35 years. The other
surprising thing was that for some reason I thought the Antarctic
had a great deal more sea ice than the Arctic!



What we lose on the arctic, we gain on the antarctic. Swings and
roundabouts.


So, according to your maths, 2.0^6 = 0.7^6.

Apart from dodgy maths, you are also ignoring the fact that there is
also a net loss of ice in the Antarctic when the land ice is included.
Ice is being lost in both locations.



Presumably the loss of land ice would lead to a freshening of the
Southern Ocean which would make it easier for sea ice to form?
Alternatively, the warming trend in the Southern Ocean is compensated
for by an increase in the freezing point of the ocean?
  #8  
Old September 25th 13, 08:41 PM posted to uk.sci.weather
external usenet poster
 
Posts: 8,164
Default Arctic and Antarctic Sea Ice: The last 35 years

On Wednesday, September 25, 2013 11:52:54 AM UTC+1, Graham P Davis wrote:
On Wed, 25 Sep 2013 11:05:36 +0100

Joe Egginton wrote:



On 25/09/2013 05:28, exmetman wrote:




Results




The Arctic graphs were how I expected them to look, with a steady


decline in sea ice from around 12.5^6 to 10.5^6 square kilometres


in the last 35 years a reduction of approximately 16%. I knew that


this year Arctic sea ice had been more stubborn to shift by


watching the SYNOP observations from northern Canada and Greenland


(see this blog). What did surprise me is even though they has been


a steady decline in sea ice how volatile the change from season to


season is.




The Antarctic graphs were a little surprising too, I did know that


there had been a slight increase in sea ice there, and this was


borne out by the area chart and the trend line showing a change


from around 11.3^6 to 12.0^6 square kilometres, an increase of


Antarctic sea ice of approximately 6% in 35 years. The other


surprising thing was that for some reason I thought the Antarctic


had a great deal more sea ice than the Arctic!








What we lose on the arctic, we gain on the antarctic. Swings and


roundabouts.




So, according to your maths, 2.0^6 = 0.7^6.



Apart from dodgy maths, you are also ignoring the fact that there is

also a net loss of ice in the Antarctic when the land ice is included.

Ice is being lost in both locations.





--

Graham P Davis, Bracknell, Berks.

'In wine there is wisdom, in beer there is freedom, in water there is

bacteria.' - Benjamin Franklin


Completely accurate. The continent of Antarctic is losing ice.
  #9  
Old September 25th 13, 10:05 PM posted to uk.sci.weather
external usenet poster
 
Posts: 2,279
Default Arctic and Antarctic Sea Ice: The last 35 years

On Wednesday, 25 September 2013 20:40:25 UTC+1, Adam Lea wrote:
On 25/09/13 11:52, Graham P Davis wrote:

On Wed, 25 Sep 2013 11:05:36 +0100


Joe wrote:




On 25/09/2013 05:28, exmetman wrote:




Results




The Arctic graphs were how I expected them to look, with a steady


decline in sea ice from around 12.5^6 to 10.5^6 square kilometres


in the last 35 years a reduction of approximately 16%. I knew that


this year Arctic sea ice had been more stubborn to shift by


watching the SYNOP observations from northern Canada and Greenland


(see this blog). What did surprise me is even though they has been


a steady decline in sea ice how volatile the change from season to


season is.




The Antarctic graphs were a little surprising too, I did know that


there had been a slight increase in sea ice there, and this was


borne out by the area chart and the trend line showing a change


from around 11.3^6 to 12.0^6 square kilometres, an increase of


Antarctic sea ice of approximately 6% in 35 years. The other


surprising thing was that for some reason I thought the Antarctic


had a great deal more sea ice than the Arctic!








What we lose on the arctic, we gain on the antarctic. Swings and


roundabouts.




So, according to your maths, 2.0^6 = 0.7^6.




Apart from dodgy maths, you are also ignoring the fact that there is


also a net loss of ice in the Antarctic when the land ice is included.


Ice is being lost in both locations.








Presumably the loss of land ice would lead to a freshening of the

Southern Ocean which would make it easier for sea ice to form?

Alternatively, the warming trend in the Southern Ocean is compensated

for by an increase in the freezing point of the ocean?


People go on with this myth of loss of land ice. It's rubbish even on the coast the average temperature is below freezing. Its a sorry excuse to explain the growing sea ice which is defying all logic and growing because Antarctica is warmed by .5 degrees Celsius.

Does anyone actually believe that?
  #10  
Old September 25th 13, 10:06 PM posted to uk.sci.weather
external usenet poster
 
Posts: 2,279
Default Arctic and Antarctic Sea Ice: The last 35 years

On Wednesday, 25 September 2013 20:41:36 UTC+1, Dawlish wrote:
On Wednesday, September 25, 2013 11:52:54 AM UTC+1, Graham P Davis wrote:

On Wed, 25 Sep 2013 11:05:36 +0100




Joe Egginton wrote:








On 25/09/2013 05:28, exmetman wrote:








Results








The Arctic graphs were how I expected them to look, with a steady




decline in sea ice from around 12.5^6 to 10.5^6 square kilometres




in the last 35 years a reduction of approximately 16%. I knew that




this year Arctic sea ice had been more stubborn to shift by




watching the SYNOP observations from northern Canada and Greenland




(see this blog). What did surprise me is even though they has been




a steady decline in sea ice how volatile the change from season to




season is.








The Antarctic graphs were a little surprising too, I did know that




there had been a slight increase in sea ice there, and this was




borne out by the area chart and the trend line showing a change




from around 11.3^6 to 12.0^6 square kilometres, an increase of




Antarctic sea ice of approximately 6% in 35 years. The other




surprising thing was that for some reason I thought the Antarctic




had a great deal more sea ice than the Arctic!
















What we lose on the arctic, we gain on the antarctic. Swings and




roundabouts.








So, according to your maths, 2.0^6 = 0.7^6.








Apart from dodgy maths, you are also ignoring the fact that there is




also a net loss of ice in the Antarctic when the land ice is included.




Ice is being lost in both locations.












--




Graham P Davis, Bracknell, Berks.




'In wine there is wisdom, in beer there is freedom, in water there is




bacteria.' - Benjamin Franklin




Completely accurate. The continent of Antarctic is losing ice.


Prove it
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


All times are GMT. The time now is 07:17 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.Search Engine Optimization by vBSEO 3.6.1
Copyright ©2004-2014 Weather Banter.
The comments are property of their posters.