The 2014 Melting Season

[Wipneus]

Recently in the Arctic is quite warm, and sunny in most areas. So the conditions for melting. According to the NSIDC and JAXA ice extent decreases. That is erroneous reading of measurement data satellite CT.

Hubert, the NSIDC and the CT data are actually both  acquired by Special Sensor Microwave Imager/Sounder (SSMIS) on board the Defense Meteorological Satellite Program (DMSP) F17 satellite.
See for instance here

For months the area/extent ratio has been below that in 2013, just for the last couple of days it is a bit above. I don't see any reason to suspect an error.
Area/Extent ratio (officially "compactness") can be seen here:

[Jim Hunt]

There's plenty of open water visible on the Barrow webcam this morning:

[crandles]

Hubbert, if ice fragments it will cover a larger area with thinner thickness. I doubt this is fully responsible for all the difference - just changing the distribution can mean that there is more area of holes that are too small to be detected. Also changes in snow cover can cause issues for the algorithm that tries to work out how much snow, ice and open water is being detected. A small change in snow cover can be equivalent to a large change in ice:water.

As Wipneus said, I don't see any reason to think anything is going wrong even though the size of the effect does appear unusually large.

[Nightvid Cole]

There's plenty of open water visible on the Barrow webcam this morning:

I wondered how long that fast ice would make it.

Now we know. She's done for! [spoken loudly with US Midwestern accent] 

[LRC1962]

Some caveats.  First, MYI has a higher melting point, as de-brining will reduce salt content.  In that case,  bottom melt depends on higher water temperatures, and to a lesser degree, the action of salt on the relatively salt free ice. You can have melt ponds, and relatively no bottom melt.

Now I have no education in ice, but I see a problem with that notion. Although very true pure ice has a higher melt point then salt water ice, that ignores one very big difference between FYI and MYI. With MYI the salt has been push out of the ice and has become far denser and with a tighter bonding of the ice structure itself. Whereas with the FYI the ice has far more fissures and access to the inner structure for melt from the inside out also.
The issues I see arising now with the 2014 type of MYI is that it is broken up into far small sections then pre 1980s which gives greater access to both thermo and mechanical melt but also the ice vertically is far weaker structurally then in the past allowing for far more inner melt then in the past.
I do know that there are those that would disagree with inner melt happening, but I think there is plenty of evidence based on how weak even thick is now there is inner melt occurring. Not taking that into consideration then confuses comparisons between the ice of 1980 and the ice of 2014. That is why in 2012 when there was a severe melt off with even pure melt weather was able to happen IMO.

[Jim Hunt]

A better look at the sea ice near the New Siberian Islands today:

http://GreatWhiteCon.info/resources/arctic-sea-ice-images/winter-201314-images/#ESS

[Frivolousz21]

The Mackenzie Delta region is progged to have a mean temp of 0C the next 9 days.

umm lol that is crazy.

The 12z EURO also blasts the same region the next 10 days.

I am almost certain that if the models forecasts are right.  We will have unprecedented open water on the Pacific side.

[sydb]

Yesterday, I flew from London to Calgary, crossing the southern tip of Greenland and Baffin Island and the northern tip of Labrador. There were many ice floes visible in the Greenland Sea and the Hudson Strait had many leads. We sew many cracks on Hudson#s Bay and when we crossed onto the mainland south of Churchill, there was open water by the coast. It was great to have clear skies past Greenland to see all this, but I couldn't help reflecting on the fact that it was also torching the ice. Some floes were noticeably much darker than others, so I assume they would be very thin. From an aircraft the albedo difference between ice and open water is very striking. All in all, fascinating to see, but I did not like what I saw. I thought April 30th very early for all this melt.

[Frivolousz21]

The Euro and GFS both show a dipole anomaly for the foreseeable future.  Oscillating in strength.

[SteveMDFP]

Baked Alaska

[jdallen]

Baked Alaska

I just took a look at climate re analyzer.  You're not far off, but only for the next 36-48 hours. That said, it does seem that plumes of heat are being driven into high latitudes; later in the week it's Siberia's turn. Next few weeks, start watching drops in snow cover and temperature changes at arctic deltas. Hard to tell what is or is not anomalous there.

[Frivolousz21]

Visible sat images show the Alaska region snow pack has been nearly obliterated.

[werther]

Barrow webcam, 02 May 2014:



The unusual early spring arrival in Alaska shows up on the boards of the Chukchi Sea.
Snow in town is melting, melt ponds show up on the fast ice. A mild +4dC today.

Let's watch MODIS tomorrow Friv!

[Laurent]

That's amazing if you look at the last 10 days radar. The ice is just gone and the flow of water is fast...
http://seaice.alaska.edu/gi/observatories/barrow_radar

[jdallen]

The unusual early spring arrival in Alaska shows up on the boards of the Chukchi Sea.
Snow in town is melting, melt ponds show up on the fast ice. A mild +4dC today.

Let's watch MODIS tomorrow Friv!

4C is rather warm, for certain (it's been in the upper 20's this week in *Seattle*).

The melt ponds concern me greatly, if what we see on the 'cam is suggestive of what is now happening on the Beaufort pack.

I'll be joining you and Friv.

[davidsanger]

I came across this 5/1 Sea Surface temperature map and you can see right at the top some very high SST anomalies west of Svalbard and also in the Beaufort Sea.

[BornFromTheVoid]

According to the NCEP/NCAR reanalysis data, April was the 5th mildest on record for N of 70N. The year to date is by far the mildest on record, and the first to average higher than -20C.

N of 70N April


January to April

[iceman]

Very striking charts, BFTV.  Yet nothing dramatic happening with area or extent.  Seems like ice dynamics has the upper hand over weather so far.  If the warmth anomaly persists and melt pond formation is unusually early or widespread, some "cliff" predictions will be showing up here soon.

[jai mitchell]

Right around day 120 there is a break from temperature trends for every year going back at least 1.5 decades.  What could cause a break from temperature trends at this day each year?

http://ocean.dmi.dk/arctic/meant80n.uk.php

Interesting, U.S. refineries are required to switch to summer blend gasoline by May 1st.  I wonder if this could have an affect?

http://www.oregonlive.com/commuting/index.ssf/2014/04/oregon_washington_gas_prices_e.html

[SCYetti]

Jai Mitchel,
 the DMI chart to which you linked goes bach to 1958 and shows just how unusual last years Arctic summer was. Despite increased melt over the last 55 years the summer temperatuers appear to me to be surprisingly consistant. Last year there was a noticeable drop. I would suggest that this was because air was exosed to -2C sea water as opposed to 0C ice and melt ponds.

[Frivolousz21]

Alaska snow cover loss is a little over 25 days early at this point versus 1981-2010 climo.
Amazing.

[ktonine]

SCYetti - the summertime temperatures essentially cannot go much above zero because of the physics.  You have a massive thermal body at the surface that is tied to 0ºC.  The air temperatures must follow closely.

Right around day 120 there is a break from temperature trends for every year going back at least 1.5 decades.  What could cause a break from temperature trends at this day each year?

jai -- When you take into account Wayne Davidson's data that shows bottom melt can commence once air temps reach -14ºC, you'll note that this is the average temperature (259K)  around day 120.  I assume this is the time of year when solar insolation typically causes temps to reach 259K, so bottom melt can begin.  With bottom melt beginning there is a phase transition in the ice over a large area.  Energy that would be going into sensible heat is melting ice. You can see a similar break around 259K in the fall.  Since summer/fall is more variable than winter/spring the fall break does not occur around a specific date the way  the spring break does.

I've seen neither the spring nor fall breaks written about in any scientific papers, but this is the only answer that makes any sense to me. 

[Frivolousz21]

Not to steal Espens thunder so I will post it here.

Jaxa down another -76K.

Weather is bad.

The wind pattern has been downright horrible

[jdallen]

Not to steal Espens thunder so I will post it here.

Jaxa down another -76K.

Weather is bad.

The wind pattern has been downright horrible

I've been looking at climate re analyzer with a certain amount of horrified fascination. Yup, horrible is an appropriate word. Pray for a cold snap?

[Jim Hunt]

When you take into account Wayne Davidson's data that shows bottom melt can commence once air temps reach -14ºC

Can you provide a link to Wayne's assertion that this is the case? As I mentioned previously, it doesn't seem that way to me after peering at lots of IMB data.

[Andreas T]

Having had a look at some current buoy data http://imb.crrel.usace.army.mil/newdata.htm 2014B 2014C 2013G  2013F 2013I (2014 has no working bottom sounder but fits the picture shown by the others) I agree with Jim.
As Wayne says "can" commence, it clearly depends very much on what the water conditions below the ice are. The buoy data mainly show how slowly the bottom of thick ice responds to temperatures at its surface. When air temperatures rise quickly, temperature profiles in the ice show ice temperatures below both bottom and top surface due to its thermal mass.

[Jim Hunt]

O-Buoy 10 is now producing some slightly fuzzy images:

[Jim Hunt]

Having had a look at some current buoy data

My own interpretation of current and past buoy data can be seen at:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/

I can see no evidence in there that bottom melt does "commence once air temps reach -14 ºC". However I am eager to view any evidence to the contrary!

[Andreas T]

Jim, the temperature profile for 2014C on 21. Mar looks odd when compared to the 30. Mar profile and the bottom sounder data which shows roughly 20cm of added thickness between these dates.
The shorter gradient on 21.Mar suggests much lower ice thickness, could this be too soon after deployment to represent the actual ice condition?
Sorry but I can't look at the buoy data file at the moment to get a clearer picture how that comes about.

[ktonine]

Jim, I believe I first saw Wayne use -14ºC in a comment at Neven's several years ago.  He has actually recorded bottom melt at surface temperatures much lower than that, but I think he may have been using -14 as a typical or average value. 

Ice thickness plays a large role.  Thicker ice (though little of it is left) has actually been observed to melt throughout the winter - despite surface temperatures reaching -40ºC.  See the 8m consolidated *unconsolidated* ridge cited in Temporal Evolution of Arctic Sea-Ice Temperature,  Perovich and Elder, Annals of Glaciology, 2001.

You can read about Wayne's observations (and ask him relevant questions) on his blog, EH2R.  This is one of the posts devoted to bottom melt. Sea Ice Phase Change from the Underside

[Andreas T]

Thanks for the Perovich and Elder link, it fits very well with my understanding of the physics, temperature in the ice being controlled by conduction, temperature at top and bottom and heat fluxes.
Wayne's blog posts are less clear, more in the nature of sketching his ideas, than outlining  physical processes. As I understand him he infers melt from his interpretation of air temperature gradients which are observed through changes in the apparent height of the horizon. I am not aware of any actual observations of ice thickness and change thereof together with his optical observations. Please link if you can point me to them.

[Jim Hunt]

Jim, the temperature profile for 2014C on 21. Mar looks odd when compared to the 30. Mar profile and the bottom sounder data which shows roughly 20cm of added thickness between these dates.

I brought 2014C up to date. I reckon on Mar 21 the water in the hole the thermistors were installed in was still in the process of freezing.

ktonine - Even having looked at the pictures in Perovich 2001 I still can't see evidence for bottom melt when the surface temperatures are -40 ºC. In all cases (except the 8m ridge where "the thickness gauges failed") bottom melt didn't set in until late June/early July. What am I missing?

[ktonine]

Jim - on page 208 you'll find under the header TEMPORAL EVOLUTION, 2nd paragraph: "The general seasonal evolution of temperature is similar at all sites .... The one exception was the 8 m thick unconsolidated ridge, where the bottom was melting the entire year."

Figure 4a on page 210 shows the air temperature in all of the areas under study reached -40ºC in January.

[ktonine]

Andreas - questions would be better directed to Wayne.  He has always replied to any questions I ask in the comments at his blog.

[Nightvid Cole]

Very striking charts, BFTV.  Yet nothing dramatic happening with area or extent.  Seems like ice dynamics has the upper hand over weather so far.  If the warmth anomaly persists and melt pond formation is unusually early or widespread, some "cliff" predictions will be showing up here soon.

Area or extent at this time of year is influenced mostly by weather conditions around the edges of the ice cover, largely outside the Arctic Ocean proper, in areas that will be gone by September no matter what. Thus, area/extent isn't really relevant at this time of year.

The important thing at this time of year is how thick or thin is the ice in the heart of the Arctic. And based on PIOMAS, the extent of ice > 2m thick is at an all time low as of March 31st (expect an update in a couple of days for the data through April 30th).

[F.Tnioli]

...
The important thing at this time of year is how thick or thin is the ice in the heart of the Arctic. ...

Yes, this. Plus also (at least to some extent) what happens with snow cover in the NH.

Few pages ago some neat cryosphere + photoshop false colors pictures of snowcover were presented. I join others saying my thanks to the author of those. I think, an occasional update of those (similar pictures comparing 2014 and 2012 same-date snow cover, and also 2014 and 2013 as well) now and then - would be bery interesting to see. And yes, removing ice (last version) makes it even better. //thumb_up

[Neven]

F.Tnioli, I think you can find that image here in the 2014 Arctic Snow Cover Melting Season thread.

[Robert Marston]

Does anyone know of a comprehensive measure for Arctic Ocean sub-sea ice water temperatures at a uniform depth? Say 5-20 meters?

[jdallen]

Does anyone know of a comprehensive measure for Arctic Ocean sub-sea ice water temperatures at a uniform depth? Say 5-20 meters?

Not comprehensive, but the tend to stay between -2 and -1.5 down to below 50M, or at least have.  Ekman pumping may change that.

[deep octopus]

Serious torching coming next week to the Pacific. Southerly winds well above freezing starting from Sunday. Tuesday the 13th's forecast looks brutal.

Unrelated to Arctic, but global anomaly of +0.93C!!

[jdallen]

Serious torching coming next week to the Pacific. Southerly winds well above freezing starting from Sunday. Tuesday the 13th's forecast looks brutal.

Time to start watching melt pond coverage closely, I suspect, and try to make some comparisons to previous years.  The NA snow pack is going to be hit very hard, as will river ice.

[Neven]

Time to start watching melt pond coverage closely, I suspect, and try to make some comparisons to previous years.  The NA snow pack is going to be hit very hard, as will river ice.

Speaking of melt ponds: do you guys (and/or gals) think that it matters where most of the melt ponding occurs during May/June?

I somehow thought that the Beaufort Sea would be the most important spot (as that's where most of the high-pressure areas are during the Arctic Dipole, which also plays a big role in how the melting season shapes up and ends), but to my surprise this image from the recent Schröder et al. paper I covered on the ASIB shows something else:



Accompanying text: Figure 2 | Spatial distribution of Arctic melt-pond area. Mean pond area over the period from 25 June to 25 July for 1996 (a) and 2012 (b). The purple line is the September ice extent of the same year from our CICE simulation, and the black line is the ice extent from SSM/I. Crosses mark those grid points where mean pond area (1 May to 25 July) is strongly correlated with SSM/I September ice extent (correlation coefficient R<

[Robert Marston]

Might be more instructive to find a comparison between 2007, 2008, 2009, and 2012 with 1996 as relative base line.

[Robert Marston]

Not comprehensive, but the tend to stay between -2 and -1.5 down to below 50M, or at least have.  Ekman pumping may change that.

Wanted to test a few storm dynamics assumptions in a warming Arctic environment.

[gerrit]

Speaking of melt ponds: do you guys (and/or gals) think that it matters where most of the melt ponding occurs during May/June?

I somehow thought that the Beaufort Sea would be the most important spot (as that's where most of the high-pressure areas are during the Arctic Dipole, which also plays a big role in how the melting season shapes up and ends), ...

<warning: amateur opinion!  >
My gut feel is that early season surface melt is driven more by warm southerly winds than by solar radiation. Remember that the melt ponds you see in May/June is a result of weeks/months of heating (or at least lack of cold conditions). In this preceding period the sun was still very low. Also, early in the season reflectance is higher (ice flatter/whiter/no open ocean) so the sun is not really 'biting' yet. The dipole on the other hand pumps in lots of balmy air, and combined with windy conditions can transfer a lot of heat to the surface. (The 'windy' is very important for heat transfer - it mixes the cool surface air up with the rest and strips the natural insulating air layer from the ice).

When considering air flow into the arctic, the melt ponds looks like it is consistent with the dipole.

[BornFromTheVoid]

Northern Hemisphere snow cover was the 6th smallest this April, with North America having it's 14th largest and Eurasia it's smallest cover on record. http://climate.rutgers.edu/snowcover/index.php



The record low snow cover over Eurasia could come into play with early heat waves and rivers melting earlier.

While the hemispheric snow cover this April was very similar to 2012 and 2007 anomaly-wise, the distribution was quite different to 2012, but somewhat similar to 2007. Whether that's playing any role in the persistent dipole pattern we've seen in the last few months is another question!

[Neven]

<warning: amateur opinion!  >
My gut feel is that early season surface melt is driven more by warm southerly winds than by solar radiation. Remember that the melt ponds you see in May/June is a result of weeks/months of heating (or at least lack of cold conditions). In this preceding period the sun was still very low. Also, early in the season reflectance is higher (ice flatter/whiter/no open ocean) so the sun is not really 'biting' yet. The dipole on the other hand pumps in lots of balmy air, and combined with windy conditions can transfer a lot of heat to the surface. (The 'windy' is very important for heat transfer - it mixes the cool surface air up with the rest and strips the natural insulating air layer from the ice).

When considering air flow into the arctic, the melt ponds looks like it is consistent with the dipole.

Thanks, Gerrit. I also wondered about which factor is most significant for May melt ponding: insolation or air temperature. The fact is, that even though anomalies can be quite high, the temp itself is still below freezing most of the time. Or at least it is during the first two weeks of May (as noticed on the Climate Reanalyzer forecast).

[Phil.]

Looking at the Barrow webcam and radar yesterday i noticed that the ice off Barrow itself had already broken up (unusually early).  What happened next on the animation was very interesting lots of floes came streaming in from the west crashing into the remaining ice off Point Barrow and appearing to disintegrate.  Looking at the webcam it appeared to be very windy, that seems to me to be a bad environment for melt ponding, a flat layer of thicker ice would be better.

[Peter Ellis]

Hmm, has anyone got a graph to show the correlation (or otherwise) between April snow extent and October minimum?

[Jim Hunt]

Does anyone know of a comprehensive measure for Arctic Ocean sub-sea ice water temperatures at a uniform depth? Say 5-20 meters?

A small sample, rather than "a comprehensive measure", can be found at the Woods Hole ice tethered profiler page: http://www.whoi.edu/page.do?pid=20781

By way of example, here's the temperature and salinity profiles from ITP 76