During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily IJIS sea ice extent (SIE) and Cryosphere Today sea ice area (SIA) numbers, which I compare to data from the 2005-2011 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything that can be of particular interest.
Check out the Arctic Sea Ice Graphs website for
daily updated graphs, maps and live webcam images.
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One is for Cryosphere Today minimum daily sea ice area, the other for NSIDC minimum monthly sea ice extent (the one that is used for the SEARCH SIO projections). More info in this blog post.
July 15th 2012
Two weeks have passed since the last ASI update. At the time the weather forecast for the Arctic showed things that pointed to a (possibly big) nosedive on sea ice extent and area charts. The forecast became even worse, showing a very big, very strong high-pressure area over the Beaufort Sea and low- pressure systems on the Siberian side of the Arctic. In other words, a hefty Dipole Anomaly, that we saw so much of in 2007.
But none of it came about. The weather forecast completely changed its tune and instead was showing a low-pressure area taking over things. Which did come about. So the nosedive didn't really live up to its weather forecast potential, and I was expecting a lull, a stalling, a levelling off of trends on graphs, but this hasn't really come about either! In the end nothing much has changed when it comes to the graphs in the past two weeks.
If the weather forecast had come about, 2012 would have undoubtedly taken a big lead, but as we say in Dutch: If my aunt had had a dick, she'd be my uncle! Instead, 2012 keeps steadily ploughing towards the minimum (two months from now), still battling it out with the big boys, apparently not much perturbed by atmospheric patterns that brought a stop to the 2010 and 2011 marches for melting season glory. Although that stop could still be coming about in the next week.
I hope I can shed some light on the how, why, and whence from here, but sometimes I feel as if all I've learned in the past two years has already turned obsolete.
Sea Ice Extent (SIE)
Right when I expected the lull to start showing up on the graphs, IJIS decided to go for a string of century breaks that kept it in the wake of 2011:
We can clearly see how 2010 levelled off when the weather switched at the beginning of the month. The same thing happened to 2011 when the weather switched halfway through the month. And maybe we are seeing the start of a similar situation for this year, now that the string of century breaks has been followed by two daily decreases of just 58 and 57K km2.
The current difference between 2012 and other years (without the unrealistic last data point that gets revised upwards) is as follows:
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