chubbs

9 hours ago, csnavywx said:

Yeah, EPS and GEFS are showing a pretty strong +AD pattern from D6 onwards. The CFSv2 has been barking on this for weeks and was for the current cold spell as well. It'll be interesting to see if that verifies as it would pretty much jump-start the melting season. Interestingly, looking back, the first 12 days or so of May 2012 were pretty cool as well before it flipped warm.

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.

13 hours ago, Snow_Miser said:

Record low volume continued into March. It would be impressive at this point if September also did not see record low volume.

 

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.

7 hours ago, WidreMann said:

Above normal heights everywhere. Wow.

Dipole is good or bad for ice?

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.

On 2/23/2017 at 6:27 PM, Hambone said:

Political agenda, funding, fear of reprisal from superiors who were pushing for the manipulation.

My irony meter is going offscale. Your description is much more apt for Fox news, Breitbart or similar than a civil service employee nearing retirement.

This is much to do about nothing, a sign of the times, "fake news":

1) The changes made in the NOAA update were not that large in the big scheme of things.

2) There are alternate data  that show similar warming.

3) The most controversial part, the sea surface temperatures. have since been tested against independent data and were found to be better than other SST data sets.

4) The data is available and anyone can analyze as they see fit

https://www.washingtonpost.com/news/energy-environment/wp/2017/02/07/as-the-planet-warms-doubters-launch-a-new-attack-on-a-famous-climate-change-study/?utm_term=.bf499617f6c8

https://www.carbonbrief.org/factcheck-mail-sundays-astonishing-evidence-global-temperature-rise

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.

On 1/9/2017 at 8:53 AM, csnavywx said:

Pretty speculative, but it could be an atmospheric heat transport feedback. There was a paper about a Blue Arctic Ocean experiment that showed an increasing propensity for AHT feedback with decreasing fall/early winter ice coverage and thickness. Makes me wonder if there's some sort of threshold behavior at work.

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.

1 hour ago, csnavywx said:

Yes, highly unusual. We've also matched the freezing degree day deficit of the entirety of the last (record warm) freezing season and it's only January. Completely unlike any other winter.

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.

1 minute ago, ORH_wxman said:

I do not agree with the graph that shows very little variability in the sea ice in the 1930s-1950s period. I had already made a post on this further back in the thread, but there is literature that supports higher variability in the sea ice during that time...there's compelling evidence that we had minimums similar to the 1980s and at least early 1990s for many of those years. We will never know for sure though...we have poor data in the Beaufort region from that period.

 

That said, I disagree with blizzard1024 that the warmth now is similar to the 1940s...we've surpassed it recently...it was more similar to the warmth about 15 years ago in the arctic. There may be some localized regions (particularly in the North Atlantic sectors) where the 1940s had similar warmth to today, but not the arctic region as a whole.

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

Here is Hadcrut 70-90N with a requirement that 25% of the grids have valid data. 

NSIDC have a nice discussion on Antarctica in the Nov monthly summary. Winds and temperatures both contributed to the unusual ice losses.

http://nsidc.org/arcticseaicenews/

I posted some rough numbers on another blog. S Hemi sea ice has been running 2500000 sq km lower than last year. That is roughly 0.7% of earth's surface. Sea ice albedo impact vs open water is roughly 0.2 after accounting for clouds. Insolation at 70S is 50% above the global average on the Dec solstice. So currently there is roughly 0.2% more solar being absorbed at the earth's surface due to the change in SHemi sea ice vs. last year. Of course the impact decreases off the solstice and disappears completely once the sun sets. Integrating over a season the impact is about the same magnitude as going from peak to bottom of a solar cycle.

S Hemi ice is highly variable and gets a reset every year since most of the ice melts so we will need to see several years to confirm any change in the sea ice trend. Biggest concern is surface melt on ice shelves that are already under pressure from bottom melting. One unusually warm year could speed things up.

November volume at record low with roughly 25% less sea ice than last November.

8 hours ago, nzucker said:

The coronal hole thing probably explains the blip, but it's superimposed on a long-term decline in Arctic sea ice that allows for such abnormally poor periods in ice extent.

Re: the temp anomaly map, that's an extreme example of the -AO warm arctic, cold continents pattern. +24C anomalies in the Arctic while Siberia, Southwest Asia, and Western North America see near record cold. It's actually fairly encouraging to see such large areas of cold anomalies, which suggest Winter 16-17 in the Northern Hemisphere will be MUCH COLDER than Winter 15-16 was in the Super El Nino, in which almost nowhere finished below average.

Yup, I am more optimistic about our winter than 75-90N. Here is Nov 2009.

5 hours ago, skierinvermont said:

Well I wouldn't say that. But as the climate warms we're going to see more and more extreme anomalies like this.

We're so far below even the modern average for the date. And what so often gets forgot in discussions of sea ice is that 1980-2000 is not "average" or normal for sea ice. There's strong evidence that there was lots more sea ice earlier in the century. The highest years of the early 1980s might be a little closer to an early 20th century normal.

This chart illustrates how 2016 compares to the range of extent in previous years.  The extreme outer edge represents the coldest years from the early portion of the satellite record. Note that 2016 is not the least expansive year in all areas.