Before kicking off this latest PIOMAS update, there's a little piece of information I'd like to share: A massive cyclone is passing through the Arctic right now. The cyclone has bottomed out about half a day ago at 966 hPa, which is slightly lower than the 968 hPa storm we saw at the end of August 2016, and slightly higher than the Great Arctic Cyclone of 2012 (963 hPa). Even though pressure levels are similar, this current storm can't match the other big ones when it comes to longevity. But at the same time, bear in mind it's only June, and not August.
And also remember what IARC chief scientist John Walsh said back in 2012:
This past week’s storm was exceptional, and the occurrence of Arctic storms of extreme intensity is a topic deserving closer investigation. With reduced ice cover and warmer sea surfaces, the occurrence of more intense storms is certainly a plausible scenario. The limitation at present is the small sample size of exceptional events, but that may change in the future.
I think it's safe to say it's changing.
Here's an image of the moment this current cyclone reached its lowest pressure, according to Environment Canada:
I will soon discuss the consequences of this storm for the ice pack, and apologize for not having started writing regular ASI updates yet (too busy).
Okay, now for the PIOMAS update.
Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:
According to the PIOMAS model, volume decrease for May 2018 has been below average: 2285 vs 2650 km3. This means that 2018 is 5th lowest right now, and the difference with last year has grown to a massive 1915 km3, which is 299 km3 more than last month. It has also been overtaken by 2012, which saw a huge volume reduction in May. Likewise for 2016 and 2011, with 2010 not far behind now either.
Here's how the differences with previous years have evolved from last month:
Here's how things are looking on Wipneus' version of the PIOMAS graph:
Despite May 2018's below average volume decrease, there has been a small downtick on the PIOMAS sea ice volume anomaly graph. The trend line will probably dive below the linear trend at some point:
What's interesting, is that there hasn't been an indication of below average melting for JAXA sea ice extent, being second lowest on record for most of the month of May. The consequence for PIJAMAS (a crude average sea ice thickness measure, which you get by dividing PIOMAS volume with JAXA extent) is that it's also relatively high for the time of year, compared to most post-2010 years:
The exact same thing goes for the Polar Science Centre thickness graph:
Even though we're only one week into June, it's already interesting to look ahead at what this month may bring volume-wise. Not only because of the short-lived, though intense storm, but also because of the current weather forecast. After bottoming out over the Kara and Laptev Seas, the ECMWF model has the storm moving over the Central Arctic, to slowly fade out over the Beaufort Sea. Meanwhile, high pressure takes over on the Siberian side of the Arctic (images retrieved from Tropical Tidbits):
Those isobars between the low and high pressure areas, especially in the 24-72 hours timespan (first three images), represent strong winds that will further pull away the ice from the Siberian coast, most of all in the Laptev region where there is already a substantial patch of open water for the time of year, at the same time bringing in lots of heat and sunshine to the entire eastern half of the Siberian coast.
The reason that all of this is interesting, is that according to PIOMAS the ice is thicker along Siberian side of the Arctic when compared to the 2011-2017 period:
This means that if this kind of weather persists during the second half of June - which remains to be seen, of course - 2018 could be moving back to third place or so. This, in turn, will have consequences for the rest of the melting season. But that's something we'll discuss, if and when it happens. Right now, everything is open.