Arctic Ice Discussion (The Melt)

[BornFromTheVoid]

Seeing as IJIS is updating again, and the new data set has been merged with the old one, I can start updating my own data again.

My data is a combination of the IJIS merged with the NSIDC "team NASA" algorithm extent.

Here's a graph of the latest sea ice extent, just the raw daily figures without any averaging of the lines or the like.

Years since 2007 are in bold.

Looking closely at the graph, we can see 2012 passed the average mark during April. This occurred on 3 dates, the 16th, 17th and 20th.

Some other stats, the average long term loss (1979-2011) for May is about 47,000km2/day. May 2012 has so far averaged about 58,000km2/day.

Similarly, despite April doing so well initially, it averaged a loss of 45,000km2/day with the long term mean being 38,000km2/day

On the other hand, the average daily change in March is a loss of about 9,000km2/day, but this year averaged a gain of 13,000km2/day

[The PIT]

I guess a new Sat has gone up then otherwise how did they fix it?

[BornFromTheVoid]

I guess a new Sat has gone up then otherwise how did they fix it?

Using a different satellite, WindSat http://www.nrl.navy.mil/WindSat/

[The PIT]

Using a different satellite, WindSat http://www.nrl.navy.mil/WindSat/

Thanks

[stewfox]

http://www.ijis.iarc...aice_extent.htm

Didn't know this was back!

Very different to the Roos 15% level isn't it?

Great news now we get daily doom and gloom or cheer and wonder

Next 6 weeks as always the most crucial time. The data set doesn't seem as easy on the eye to read as it was before.

[Gray-Wolf]

Great news now we get daily doom and gloom or cheer and wonder

Next 6 weeks as always the most crucial time. The data set doesn't seem as easy on the eye to read as it was before.

181406 sqkm losses yesterday according to JAXA yesterday Stew? (pre-adj)

It's what you get when you reach 'average ' ice levels with ice outside the basin?

Edited May 22, 2012 by Gray-Wolf

[songster]

Since the satellite change, the latest (pre-adjustment) daily IJIS value has been useless. It's always showing a loss of ~200k or more, and then a huge upward readjustment the next day. Just don't look at it, it's obviously only a partial reading. Possibly something to do with the satellite's orbital parameters meaning they don't have full coverage in a single 24 hr cycle?

[BornFromTheVoid]

Since the satellite change, the latest (pre-adjustment) daily IJIS value has been useless. It's always showing a loss of ~200k or more, and then a huge upward readjustment the next day. Just don't look at it, it's obviously only a partial reading. Possibly something to do with the satellite's orbital parameters meaning they don't have full coverage in a single 24 hr cycle?

Yeah, I was noticing that too. If you go onto the extent image here you can see how little of the sea ice has been passed over. Seems almost pointless giving data based on that. The swath width is probably the main issue, maximum of 1,000km for WindSat and 1,445km for AMSR-E, so it just takes a little longer to get decent coverage.

Edited May 22, 2012 by BornFromTheVoid

[songster]

To be fair, I think the relevant picture is this one, where the coverage is almost complete, but there's a hole in Hudson Bay:

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

The one you linked is today's data, which will (presumably) get more swaths added in the next few hours, and then a preliminary extent figure published tomorrow.

[BornFromTheVoid]

So you mean yesterdays pre-adjusted figure, rather than todays? Yesterdays images is also missing the main part of sea ice left in the sea of Okhotsk.

Btw, I don't think you can link to individual daily images.

EDIT: From some posts online, it seems the WindSat's spatial resolution (for sea ice at least) is 25km compared to AMSR-E's of 12.5km.

Edited May 22, 2012 by BornFromTheVoid

[stewfox]

181406 sqkm losses yesterday according to JAXA yesterday Stew? (pre-adj)

It's what you get when you reach 'average ' ice levels with ice outside the basin?

Regardless of its merits I do like the easy to read graph

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

It will be interesting to see the 2010's average but we will have to wait 8 years for that.

204,000 loss yesterday but again they guys that present the data haven't been on a Excel course

http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv

[Richie V]

181406 sqkm losses yesterday according to JAXA yesterday Stew? (pre-adj)

It's what you get when you reach 'average ' ice levels with ice outside the basin?

Outside the basin!!!

Check this out http://arctic.atmos.uiuc.edu/cryosphere/

Those 2 wamming great uguly holes (one to the north west of greenland and the other NE of Alaska near the basin edge) to me is rather worrying. Surely this screams Very thin Ice only left now and would suggest the whole blummin pack is now weak as FCUK.

Just my thaughts, I'm no expert.... I promise!

[BornFromTheVoid]

A very short update. Average daily loss to the 23rd is about 52k/day, which is 14k above the long term mean.

The graphs below are up to the 23rd. 2007 is in green and the long term mean is yellow.

[Methuselah]

Time to amend the title, methinks...

[Geordiesnow]

Outside the basin!!!

Check this out http://arctic.atmos....edu/cryosphere/

Those 2 wamming great uguly holes (one to the north west of greenland and the other NE of Alaska near the basin edge) to me is rather worrying. Surely this screams Very thin Ice only left now and would suggest the whole blummin pack is now weak as FCUK.

Just my thaughts, I'm no expert.... I promise!

The polynyas(or ugly holes as you rather amusingly called them) to the NW of Greenland is not all that unusual at this time of year, perhaps what is unusual is that the open water seems to be more wide open than in previous years but in terms of how it affects the ice in general then I think its not much to worry about as its seasonal ice in general so will melt regardless what happens. The polynyas in the Beaufort and the developing polynya in the Laptev sea is more concerning however as it does tell us the ice is weak and in all honesty, the weather patterns look horrible, there are only minimal signs we may see the dipole pattern easing as we head into June but it doesn't look promising really when you consider how weak the ice must be in the Kara Sea as it never fully frozed over until March for a brief while and the general mild winter we had in the Laptev Sea.

I did predict we could head to the lowest extent on record by the end of May, this was with how weak the ice is in the Kara Sea but it seems the large but "spread out" ice in the Bering Sea has kept the extent up somewhat.

Of course, as we head into the summer and we get more favourable set ups, then we may avoid the lowest extent on record but I'm finding hard to see much signs that we are going to see anything spectacular in terms of extent on a positive note.

[BornFromTheVoid]

The ice area anomaly is really increasing lately, now at 946,000km2 below average. The Sea of Okhotsk ice has almost gone completely now, so the losses from there that have been contributing the the NH losses will end. The Bering sea ice is rapidly declining and has been the last 4 weeks, and is likely to be gone before the middle of June with just ~250,000km2 left now compared to 950,000km2 at its peak in April.

Hudson Bay sea ice is beginning its retreat, having lost around 100,000km2 in the last 10 days, while Baffin sea ice is continuing it's steady decline since March, from about 1.3m km2 to 650k recently.

Barents sea ice continues close to record large -ve anomalies, with just 150,000km2 left, while Kara sea ice has been rapidly declining in the last month, and what's left has very low concentration and is likely to melt out quickly once any mild southerly winds arrive.

All around the Arctic ocean, large open water areas are appearing now along the coasts (not polynyas). The biggest being in the Beaufort sea and Laptev sea, both of which are now running below average.

The only years that we're ahead of now for area in 2006, 2010 and 2011.

http://arctic.atmos....edu/cryosphere/

http://rapidfire.sci...12149.terra.4km

Sea ice extent is looking marginally better, as we're ahead of most years since 2002, but still well below the longer term average.

http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_prev_L.png

The last 2 days readings need to be taken with a pinch of salt on the IJIS page, as they're usually adjusted upward.

[BornFromTheVoid]

For the first time since early March (I think) we are back to over 1,000,000km2 below average on CT. This leaves us 2nd lowest on record, with just 2011 with lower sea ice this time of year.

The main areas of loss, which contributed to the 160k loss in the last day (up to day 149, May 28th) seems to have come from the Laptev Sea and perhaps the Arctic Basin.

The short to medium term looks quite bad for the sea ice. Uppers of -10C look like disappearing within the next 3 days and the old familiar Dipole Anomaly looks like becoming established for a while. By 5 days out, even uppers below -5C look like largely disappearing with most of the Arctic Ocean above 0C, even at the surface. Very mild uppers and surface temps look like dominating Hudson from the weekend onwards, so I'd expect the ice to fall rapidly here over the next week.

Overall, I'd say lowest on record by the end of the weekend or early next week looks probably.

The Dipole Anomaly at t6, t96 and t168.

Uppers for t6, t96 and t168

And surface temps for the same times

[Gray-Wolf]

Thanks for the work BFTV!

I'd started to believe my own 'Doomsayer ' press esp. when I'd mooted we reach lowest by late May but , as I'd originally suggested, once the peripheral ice retreats we start to see the underlying picture. The Flow out of Fram over winter leads to late formation ice (with low snow cover) and the same for the period that Bering took ice out of the basin (thin ice with low snow cover). With first year ice already easy to melt out the thinner snow covers that they end up with (the first winters snow falls onto open water where the FY is to develop as opposed to on the ice where MY ice is in-situ). once the highly reflective snow goes , in early spring, then the ice is under attack.

We shall see over the next 2 months how vulnerable the FY ice at the pole is but I still fear we are headed for a record low come sept (take heed all you folk that thought the high finish point for extent was a 'positive'). when the increases in FY ice this year are taken into account.

Edited May 31, 2012 by Gray-Wolf

[BornFromTheVoid]

The dipole pattern already looking much stronger than 2007 for the April to May period.

2007 & 2012

And with a forecast like this for just 7 days away, the prognosis ain't too good.

[Gray-Wolf]

I'm wondering whether we'll see quite a record retreat in June/July?

With so much F.Y. ice in the Basin and not so kind 'weather' we may see faster retreats than the 07' period and ,without the buffer of perennial ice across much of the basin baring N.Greenland, a continued retreat throughout Aug without slowing.

By Sept only the 'bare bones' of the thicker ,older ice, will remain meaning much of the central basin will be open water (watch out for the jokers calling recovery as we also see record growth rates come re-freeze esp. with so much water to re-freeze!). Only time will tell how such a large expanse of open water will impact the whole basin as re-freeze tries to start?

We have seen, through the noughties, how a couple of adjacent sea areas impacted the air column above them as the ocean shed heat prior to refreeze but what of the majority of the Arctic ocean if it has to do this prior to re-freeze? What of the weather patterns in the areas due south with no proper Arctic cold being ingested into it's weather systems? Will we have a very 'odd' 6 weeks with only the heights of Greenland showing the normal 'cold' winter low temps?

If not this year then we must ,soon enough, find ourselves in this position with the whole Arctic Basin having an extended 'Fall season' as the ocean sheds the heat it accrued over the summer 'open water' period (remember, it will absorb 80% of the incoming solar instead of reflecting over 80% of the incoming solar....quite a step change really would you not say?).

If we have indeed been seeing an abnormal 'warm high' developing over areas that have been open water over summer then if we expand this across the whole basin we leave no room for cold air to develop even with winter dark approaching? If in past 'warmer epochs' we have plants intolerant of sub 50f temps growing inside the Arctic ocean then this could mean that ,eventually, the season long open water heated so much as to be shedding heat all winter without falling below the 50f mark (even through the 24hr dark) so a shorter duration version of this would not be pushing things too much? This would drastically reduce 'winter' over the Arctic meaning thinner ice forming over the period and FY ice melting out even faster come summer leaving open water to soak up more heat for longer impacting upon re-freeze dates as this extra energy sheds come autumn etc,etc.

In some ways this could be another 'step change' and instead of seasons extending seasons (spring/Summer/autumn) by days over decades (as we have been seeing) we see Autumn increasing by weeks, and winter shortening by weeks,over a period of years?

With this occurring what of the methane reserves (both terrestrial and submerged)?

Some days my mind runs wild eh?

[BornFromTheVoid]

Both the ECM and GFS over the next 7 days show some slight variations across the Arctic with small shifts between a -ve AO and the dipole anomaly pattern.. The strong dipole anomaly over the last 2 months hasn't had much of an effect on sea ice extent/area, as the correlation between the dipole and extent/area is actually positive in April and May, so as the winds move ice southward, increasing the extent in lower latitudes it's still cold enough to get a thin refreeze taking the place of the exported ice. If the strong dipole pattern continues over the rest of the summer, as the correlation turns strongly -ve and open ocean is left rather than new thin ice, the -ve anomaly is likely to increase further.

As the ncep reanalysis data updates, I'll add the May dipole values to the list and see how it compares to other years since '48 but judging based on the composite charts posted earlier, it's very likely to come in the top 10 on record (for May) and maybe even the top 3, and that's after an April that was 11th out of 65.

Anywho, CT has updated, and we are now just 10,000km2 of the lowest on record (2010) for the time of year. Very large losses are continuing in the Laptev Sea, with about 200,000km2 lost in the last week, the Bering Sea, with about 100,000km2 lost in the last week and the Kara Sea with about 100,000 lost in the last 3 or 4 days.

Warm air is now in place over most of Hudson Bay, and so large losses are to be expected there over the next week.

Comparing the latest extent and concentration images

We can see above, that there is a lot of low concentration cover around the Bering, Laptev, Kara seas, which have been contributing heavily to the large area losses recently. It's likely then that as the concentration in these areas slip below 15%, we'll see some large losses in the extent also quite soon.

I suppose the most important thing to look out for is the dipole anomaly over the coming weeks. All of the last 5 sea ice record minima have been associated with +ve summer dipole patterns (high pressure over the Canadian side, low pressure over the Eurasian side), with 2007 having the strongest such pattern since the 1968. So the strength of the dipole anomaly this year may well decide whether we see a new record minimum or not.

[songster]

It looks to me as though the losses in the Laptev at least are illusory. If you look at it on MODIS, you'll see it's still a solid ice sheet, but over the last few days it's turned blueish (which I believe indicate melt ponding). Melt ponds are often erroneously seen as open water by the microwave satellites.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r05c05.2012155.terra

[BornFromTheVoid]

It looks to me as though the losses in the Laptev at least are illusory. If you look at it on MODIS, you'll see it's still a solid ice sheet, but over the last few days it's turned blueish (which I believe indicate melt ponding). Melt ponds are often erroneously seen as open water by the microwave satellites.

http://rapidfire.sci...5.2012155.terra

The blue ice is certainly interesting, perhaps the warmth has allowed the river Lena to release some water across the sea ice, which may have frozen causing some diffraction, or covering it in a layer of freshwater? It's interesting either way.

Around the blue ice though, is a lot of open water that has appeared over the last week, I'd imagine that has contributed to much of the Laptev ice loss.

[BornFromTheVoid]

Actually scrap my idea!

The blue ice now appears to have spread all the way up to the East Siberian sea now, so it's likely some other factors are involved.

[BornFromTheVoid]

Lowest on record now on Cryosphere Today, only by about 11,000km2 though...