chubbs

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.

In March I posted a CFSv2 forecast for April-June that called for above normal heights over the arctic. Too early for verification but that forecast doesn't look bad currently.

Daily sea ice anomaly and 12-month running mean from Zeke Hausfather. The 12-month mean has dropped more quickly in recent years drven by reduced cool season sea ice.

33% chance of a new record in 2017 per James Screen, 97% chance of bottom 3.

From Wipneus on ASIF - as is typically the case not much change in the volume anomaly in March. Yes, will take a 2008/2014 or even better a pre-2007 type year to avoid a September record.

Depending on details dipole is generally bad due to high pressure over Beaufort, warm air from Russia and increased fram transport.

CFS for April through June. CFS has been predicting that a dipole pattern will be favored this spring for a while now. Of course these long lead forecasts are quite uncertain. Posting this now to document for a later re-check.

PIOMASS volume is out for February. 2017 gained more volume than 2016 as conditions turned a little colder (still warmer than normal) but the spread between 2017 and other low volume years increased.

Wipneus has updated PIOMASS sea ice volume for January. As expected, ice volume growth continued to lag in January increasing the shortfall vs. 2012 and 2013. In January, 2017 had roughly the same volume growth as last year, maintaining a roughly 2.3 1000 km^3 gap. If 2017 continues to have volume growth rates similar to 2016, then the volume peak this year should be somewhere around 20,000 km^3 in April.

Grabbed this chart from ASIF. Despite the different enso and NHemi temp and circulation, 2017 isn't far from 2016.

Yes I posted a link to that paper earlier. This is an area of increasing research following up on Jennifer Francis' work. Here is a recent paper on jet stream meandering with further support for Francis' ideas. Open source and with a video (second link) from the author giving an overview. " The most robust changes are detected for autumn which has seen a pronounced increase in strongly meandering patterns at the hemispheric level as well as over the Eurasian sector. " http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094028/meta http://bcove.me/zccol3mi

This freezing degree day chart, from ASIF, integrates the DMI above 80 temperature curve. This freezing year is unique and to this date much warmer than last year. We are roughly one month behind recent years with two months of hard winter to go.

Will be interesting to see the studies to come on this years pattern. Open water and/or nino can't be the full explanation because they haven't triggered this behavior in the past and conditions are even worse so far this year despite the switch to nina.

PIOMAS data for December is in. In January, 2016 started with higher sea ice volume than 2011, 2012 and 2013 but ended with record low December volume. Eyeballing the chart, it looks like 2016 is the worst year ever in terms of sea ice volume lost. Very unusual, in that lack of gain in the non-summer months drove the the decline instead of big summer losses.

Here is a chart of global ice volume from Wipneus. Roughly 5000 cubic kilometers of ice has been lost this year. That is 5 trillion tons of ice. It took 4 times 10 to the 20th power calories to melt that ice or roughly 4% of the earth's typical energy gain from GHG. Considering that it has happened in less than half a year that is a significant heat loss for atmosphere and ocean surface waters this fall.

I don't buy the pre-1940 infilled data either. There just isn't enough data available. My main point is that you can't use Hadcrut to support an argument that the 1930s were as warm as present because HADCRUT doesn't have enough 1930s data coverage. Even now 70-90N coverage is not much more than 50% and the infilled series shows that the data void areas are likely to be warming the most.

Here is hadcrut 70-90N infilled per cowtan+way