Are we setting up for a Blue Ocean Event in Sept 2017?
Many climate scientists expect a gradual transition, with ice free not likely for at least a decade or more. Wadhams and a few others expect a phase change, with feedbacks leading to a rapid transition of the Arctic to open ocean much sooner.
Most climate scientists follow Chris Reynold's "Slow Transition" idea.
ktonine at the Arctic Sea Ice Forum offers this summary of it.
Critical to all this is that I am becoming convinced that the approximate levelling of PIOMAS volume over the last few winters is telling us that the pack is becoming dominated by FYI, whose thermodynamic equilibrium thickness is largely setting the peak volume in April. Even if one year, with exceptionally good melt weather, were to lead to extent below 1 million kmsq, this will be unlikely to be repeated, and for the record, I do not think this is likely anyway. To get to a state of near ice free conditions in late summer we will need to see significant thinning of the winter peak thickness, which needs far greater winter warming. I don't think this is likely to be a fast process.
So I do not expect to see a virtually sea ice free state until later in the next decade - at the earliest, I suspect that Overland and Wang may be proven right in pinning it on the 2030s. In terms of expectations amongst many in the amateur sea ice community this is a slow transition. However in geological terms it remains abrupt.
This year we *are* seeing significant thinning in winter thickness, but it still requires an even thinner pack to meet the requirements to get reliably under 1 million kmsq. So, the question still remains: is this winter's lack of FDDs a step change or is it an anomaly?
I've always been an advocate of slightly faster timing than Chris for these processes, but the arctic has always managed to surprise me with it's resilience. And in the end we're realistically talking about a difference of 10 to 15 years -- virtually no difference at all in scientific terms.
What I think we should also remember is that the scientist that first really went out publicly on a limb with an "over-the-top" prediction was Wieslav Maslowski. Back in 2006 Maslowski predicted a nearly ice free arctic in 2016 +/- 3 years. What many don't know is that Maslowski was not talking about sea ice are or extent - but volume. And 'nearly ice free' he defined as losing 80% of the 1979-2000 summer volume (see article by Joe Romm at ThinkProgress). 2012 came close. 2017 should come even closer - perhaps even make that prediction come true. [emphasis mine]
oren offers this caveat about Freezing Degree Days (FDD), which have been drastically lower this season.
Chris R's main assumption was that the freezing season remains mostly the same, with FDDs stable or perhaps undergoing a small decline, and that therefore arctic sea ice cannot just pass a tipping point and disappear following its first ice-free summer. Instead, even if a freak summer came along and melted all the ice, the refrozen arctic would still not necessarily melt out the year after. This is what he dubbed a "slow transition", as opposed to a one-way phase change.
The theory is very strong and Chris at the time gave many good arguments and explanations, but I believe this year has already shown its main flaw, and that is the FDD assumption. FDDs crashed this winter, leading to the possibility of a melt-out with a regular un-freakish summer. [emphasis mine]
So we have two schools of thought, and Freezing Degree Days is the pivot between them.
Amateurs such as Paul Beckwith expected melt-out last year. I can't imagine it will take longer than September 2017 or possibly 2019. Many new behaviors have emerged: jet stream changes, low Arctic pressure where there used to be high pressure, Atlantic storm tracks near or into the Arctic bringing both heat and moisture, stratosphere anomalies, shifts of the Hadley and Polar Cells, and the virtual disappearance of multiyear ice. The appearance of clouds in Spring and Summer the last couple of years helped the ice. This is also novel behavior. Overall I agree with the comparison to hysteresis, a nonlinear system fluctuating back and forth between two states, that often proceeds shifting from a previous stable state to a new one.
Hold on to your hats.
So far there's no consensus on whether this year's Arctic Sea Ice minimum will only be a new record low or a state change will occur. The recent encouraging refreeze has ended.
Sea Ice volume is low.
There's a chance more open water will generate Spring cloudiness, shading the ice. Here's a diagram of when sunlight gets intense at different latitudes, from the same page.
The weak to moderate El Nino predicted for around September will factor in, but will have much less impact on melting in Fall than if it happened in Spring.
We’re in about the same volume range during winter now as we were during summer in the late 1970s and early 1980s. This happened in just 35-odd years. Same loss trend would render the Arctic ice free for 1/2 to 3/4 of the year by the 2040s. [emphasis mine]
Arctic Sea Ice volume had a brief reprieve, without actually increasing to previous levels. Another setback looms as warm air will invade from the Pacific.
Multi-day above freezing temperatures for the Chukchi sea predicted for later this week is not a normal event for early March.
This recent warm wind invasion is one of many observed over the past five years in which enormous bulges in the Jet Stream have pierced deep into what was once a mostly impenetrable pall of winter chill hanging over the Arctic. It’s a new atmospheric condition associated with rampant fossil fuel burning. [Green means above freezing air temperature.]
This looks serious! We had better prepare for a rough ride.
The Arctic melt season is underway, after the lowest sea ice extent on record.
It's a new lowest maximum record, and the third time in a row that extent stayed below the 14 million km2 mark.
A long range model (U.S. CFS) predicts an extra warm Northern Siberia through Spring, due to atmospheric circulation patterns. FishOutofWater at Arctic Sea Ice Forum
... north Siberian temperatures will average well above normal for months. Apparently, the ocean heat patterns are driving this general circulation pattern.
This portends a catastrophic summer for sea ice and Siberian permafrost.
The atmosphere is efficiently removing the cold air from the Arctic and eliminating the cold by ramming it over the northwest Pacific and the NW Atlantic. This has happened because the Pacific decadal oscillation has shifted to the warm phase and the overturning circulation in the north Atlantic has gone into its more active mode. This PDO (or IPO) pattern expands the jet stream southward over the Pacific ocean. It also brings more heat from the Atlantic to central and northern Europe.
… expect a bad fire season in Russia and Siberia to start early and for the soot to amplify the rate of snow melt and ice loss.
Arctic Sea Ice volume.
This is called the Arctic's March to Zero Volume. How many years till volume reaches 2500 km3, which is about what Maslovski called a practically ice free Arctic (80% less ice than the average)? At that point there's just remnants pushed up against the coast along the Canadian Archipelago.image source
Artic Sea Ice volume continues at record low.
Arctic Sea Ice did a tiny bit better the past few weeks. You can see temperatures actually touched the average curve.
But Arctic sea ice volume is still extra low, and Greenland is melting now due to a high pressure center pushing warm Atlantic air up over it.
Talk at the Arctic Se Ice Forum is about ridges (Jet Stream Waves) pushing warm air into the Arctic from both the Atlantic and Pacific, and the Arctic not being able to hold the cold - cold spilling out to kill crops in mid latitudes.
"High pressure over the Arctic basin as far as the forecasts can see - 18 days - especially on the American side." is explained by FishOutofWater as 1. enhanced atmospheric blocking "Warming of the tropical and subtropical oceans oceans has enhanced wave coupling of the subtropical jet stream with the winter night jet in the stratosphere." and 2." Enhanced south to north warm air transport from the Atlantic and Pacific ocean basins to the Arctic associated with a wavier jet stream."
"Greenland is one of the most prominent locations on earth for blocking highs to form because there is so much heat in the Atlantic ocean basin that can be advected northwards over Greenland by Rossby waves. As warm air moves north and up the Coriolis effect tends to make it spin counterclockwise. Thus "blocking highs" are formed."
Meanwhile Robert Scribbler reports that Russian/Siberian/Asian wildfires are flaring up in and just south of the permafrost zone, with temperatures 5-15 C above average .