chubbs

6 hours ago, snowlover91 said:

Care to post some graphs which account for calving and discharge? No matter how you slice it it’s clear that this season’s SMB is well above average and is close to breaking levels we haven’t seen in the past 30 years.

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.

5 hours ago, PDIII said:

This is probably not real given that noaa maybe fudging the numbers.

http://www.breitbart.com/big-government/2018/02/20/delingpole-noaa-caught-adjusting-big-freeze-out-of-existence/

 

No point in reading, Delingpole is full of BS

On 2/14/2018 at 1:55 AM, wolfpackmet said:

Jason-3 data through January 5 released today.  60/370-day running mean has been above the linear trend for over 3 years now.  With La Niña conditions fading this trend will likely continue.   Acceleration imminent or happening now?

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

On 8/10/2017 at 0:57 PM, bluewave said:

There may also be a higher degree of uncertainty in the PIOMAS data compared to other years. But we saw how the the PIOMAS and NSIDC extent widely diverged in 2013 compared to the 2007 season. Lower PIOMAS in 2013 vs 2007,but the cool 2013 summer resulted in a much higher higher September extent than 2007.

http://nsidc.org/arcticseaicenews/2017/03/

It was a very warm autumn and winter. Air temperatures at the 925 hPa level (about 2,500 feet above sea level) over the five months spanning October 2016 through February 2017 were more than 2.5 degrees Celsius (4.5 degrees Fahrenheit) above average over the entire Arctic Ocean, and greater than 5 degrees Celsius (9 degrees Fahrenheit) above average over large parts of the northern Chukchi and Barents Seas. These overall warm conditions were punctuated by a series of extreme heat waves over the Arctic Ocean.

Data from the European Space Agency’s CryoSat-2 satellite indicate that this winter’s ice cover may be only slightly thinner than that observed at this time of year for the past four years. However, an ice-ocean model at the University of Washington (PIOMAS) that incorporates observed weather conditions suggests the volume of ice in the Arctic is unusually low.

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.

1 hour ago, etudiant said:

I'd thought the air temperature was not as significant as the water temperature in driving the amount of melting in the Arctic. Is this a misperception?

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.

20 hours ago, bluewave said:

................................................................................We expect the long-term decline in Arctic sea ice to continue as global temperatures rise. There will also be further bounces, both up and down. Individual years will be ice-free sometime in the 2020s, 2030s or 2040s, depending on both future greenhouse gas emissions and these natural fluctuations.

 

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.

1 hour ago, bluewave said:

Yeah, the HadGEM1 did a great job.

https://www.the-cryosphere.net/7/555/2013/

Mechanisms causing reduced Arctic sea ice loss in a coupled climate model

A. E. West, A. B. Keen, and H. T. HewittMet Office Hadley Centre, Exeter, UK

Received: 09 May 2012 – Discussion started: 18 Jul 2012
Revised: 04 Feb 2013 – Accepted: 18 Feb 2013 – Published: 26 Mar 2013

 

Abstract. The fully coupled climate model HadGEM1 produces one of the most accurate simulations of the historical record of Arctic sea ice seen in the IPCC AR4 multi-model ensemble. In this study, we examine projections of sea ice decline out to 2030, produced by two ensembles of HadGEM1 with natural and anthropogenic forcings included. These ensembles project a significant slowing of the rate of ice loss to occur after 2010, with some integrations even simulating a small increase in ice area. We use an energy budget of the Arctic to examine the causes of this slowdown. A negative feedback effect by which rapid reductions in ice thickness north of Greenland reduce ice export is found to play a major role. A slight reduction in ocean-to-ice heat flux in the relevant period, caused by changes in the meridional overturning circulation (MOC) and subpolar gyre in some integrations, as well as freshening of the mixed layer driven by causes other than ice melt, is also found to play a part. Finally, we assess the likelihood of a slowdown occurring in the real world due to these causes.

 

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

5 hours ago, csnavywx said:

2012's August losses were one of a kind ridiculous. EOSDIS doesn't show the kind of weak, broken ice pack that would be susceptible to mass extent/area loss in August like 2012 (and to some extent last year). With this turbo +AO remaining in place into the extended, there's a chance we could get get above 5M for extent in Sept if that pattern doesn't break appreciably.

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

8 hours ago, bluewave said:

June officially continues the post 2012 pattern of a more active polar vortex and cooler temps.You can see the long range ensembles continuing this general pattern right into July.

 

 

 

 

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.

35 minutes ago, so_whats_happening said:

curious what causes the low around the beginning of july to not continue does it have to do with at this point most of the outer regions have melted out and you just have the core which usually maintains?

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.

1 hour ago, bluewave said:

While the overall annual temperature  trend is an unmistakable up, it would be interesting to know what changed after the 2012 summer. To get a 6 year historic stretch of dipole patterns during the summer and then a reversal is pretty extreme 500 mb behavior.

 

Hopefully not the sun.

48 minutes ago, bluewave said:

June officially continues the post 2012 pattern of a more active polar vortex and cooler temps.You can see the long range ensembles continuing this general pattern right into July.

 

 

 

 

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

4 hours ago, Joe Vanni said:

Well it seems they rushed it. The research and forecasters I've found to be most accurate at long ranges have stayed with the same story. But that's like me saying how some on the AGW side was claiming ice free Arctic in 2012, 2013, 2014 and so on. It's not going to happen anytime soon; and yes I know how's it's trended since 1979, the beginning of the global warming period. Or how the Atlantic hurricanes were only going to get worse after 2005's record season. They misjudged, but they have misjudged more than just the reason for melting ice and hurricanes.

I think the peak will happen during solar cycle 26/27 but it'll become much more obvious as we approach 25 that something has switched.  I can see why you would point out how we have warmed despite s super weak cycle. But there is actually a legit lag and a point needed to cross to see the real effects on a longer-term. But as I said before, debating this will get us nowhere. People are going to have to start seeing effects at their own house before they realize something is up. 

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.

1 hour ago, csnavywx said:

Stable 5-wave pattern showing up on ensembles now for the first week of June. That leaves the door open to ridging over/near the pole but doesn't guarantee it.

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.

22 hours ago, ORH_wxman said:

It has to get going pretty quick if 2012 wants to be in the discussion. We'll want to see a pretty widespread warm pattern sustain over more than just the Chukchi/Beaufort...preferably over the Eurasian side too to get the melt ponding feedback going.

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.

On 5/17/2017 at 7:58 AM, bluewave said:

So which June weather pattern shows up in the Arctic this year? The record dipole pattern of 2007-2012 or the more favorable lower pressure regime of 2013-2016. The other option is an intermediate pattern between those two extremes.

 

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