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Kevin McKinney

As always, Neven, thanks for updating us. Once again, 'the stage is set,' and we'll just have to watch the drama unfold.

Jim Hunt

I'm afraid I can't help but wonder about the PIOMAS "average thickness". Ice mass balance buoy 2013F has survived 2 winters in the Beaufort Sea with its temperature sensors intact. Here's what they revealed at the end of the freezing season last year:

and here's where we're up to so far this winter.

Click the images for larger versions! For an explanation of the graphs see:


Now this is of course a very small sample from a very large Arctic, but the floe 2013F is sat on undoubtedly counts as multi-year ice. However currently it's only slightly thicker than it was at the same time last year. The top and bottom sensors on the buoy say the floe is 1.8 m thick. The temperature sensors, which are located in a slightly different place, suggest it's more like 1.3 m thick. PIOMAS has the thickness of that area of the Beaufort Sea at around 2.2 m.

Void and Null

How does this relate to this?


Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations

Abstract. Sea ice thickness is a fundamental climate state variable that provides an integrated measure of changes in the high-latitude energy balance. However, observations of mean ice thickness have been sparse in time and space, making the construction of observation-based time series difficult. Moreover, different groups use a variety of methods and processing procedures to measure ice thickness, and each observational source likely has different and poorly characterized measurement and sampling errors. Observational sources used in this study include upward-looking sonars mounted on submarines or moorings, electromagnetic sensors on helicopters or aircraft, and lidar or radar altimeters on airplanes or satellites. Here we use a curve-fitting approach to determine the large-scale spatial and temporal variability of the ice thickness as well as the mean differences between the observation systems, using over 3000 estimates of the ice thickness. The thickness estimates are measured over spatial scales of approximately 50 km or time scales of 1 month, and the primary time period analyzed is 2000–2012 when the modern mix of observations is available. Good agreement is found between five of the systems, within 0.15 m, while systematic differences of up to 0.5 m are found for three others compared to the five. The trend in annual mean ice thickness over the Arctic Basin is −0.58 ± 0.07 m decade−1 over the period 2000–2012. Applying our method to the period 1975–2012 for the central Arctic Basin where we have sufficient data (the SCICEX box), we find that the annual mean ice thickness has decreased from 3.59 m in 1975 to 1.25 m in 2012, a 65% reduction. This is nearly double the 36% decline reported by an earlier study. These results provide additional direct observational evidence of substantial sea ice losses found in model analyses.


I agree Kevin, it is time to see what will happen, but also test our skills. Many here try to predict what will happen in September while it seems very hard to do 2 weeks.

Hi Jim , click on images turn to blank!


With more storms entering the Arctic than 30 years ago, more snow is falling in the normally cold dry winter months. Therefore, the proportion of low density snowy ice has very likely been increasing. That might explain some of the discrepancies. -FishOutofWater aka George

Jim Hunt

Sorry Wayne. Things should now work as advertised!


This figure shows the behaviour of the arctic sea ice volume (PIOMAS) as the relative anomaly vs. average of 2000...2013:
Maybe it's more clearly presented than the figures in the post.


That plot shows only 10 years vs 35 years of data show in the figures above. It may be more clearly presente, but it surely is less informative


Looks like conditions are in place for an early volume peak: high anomaly, above-normal air temps in the forecast, and lots of ice getting pushed out into warmer waters during the latter part of March. I'll put in a guess that the max arrives the first few days of April, which would be earliest in recent decades if I'm reading PIOMAS graphs correctly.

Colorado Bob

A really great before and after picture here -

The Arctic’s Ponds Are Disappearing Even As the Region Melts

New research has revealed that the Arctic is losing its ponds, with the important habitats shrinking more every day. This may seem like a strange revelation for some, as past research has revealed that the Arctic continues to melt in the wake of climate change. Wouldn’t more melt water mean more ponds? Now, a pair of researchers explain what’s really going on.

“Plants are taking over shallow ponds because they’re becoming warm and nutrient-rich,” Christian Anderson, a postdoctoral fellow at the University of Texas at El Paso, said in a recent statement. “Before you know it, boom, the pond is gone.”

Colorado Bob

Several good maps with this article –

Global warming could happen quicker in Russia’s coldest region

Temperatures are rising twice the global rate in Russia’s coldest region because of warming, and this is likely to continue in the future, says a leading scientist.

Delivering a lecture in Yakutsk, Professor Oleg Anisimov, from the State Hydrological Institute in St Petersburg said: ‘The UN group of climate experts anticipate global temperature increase from two to four degrees Celsius by the end of the century.’

For Yakutia – also known as the Sakha Republic – climate models predict up to 8 degrees Celsius temperature rise.


Colorado Bob

There is an 1884 map that shows 3 sets of islands that are now gone .

Chris Reynolds


The increased thickness in Baeufort seems mainly due to export from the Central Arctic. So that wouldn't affect the floe you cite.

Virtually all of the volume increase is contained in the Central Arctic. So that wouldn't affect the floe you cite.

Chris Reynolds


Just to back up my last statement:

Jim Hunt


I wanted to include some videos in my response, so I've endeavoured to continue the conversation over on the forum:


There's undoubtedly been some export from the Central Arctic, but what has filled the space left behind?

In brief, whether looking at the current state of play from the micro level of a single buoy or the macro level of a basin wide overview I'm still not convinced PIOMAS has a particularly good handle on the "reality" around the margins, even if it is right about continuing volume increases in the centre. And if it's wrong around the margins who's to say it's not wrong in the centre also?

Jim Hunt

V&N - An extract from the conclusions of Lindsay and Schweiger 2015:

There is no gold standard for the estimation of the mean thickness of sea ice. All of the existing measurement techniques have one or more large sources of uncertainty. In situ measurements from the surface cannot sample the full thickness distribution. The submarine ULS measurements depend of the first-return echo to determine the ice draft, which is a potential source of unknown bias that may be a function of the bottom roughness. The mooring ULS measurementsmay also be subject to this same source of error. Both have potential errors in determining the open water level and accounting for the correct snow water equivalent. The satellite and airborne lidar observations depend on reliable detection of the surface height of nearby leads to accurately determine the height of the ocean surface and hence the total freeboard. The Air-EM measurements require an independent estimate of the snow depth, as do the satellite lidar measurements. All of the measurements struggle with obtaining an accurate mean value when the thickness is highly variable within the sensor footprint due to ridging. Finally, none of the measurements have been verified against other observations over regions that encompass the full ice thickness distribution of the area.

All of which indicates that measuring sea ice thickness (and hence volume) is a decidedly tricky undertaking. I fear much the same applies to modelling it also.


In search of an Arctic 'holy grail'
“Thickness is the holy grail of sea ice knowledge,” said Ben Holt, a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “Sea ice has been one of the most important indicators of global warming. But sea ice thickness, this really important variable, is hard to measure. It’s spatially variable – it grows in some places and has been deformed in others. There’s also a snow cover, and some instruments see just the tops of the formations, which are snow.”
There is a compounding problem. Any study that deals with thinning ice tends to use data 2-3 years and older. Reasons for this include, data collection,analysis, write up, then peer review and analysis and that is not done overnight. End result maybe you end up with the year 2012 as their most studies, and we all know what happened then which could then skew some conclusions. As has been stated many times. The Arctic is always full of surprises. But then that is what makes it so much fun to watch.

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