Arctic Spring 2015: A minimum maximum?

The extent of arctic sea-ice (in millions of kilometres squared) in recent months. The figure is downloaded for the US National Snow and Ice Data Centre .It looks like this year's maximum could cover less than ever before - a minimum maximum.

The extent of arctic sea-ice (in millions of square kilometres) in recent months. The figure is downloaded for the US National Snow and Ice Data Centre .It looks like this year’s maximum could cover less than ever before – a minimum maximum.

Spring is springing into life in Teddington, and lifting my spirits.

Meanwhile, further north, the winter growth of sea-ice in the Arctic is slowing, and about to reach its maximum extent.

As the graph at the head of page shows, it looks like this years ‘sea-ice maximum’ (blue line on graph) will not cover the same extent as previous maxima.

In fact, it could prove to be a minimum maximum.

Graph showing the February monthly average of Arctic Sea-Ice Extent since 1979.

Graph showing the February monthly average of Arctic Sea-Ice Extent since 1979.

The graph above shows the trend in February monthly-averaged sea-ice extent since 1979.

The downward trend is pretty clear: typically 1.5 million square kilometres of sea-ice that used to form in 1979 no longer forms.

But there is also the variability – typically ± 0.3 million square kilometres of sea-ice either forms or doesn’t because of the weather: the arctic too can have ‘mild’ and ‘harsh’ winters.

There  is still time for a little more sea-ice growth before the summer melt commences. So this might not be an minimum maximum, but it will be close.

Will a minimum maximum lead to a minimum minimum?

One might think that a smaller extent of sea-ice would automatically lead – after a summer of melting – to a minimum sea ice extent this September.

This is a possibility, but the data suggests there is not a direct link.

For example, in summer 2012, the sea-ice extent ‘collapsed’ to a new record minimum. However, the March before that ‘collapse’, the  winter maximum in the sea-ice extent had been ‘on the high side’ of the recent trend.

Charctic Amusement?

You can review the data yourself over at the US National Snow and Ice Data Centre.

They have a clever ‘Charctic’ tool for plotting the data year by year. Enjoy 🙂

2 Responses to “Arctic Spring 2015: A minimum maximum?”

  1. edaviesmeuk Says:

    My previous look at the connection between extents earlier in the year and the annual minimum: http://edavies.me.uk/2013/06/seasonal-sea-ice-variation/

    • protonsforbreakfast Says:

      Thanks: that’s a nice discussion. As I read it I wanted to say ‘try correlating the previous maximum (March) with the value of the next minimum’ but you did in fact effectively do that. In 2012 you can see that in ‘plummeting trend’ begins in June and I think I read it was associated with particular weather events – warm air and a storm that broke up some thin ice if I remember. But it is interesting just how de-coupled these data sets are.

      And yes, I share that sense of sick fascination – like watching a car crash in ultra slow motion.

      Thanks

      Michael

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