Update on Arctic annual minimum extent and volume

Back in July, I wrote two posts on the Arctic sea ice annual minimum, one about the sea ice extent and one about sea ice volume. In the meanwhile, there was a new minimum in September 2022 and I wondered what the evolution was of those minima. This post is an update on the volume as well as the extent graphs.

Let’s start with the volume data. This is a plot of the annual sea ice minimum extent from 1979 until 2022:

Arctic sea ice minimum volume (scatter plot)

The 2022 minimum (blue diamond) is just above that of 2021, but only just.
This scatter plot is a blank canvas at which I can add some trend lines. I will provide three different flavors. The first is the linear trend:

Arctic sea ice minimum volume (linear trend)

If one want to write a scary story, then the linear trend surely is the one to go for.

If this process really follows a linear trend, then the Arctic would be ice-free within this decade. However, my guess is that the trend follows a curve rather than a straight line:

Arctic sea ice minimum volume (cubic trend)

This seems to fit more snugly.

Both however mask the change of trend that occurred in the last decade. Remember, there was the claim in 2012 that the Arctic could be ice-free by 2015, based on this Arctic sea ice volume decline graph. Comparing the trajectory that was expected in 2012 with the actually observed minimum volume data better shows that there was an unexpected trend break:

Arctic sea ice minimum volume vs 2012 dead spiral projection

Let’s continue with the extent data. This is the blank canvas:

Arctic sea ice minimum extent (scatter plot)

The linear also looks scary but not as bad as the volume data (it will take several decades before this trend line crashes into the x-axis):

Arctic sea ice minimum extent (linear trend)

Also here, a curve seems to be a better fit than the straight line:

Arctic sea ice minimum extent (cubic trend)

Inspired by volume decline graph above, this is the comparison of the 2012 death spiral projection with the actual data:

Arctic sea ice minimum extent vs 2012 dead spiral projection

In the end, neither volume nor extent changed much compared to last year. It’s too early to see where this is heading to. This stable trend could continue for a while, but it is also possible that the trajectory is sinusoidal or that sea ice start spiraling down again. Time will tell.

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