Arctic ice. Melting away at an incredible rate or just a fiction.
Satellite records, used in the past by the IPCC from 1973 but now only shown from 1979 show a rapidly decreasing ice pack with occasional large drops and some smaller large gains.
What should the actual volume be in a world with a an average annual global temperature of say14.8 C. How much different would it have been 168 years ago with an average temp of 14 C How much should have melted in in that time. How much should it be melting per year?
Now the gist of the problem. How much variability per year and per 10 years and per 30 years is involved in the melting? A recent small event documented in the Arctic Sea Ice blogs [Neven] shows the problem acutely.
Those poor souls who like to watch yacht races or grass growing have nothing on ice watchers. This year there was an incredible fuss about whether we would have the lowest satellite extent on record [just failed]
1.1111 9.9999 = 11
o.000 actually moust be 0.0000 pos or neg
Natural variability in the Arctic Sea Ice Extent
This metric is often used as a metaphor for global warming as the Arctic Sea Ice has suffered several large falls in the last 4 decades on top of a general decline.
However analysis of events show an alarming under-assessment of the actual amount of natural variability that can occur. This in turn throws doubt on how reliable the actual data patterns are.
The first domino was a rise of the total global sea ice to the highest level for that metric in December 2014 when it briefly, after 30 years of records and 30 years of global warming attained that record. At that time the Antarctic Ice had made a concerted rise of over 2 1/2 SD and in conjunction with a reasonable Arctic extent passed all satellite recorded levels for that time of year.
The Antarctic then dropped to a 2 1/2 SD low in less than a year leading to a 3 year period of lower than normal extent which in combination with a big drop in extent of Arctic ice in 2016 led to a nearly 8 SD variation in less than 2 years.
That is an amazing amount if the SD are correct. It is something that should happen only once in 500 years and would indicated, if correct, warming on an unexpected scale.
Cue this year with the Arctic ice. Despite gloomy prognostications based on a low winter maximum extent, the ice, aided by an unexpectedly large volume for the extent refused to shrink and ended up the 6th lowest for the summer. It then failed to freeze up as expected, dropping to the 2nd lowest recovery extent for a few days before a massive rise from 2nd to 13th place over 3 weeks of freezing with many days over 100,000 sq K despite above average arctic air temperatures.
No sooner than it had done this it went into hibernation for 2 weeks dropping back to second lowest. A small recovery and then today one of the largest increases I have seen, vis.
(JAXA)] ASI Extent.December 16th, 2018: 11,752,725 km2, an increase of 263,728 km2. 2018 is now the 9th lowest on record.
My observation is this, with movement ranges mid melting or freezing varying between negative to 270,000 sq K in a single day, with ice volumes going from 2 1/2 plus SD to -5 in 2 years we do not have a handle on the year to year let alone decadal Arctic and global sea ice extents. The causes of melt and freeze are much more than simple air temperature or albedo, the currents and the temperatures they run at up to a year after they come from the tropics are very poorly understood.
My suggestion to both sides is that they are best not used to support the global warming theory as the variabilty is too great to make any satisfactory argument either way.
Yo yo ice, probability and natural variation..
While everyone has been focusing on CO2 and MGST a funny thing has been happening [at the forum] with the sea ice extents this last 8 months. Which should cause some scratching of heads and readjustments in the range we currently give to natural variability, in our assessment of the causes of sea ice growth and the reliability of Arctic and Antarctic temperature recording.
2018 had the lowest winter maximum extent of the last 40 years of the satellite record despite a promising early regrowth. As such it was expected that it could set a new low record for the minimum summer extent comparable to that of 2016. Arctic temperatures fluctuated much higher than average though possibly on a par with the last 4 years during the melting season. Robust claims were made but the ice stubbornly refused to play along. Arctic hurricanes and large sea swells were predicted to break it up very quickly but the ice stubbornly sat there melting very slowly on top of an even more unexpected slow volume loss.
Consequently when the minimum arrived despite the heroic high temperatures it had gone from the lowest maximum extent to the 8th lowest minimum in September. Skeptics were crowing and then it refused to refreeze dropping rapidly to the second lowest recovering extent in October.
Then weirdness set in with pockets of quick refreeze in November in areas, Barents and Chukchi, which were sadly lacking the previous year. The East Siberian Sea, stalwart in not melting early but a long slow late melt refroze overnight [well not quite but rapidly]. The Hudson Bay started to freeze and November offered up an impossible freezing sequence of 16 days of way well above average freezing rates despite the high temperatures. From 2nd lowest to 13th or 14th lowest in that time. Unprecedented, alarming freezing. The trend went from below 2010 to equal to the 2010 average and then, almost, to the 2000 average in that 16 days. Why? Silence.
As suddenly as it did the freeze it stopped. 2 weeks of below par freezing brought it back to the 2nd lowest. Then two human comedies. NASA mucked up with a graph on incomplete data that showed an impossible regrowth day that took 3 days to correct. Finally the last week into December. Ice growth recouped again helped by a shuffle at the end of December where growth rates are reset by the algorithms they use which give a jump to reflect an offset that develops each month [Masking].
Currently we sit in 8th place with a steep rise occurring and looking likely to continue.
What is to like? A recovery of sorts from the warm weather and currents stimulated by the 2016 El Nino and the 2017 rewarmth has occurred as expected due to the warming lag in these events finally wearing off. Further melting rate increase might occur in 4 months when the 2018 baby El Nino currents again reach the Arctic. This recovery might be big enough to give all concerned pause for thought as to how we should be assessing Arctic variability.
What is not to like? When 16 days can give a fluctuation that should normally take 10 or more years to develop without due cause [unpredicted, unprecedented] The problem is not with the fluctuations but the concept of how much natural variation is actually capable of occurring. These results strongly suggest that variability in the Arctic is much greater than the trends of the last 40 years predict.
The take home message is good for both sides. The last 10 years of data show a slowdown or pause in melting which might be the bottom of a cycle that is going to turn upwards if we choose to believe in 60 yar cycles. For warmists the fact that such large fluctuations can exist [independent of CO2 and surface temperatures] means there is also an outside chance of further large downward fluctuations.
JAXA ARCTIC EXTENT 6,731,603 km2?October 24, 2018?- Extent is lowest in the satellite record- Extent increase at 156 k is about 55 k ABOVE the average (2008-2017) on this day,
JAXA ARCTIC EXTENT 6,933,069 km2?October 25, 2018?- Extent is 2nd lowest in the satellite record,
– Extent increase at 201 k is about 110 k ABOVE the average (2008-2017) on this
JAXA ARCTIC EXTENT 7,182,053 km2?October 26, 2018?- Extent is 3rd lowest in the satellite record,
– Extent increase at 249 k is nearly 160 k ABOVE the average (2008-2017) on this day,
JAXA ARCTIC EXTENT 8,624,638 km2?November 5, 2018?- Extent is 4th lowest in the satellite record,
JAXA ARCTIC EXTENT 9,278,237 km2?November 14, 2018?– Extent is 6th lowest in the satellite record,
JAXA ARCTIC EXTENT 10,272,807 km2?November 22, 2018?– Extent is 13th lowest in the satellite record.
JAXA ARCTIC EXTENT 11,197,247 km2?December 11, 2018?– Extent is 2nd lowest
(JAXA)] ASI Extent. December 16th, 2018: [The error]
11,752,725 km2, an increase of 263,728 km2. 2018 is now the 9th lowest on record.
JAXA ARCTIC EXTENT 11,752,393 km2?December 22, 2018? – Extent is 4th lowest
JAXA ARCTIC EXTENT 11,871,945 km2?December 28, 2018? – Extent is 2nd lowest JAXA ARCTIC EXTENT 12,590,152 km2?January 4, 2019 – Extent is 8th lowest