Arctic Sea Ice Extent, Area, and Volume

[bdgwx]

7 hours ago, chubbs said:

IPO phase could bring September ice-free date forward.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL081393

Yeah so it looks like the ensemble range on this study is 2040 to 2055 with a mean of about 2047 for the first ice-free (< 1e6 sq km) September.

[ORH_wxman]

Still about another month to go before max volume....but February data is in and we're currently 7th lowest volume on record....between 2013 and 2014 right now. Spring volume is more predictive than extent/area this early, but it's still not nearly as good as area in the month of June.

As an example, the highest volume since 2009 in spring was 2015 and that year had poor weather in summer bring it lower than many other years that were lower in the spring. We're not that far above 2012 either, and that year was by far the lowest on record by the time we got to September.

 

Graph courtesy of user wipneus at arctic sea ice forum

 

This is an anomaly graph, not a raw value graph

 

[bluewave]

https://www.adn.com/alaska-news/2019/03/04/bering-sea-ice-is-at-an-unprecedented-low-right-now/

Bering Sea ice is at an ‘unprecedented’ low right now

Sea ice is again at a historic low in the Bering Sea.

At the time of year when ice usually reaches its maximum, there’s open water in a vast area stretching from Bristol Bay to the Bering Strait, said Rick Thoman, a climate specialist with Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks.

“You could take your sailboat and sail from Dillingham all the way to Little Diomede and never see much more than an ice cube,” he said.

March and early April are typically when sea ice in the Bering Sea reaches its maximum extent, and when communities that live along the coast travel on the ice for subsistence hunting and fishing.

The unprecedented lack of ice in the Bering Sea follows another record-breaking winter. Last spring, in 2018, the extent of ice in the Bering Sea only reached half of its previous lowest size, which was recorded in 2001. Thoman called the lack of ice “stunning” at the time.

This spring, the situation is even more extreme. While there’s more ice on the Russian side of the Bering Sea, there’s virtually none on the Alaska side.

Watch the anomalous southerly flow push sea ice poleward through the Bering Strait since February

https://mobile.twitter.com/ZLabe/status/1103690280576802818?ref_src=twsrc^google|twcamp^serp|twgr^tweet

 

 

 

[bdgwx]

Arctic sea ice extents have taken a plunge recently and are now in record territory for this date dropping below 2006, 2016, 2017, and 2018 levels. So the melt season is already off to an aggressive start.

[Gray-Wolf]

We are also seeing some massive temp anoms across areas of the basin so not only do we enter melt season lowest on record but with some pretty aggressive conditions on the ground?

[bluewave]

https://mobile.twitter.com/bhensonweather/status/1112750445397577728

Arctic sea ice extent has broken into record-low territory for the start of April. Late-spring & summer weather are bigger factors in determining how much ice cover is lost during the warm season. Still, this is a disconcerting drop. (link: http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/) nsidc.org/arcticseaicene…

https://mobile.twitter.com/IARC_Alaska/status/1112768243251314688

March was the warmest of record over all nearly of Alaska north of the Alaska Range & Bristol Bay. Some places on the North Slope & in Northwest Arctic Borough were more than 20F (11C) above normal. Early snowmelt southern areas.

https://mobile.twitter.com/AlaskaWx/status/1112711147415691264

Utqiaġvik (Barrow): average March temperature +5.9F (-14.5C) is highest of record, 18.6F (10.3C) above 1981-2010 normal & 6.6F (3.7C) above the previous warmest March (2018). 8 of 10 warmest Marchs since mid-90s.

https://mobile.twitter.com/AlaskaWx/status/1112754212293636096

Kotzebue average temperature for March 23.0F (-5.0C) is 21.9F (12.2C) above normal and 9.5F (5.3C) warmer than ANY other March in the past 90 years. That is so warm it would be a top ten warmest APRIL

https://mobile.twitter.com/Pat_wx/status/1112766213913042945

At 14.4°C above normals, this past month was the most anomalous month on record in #Inuvik, including all months and both cold and warm anomalies! Note that February 2019 also made it into the top 10.

 

 

 

[bluewave]

Looks like we are on track for a new lowest April average sea ice extent.

NSIDC monthly record lowest average sea ice extents 

Jan...2018

Feb.. 2018

Mar...2017

Apr....2019...so far...previous record 2016

May...2016

Jun....2016

Jul.....2012

Aug...2012

Sep...2012

Oct...2012

Nov...2016

Dec...2016

https://mobile.twitter.com/bhensonweather/status/1115700868723003392

Arctic sea ice extent is plummeting into truly uncharted territory for mid-April. (link: http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/) nsidc.org/arcticseaicene…

 

 

[AfewUniversesBelowNormal]

That looks like a graph of strength of the global system imo. It's been +AO though. 

[chubbs]

Recent summer warming in the Yukon exceeds the Holocene climatic maximum despite reduced summer insolation vs early Holocene.

https://t.co/gCPWogUB5N

[Gray-Wolf]

Well we are certainly still on track for a 'perfect melt storm' summer......just without the 'perfect melt storm' synoptics???

Is this what the last 5 years of 'winter preconditioning' was all about?

Taking us to the point where an 'average summer' feeds us a sub 2007 finish and , over time, the 'Blue Ocean' event?

 

 

[forkyfork]

this would be an interesting start to may

[Gray-Wolf]

Indeed forkyfork!

Not just the forcing toward Fram exit all the way from the Pacific entrance but the conditioning this will put on a pack that is mainly small floes 'glued together' by late formed ice? Such a dynamic fragmentation event will also lead to mechanical weathering of floes as they bump and barge one another on their travels?

Then we have Barentsz and the open waters maintained over winter ( again) hinting at what awaits ice pushed into that region?

'Collapse and spread' of ice entering open water may see extent/area figures but this will be temporary and illusory. 

 

Something feels 'off' about this melt season?

I do not know if it is the record summer the southern Hemisphere just had, and the fear of such conditions transfering North with the sun or the strange amounts of High Pressure across the hemisphere?

The 'Greenland high' caused issues across Greenland in 2012 and now , after a few years of it not performing, we see it apparently back to strength?

Then there is the 'Perfect melt storm synoptic'? 

If we are still able to see such develop, and we have not mangled the atmospheric too much for such to develop, then we are still in its return period......

 

[ORH_wxman]

Looks like Cryosat2 is done scanning for the season....based on the prelim results this year, it looks like the Beaufort, Chukchi, and western ESS are thicker than last year, but the eastern ESS and parts of Laptev are thinner.

[bluewave]

Great write-up on the conditions leading to April 2019 beating the minimum sea ice extent record set in 2016. Also an analysis on sea ice age and transport. 

https://nsidc.org/arcticseaicenews/2019/05/rapid-ice-loss-in-early-april-leads-to-new-record-low/

Rapid ice loss in early April leads to new record low

May 2, 2019

April reached a new record Arctic low sea ice extent. Sea ice loss was rapid in the beginning of the month because of declines in the Sea of Okhotsk. The rate of ice loss slowed after early April, due in part to gains in extent in the Bering and Barents Seas. However, daily ice extent remained at record low levels throughout the month.

Overview of conditions

Figure 1. Arctic sea ice extent for April 2019 was 13.45 million square kilometers (5.19 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Arctic sea ice extent for April 2019 averaged 13.45 million square kilometers (5.19 million square miles). This was 1.24 million square kilometers (479,000 square miles) below the 1981 to 2010 long-term average extent and 230,000 square kilometers (89,000 square miles) below the previous record low set in April 2016.

Rapid ice loss occurred in the Sea of Okhotsk during the first half of April; the region lost almost 50 percent of its ice by April 18. Although sea ice was tracking at record low levels in the Bering Sea from April 1 to 12, the ice cover expanded later in the month. Elsewhere, there was little change except for small losses in the Gulf of St. Lawrence, the southern part of the East Greenland Sea, and southeast of Svalbard. In addition, open water areas developed along coastal regions of the Barents Sea. The ice edge expanded slightly east of Novaya Zemlya.

Conditions in context

Figure 2a. The graph above shows Arctic sea ice extent as of May 1, 2019, along with daily ice extent data for four previous years and 2012. 2019 is shown in blue, 2018 in green, 2017 in orange, 2016 in brown, 2015 in purple, and 2012 in dotted brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Figure 2b. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for April 2019. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Division
High-resolution image

Air temperatures at the 925 hPa level (approximately 2,500 feet above the surface) were above average across the Arctic during the first two weeks of April, especially over the East Siberian Sea and the Greenland Ice Sheet where air temperatures were as much as 9 degrees Celsius (16 degrees Fahrenheit) above average (Figure 2b). Elsewhere, 925 hPa temperatures were between 3 to 5 degrees Celsius (5 to 9 degrees Fahrenheit) above average, including the Sea of Okhotsk where ice loss early in the month was especially prominent. These relatively warm conditions were linked to a pattern of high sea level pressure over the Beaufort Sea paired with low sea level pressure over Alaska, Siberia, and the Kara and Barents Seas. This drove warm air from the south over the East Siberian Sea. Similarly, high pressure over Greenland and the North Atlantic, coupled with low sea level pressure within Baffin Bay, helped usher in warm air over southern Greenland from the southeast.

During the second half of the month, temperatures remained above average over most of the Arctic Ocean, and up to 8 degrees Celsius (14 degrees Fahrenheit) above average over the East Greenland Sea. However, temperatures were 1 to 5 degrees Celsius (2 to 9 degrees Fahrenheit) below average over the Bering Sea, and up to 8 degrees Celsius (14 degrees Fahrenheit) below average over the Canadian Arctic Archipelago. Air temperatures were slightly below average in the Kara Sea.

April 2019 compared to previous years

Figure 3. Monthly April ice extent for 1979 to 2019 shows a decline of 2.64 percent per decade.

Credit: National Snow and Ice Data Center
High-resolution image 

The 1979 to 2019 linear rate of decline for April ice extent is 38,800 square kilometers (15,000 square miles) per year, or 2.64 percent per decade relative to the 1981 to 2010 average.

Sea ice age update

Figure 4. The top maps compare Arctic sea ice age for (a) April 8 to 14, 1984, and (b) April 9 to 15, 2019. The time series (c) of mid-April sea ice age as a percentage of Arctic Ocean coverage from 1984 to 2019 shows the nearly complete loss of 4+ year old ice; note the that age time series is for ice within the Arctic Ocean and does not include peripheral regions where only first-year (0 to 1 year old) ice occurs, such as the Bering Sea, Baffin Bay, Hudson Bay, and the Sea of Okhotsk. 

Credit: W. Meier, NSIDC
High-resolution image

Younger sea ice tends to be thinner than older ice. Therefore, sea ice age provides an early assessment of the areas most susceptible to melting out during the coming summer. The Arctic sea ice cover continues to become younger (Figure 4), and therefore, on average, thinner. Nearly all of the oldest ice (4+ year old), which once made up around 30 percent of the sea ice within the Arctic Ocean, is gone. As of mid-April 2019, the 4+ year-old ice made up only 1.2 percent of the ice cover (Figure 4c). However, 3 to 4-year-old ice increased slightly, jumping from 1.1 percent in 2018 to 6.1 percent this year. If that ice survives the summer melt season, it will somewhat replenish the 4+ year old category going into the 2019 to 2020 winter. However, there has been little such replenishment in recent years.

The sea ice age data products were recently updated through 2018 (Version 4, Tschudi et al., 2019). Data is available here. In addition, an interim QuickLook product that will provide preliminary updates every month is in development.

Changing ice and sediment transport

Figure 5a. This map shows the main sea ice drift patterns. 
Figure 5b. This illustration shows how sediments can be ingrained into the newly forming sea ice. 
Figure 5c. This graph shows the probability that newly formed ice in the winter will survive the summer. 

Credit: T. Krumpen
High-resolution image

Figure 5d. This image shows sediment-rich sea ice in the Transpolar Drift Stream. A crane lowers two researchers from the decks of the icebreaker RV Polarstern to the surface of the ice to collect samples.

Photo Credit: R. Stein, Alfred Wegener Institut
High-resolution image

Scientists from the Alfred Wegener Institut (AWI) monitored and analyzed sea ice motion using satellite data from 1998 to 2017 and concluded that only 20 percent of the sea ice that forms in the shallow Russian seas of the Arctic Ocean now reaches the central Arctic Ocean to join the Transpolar Drift Stream(Figures 5a and b). The Russian seas, including the Kara, Laptev, and East Siberian Seas, are considered the ice nursery of the Arctic. The remaining 80 percent of this first-year ice melts before it has a chance to leave this nursery. Prior to the year 2000, that number was about 50 percent (Figure 5c).

These conclusions find support from sea ice thickness observations in Fram Strait, which is fed by the Transpolar Drift Stream. AWI scientists regularly gather ice thickness data in Fram Strait as part of their IceBird program. The ice now leaving the Arctic Ocean through the Fram Strait is, on average, 30 percent thinner than it was 15 years ago. There are two reasons for this. First, winters are warmer and the melt season now begins much earlier than it used to. Second, much of this ice no longer forms in the shallow seas, but much farther north. As a result, it has less time to thicken from winter growth and/or ridging as it drifts across the Arctic Ocean.

These changes in transport and melt affect biogeochemical fluxes and ecological processes in the central Arctic Ocean. For example, in the past, the sea ice that formed along the shallow Russian seas transported mineral material, including dust from the tundra and steppe, to the Fram Strait (Figure 5d). Today, the melting floes release this material en route to the central Arctic Ocean. Far less material now reaches the Fram Strait and it is different in composition. This finding is based on two decades of data sourced from sediment traps maintained in the Fram Strait by AWI biologists. Instead of Siberian minerals, sediment traps now contain remains of dead algae and microorganisms that grew within the ice as it drifted.

Putting current changes into longer-term perspective

Figure 6. This map shows Arctic regions used in the Walsh et al. study and how much each area’s September extent contributes to the total September sea ice extent. The top number gives the percentage (as squares of correlations, or R2) when the raw 1953 to 2013 ice extent time series is used. The bottom number (bold) gives what the percentage drops to after the time series data have been detrended. For example, about 70 percent of the September Arctic-wide extent number is explained by the September extent in the seas north of Alaska, but that drops to about 20 percent once the trends have been removed. 

Credit: Walsh et al., 2019, The Cryosphere
High-resolution image

While changes in sea ice extent over the past several decades are usually shown as linear trends, they can mask important variations and changes. A recent study led by John Walsh at University Alaska Fairbanks compared various trend-line fits to sea ice extent time series back to 1953, for the Arctic as a whole and various sub-regions. This data set extends the satellite record by using operational ice charts and other historical sources (Walsh et al., 2016). They found that a two-piece linear fit with a break point in the 1990s provides a more meaningful basis for calculations of sea ice departures from average conditions and their persistence, rather than a single trend line computed over the period 1953 to the present. Persistence of sea ice departures from average conditions represents the memory of the system, which can be used to forecast sea ice conditions a few months in advance. September Arctic-wide ice extent can also be predicted with some limited skill when the data include the trend. However, this apparent skill largely vanishes when the trend is removed from the data using the two-piece linear fit. This finding is consistent with the notion of a springtime predictability barrier, such that springtime sea ice conditions are usually not a strong predictor of the summer ice cover because atmospheric circulation patterns in summer erode this memory in the system. For example, despite the extensive coverage of fairly young—and hence thin—ice this spring, cool summer weather conditions may limit melt, leading to a higher September ice extent than might otherwise be expected.

April snow melt in Greenland—notable but not unusual

Temperatures were well above average over Greenland for much of April but were still below freezing except near the coast. Satellite data indicate that there was a small area surface melt on the southeastern coastal part of the ice sheet early in the month. In the last week of April, melt became more extensive, spreading further north on the east coast and starting on the west coast. While interesting, this is not especially unusual. Most years of the past decade have some surface melt in April. In 2012 and 2016, strong melt events occurred in April that covered a much larger area than in 2019. NSIDC is now trackingGreenland surface melt for 2019 on a daily basis.

 

[nzucker]

On 5/2/2019 at 12:27 PM, ORH_wxman said:

Looks like Cryosat2 is done scanning for the season....based on the prelim results this year, it looks like the Beaufort, Chukchi, and western ESS are thicker than last year, but the eastern ESS and parts of Laptev are thinner.

Also looks like significant improvement north of the CAA and Greenland.

[AfewUniversesBelowNormal]

It looks like a -AO period really takes hold in the medium and long range. 

[Gray-Wolf]

And still we continue on the 'perfect melt storm' trajectory!

The latest outlooks place a big high right across the pole for the most intense dose of solar that the season has to offer!!

Let's not forget that the pole gets its solar 24/7 this time of year so that is a lot of energy pilling onto the thin ice and a healthy export of our oldest ice through Fram.

If we get through to July in similar shape I think it will be safe to call a challenge on 2012's assortment of records?

[SN_Lover]

Wonder if homes in Iceland have AC. Crazy warmth coming. 

 

[FPizz]

On ‎5‎/‎26‎/‎2019 at 1:30 PM, SN_Lover said:

Wonder if homes in Iceland have AC. Crazy warmth coming. 

 

A 384 hour map?

[forkyfork]

On 11/16/2018 at 5:37 PM, snowlover91 said:

Yep nothing surprising there but it IS interesting that the current volume is close to the 2004-2013 average. Making up some good ground this year so far and encouraging to see. 

 

[Gray-Wolf]

So the 'Perfect melt storm' synoptic rolls on with the high intensifying over the pole this coming 10 days.

You need remember it takes 70 cals of energy to melt a 1cm cube of ice (due to the demands of the latent heat of fusion) but add another 70 cals to that water and it warms to 70c!!!

Unlike 07' when we had the last 'Perfect Melt storm' there is already open water both around ,and inside, the pack this year so we will see warmed 'kill zones' for ice to float into later in the season ( unlike 07')

Should those warmed waters help feed cyclones over Aug/Sept, tossing the ice around in those warmed waters, then we will be in serious trouble!!!

[bluewave]

Warmest May on record for the Arctic.

https://sites.uci.edu/zlabe/arctic-temperatures/

 

[Gray-Wolf]

I've now realised that what has happened is that , post 07' ,I was keeping an eye out for the return of such extreme forcings ( as we saw in 2007?) to cause us to see another record low 'step down' in ice extent/area/volume, but in reality the pack was becoming conditioned to see '07' scale losses in an 'average summer'?

But this year is not setting up to be 'an average summer' is it?

With us still seeing a 'perfect melt storm-esque' synoptic hammering the ice we appear to be building melt momentum for at least record low sea ice territory if not worse?

Forecasts show lots of heat , from the land masses, flowing over sectors of the basin these coming 10 days and this is coupled with peak insolation for the rest of the pack sitting under HP domination?

By months end , with Hudson & Baffin then in play, we will be seeing big daily losses and an ever more opened pack ( with plenty of 'dark water' to capture the suns energy) in time for 'peak melt'

If ,by Aug, we see home grown cyclones in the basin then the 'bottom melt' phase of the season will be devastating considering the warmth in the waters the ice will be tossed around in as the lows pass over.

We'll see what tRump & co. have to say if we do end on a disastrous low figure this year & see even more energy flood the Arctic atmosphere as the basin tries to prepare for re-freeze.

[ORH_wxman]

5 hours ago, Gray-Wolf said:

I've now realised that what has happened is that , post 07' ,I was keeping an eye out for the return of such extreme forcings ( as we saw in 2007?) to cause us to see another record low 'step down' in ice extent/area/volume, but in reality the pack was becoming conditioned to see '07' scale losses in an 'average summer'?

But this year is not setting up to be 'an average summer' is it?

With us still seeing a 'perfect melt storm-esque' synoptic hammering the ice we appear to be building melt momentum for at least record low sea ice territory if not worse?

Forecasts show lots of heat , from the land masses, flowing over sectors of the basin these coming 10 days and this is coupled with peak insolation for the rest of the pack sitting under HP domination?

By months end , with Hudson & Baffin then in play, we will be seeing big daily losses and an ever more opened pack ( with plenty of 'dark water' to capture the suns energy) in time for 'peak melt'

If ,by Aug, we see home grown cyclones in the basin then the 'bottom melt' phase of the season will be devastating considering the warmth in the waters the ice will be tossed around in as the lows pass over.

We'll see what tRump & co. have to say if we do end on a disastrous low figure this year & see even more energy flood the Arctic atmosphere as the basin tries to prepare for re-freeze.

We'll have a better idea soon....the next 3 weeks will basically decide if a new record is possible in September. This is definitely our best shot since 2016....2016 just didn't quite have the melt ponding that 2012 did in June, so the momentum wasn't able to carry us to a new record. The last two years (2017 and 2018) haven't even been close. We knew those seasons would be pedestrian in the post-2007 sense by the end of June.

[forkyfork]

12 minutes ago, ORH_wxman said:

We'll have a better idea soon....the next 3 weeks will basically decide if a new record is possible in September. This is definitely our best shot since 2016....2016 just didn't quite have the melt ponding that 2012 did in June, so the momentum wasn't able to carry us to a new record. The last two years (2017 and 2018) haven't even been close. We knew those seasons would be pedestrian in the post-2007 sense by the end of June.

does this low scoot out or rot in place? 

[bluewave]

Looks like the earliest in the season that north of 80N went above freezing.

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

 

 

 

[csnavywx]

The aggressive final warming of the PV in late April seems to have done a number on the pattern this year. It's shaping up to be much closer to the 07-12 pattern than we've seen in recent years (with the possible exception of '16). The Beaufort and Chukchi are in record low territory already (by a long shot) with a continuous open water front establishing very early in the season.

It's been very warm in May, though slightly cooler than 2012 as of the last week or two. That could change over the next 5-10 days as a big Greenland block looks to get going and the EPS and FV3 hint at what could turn into a big classic dipole by mid-month. It'll be warm until then, so losses should continue apace, but some real fireworks would get going if that verifies. This year's tendency has been strongly towards blocking, and I suspect that dynamic PV breakdown this spring has something to do with it. Unlike the last several years, where we would slide inevitably into a PV-dominated pattern, that does not seem to be the case this time around. These blocking patterns have actually been verifying.

[forkyfork]

silence, denier

[forkyfork]

On 7/10/2018 at 8:34 AM, Weatherdude88 said:

NSIDC northern hemisphere sea ice extent is now 12th place for 7.9.2018 with a daily value of 9.217 millions of square kilometers. July 9th, of 1995 had a daily value of 9.655 millions of square kilometers. It is possible, given the modeled favorable arctic sea ice retention conditions, we will have a greater sea ice extent value than 1995 within 2 weeks.

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/   

what a trash prediction 

[etudiant]

19 minutes ago, forkyfork said:

what a trash prediction 

Au contraire! 

A consensus prediction is pretty worthless, we make progress when things go different from what everyone expects and we reappraise.

Of course it is always easier to burn the deniers at a stake....