Fram Export

[uniquorn]

Some of the ongoing research about the Fram Strait presented at this week's International Symposium on Sea Ice across Spatial and Temporal Scales hosted by the International Glacial Society

Using a new year-round sea ice thickness product to quantify the complete annual record of sea ice volume export through Fram Strait (2010/21)
David Babb, Sergei Kirillov, Jack Landy, Stephen Howell, Julienne Stroeve, Jens Ehn

Fram Strait is the primary pathway for sea ice export from the Arctic Ocean. The volume of sea ice exported exerts a significant influence on both the ice mass balance of the Arctic Ocean and the freshwater budget of the North Atlantic. Despite its importance, present estimates of sea ice volume export are either confined to the winter season, extrapolated from sparse in situ observations of ice thickness or rely on modeled estimates of thickness. Here, we use a new year-round ice thickness product derived from Cryosat-2 to provide a consistent estimate of the annual record of sea ice volume export through Fram Strait from 2010–2021. We estimate that on average 1733 km³ was exported annually across a flux gate at 82° N, with 80% occurring during the ice growth season (October–April) and only 20% occurring during the melt season. Our record is too short to confirm the previously reported trend towards reduced sea ice volume export through Fram Strait; howeverwe find export to be highly variable with a peak of 2500 km3 in 2015 and a minimum of 900 km3 in 2018. Our estimate of export during the growth season is slightly less than previous estimates of seasonal ice export using Cryosat-2, which we attribute to differences in the ice thickness products, specifically ways of accounting for snow, and a longer study period that includes the minimum in 2018. Furthermore, for comparison with previous studies we calculate sea ice volume flux across gates at different latitudes. Although comparisons are limited by the different methods used to quantify ice thickness in the volume flux calculations, there was a clear transition over the past 30 years towards a thinner ice pack being exported through Fram Strait. Additionally, calculating ice volume flux at different latitudes reveals that ice volume export declined linearly at a rate of 311 km³/° between 82° N and 79° N and accounts for a nearly 50% reduction in ice volume export over these 4°. Ultimately, we provide a consistent and temporally complete analysis of sea ice volume export through Fram Strait, and briefly examine its contribution to the overall sea ice volume budget of the Arctic Ocean.


The evolution of the Fram Strait sea ice volume export decomposed by age: estimating with parameter-optimized sea ice–ocean model outputs
Yijun Yang, Chao Min, Hao Luo, Frank Kauker, Robert Ricker, Qinghua Yang

Sea ice export through the Fram Strait is crucial in the dynamic evolution of Arctic sea ice and can further modulate Arctic sea ice mass balance as well as the ocean thermohaline circulation. In this study, based on outputs from a parameter-optimized and fully physical ocean-sea ice coupled model and sea ice age observation, we estimate sea ice volume (SIV) flux and its age evolution via the Fram Strait. The estimate of mean annual SIV flux is about 1605±315 km³ a^–1 without a significant trend for 1979–2021. Combining with sea ice age data, the variation of the sea ice age and its corresponding SIV flux are obtained for 1984–2020. The SIV flux of first-year ice significantly increases as expected, but it still contributes very little to the total flux in the 2010s, with a proportion of 3.5%. SIV fluxes of different ages in multi-year ice present diverse variations. The proportions of second-year ice and third-year ice in the annual SIV flux show an extreme increase from 6.8% and 25.0% in the 1980s to 49.0% and 38.8% in the 2010s, respectively, while the proportions of fourth-year ice and fifth-year and older (5+-year) ice significantly decrease from 22.8% and 45.0% in the 1980s to 7.1% and 1.6% in the 2010s, respectively. Meanwhile, the prevailing age of annual volume export via Fram Strait shifts from fourth-year and 5+-year ice to second-year and third-year ice around 2007/08. It’s worth noting that the variation in Fram Strait ice export modulates the variation in Arctic SIV prior to 2008, but the reverse is true after 2008, indicating a decreasing influence of Fram Strait SIV export on Artic SIV variability with decreasing sea ice age. The results are beneficial to promote the understanding of the evolution of Fram Strait SIV export under the warming Arctic.


Observations of summer ice melt and ice–ocean boundary layer heat fluxes in the marginal ice zone north of Fram Strait
Simon F. Reifenberg, Wilken-Jon von Appen, Ilker Fer, Christian Haas, Mario Hoppmann, Torsten Kanzow

Given the prospect of a merely seasonally ice-covered Arctic Ocean in the future and a consequential new quality of atmosphere–ocean coupling, understanding and quantifying oceanic processes that contribute to sea ice melt is of particular relevance. A region of intense melting is the marginal ice zone north of Fram Strait, where inflowing warm Atlantic Water meets sea ice advected southward by the Transpolar Drift. We present observations of the ice–ocean boundary layer (IOBL) from a cruise of the German research vessel Polarstern to that region in summer 2022, where we gathered continuous-in-time hydrographic observations from autonomous drifting stations on three separate ice floes, supplemented by intense observation periods of vertical microstructure profiles and ice cores from crewed stations during three revisits per floe throughout the drifting period. The three occupied floes were oriented on a line approximately perpendicular to the ice edge, initially about 25 km apart from each other, with the southernmost floe located 75 km away from the edge. The drifting instrument platforms cover a common time period of approximately 2 weeks, under relatively quiescent atmospheric conditions. First results show that, while the floes exhibited similar drift trajectories dominated by superimposed diurnal and semidiurnal oscillations, the evolution of key IOBL variables, such as stratification, melt rates, friction velocity and turbulent fluxes, varied considerably – both in time and among the occupied floes. We plan to assess how this observed variability relates to other measured properties of sea ice (e.g. ice roughness, ice thickness distribution, floe size distribution) and of the upper ocean (e.g. ice–ocean velocity shear, turbulence, surface waves, internal waves and tides) and their interaction, in order to put our preliminary findings into the broader context: ocean controls on sea ice melt in the marginal ice zone north of Fram Strait.


Summer sea ice drift tracking and variation analysis in Fram Strait from 2011–20
Xue Wang, Yan Fang

Accurate sea ice drift information in Fram Strait plays important roles in quantifying the sea ice export through the Strait and reducing uncertainty of the Arctic sea ice loss estimation. Due to the limitations of data sources and algorithms, performance of the existing methods in summer sea ice drift retrieval is poor. In this study, a summer daily sea ice drift monitoring method based on time series MODIS data and the A-KAZE algorithm was proposed. Furthermore, daily sea ice motions in Fram Strait for April–September 2011–20 were retrieved based on the proposed method, and the characteristics of sea ice motion in Fram Strait for these 10 years were analyzed based on the tracking results. The proposed method was evaluated over a portion of the Strait from 29 April–5 May 2020. The results showed that the proposed method outperformed the classic MCC algorithm in sea ice drift retrieval, with velocity and direction RMSE decreases of 2.13 km d^–1 (73%) and 10° (38%), respectively. Furthermore, it retrieved more sea ice drift vectors with larger spatial coverage than did the SIFT and SURF algorithms. Meanwhile, compared with the daily sea ice motion vectors generated with daily synthetic data, the motion vectors obtained by the proposed method using time series MODIS images covered more areas, with an average increase of 862.62 km² (nearly 16 times), which demonstrated that the proposed method greatly reduced the cloud effect on optical data. Furthermore, it was found that the spatial distribution of sea ice velocity in Fram Strait for the last 10 years is relatively consistent: ice velocity in the south of the Strait is higher than that in the north, and the velocity away from the coast is higher than that near the shore. The annual average summer sea ice velocity in Fram Strait does not show a significant increase or decrease trend, but there is a downward trend from April to July and an upward trend from August to September. The proposed method provides new idea for daily sea ice drift monitoring in summer and the analysis of summer sea ice velocity in Fram Strait for the last 10 years is applicable to research such as rapid change of Arctic sea ice.

[binntho]

Thanks uniquorn. Any changes of link to open access of the second paper "The evolution of the Fram Strait sea ice volume export decomposed by age: estimating with parameter-optimized sea ice–ocean model outputs" ?

[oren]

https://iopscience.iop.org/article/10.1088/1748-9326/acaf3b/meta

LETTER • THE FOLLOWING ARTICLE ISOPEN ACCESS
The evolution of the Fram Strait sea ice volume export decomposed by age: estimating with parameter-optimized sea ice-ocean model outputs

[Tammukka]

I repeat my warning that using the PIOMAS regional volume/thickness data to draw any conclusion about the influence of Fram export is problematic. That is not what PIOMAS is designed for, and that is not what PIOMAS can do.

Their regional volume data in the Greenland sea specifically may be off by an order of magnitude, and so could be the long term trend. See the discussion starting here and up to here.

An order of magnitude? Is that an opinion or a peer reviewed statement?

It is an observation. The three models for sea ice thickness (DMI, HYCOM, and PIOMAS) that were mentioned in the discussion I linked show thicknesses for most of the Greenland sea that vary between about 20 cm and 5 metres. (That's variation from model to model, for the same region and time; I am not talking about the variation within the region in a given model.)

Here's the example I gave (31 May 2023). DMI has some of the thickest ice of the entire arctic "hugging" the eastern coast of Greenland. PIOMAS has little more than a thin veneer throughout that region. They may give similar answers for total volume once you average over the entire arctic, but regionally, the differences are striking.

Having looked. I agree.

There is more fast ice there than at virtually any point for 07/06 going back to 2000 (and its right where the dead space is for PIOMAS). The estimates will probably be close to, in not, magnitudes out for that region.

Perhaps they need to recalibrate their model to be aware of the possibility of such extensive fast ice at that location (it might be misclassifying it as glacial ice?)

I think that part of that fast ice broke. I might be wrong, but its been windy out there.

[gerontocrat]

PIOMAS Data from Polar Science Center as extracted by Steven to 15th July.

From 18th to the 10th June Fram Export went into reverse, and then apart from 3 days (6th to 8th July) resumed in July to date. However daily Fram Export in July is modest as is usual this time of year.

Cumulative 2023 Fram Export Volume at 1,400 km3 is high, though not to the extent shown in Cumulative Fram Export Area at 900,000 km3.

Average thickness (see next post) is a little below that of the 2010's average.

[gerontocrat]

& the thickness graph...

I also attach the Annual Average Ice Thickness graph 1979-2022

[gerontocrat]

From Steven's data files it is possible to get a good estimate of ice movements to and from the High Arctic to the Barents between Svalbard and FJL.

It has been high this year, and is still happening., which is maybe why the Barents is refusing to fully melt out.

[Glen Koehler]

     Interesting that 2003 was the year of maximum export to Barents by a large margin.  That coincides with the great MYI reduction attributed to other causes.  Leaves me wondering if CAB export to Barents (for whatever reasons) played a big role in the precipitous early 2000s MYI decline.

[FishOutofWater]

That ice export from the Barents sea to the Fram strait in 2003 coincided with the beginning of a surge of Atlantic water into the Barents sea and European side of the Arctic ocean. The surge of warm salty Atlantic water was a key to the decline in Arctic ice later in that decade.

Yes, the winds and weather that exported ice also imported Atlantic water into the Barents sea.

[gerontocrat]

Fram Export in August was almost zero

[Steven]

I upgraded the Fram export and sea ice drift page on my Google Site:

https://sites.google.com/view/arctic-sea-ice/home/fram

I also added a new feature to it, so that you can manually select a start date and end date and get the (pointwise) average drift map over that period.  This complements the 3 fixed drift maps that were already on the page (10-day, 30-day and October-onward).

Note: Since I only used free tools to deploy the new feature, it's slow to run.  It turns out the backend server automatically shuts down after 15 minutes of inactivity and then it needs to restart when someone makes a new request.  These issues could be avoided by upgrading to a paying version but I'm not planning to do that.

Any feedback on this page is welcome.

[kassy]

That is fun.

The calendar does allow you to select dates before June 2017.
And you can select today as the end date while that is not valid either.

The feed back the site gives is clear enough but i really wanted to look at 2012. 

Easiest solution is probably to mention the start date.

[Steven]

That is fun.

The calendar does allow you to select dates before June 2017.
And you can select today as the end date while that is not valid either.

The feed back the site gives is clear enough but i really wanted to look at 2012. 

Easiest solution is probably to mention the start date.

Thanks, I made a few changes to make the date limits more clear, as you suggested.

The OSISAF data start in October 2015, but the first two years have some data gaps so I'm using data from June 2017 onward.

Meanwhile I also added some javascript code that automatically triggers a restart of the backend server (if necessary) as soon as someone visits the Google Site.  That should get rid of the worst delays.

[kassy]

How bad are the gaps for 2016? That was going to be my next target after 2012.

[Steven]

How bad are the gaps for 2016? That was going to be my next target after 2012.

No data between early May and late September 2016.  And no data for May 2017 either.  You can also see this in the Fram Export graph being fully flat over those two periods.

[kassy]

Yeah that is not going to work.

Anyway it is nice how you can look back at certain weeks/months or any period you desire in the dataset. It is a helpful feature which would be nice for many other data sets.

[Renerpho]

While we're at it: Fram/FJL export has picked up considerably in the last six weeks, and is at record pace.

[oren]

Thank you so much, Steven. The drift page is one I use regularly.

[Steven]

Glad you think it's useful.

Meanwhile I added a graph for the Fram/FJL export for the OSISAF data (similar to the one for PIOMAS).

I also fixed a few small bugs in the dynamic map generator tool.

I'm not sure if the three sea ice drift maps should remain on the website (i.e., the 10-day, 30-day, and 90-day maps)?  They are kind of redundant now that there's a dynamic map generator.  Or maybe another choice of periods could be used in the fixed maps (5-day? 7-day?)

https://sites.google.com/view/arctic-sea-ice/home/fram

[kassy]

I think 10 days is fine. It is a bit over a week. 30 days is almost a month so they are fine proxies for those periods.

If you make the total period longer you lose detail. I did this in 2 month increments. It kept going towards the Greenland Sea so there´s that but if you want to drop any map i would suggest the 90 day map.

[Phil.]

All of the graphs on the site don't show up for me, just a space with a little blue ?.

[Steven]

All of the graphs on the site don't show up for me, just a space with a little blue ?.

Does that problem persist when you reload the page?  What browser are you using?

Each of the images on that page is on Google Drive.  I've just added a direct link below each image to open the image directly in case if fails to load, does that help?

[gerontocrat]

All of the graphs on the site don't show up for me, just a space with a little blue ?.

That happened to me for a time on Nico Sun's  https://cryospherecomputing.com/
It was after a big Windows11 update. Coincidence?

I found that clicking on the little blue thing sometimes gave me a download, so I could at least then look at it.

A few days later order was restored - maybe Window11 did another update?

[Phil.]

All of the graphs on the site don't show up for me, just a space with a little blue ?.

Does that problem persist when you reload the page?  What browser are you using?

Each of the images on that page is on Google Drive.  I've just added a direct link below each image to open the image directly in case if fails to load, does that help?

The direct links work thanks.  The browser is Safari.

[oren]

Please keep the 10 days, I post it every week or so, having to select dates every time would make it more cumbersome.
The 90 days is indeed superfluous.

[Steven]

The direct links work thanks.  The browser is Safari.

Based on what I find online, it looks like Safari (depending on how it is configured) may refuse to load embedded Google Drive images.  So I added a direct link below all the other Google Drive images on my site.  And I moved the OSISAF images from Google Drive to Dropbox, to spread the load a bit better.

Please keep the 10 days, I post it every week or so, having to select dates every time would make it more cumbersome.

But maybe 7-day would be a better option for weekly updates?  Anyway I'll keep it as is for now (10-day and 30-day).

[gerontocrat]

Here are some FRAM EXPORT graphs using PIOMAS data analysed & extracted by Steven. Data to October 31.

Attached are daily and cumulative Fram Export volume and area.

Sea ice volume export is high but well below the 1995* ( highest in the satellite record) level.
Sea ice area  export is very high, at Oct 31 just below the 1995 level (2nd highest).

*1995 was the year where both sea ice export volume area and thickness were at record or near record levels.( see next post for thickness)

Note: 7 day averages are used for daily data to reduce graph noise to acceptable lvels.

[gerontocrat]

FRAM EXPORT graphs using PIOMAS data analysed & extracted by Steven. Data to October 31.

Thickness

Average thickness for the year to date has stayed close to the 2010's average from March onwards.
The graph decadal averages of thickness show clearly the substantial drop in average thickness of ice exported,down from around 2.13 metres in the 1980s to 1.45 metres in the 2010s.

1995 was the year of greatest average Fram export sea ice thickness and record or near record sea ice volume and area export, which does not seem to correspomd with a year of a big drops in MYI. (see last image)

Note: To remove extreme noise in the daily thickness graph I have had to use 10 day (mid-point) daily averages of volume and rea, and even then replace extreme values with gaps. Neverhless you can see that in general, daily sea ice thickness tends to increase January to mid-May, decline during the melting season, and start to rise again when refreeze gets underway in mid to late September.

1995 broke that pattern with very high thickness notably in August.

[johnm33]

On steroids currently and with a high over Beaufort setting the wind patterns almost perfect even more inertia is going to build. This should ease the pressure against the coasts and allow for more rotation, then we have another low set to pass through the Faroes gap before[?] the full moon of the 25^th. More penetration via Bering and Barents will follow. 

[uniquorn]

A lot of older ice already exported during the freezing season leaving mostly first year ice with some dispersed second year between Greenland and the pole. Much depends on how the CAA fares this season.

[gerontocrat]

Sea ice area in the Greenland sea strongly increasing in recent days - Fram export accelerating?

[HapHazard]

A lot of older ice already exported during the freezing season leaving mostly first year ice with some dispersed second year between Greenland and the pole. Much depends on how the CAA fares this season.

Well that first pic looks like a funnel if I've ever seen one.

[johnm33]

CAA
 I suspect that warm water is flowing in through Bering at depth whilst the ice has actually been blown out. Since the CAA has shown signs of movement all winter, and only small amounts of thick ice have been available to move into Mclure the main channel could clear early, we may see some evidence of it in the coming tidal cycle. It seems as if the flow from the Pacific is already on it's way though it could be just an artifact of the high pressure zones ice acceleration.
https://go.nasa.gov/3VsEes6

[HapHazard]

I was just poking around Wolrdview, and it looks like Fram export is humming along at a decent pace. A funnel extends back to the pole or thereabouts.

[johnm33]

At least it can't get much worse, the 30 day looks bad but the 10 day shews all of the compression zones are being vacated, even the Beaufort is tied in to the exit rotation atm. This suggests that it's more than just an ice flow, and that the harmonic of tidal forces, being in opposite phases at Fram and Bering, is currently strongly connected.