chubbs

Here is your bolded text " there is more extensive Arctic and Antarctic sea ice during recent decades than there has been for nearly all of the last 10,000 years. ". The chart I posted shows that sea ice is lower than any time in the past 2000 years. So your bolded text is clearly incorrect. You are talking about the early Holocene 10,000 years ago when the summer sun was much stronger in the northern hemisphere. Yes, sea ice was also low then when the sun was stronger, but I don't find it comforting given our current rapid downward trend. I

Nice try. Sea ice below is a 5-year mean.

You claimed the article was correct. Here is the headline "Arctic and Antarctic Sea Ice Now at Historic High Levels" Obviously the main objective of the article is to mislead.

OK

Here is the latest on antarctic sea ice and on ice sheet mass. I don't see much change in antarctic sea ice. More importantly Antarctic ice sheet losses are accelerating and now contribute significantly to sea level rise. https://www.nature.com/articles/s41586-018-0179-y

No that article is not correct. Its full of inaccurate and misleading statements. The article chart conveniently doesn't include the past 4 years with low sea ice - see chart below. There is no long-term trend in sea ice around Antarctica. Climate models predict very slow warming near Antarctica due to the time needed to heat up the deep oceans there. So the sea ice behavior there is not surprising. Of bigger concern is the ice sheet disintegration that is starting in Antarctica, due to ocean warming at depth, but you won't read about that at "electroverse".

A couple of comments: 1) One year in the arctic or antarctic is not very important. 2) GRACE data in graph is through 2017. See post above for papers on Greenland mass balance. 3) Regarding arctic sea ice, this year so far looks unremarkable to me. Its not a big melt year like 2012, but its not far from the long-term trendline on most metrics either. (see chart below) 4) There hasn't been any long-term trend in Antarctic sea ice so smack dab on the median is as expected. Ice shelves and ice sheets are the big concern in Antarctica, not sea ice.

Here is a chart from DMI which shows total mass change for Greenland by region reflecting both SMB and glacier discharge and iceberg calving. Biggest mass losses have been on the west coast which doesn't get as much precipitation as the east coast. Greenland SMB is up this year due to heavy precipitation, unusual compared to some recent big melt years, but not unexpected given natural variability.

Last Feb's SSW may be a factor in the benign melt so far this year. https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-17-0495.1

CU just published first paper to detect acceleration in satellite record. http://sealevel.colorado.edu/content/climate-change–driven-accelerated-sea-level-rise-detected-altimeter-era

This year has been cool like 2013 so the volume and extent data are not inconsistent.

This year's low volume/high NSIDC area status is unusual. Looks like the mild winter is having some impact but is a weaker factor than a slow start to the Arctic Ocean melt season.

Yes, in August most melting is from water below the ice. Of course colder air cools the water also. Last season saw strong late season melting due to storminess even though temperatures were cool.

Interesting chart from Wipneus on the ASIF today showing the area of various ice thicknesses on July 22. 2017 lags in the thinnest categories but leads in the thicker. Wipneus notes that 0.26 on July 22 always melts and 0.71 sometimes melts in severe late summers. So a range of outcomes is still possible this year depending on weather.

This is a good summary. Every year is a roll of the dice but gradually the dice are being loaded. Recently winters have been the most problematic. Perhaps we will see some temporary sea ice rebound with reversion to more normal conditions this winter.

We are running below the trendline so can't give this prediction a gold star yet..

Just have to avoid unusually strong storms like 2012 or prolonged storminess like 2016.

July often reverses the June 500 mb tendency in the arctic with 2009+2015 being recent high height years in July and 2010+2012 relatively low.

That is my guess - there is less volume to lose late in the melt year. On a percentage basis, the volume anomaly is largest at the September low.

Hopefully not the sun.

Interesting charts. Highlights the difficulty in predicting sea ice, particularly a record low, with any lead time. Note though that the trend in 925 mb temps is upward so the dice are slowly being loaded.

PIOMAS is out for June. As expected volume loss was slower in May and June than 2012 and other recent big melt years, but 2017 has retained the lowest PIOMAS volume, not far from 2012 in the last week of June.

The SIPN June predictions have a median forecast a little below last year but well above 2012. Forecasts are for the average monthly extent in September with 2012 at 3.6 M. https://www.arcus.org/sipn/sea-ice-outlook/2017/june

There is no significant lag to a change in solar forcing but luckily solar forcing doesn't change very much. Solar irradiance varies by 0.25 Watts per square meter from the peak to the bottom of a normal solar cycle. Despite the current weak solar cycle, the earth's energy imbalance due to GHG has stayed around 0.8 W per square meter. In addition GHG forcing is increasing by roughly 0.4 W per square meter per decade, so even a repeat of the Maunder minimum isn't going to have much impact on the warming trend.

Wipneus' daily sea ice volume anomaly chart updated through May. The volume gap between 2017 and other years narrowed in May due to a relatively slow start to the melting season vs recent years. Melting accelerated though in the second half of May leaving a record low well within reach this year depending on the weather.