chubbs

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

Euro-reanalysis shows another arctic amplification winter with continental cold focused in Canada+Ntier US.

No point in reading, Delingpole is full of BS

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

Here is another forecast using statistical methods. https://patricktbrown.org/2018/01/18/global-temperature-2018-likely-to-be-colder-than-2017-record-high-possible-in-2019/

To kick-off 2018, below is the recently issued UK Met Office Decadal forecast. Per write-up, PDO+ and AMO+ favor warming over the 5-year outlook period after a relatively cool 2018. Green is the CMIP5 predicted range. https://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/long-range/decadal-fc

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.

This is about the time we saw a pattern flip to lower arctic heights last year. Maybe we will see the reverse this year...or maybe not.

Forecasts are not that reliable currently so we will have to see how it plays out over the next couple of weeks. Currently I'm leaning for somewhere between 2007 and 2012. Volume is low but melting progress has been slow for both sea ice and snow. That would keep my 2018-19 guess for the next min alive.

Here is the past 30 days. Overall an intermediate regime, but with persistent flow from the Pacific to the Atlantic side.