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Arctic Sea Ice Extent, Area, and Volume


ORH_wxman
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  • 3 weeks later...

We spend all this time obsessing over the Arctic when in so far as climate change ramifications is a concern... it's the other one that's the biggest problem. 

https://phys.org/news/2024-03-scientists-fret-antarctic-sea-ice.html

 

But... I don't really think a lot of the Arctic focus in here is really about climate change per se.  More about preserving chances for cold and snow in people's winters, and having connected that to the state of north pole. Call me a 'motivational cynic' -

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  • 3 weeks later...

Probably a bit too early to know for sure but there does seem to be some see-sawing situation between the poles. Will be interesting to watch it over the next 5 years.

Thickness levels I don't think can recover meaningfully going forward but we shall what happens with extent (not that this is all too important in the long run).

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On 3/26/2024 at 9:37 AM, Typhoon Tip said:

The satellites that measured the ice from say 79-90 vs the 1000s more we have today, do you think that makes a difference at all?  They are probably way more precise today with many more doing calculations than the handful we had 40 years ago.  I wonder if we were to use 1980 tech to measure today what that would have come up with.  

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  • 1 month later...

A recent study confirms that a fundamental shift occurred with the Arctic sea ice around the 2007 season. The Arctic lost so much older ice that it makes it harder to set new extent records. This is why the 2012 low extent record has been so difficult to beat. While the 2020 season came close, it came up short of the 2012 record. This is also why no season since 2007 has been able to see a recovery to pre-2007 extents and thickness. Most seasons since then finished in the 4 to 5 million sq km range for extent since extents change more slowly with younger ice dominating the Arctic instead of older.
 


https://www.nature.com/articles/s41586-022-05686-x

Manifestations of climate change are often shown as gradual changes in physical or biogeochemical properties1. Components of the climate system, however, can show stepwise shifts from one regime to another, as a nonlinear response of the system to a changing forcing2. Here we show that the Arctic sea ice regime shifted in 2007 from thicker and deformed to thinner and more uniform ice cover. Continuous sea ice monitoring in the Fram Strait over the last three decades revealed the shift. After the shift, the fraction of thick and deformed ice dropped by half and has not recovered to date. The timing of the shift was preceded by a two-step reduction in residence time of sea ice in the Arctic Basin, initiated first in 2005 and followed by 2007. We demonstrate that a simple model describing the stochastic process of dynamic sea ice thickening explains the observed ice thickness changes as a result of the reduced residence time. Our study highlights the long-lasting impact of climate change on the Arctic sea ice through reduced residence time and its connection to the coupled ocean–sea ice processes in the adjacent marginal seas and shelves of the Arctic Ocean.

Our analysis demonstrates the long-lasting impact of climate change on Arctic sea ice through reduced residence time, suggesting an irreversible response of Arctic sea ice thickness connected to an increase of ocean heat content in areas of ice formation. The large reduction of summer ice extent in the Alaskan and Siberian sectors in 2005 and 2007 triggered intensive ice–albedo feedback42,45 and initiated the perennial increase of ocean heat content in these areas44. This resulted in the stepwise reduction of residence time of sea ice in the Siberian sector of the Arctic, and hence a nonlinear response of the system.


https://www.jpl.nasa.gov/news/with-thick-ice-gone-arctic-sea-ice-changes-more-slowly

The Arctic Ocean's sea ice blanket has already lost most of its old ice and two-thirds of its thickness. The younger ice is thinning more slowly and variably.

The Arctic Ocean's blanket of sea ice has changed since 1958 from predominantly older, thicker ice to mostly younger, thinner ice, according to new research published by NASA scientist Ron Kwok of the Jet Propulsion Laboratory, Pasadena, California. With so little thick, old ice left, the rate of decrease in ice thickness has slowed. New ice grows faster but is more vulnerable to weather and wind, so ice thickness is now more variable, rather than dominated by the effect of global warming.

Working from a combination of satellite records and declassified submarine sonar data, NASA scientists have constructed a 60-year record of Arctic sea ice thickness. Right now, Arctic sea ice is the youngest and thinnest its been since we started keeping records. More than 70 percent of Arctic sea ice is now seasonal, which means it grows in the winter and melts in the summer, but doesn't last from year to year. This seasonal ice melts faster and breaks up easier, making it much more susceptible to wind and atmospheric conditions.

Kwok's research, published today in the journal Environmental Research Letters, combined decades of declassified U.S. Navy submarine measurements with more recent data from four satellites to create the 60-year record of changes in Arctic sea ice thickness. He found that since 1958, Arctic ice cover has lost about two-thirds of its thickness, as averaged across the Arctic at the end of summer. Older ice has shrunk in area by almost 800,000 square miles (more than 2 million square kilometers). Today, 70 percent of the ice cover consists of ice that forms and melts within a single year, which scientists call seasonal ice.

Sea ice of any age is frozen ocean water. However, as sea ice survives through several melt seasons, its characteristics change. Multiyear ice is thicker, stronger and rougher than seasonal ice. It is much less salty than seasonal ice; Arctic explorers used it as drinking water. Satellite sensors observe enough of these differences that scientists can use spaceborne data to distinguish between the two types of ice.

Thinner, weaker seasonal ice is innately more vulnerable to weather than thick, multiyear ice. It can be pushed around more easily by wind, as happened in the summer of 2013. During that time, prevailing winds piled up the ice cover against coastlines, which made the ice cover thicker for months.

The ice's vulnerability may also be demonstrated by the increased variation in Arctic sea ice thickness and extent from year to year over the last decade. In the past, sea ice rarely melted in the Arctic Ocean. Each year, some multiyear ice flowed out of the ocean into the East Greenland Sea and melted there, and some ice grew thick enough to survive the melt season and become multiyear ice. As air temperatures in the polar regions have warmed in recent decades, however, large amounts of multiyear ice now melt within the Arctic Ocean itself. Far less seasonal ice now thickens enough over the winter to survive the summer. As a result, not only is there less ice overall, but the proportions of multiyear ice to seasonal ice have also changed in favor of the young ice.

Seasonal ice now grows to a depth of about six feet (two meters) in winter, and most of it melts in summer. That basic pattern is likely to continue, Kwok said. "The thickness and coverage in the Arctic are now dominated by the growth, melting and deformation of seasonal ice."

The increase in seasonal ice also means record-breaking changes in ice cover such as those of the 1990s and 2000s are likely to be less common, Kwok noted. In fact, there has not been a new record sea ice minimum since 2012, despite years of warm weather in the Arctic. "We've lost so much of the thick ice that changes in thickness are going to be slower due to the different behavior of this ice type," Kwok said.

Kwok used data from U.S. Navy submarine sonars from 1958 to 2000; satellite altimeters on NASA's ICESat and the European CryoSat-2, which span from 2003 to 2018; and scatterometer measurements from NASA's QuikSCAT and the European ASCAT from 1999 to 2017.

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Slow start to the season for melt in May so far. The updates will be more interesting as we get into mid-June. The next week looks pretty slow too except up in the Laptev where some warm air could start eating into the pack there and create meltponding.

The Beaufort looks a bit vulnerable this year, so if a dipole pattern can set up, then we could see a chance to make up some ground since the Beaufort/CAA region is always crucial for trying to go big in a melt season.

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  • 2 weeks later...
On 5/30/2024 at 2:38 PM, ORH_wxman said:

Slow start to the season for melt in May so far. The updates will be more interesting as we get into mid-June. The next week looks pretty slow too except up in the Laptev where some warm air could start eating into the pack there and create meltponding.

The Beaufort looks a bit vulnerable this year, so if a dipole pattern can set up, then we could see a chance to make up some ground since the Beaufort/CAA region is always crucial for trying to go big in a melt season.

Looks like we're getting that. Lots of surface darkening and blue melt ponds showing up in the past week on Worldview.

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Weird start to the melting season....the Beaufort is getting preconditioned and melting out quickly. It's the lowest since 2020 at this point, and 2020 was a big melt season. The only other two lower in the Beaufort at this point were 2012 and 2016, also huge melt seasons. Though 2008 was fairly close.

OTOH, the Chukchi and ESS are the slowest start we've seen post-2007. In fact, both have area higher than the 1980s mean at this point in June. The only other post-2007 years that started even close to that slow in Chukchi/ESS were 2008 and 2014. We'll see how these competing forces behave in the next 2-3 weeks.

Overall, ice area is currently 3rd highest in the post-2007 context....only 2009 and 2013 were higher at this point. I wouldn't predict that type of season though yet because of the Beaufort situation. All the slow melt seasons since 2007 had slow early melting in the Beaufort and this year does not. I suspect that is going to help eat into the Chukchi positive anomalies quickly over the next few weeks. 2008 which was mentioned above could give us a good clue. That year had pretty high area in Chukchi/ESS in June but the Beaufort was low. That year ended up close to the middle of the pack in the post-2007 context.

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29 minutes ago, ORH_wxman said:

Weird start to the melting season....the Beaufort is getting preconditioned and melting out quickly. It's the lowest since 2020 at this point, and 2020 was a big melt season. The only other two lower in the Beaufort at this point were 2012 and 2016, also huge melt seasons. Though 2008 was fairly close.

OTOH, the Chukchi and ESS are the slowest start we've seen post-2007. In fact, both have area higher than the 1980s mean at this point in June. The only other post-2007 years that started even close to that slow in Chukchi/ESS were 2008 and 2014. We'll see how these competing forces behave in the next 2-3 weeks.

Overall, ice area is currently 3rd highest in the post-2007 context....only 2009 and 2013 were higher at this point. I wouldn't predict that type of season though yet because of the Beaufort situation. All the slow melt seasons since 2007 had slow early melting in the Beaufort and this year does not. I suspect that is going to help eat into the Chukchi positive anomalies quickly over the next few weeks. 2008 which was mentioned above could give us a good clue. That year had pretty high area in Chukchi/ESS in June but the Beaufort was low. That year ended up close to the middle of the pack in the post-2007 context.

What is the supposed relationship between sea ice and mid latitude winter? I don't really use that and can't seem to recall...thanks.

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31 minutes ago, 40/70 Benchmark said:

What is the supposed relationship between sea ice and mid latitude winter? I don't really use that and can't seem to recall...thanks.

I haven't found a big relationship between the two. Granted, I haven't looked in years but previous studies were negligible. There was some weak (but statistically significant) relationship between the rate of ice gain in the fall and cold outbreaks....I know @Typhoon Tip and I discussed this many years ago.

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9 hours ago, ORH_wxman said:

I haven't found a big relationship between the two. Granted, I haven't looked in years but previous studies were negligible. There was some weak (but statistically significant) relationship between the rate of ice gain in the fall and cold outbreaks....I know @Typhoon Tip and I discussed this many years ago.

Correct 

… and correct. 

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This is a visual/graphical perspective for folks for each region. I am kind of surprised to see the Kara sea region holding a bit more ice than past seasons (at least of recent) for this time of year. One thing for sure that seems to be helping it out is the snow in the surrounding lands has not melted out yet so another visual of how snow impacts the overall health of the ice into summer time. Snow near the Chukchi/ ESS region also holding on a bit.

 https://cryospherecomputing.com/regional.html

Things may try to steady out a bit coming up here in the CAA and Beaufort regions maybe leading to less overall decline but that region is looking rather ragged.

Is the Labrador sea grouped in with CAA data?

Arctic-1.png

NOAA_Snowmap.png

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9 hours ago, so_whats_happening said:

This is a visual/graphical perspective for folks for each region. I am kind of surprised to see the Kara sea region holding a bit more ice than past seasons (at least of recent) for this time of year. One thing for sure that seems to be helping it out is the snow in the surrounding lands has not melted out yet so another visual of how snow impacts the overall health of the ice into summer time. Snow near the Chukchi/ ESS region also holding on a bit.

 https://cryospherecomputing.com/regional.html

Things may try to steady out a bit coming up here in the CAA and Beaufort regions maybe leading to less overall decline but that region is looking rather ragged.

Is the Labrador sea grouped in with CAA data?

Arctic-1.png

 

 

They keep the regions pretty tightly classified. Labrador is pretty much completely melted out....but the adjacent Baffin Region still has a lot of ice.

image.thumb.png.2c6f43031d7ab4609d03b2fb6a3ada43.png

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3 hours ago, ORH_wxman said:

 

They keep the regions pretty tightly classified. Labrador is pretty much completely melted out....but the adjacent Baffin Region still has a lot of ice.

image.thumb.png.2c6f43031d7ab4609d03b2fb6a3ada43.png

Thanks that is where I meant, Baffin Bay. For some reason that completely slipped my mind, appreciate the correction.

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  • 3 weeks later...

One more day until I’ll calculate my final SIA predictions but this year has potential to be a higher end melt season. We’re running close to years like 2020 and 2016 right now but still decently above 2012. Only inhibiting factor might be that the favorable melting pattern that we’ve seen the last 10-12 days or so is flipping to a better retention pattern for the ESS/Chuchki/Beaufort side which is often a key region to have high end melt seasons. 

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17 minutes ago, ORH_wxman said:

One more day until I’ll calculate my final SIA predictions but this year has potential to be a higher end melt season. We’re running close to years like 2020 and 2016 right now but still decently above 2012. Only inhibiting factor might be that the favorable melting pattern that we’ve seen the last 10-12 days or so is flipping to a better retention pattern for the ESS/Chuchki/Beaufort side which is often a key region to have high end melt seasons. 

Interesting...  because I've noted an early bias toward a quasi +AO rest state.   I mean not huge, as that would imply.  

I'm not sure what thresholds are like prior to August 8th -10th ... which is the hemisphere's solar maximum.  Post that, we're dimming rather fast up there.  But prior to, it might be that +AOs have better retention capacity after early August, and that the +AO we've seen ( low amplitude ) is just not enough?   hm

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Looks like the 2012 record low extent could be safe for another year. Latest CPOM UCL forecast for September average extent is around 4.1 million sq km. This forecast has been close every year over the last decade. It’s a statistical model based on May melt ponding. While their full forecast discussion isn’t available yet in the link, they probably observed the melt ponding back in May to be less extensive than 2020 and 2012. 

2024…..4.10…Forecast

2023…..4.37

2022….4.87

2021……4.92

2020……3.92…2nd lowest

2019……4.32

2018…...4.71

2017……4.87

2016……4.72

2015…..4.63

2014…..5.28

2013…..5.35

2012…..3.60….lowest

2011……4.61

2010…..4.90

2009….5.36

2008….4.67

2007…..4.28

 

https://www.arcus.org/files/sio/main/June_2024_SIO_Report_Corrected.pdf

 

 

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You can see the regions that have not had strong ice melt from how the 500mb pattern has setup. The region of the Beaufort was already rather worrisome as we left winter ~1.5 meter thick ice as we were heading into spring spells for bad results in the summer. Strange to see the Kara sea holding up rather well still.

I know it is the Navy model some folks do not like but still believe it shows how things are going relatively well. 

arcticictn_nowcast_anim30d.gif

compday.3M3SV67FbO.gif

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4 hours ago, bluewave said:

Looks like the 2012 record low extent could be safe for another year. Latest CPOM UCL forecast for September average extent is around 4.1 million sq km. This forecast has been close every year over the last decade. It’s a statistical model based on May melt ponding. While their full forecast discussion isn’t available yet in the link, they probably observed the melt ponding back in May to be less extensive than 2020 and 2012. 

2024…..4.10…Forecast

2023…..4.37

2022….4.87

2021……4.92

2020……3.92…2nd lowest

2019……4.32

2018…...4.71

2017……4.87

2016……4.72

2015…..4.63

2014…..5.28

2013…..5.35

2012…..3.60….lowest

2011……4.61

2010…..4.90

2009….5.36

2008….4.67

2007…..4.28

 

https://www.arcus.org/files/sio/main/June_2024_SIO_Report_Corrected.pdf

 

 

I could see them revising lower when the June data is in. Def had an acceleration in positive melt pond anomaly in June. I agree that 2012 is still prob out of reach though. 

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I'm a little intrigued at the integrity of the PV as we are passing into the heart of summer. 

There's a couple of competing geophysical aspects going on though.  

1   That observation above - I have found - is also related to the d(cryo) toward the end of Aug+   The presence of a stronger than normal summer PV structure over the longer term mean of the anomalies, tends to precede a more rapid land replacement/ happening earlier. Sea ice comes along with that rate of change.

2  Climate change is unfortunately "getting in the way" of this type of correlation.  It's not abundantly clear whether we are over thresholds too far to where the previous climate mode's correlations have necessarily broken completely down. I don't think so ... buuut  -

I'll be particularly interested in the rapidity in which the late summer and autumn cryospheric recovery is going ... *IF* this mid summer PV integrity remains robust. 

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2 hours ago, Typhoon Tip said:

I'm a little intrigued at the integrity of the PV as we are passing into the heart of summer. 

There's a couple of competing geophysical aspects going on though.  

1   That observation above - I have found - is also related to the d(cryo) toward the end of Aug+   The presence of a stronger than normal summer PV structure over the longer term mean of the anomalies, tends to precede a more rapid land replacement/ happening earlier. Sea ice comes along with that rate of change.

2  Climate change is unfortunately "getting in the way" of this type of correlation.  It's not abundantly clear whether we are over thresholds too far to where the previous climate mode's correlations have necessarily broken completely down. I don't think so ... buuut  -

I'll be particularly interested in the rapidity in which the late summer and autumn cryospheric recovery is going ... *IF* this mid summer PV integrity remains robust. 

Yeah, it’s one of the reasons that the 2012 extent minimum record has endured for so long. These strong reverse dipole summer patterns have become more frequent during the post 2007-2012 record dipole era. The other has been the much thinner pack making new records more difficult to achieve. Plus the lack of major May preconditioning like we saw in 2012 and 2020. Judah Cohen recently commented on this more favorable pattern for sea ice retention. 

IMG_0440.png.698433f7d1d86b45ae47440095ad423e.png

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

I do want to once again conclude with the PCHs this summer. I really don’t know what to make of the PCH plot as shown in Figure 11 once again this week, which looks very strange to me.  To highlight how bizarre it has been I include in Figure iii the same plot from one year ago.  This plot of episodic  warming or what I like to desribe as “pulsing red”of tropospheric PCHs with cold stratospehric PCHs that occasionally descend to the surface makes much more physical sense to me.  Larger amounts of greeenhouse gases in the polar stratosphere should result in cooling of the polar stratosphere punctuated by warming when upwelling wave energy is absorbed and thus warms the polar stratosphere but limited to the winter months but in particular January and February.

The warm PCHs in the stratosphere I assume have the potential to descend to the surface and increase high latitude blocking resutling in cooler temperatures in the Eastern US and Northern Europe, yet for the most part this has not happened and it is looking less likely to ocuur for a significant aount of time this summer.

This pattern or low pressure over the Central Arctic surrounded by high pressure across the mid-latitudes, which results in a quasi zonal flow is favorable for preserving Arctic sea ice.  We can see in Figure iv that sea ice extent is comparable to the best two summers and I would expect the trends to continue.  Arctic sea ice is tracking below normal and should continue right through the September minimum. However, the possibility of a new record low sea ice minimum is looking less and less likely.

IMG_0439.gif.119e081363b1874aedbb0ede2891d91c.gif
IMG_0438.thumb.png.1fdbab34e0f9721f547e5669e55ee767.png

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17 hours ago, Typhoon Tip said:

I'm a little intrigued at the integrity of the PV as we are passing into the heart of summer. 

There's a couple of competing geophysical aspects going on though.  

1   That observation above - I have found - is also related to the d(cryo) toward the end of Aug+   The presence of a stronger than normal summer PV structure over the longer term mean of the anomalies, tends to precede a more rapid land replacement/ happening earlier. Sea ice comes along with that rate of change.

2  Climate change is unfortunately "getting in the way" of this type of correlation.  It's not abundantly clear whether we are over thresholds too far to where the previous climate mode's correlations have necessarily broken completely down. I don't think so ... buuut  -

I'll be particularly interested in the rapidity in which the late summer and autumn cryospheric recovery is going ... *IF* this mid summer PV integrity remains robust. 

Could you elaborate on the strong PV. Haven't been following since last winter to be honest. Is there any relation to the current melt season which has accelerated from slow to fast in the past couple of weeks or are they completely (Doesn't appear to be).

nsidc-area-arctic.png

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23 hours ago, chubbs said:

Could you elaborate on the strong PV. Haven't been following since last winter to be honest. Is there any relation to the current melt season which has accelerated from slow to fast in the past couple of weeks or are they completely (Doesn't appear to be).

nsidc-area-arctic.png

This presentation from 2014 showed how some of the climate models were forecasting these lower summer pressures over the Arctic. This has been the pattern we have seen since 2013. Much different from the 2007 to 2012 era. It’s one of the reasons that the rate of sea ice decline slowed during 2013 to 2023 relative to 2007 to 2012.

 


IMG_0440.png.63bd06dbeaf21862ad451745b028fd55.png
 

IMG_0469.jpeg.a33fd11f0f8703f301fa00ea7ff2cee4.jpeg

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