Nasa has been measuring the Ice extent for three decades now and the NSIDC offers a nice chart for displaying the annual variation in ice extent.
You can also obtain some interesting data in spreadsheets that can be downloaded.
However, remember a few important things:
- Ice coverage varies hugely on an annual basis – winter ice extent is 3x larger than summer ice extent. And the reason for this is obvious. The planet’s axial tilt causes the poles to have 100% of daily sunlight during the summer and 0% of sunlight in the winter.
- Year on year variation is also quite large
- Satellite measurement of ice extent is relatively new and we haven’t been measuring change long enough to show the behaviour of even one cycle. i.e. Atlantic mult-decadal Oscillation (AMDO) cycle has 30 years of warming and 30 years of cooling. It is entirely possible that we have only observed the 30 years of warming.
- While Arctic ice extent was declining during this period, Antarctic ice has been growing, which is kind of surprising for a warming earth. I would like to explore more into the possibility of oscillations between the northern and the southern hemispheres.
Ice, Arctic, Antarctic
- NASA – The “Mystery” of Antarctic Cooling – YouTube
- NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses | NASAa
- Ice Age Maps showing the extent of the ice sheets
- Arctic Sea Ice Thickness Increasing For Ten Years | The Deplorable Climate Science Blog
- New Science: Arctic AND Antarctic Sea Ice More Extensive Today Than Nearly All Of The Last 10,000 Yearsa
- Arctic Sea Ice Nonsense – The Media, NASA and NOAA Blatantly Lie To The Public – YouTube
- Ice Doesn’t Lie – But NASA And NOAA Scientists Do – YouTube
- Global Science Report: Antarctic Updates | Cato @ Liberty
- Ice core basics
Source: Ice core basics