Sea Ice News: rapid re-refreeze of the Arctic in October, 40% faster than normal

From NSIDC: A rapid freeze-up

Arctic sea ice extent increased rapidly through October, as is typical this time of year. Large areas of open water were still present in the Beaufort and Chukchi seas at the end of the month. The open water contributed to unusually warm conditions along the coast of Siberia and in the Beaufort and Chukchi seas.

map from space showing sea ice extent, continents

Figure 1. Arctic sea ice extent for October 2011 was 7.10 million square kilometers (2.74 million square miles). The magenta line shows the 1979 to 2000 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. —Credit: National Snow and Ice Data CenterHigh-resolution image

Overview of conditions

Average ice extent for October 2011 was 7.10 million square kilometers (2.74 million square miles), 2.19 million square kilometers (846,000 square miles) below the 1979 to 2000 average. This was 330,000 square kilometers (127,000 square miles) above the average for October 2007, the lowest extent in the satellite record for that month. By the end of October, ice extent remained below the 1979 to 2000 average in the Beaufort and Chukchi seas and in the Barents and Kara seas. Extent was near average in the East Greenland Sea. New ice growth has closed both the Northwest Passage and the Northern Sea Route.

graph with months on x axis and extent on y axis

Figure 2. The graph above shows daily Arctic sea ice extent as of October 31, 2011, along with the lowest ice extents in the preceding decades, 1984 and 1999. 2011 is shown in light blue. 2007, the year with the record low minimum, is dashed green. Purple indicates 1999 and light green shows 1984. The gray area around the average line shows the two standard deviation range of the data. Sea Ice Index data. —Credit: National Snow and Ice Data Center

High-resolution image

Conditions in context

Arctic sea ice extent increased rapidly through October. Ice extent during October 2011 increased at an average rate of 114,900 square kilometers (44,360 square miles) per day, about 40% faster than the average growth rate for October 1979 to 2000. On October 30, Arctic sea ice extent was 8.41 million square kilometers (3.25 million square miles), 226,000 square kilometers (87,300 square miles) more than the ice extent on October 30, 2007, the lowest extent on that date in the satellite record.

During the month of October, the freeze-up that begins in September kicks into high gear. The rate of freeze-up depends on several factors including the atmospheric conditions and the amount of heat in the ocean that was accumulated during the summer. However, each decade, the October extent has started from a lower and lower point, with the record low extent during the 1980s (1984) substantially higher than the record low extent during the 1990s (1999), which in turn is substantially higher than the record low extent during the 2000s (2007).

graph with months on x axis and extent on y axis

Figure 3. Monthly October ice extent for 1979 to 2011 shows a decline of 6.6% per decade.

—Credit: National Snow and Ice Data Center

High-resolution image

October 2011 compared to past years

Ice extent for October 2011 was the second lowest in the satellite record for the month, behind 2007. The linear rate of decline for October over the satellite record is now -61,700 square kilometers (-23,800 square miles) per year, or -6.6% per decade relative to the 1979 to 2000 average.

graph with months on x axis and extent on y axis

Figure 4. This map of air temperature anomalies at the 925 hPa level (approximately 3000 feet) for October 2011 shows unusually high temperatures over most of the Arctic Ocean (yellow shading) and unusually low temperatures over the eastern Canadian Arctic Archipelago and Greenland (blue shading).

—Credit: National Snow and Ice Data Center

High-resolution image

Atmospheric conditions

In recent years, low sea ice extent in the summer has been linked to unusually warm temperatures at the surface of the Arctic Ocean in the fall. This pattern appeared yet again this fall.

Air temperatures over most of the Arctic Ocean for October 2011 ranged from 1 to 4 degrees Celsius (1.8 to 7.2 degrees Fahrenheit) above average, measured at the 925 millibar level, about 1,000 meters or 3,000 feet above the surface. However, over the eastern Canadian Arctic and Greenland, temperatures were as much as 3 degrees Celsius (5.4 degrees Fahrenheit) below average.

These temperature anomalies in part reflect a pattern of above-average sea level pressure centered over the northern Beaufort Sea, and lower than average sea level pressure extending across northern Eurasia. This pattern is linked to persistence of the positive phase of the Arctic Oscillation through most of the month. These pressure and temperature anomalies tend to bring in heat from the south, warming the Eurasian coast, but they also lead to cold northerly winds over the eastern Canadian Arctic Archipelago. However, along the Siberian coast and in the Beaufort and Chukchi seas, warmer temperatures came primarily from the remaining areas of open water in the region, as heat escaped from the water. These effects are more strongly apparent in the surface air temperatures: average October temperatures in the region were 5 to 8 degrees Celsius (9.0 to 14.4 degrees Fahrenheit) above average.

graph with months on x axis and extent on y axis

Figure 5. The top panel of this figure shows the number of open water days for the approximate 75 kilometer (46.6 mi) coastal zone along the Beaufort Sea (data for each year and linear trend). The bottom panel shows the average annual coastal erosion rate for three periods, 1979-1999, 2000-2007 and 2008-2009.

—Credit: NSIDC courtesy Irina Overeem, CU Boulder

High-resolution image

Sea ice loss and coastal erosion

Declining sea ice in the Arctic has led to increasing erosion rates along the coast of the Beaufort Sea over the past fifty years, according to a new study led by Irina Overeem of the University of Colorado Institute for Arctic and Alpine Research (INSTAAR). Their study used a wave model driven by sea ice position and wind data.As the period of open water on the coast of the Beaufort Sea has increased, so has the mean annual erosion rate, the study showed. From 1979 to 1999, the average erosion rate was 8.5 meters (27.9 feet) per year. The average rate over the period 2000 to 2007 was 13.6 meters (44.6 feet) per year, while the rate for the last two years of the record, 2008 to 2009, was 14.4 meters (47.2 feet) per year.

With a longer open water season, ocean water warms more and waves eat away at the coastline. The sediments comprising the coastal bluffs are locked together by permafrost—hard frozen ground with a concrete-like consistency. As the waves lap at the permafrost, they also help to thaw it, making the ground much more vulnerable to erosion.

Further Reading

Overeem, I., R.S. Anderson, C.W. Wobus, G.D. Clow, F.E. Urban, and N. Matell. 2011: Sea ice loss enhances wave action at the Arctic coast. Geophysical Research Letters, 38, L17503, doi:10.1029/2011GL048681.

Serreze, M.C., and R.G. Barry. 2011: Processes and impacts of Arctic Amplification: A research synthesis. Global and Planetary Change, 77,85-96.

Advertisements

  Subscribe  
newest oldest most voted
Notify of
dp

The ice extent at this time of year is most famous not for what it is but for when it is. We’re within days of every other data point. I don’t see what the worry is. The rate of change, regardless of the when, is rather constant year after year. What I see is the start/stop of the seasons is variable. So? Why the hell wouldn’t it be variable?
Additionally the absolute area of the ice extent after sea currents, wind, and climate get finished with it changes continually. Why wouldn’t it? What is missing is a trend that is walking off the charts. It just isn’t there. The recorded history is short. We don’t know what the situation will be or should be. We don’t understand it. What we do know with laser accuracy is that what the current extent is is exactly what the current context demands it be. And damn if the extent isn’t what it is as a result. Somebody post a note when you really understand the changing complexity of the context.
This annual variability and drift is what I consider to be the bracket limits of what the current climate allows (climate being the framework within which weather happens). You can take this to the bank – it will be different next year and while anyone can guess what it will be, none of you knows what it will be. If you do, place a bet equal to or in excess of your next 12 paychecks. Anyone think Team BEST is up to it?

MikeN

Of course ice growth was faster than normal, there was more water available to freeze because of the high melt in August and September.

Did anyone send Al Gore a link to this? #justaskin

wayne

All of Beaufort Sea’s coasts eroding away at 47 feet per year? Don’t you see the bright red bars NSIDC has supplied? Enjoying being warm tonight in your home, huh? Well it’s all your damn fault that our world is washing away!!! ☺
Knew they would get something like that in there somewhere. Why is it always at the bottom? And, anyone have some confirmation of this from some sane locals up north? Sorry, but I so distrust any such information from any such government science site anymore. My trust is gone.

Bill Jamison

That chart in Figure 2 doesn’t show data through Oct 31, more like Oct 15th. The rapid increase isn’t really shown.
Nice to see the ice growing quickly this winter. It sure looks like it’s going to be a cold one if November is any indication. We’ve been setting records down here in San Diego this weekend including lowest high temp today.

Bill Jamison

The chart in Figure 2 is date Oct 18th.
Are they hiding the incline? 😀

Jean S

There seems to be a mistake in Figure 1 (NSIDC/Oct. sea ice extend). According to it, Gulf of Finland is frozen. It certainly isn’t and it does not usually freeze completely until, say, late January. In some mild winters it does not freeze completely at all.

Günther Kirschbaum

Of course there was a relatively rapid refreeze. If you have a record low at the end of the melting season there is much more sea surface to refreeze.
No mention of global sea ice area about to hit the lowest max on record?
REPLY: Gosh Günther (or should I say “Neven”?), you really are a pathetic whiner aren’t you? I post the NSIDC report, and you blame me (rather than them) for not posting an obscure graph that I’ve never seen and few people have heard of and actually hasn’t reached the peak yet. If there’s news when it does reach the peak, I’m sure both NSIDC and I would mention it.
Of course previously, you were whining that I didn’t post something from NSIDC:

Günther Kirschbaum
Submitted on 2010/12/06 at 2:17 pm
NSIDC has just updated. Lots of interesting stuff that Anthony Watts won’t cover. His analysis consists of copypasting a few graphs and reporting ‘recovery’ when the trend line is over the others a bit.

Now you are whining that I did post NSIDC, but didn’t include something they didn’t. LOL!
This is a new low for you Gunther, and quite frankly I’m tired of your constant barrage of attacks. I’m still waiting for an apology for your last baseless accusation, where you accused me of leaking somebody’s personal info when in fact they posted it themselves as part of a movie promotion. Since I’m not likely to ever get an apology due to your overbearing, condescending, and hateful nature, and because your contributions here are nothing but off topic snark, I’m giving you the honor of permanent troll-bin status. Be as upset as you wish. – Anthony

Ralph B

A big summer melt and resultant big “re-freeze” act like a radiator releasing more heat out to space. The latent heat released during the phase change from liquid to solid at these late times of year goes where…straight out to space.

wayne Job

The loss of ice at the North Pole is a worrying sign, my understanding of an ice age is a 160 metre drop in sea levels and an ice free summer at the pole. The cold and ice move into the north of America and the southern part of south America , Africa and Australia.
Ice loss it would seem is a colding problem and not a warming one. It would seem people colonized the Arctic regions and walked to the American continent in ice ages. The last thing this world needs is cold, it is bloody cold enough already. Double CO2 and add 4C to the temperate zones we would have paradise.

Byz

I wonder if the warmer conditions in Siberia have contributed to larger than average snowfall in Asia.
This could be a positive feedback loop so that less ice causes more snow (due to increased evaporation) and this then causes lower latitudes of asia to get snow they normally wouldn’t, thus reflecting incoming sunlight 😮

Gator

Why are we still using a 1979 to 2000 ‘average’? This is absurdly stupid.

H.R.

I’m not seeing “death spiral” here. 127,000 square miles added in a month is nothing to sneeze at.

Both the winter maximum and summer minimum are falling, but the summer melt minimum is falling faster than the winter maximum for Arctic sea ice.
Therefore it is inevitable that the autum re-freeze will be faster than in the past because the absolute difference between winter and summer extents is increasing.

LazyTeenager

Gator on November 7, 2011 at 2:53 am said:
Why are we still using a 1979 to 2000 ‘average’? This is absurdly stupid.
———
Because a fixed baseline is need for comparison purposes. If you change the averaging period the baseline changes and you don’t want that if you want an honest comparison,
Or maybe you do if you want to deceive people into believing no change is happening when it actually is.

LazyTeenager

Wayne says
Knew they would get something like that in there somewhere. Why is it always at the bottom? And, anyone have some confirmation of this from some sane locals up north? Sorry, but I so distrust any such information from any such government science site anymore. My trust is gone.
———
Maybe you’ll trust Exxon or BP then. They have been doing deals with the Russians to gain access to the Arctic.
Exxon won and paid 15% of the company on the assumption that the Arctic is becoming ice free.
So who do I believe? You skeptic guys or BP and Exxon? Such a hard question to answer.

David Banks

What I am noticing is the large amount of snow already on the ground compared to 2007. I look at the sea ice page daily and snow started early and covers a lot more ground than 2007. That is a lot of reflected sunlight and heat.

Archonix

LazyTeenager says:
November 7, 2011 at 4:26 am
Wait, I thought they were paying us to be sceptical and deny things so they could make a profit. Now you suddenly want to believe everything they say? What’s up with that?

Gator

“Because a fixed baseline is need for comparison purposes. If you change the averaging period the baseline changes and you don’t want that if you want an honest comparison,
Or maybe you do if you want to deceive people into believing no change is happening when it actually is,”
Thanks for the reply LT, but an ‘average’ utilizes the data from all years, unless you are picking cherries. What would happen to the average if we were to include all years? The curent data would look very avergae. And the alarmists will not have that.

Bloke down the pub

One thing to take into consideration when looking at sea ice extent is the limits imposed by the coastline. If the prevailing wind blows the ice that has formed out into open water, the sea ice extent will increase. The same temperatures and amount of ice, but with an onshore wind, and the extent will not increase. This is why I suggested in tips a while back that a graphic showing wind strength and direction in the Arctic could be a useful addition to the sea ice ref page.

Gator

LT says…
“Exxon won and paid 15% of the company on the assumption that the Arctic is becoming ice free.”
No, it’s like what Wille Sutton said when asked why he robs banks, “Because that’s where the money is”.
Massive amounts of oil are found in the Arctic, and that’s why they want to drill there. It’s where the money is. Noone in their right mind believes the Arctic is about to be ice free.
Take a logic class, or three.

RACookPE1978

Ah, the NSIDC’s decade’s long fascination with the “Arctic Death Spiral” of ice-loss positive feedbacks.
Now, just how is that supposed to happen? Their assumed “physics” doesn’t match the world’s actual geography up there.

Jim

Check this out this guy is in once a month with this garbage.
]
http://pressrepublican.com/0205_columns/x867534717/Arctic-Climate-changing-fast

Jon

Were the October temperatures unusually low in the Eastern Canadian Arctic? The average temperature in Pond Inlet for October 2011 was -9.0°c … the October average for that location from 1979 to present is -11.0°c (S.D.3.1). Pond Inlet is located at the northern end of Baffin Island (72° 41′ 22″N 77° 58′ 08″W).
ref: http://www.climate.weatheroffice.gc.ca/climateData/dailydata_e.html?Prov=NU&StationID=47488&timeframe=2&Month=10&Year=2011&cmdB1=Go&Day=6

@- Gator says: November 7, 2011 at 5:16 am
“Thanks for the reply LT, but an ‘average’ utilizes the data from all years, unless you are picking cherries. What would happen to the average if we were to include all years? The curent data would look very avergae. And the alarmists will not have that.”
If you changed the average every year by including that year within it then the ‘average’ would fall as the ice extent dwindles and as a comparison it might look less dramatic, but it would no longer be a comparison with a fixed value but with a moving parameter which fell with the value you are wanting to compare. Not ideal even if less ‘alarmist’.
However whatever ‘tricks’ you play with averages it would NOT make the percentage decrease per year of ice extent in ALL months change, and that IS alarming.

Nostrumdammit

“Exxon won and paid 15% of the company on the assumption that the Arctic is becoming ice free.”
Lazy Teenager….. I’m going to indulge you in your choice of nom de guerre and provide you with a little bit of information. Here…..
http://online.wsj.com/article/SB10001424053111904199404576540350519892620.html
read the article.
Get back to us when you discover any mention of the Arctic becoming ice free. Take time to understand the profitability of exploration and excploitation of a much in demand resource such as petroleum – even in very cold [ icy ] conditions. You might want to ask your parents to help you with some concepts such as research, evidence based decisions, and the trustability of agenda poltics.

J Bowers

More open water releasing heat and moisture into the atmosphere leading to rapid refreeze. I wonder how come there’s more open water? Hmmmm…..

Gator

Hey Izen! GPA’s are not static. 1979 to 2000 average is cherry picking. Period.

Grumpy Old Man

For Gawd’s sake people, the only thing constant about this planet is change. The climate is cyclical, it goes through warming and cooling stages. Does mankind affect it? Of course but it’s the extent that is arguable. Are we all going to die? Yep, guaranteed. Is the planet going to burn up? Yep, that’s pretty much guaranteed too – when Sol reaches it’s end of days. Right now we are in an interglacial period and there will be WARMING and we will see ice melt and guess what? Mankind is adding to the effect by such a miniscule amount it just doesn’t matter. All you Al Gore acolytes need to take a basic science class and try to wrap your brains around the facts.

Gail Combs

The Article says:
“This map of air temperature anomalies at the 925 hPa level (approximately 3000 feet) for October 2011 shows unusually high temperatures over most of the Arctic Ocean (yellow shading) and unusually low temperatures over the eastern Canadian Arctic Archipelago and Greenland (blue shading)…..”
Where the heck did they get the temperature measurements from? As I recall the global avg temp do not actually use temps in the Arctic but smear lower latitude measurements into the area.
Are these REAL temperatures are model generated temperatures???
GISS Swiss Cheese: http://wattsupwiththat.com/2010/07/26/giss-swiss-cheese/
GISS Deletes Arctic And Southern Ocean Sea Surface Temperature Data: http://wattsupwiththat.com/2010/05/31/giss-deletes-arctic-and-southern-ocean-sea-surface-temperature-data/
DMI: http://wattsupwiththat.com/2010/07/28/giss-arctic-vs-dmi-arctic-differences-in-method/

…As has been well covered by Steve Goddard on WUWT, the “interpretation” of Arctic conditions by NASA/GISS is based on astonishingly little data north of 80 degrees latitude, which is to say no data at all…..

More Soylent Green!

Obviously, the warming is worse than we thought. Imagine how little ice we would have if it wasn’t so damned warm! Curse you, carbon dioxide!

Pamela Gray

So basically, what the alarmist “run-for-your-lives-the-ice-is-melting” head guy is saying is that weather pattern variations appear to be driving the ice melt patterns. And this has to do with global warming how? He must be up late at night, his head pounding with that question, trying to come up with the “global warming is the key” report without it being laughable.

Gneiss

H.R. writes,
“I’m not seeing “death spiral” here. 127,000 square miles added in a month is nothing to sneeze at.”
You’re confusing changing seasons with climate change. Ice area is growing rapidly right now because it’s winter up there, and at the end of the near-record summer melt, there was a lot of open water to freeze. The NSIDC graph compares Octobers with Octobers instead of today with yesterday, and the climate change stands out strongly there. This October had the second-lowest measured average, and is well below the trend of linear decline.

Gneiss

Gator writes,
“Thanks for the reply LT, but an ‘average’ utilizes the data from all years, unless you are picking cherries.”
If you look at any climatology data, including hundreds of examples on this site, you’ll see that they almost always use a baseline comparison period, and not the “data from all years.” For example, see Roy Spencer’s post about October mean temperatures just a few days ago.
“What would happen to the average if we were to include all years?”
Then the anomalies would all change with every new data point. Think about it, would that make sense?

Pamela Gray

J Bowers, did you not read the entire article? It clearly says what is likely to be the cause of open water. Read it again. What has yet to be done by IPCC, BCDD, and EFGG is to mechanize a relationship between well known weather pattern variations (those that occur frequently and those that occur less frequently) with a CO2 driver strong enough to overcome natural drivers and sustain an unusual pattern.
I cannot take alarmism seriously until that mechansim can be shown and well-reasoned to be the culprit.

Gneiss

Pamela Gray writes,
“So basically, what the alarmist “run-for-your-lives-the-ice-is-melting” head guy is saying is that weather pattern variations appear to be driving the ice melt patterns. And this has to do with global warming how?”
Weather and climate. Weather drives the short-term variations, as NSIDC carefully describes. Climate drives the 32-year decline, which they show in their graph. Or, in their own words,
“During the month of October, the freeze-up that begins in September kicks into high gear. The rate of freeze-up depends on several factors including the atmospheric conditions and the amount of heat in the ocean that was accumulated during the summer. However, each decade, the October extent has started from a lower and lower point, with the record low extent during the 1980s (1984) substantially higher than the record low extent during the 1990s (1999),which in turn is substantially higher than the record low extent during the 2000s (2007).”

More Soylent Green!

LazyTeenager says:
November 7, 2011 at 4:26 am
Wayne says
Knew they would get something like that in there somewhere. Why is it always at the bottom? And, anyone have some confirmation of this from some sane locals up north? Sorry, but I so distrust any such information from any such government science site anymore. My trust is gone.
———
Maybe you’ll trust Exxon or BP then. They have been doing deals with the Russians to gain access to the Arctic.
Exxon won and paid 15% of the company on the assumption that the Arctic is becoming ice free.
So who do I believe? You skeptic guys or BP and Exxon? Such a hard question to answer.

Did Exxon or BP release data on the ice refreezing? Did I miss that announcement, or are you just being an ass again?

Jon

Gneiss … the baseline period from 1979-2000 represents only 21 years of data. Do you feel that this is statistically representative of the population mean?

Jackstraw

LazyTeenager says:”Exxon won and paid 15% of the company on the assumption that the Arctic is becoming ice free.”
Arctic offshore exploration is primarily conducted in the winter. Ice Islands are formed by pumping seawater on top of the ice and allowing it to freeze, until the ice is so thick that it sits on the bottom.
Does that sound like Exxon is betting on global warming?
Do your homework LazyTeenager

John from CA

30 day animation — lets see if Hudson Bay freezes on schedule this year. Its been running about 2 weeks behind which appears to be what all the hubbub is about. Comparing Octobers seems misleading.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticice_nowcast_anim30d.gif

Gneiss

Jon, a climatology baseline is not meant to represent a “population mean.” It is meant to give a numerical level for comparison. Scientists usually are careful to explain what their baseline is, and other scientists can read and understand that. Confusion sometimes arises when non-scientists see graphs or numbers, and think the use of a baseline must somehow be tricky. It’s not.
Ideally, you’d want to choose as baseline an earlier period when the trend was reasonably flat. We don’t have such a period beyond a few years in the ice record, but 1979-2000 comes closer to this ideal than, say, 1979-2010 would. The most dramatic feature of sea ice time series has been their steeper than linear decline after about 2000. That decline would have exactly the same steepness no matter what baseline you chose.

Hey Gneiss! I was a climatology major for a time, geology is my background, so I am more than familiar with the ways data have been displayed. But that does not make it right.
Batting averages, grade point averages, temperature averages, etc… are judging current performance against all known relevant data. This is how an honest assessment is made. However, if you want people to believe that a certain period is ‘normal’ or ‘average’, you just start speaking in those terms and pretty soon it is established ‘fact’. Orwell warned of this.

Gneiss

gator69, I have a hard time seeing how this statement,
“Hey Gneiss! I was a climatology major for a time”
fits with this one,
“Batting averages, grade point averages, temperature averages, etc… are judging current performance against all known relevant data. This is how an honest assessment is made.”
Have you really looked at climatology data? Have you tried applying your idea that anomalies should be calculated from “all known relevant data” to real time series that are constantly changing?
In any event the decline graphed above is real, and does depend in any way whatsoever on choice of baseline. Using a more recent (lower-ice) baseline won’t do anything to hide the decline.

[snip – stop using this blog to promote your pet theories – Anthony]

“fits with this one,”
Hey Gneiss! Yes we see you have issues deprogramming.
If you want a ‘baseline’, then have one. It sounds more like someone needs a BSline. But if you really want an ‘average’, and we are observing changes in sea ice, then we need to include all years. Anything else is stupid, dishonest, or both.

Jon

Gneiss … we know very little about historical fluctuations in Arctic ice cover … what I am trying to say is that the baseline does not really tell us anything … other than there has been a decrease in ice cover over the short term. We know nothing with respect to the real “mean” and associated variance.

dp says ice is “famous for when it is”
This is something that’s always bothered me. The impression is always given that ice is missing but as dp correctly notes, regions with missing ice at this time of year are a function of it forming a few days later than the mean. For example, the Laptev sea ice this year formed late but could only be considered missing or in decline if you stop time (since it is now totally iced over).
Calling ice in decline when it is still forming strikes me as just a little bit dishonest. Untill the maximum extent is reached, the worst you can really say is that ice is late.
I guess telling everyone that ice is a few days late doesn’t have the same scare as ice is declining or missing.

Eric

I am in the group that doesn’t agree with the 1979-2000 average as a baseline…
Every AGW promoter site/post/research states that you must have at least 30 years worth of data to show a climatic “trend” or shift. We now have 30 years worth of satellite ice data (1979-2009), why is this not now the baseline by which future years are measured?
21 years of data makes no sense what so ever as a “baseline”…

G. Karst

There is far too much sea ice in the Arctic (7.1 million km2). This is a constant reminder, that we are still embedded, within the current ICE AGE. Why do some people think that an ice age is a good thing (Izen?). Ice ages are a curse for the planet.
I once thought, that I might witness, the end of the current ice age, with the removal of summer sea ice from the Arctic. Now, I see that it was just a warmist pipe-dream. Oh Well, I did get to see the first man walk on the moon! GK

paddylol

Gneiss:
“Weather and climate. Weather drives the short-term variations, as NSIDC carefully describes. Climate drives the 32-year decline, which they show in their graph.”
Climate drives nothing. It is a historical compendium of weather data to determine trends over time.