Now we start the slow slide into the Arctic Ice Minimum, likely sometime in September.
It is important to point out that there’s a lot of ice up there, and as illustrated by the images below, the losses at ICEmax are at the periphery, not at the core.
click to enlarge
What I find curious is the fact that NSDIC’s opening statement (below) in the press release has these words: “Arctic sea ice extent” but if you look at the NSIDC provided plot above, you’ll note that they include normal lines (in orange) for areas that are outside of the Arctic circle. While perhaps a small point, it does speak to accuracy in reporting. For example, I really don’t see how sea ice off the north coast of Newfoundland can be considered “Arctic” when it doesn’t even come close to being within the Arctic Circle.
[Update: Dr. Walt Meier of NSIDC in an email agrees that the orange boundaries are “somewhat arbitrary” and has agreed to explore a “what if” question for me. I hope to have a plot from him using Arctic circle as a boundary in a couple of weeks to see if there is any significant difference – Anthony]
It’s also important to note that this NSDIC claim only represents data from a 30 year satellite record, not the all time ice record, which is spotty and incomplete. From historical anecdotes, it appears the Arctic has gone through periods of reduced ice in the past. While NSIDC claims the maximum to be a tie with the 2006-2007 period on their plot (see their press release below), I’ll point out that NANSEN’s plot, using the same SSMI sensor platform, shows it nowhere near the 2007 value at present, though there was an intersection in the month of February:
In fact, NSIDC claims the maximum was reached on March 7th, but as we see in the NANSEN plot above, the ice continues to grow as late as 3/23 when that plot was produced. This discrepancy between two organizations that use the SSMI data is curious. However, the JAXA AMSRE data does seem to support NSIDC’s claim.
More live plots are available on the WUWT Sea Ice Page
======================================================================
Here’s NSIDC’s announcement:
Annual maximum ice extent reached
Arctic sea ice extent appeared to reach its maximum extent for the year on March 7, marking the beginning of the melt season. This year’s maximum tied for the lowest in the satellite record. NSIDC will release a detailed analysis of 2010 to 2011 winter sea ice conditions during the second week of April.
Figure 1. Arctic sea ice extent on March 7 was 14.64 million square kilometers (5.65 million square miles). The orange line shows the 1979 to 2000 median extent for that day. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
—Credit: National Snow and Ice Data Center
Overview of conditions
On March 7, 2011, Arctic sea ice likely reached its maximum extent for the year, at 14.64 million square kilometers (5.65 million square miles). The maximum extent was 1.2 million square kilometers (471,000 square miles) below the 1979 to 2000 average of 15.86 million square kilometers (6.12 million square miles), and equal (within 0.1%) to 2006 for the lowest maximum extent in the satellite record.
Figure 2. The graph above shows daily Arctic sea ice extent as of March 22, 2011, along with daily ice extents for 2006, which had the previous lowest maximum extent, and 2007, the year with the lowest minimum extent in September. Light blue indicates 2011, green shows 2007, light green shows 2006, and dark gray shows the 1979 to 2000 average. 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
Conditions in context
As of March 22, ice extent has declined for five straight days. However there is still a chance that the ice extent could expand again. Sea ice extent in February and March tends to be quite variable, because ice near the edge is thin and often quite dispersed. The thin ice is highly sensitive to weather, moving or melting quickly in response to changing winds and temperatures, and it often oscillates near the maximum extent for several days or weeks, as it has done this year.
Since the start of the satellite record in 1979, the maximum Arctic sea ice extent has occurred as early as February 18 and as late as March 31, with an average date of March 6.
@ur momisugly Mike Lorrey says: March 24, 2011 at 9:49 pm “Here’s an idea: get the raw sensor data from the satellite and do our own analysis…”
You might be interested in this:
http://www.skepticalscience.com/Primer-Tropospheric-temperature-measurement-Satellite.html
A question for the moderator. Why is it I git snipped if I say someone is a denier while this is permitted?
” Jer0me says: March 24, 2011 at 8:16 pm ….
They really deserve the title ‘ecotards’ I’m afraid.”
It is your blog and you have the right to moderate it as you see fit. I am just curious.
The ice extent is completely within a reasonable explanation that centers on ENSO-warmed waters that were sent there, as well as AO parameters that moved ice and especially ice edges around. I see no reason to add CO2 affects to ice area or extent. Natural variability, both from oceanic and atmospheric sources, explains it well enough.
Until we get oceanic and atmospheric conditions that historically lead to more ice building in depth beyond its current edge, and staying through the melt season, yet ice is melting, the discussion of CO2 effects are entirely academic. Unless the warmists here are postulating that oceanic and atmospheric conditions are being driven by the CO2 in the air.
sharperoo, the map you linked to in Wikipedia clearly shows the Arctic circle boundary marked just north of the 60th parallel on the coast of Labrador. The NCIDC sea ice extent map boundary extends hundreds of miles south of 60 degrees, along the coastline of Newfoundland and well into Nova Scotia.
I understand the general ignorance about Canadian geography, but the NCIDC line extends considerably south of Cape Breton, Nova Scotia, which is located near 46 degrees latitude. I can rest assure you their temperatures exceed 10 degrees C in summer and they definitely have an abundance of trees, just as their neighbour to the west, across the Atlantic Ocean, the state of Maine.
Humans have a silly grandiose perspective on themselves because they reduce gargantuan things in nature down to size and then think themselves now much bigger.
Ants don’t care whether or not a blade of grass is an inch taller or an inch shorter. And they thrive just the same.
We see the orange line around the Arctic and get our knickers in a twist because the ice isn’t snuggled up to, or even better, beyond that orange line.
Hubris. Plain and simple hubris.
gaya hap says:
March 24, 2011 at 7:01 pm
REPLY Thank you, Prof. Hap, for your insightful and logical argument. At the University of Illinois where I teach, our Agronomy folks have done the analysis of the effect of a warmer, wetter world climate upon the agronomy and agricultural output of the state. Curiously, they have discovered that Illinois will fare very well with shorter, warmer winters and longer, wetter growing seasons.
If you ever get hungry, come to Illinois, I’ll buy you a pork chop sandwich. With gravy.
Arctic sea ice volume and extent appear to be closely related to Arctic ocean heat content. From Bob Tisdale:
http://i51.tinypic.com/2eb5t39.jpg
From the above graph we observe that sattelite monitoring of sea ice extent began in 1979 when the arctic ocean heat content was at a low. Note that since 2007 heat content has rapidly dropped as sea ice volume has grown based on pips2 modeling.
This is expected from the development of negative NAO over the last two years. Climate modelers expected the NAO to remain positive and the ice cap to continue to shrink. Furthermore it is now understood that ice free waters around the perimeter of the sea ice in the winter allow heat to escape and thus provide a negative feedback to arctic sea ice melting.
While knowledge of sea ice extent before 1979 is limited, sea ice volume has been modeled and we see from the following graph that the thirty year decline in sea ice was due to positive NAO that is no longer with us.
http://psc.apl.washington.edu/zhang/IDAO/retro.html#NAO
I suspect that most arctic experts are quietly telling each other that we have begun a thirty year recovery of arctic sea ice volume. The Cryosat 2 sattelite launched last April will likely document the recovery to the embarassment of alarmists.
Pamela Gray says:
March 25, 2011 at 9:02 am
The ice extent is completely within a reasonable explanation that centers on ENSO-warmed waters that were sent there, as well as AO parameters that moved ice and especially ice edges around. I see no reason to add CO2 affects to ice area or extent. Natural variability, both from oceanic and atmospheric sources, explains it well enough.
____
Pamela, what natural cycle can account for the warmest water in 2,000 years moving into the Arctic? Re:
http://www.reuters.com/article/2011/01/28/us-climate-arctic-idUSTRE70P6TE20110128
There is no “natural variability” that lasts 2,000 years that would be causing this warming (by Milankovitch cycles, we should be level to cooling slightly over this period). The Arctic is warming, sea ice declining, permafrost melting– all in line with GCM model expectations when factoring in the 40% increase in the GH gas CO2 (and it’s related positive feedback effects) since the 1700’s. Polar amplfication of GH warming from CO2 is shown to occur in EVERY GCM, which is significant, because they show mechanism and an expected and varifiable trend and reason why the sea ice is declining. To suggest this is mere “natural variability” seems to be missing the bigger picture.
I suspect that most arctic experts are quietly telling each other that we have begun a thirty year recovery of arctic sea ice volume. The Cryosat 2 sattelite launched last April will likely document the recovery to the embarassment of alarmists.
____
Your suspicion would be dead wrong. Quite the contrary is what the experts in sea ice are saying. The experts in the cryosphere (sorry, Joe Bastardi is not an expert in this area) are all in agreement that arctic sea ice is in a long-term decline which will likely lead to an ice-free summer arctic sometime this century (and most likely sooner than later this century). Not only are they in agreement that it is in a long-term state of year-to-year decline, but they are in agreement that the cause in most likely the 40% increase in CO2 and it’s related positive feedback effects, with polar amplification of warming being key to the decline of sea ice.
@RGates
Please name one index since 2003 that supports GCM assumptions concerning Arctic warning.
I recently found out that a distant relative of mine was a rigger, in the London area, back in 1860’s. He went around the world a few times applying his trade on a few sea fairing ships sometime after 1860. I would be interested in knowing what the Arctic sea ice was like back then (and when all the activity was occurring to find the Northwest passage) as he ended up emigrating to Canada (then down to the US).
A personal thank you to the kind souls in the UK for having provided for orphan’s back in the 1840 and 1850 as my great great uncle lost his parents in India and spent some time at a government sponsored work house (from age 8-14 it appears from the records). It looks like he was a labor for 6 years while at the work house and he was classified as a pauper as he parents had passed away. I was thinking of sending some money to your climate change departments to offset his former carbon footprint- until I learned that the other side of my family ended up being on the wrong side of the war of the Roses and the family lands (near Cork) were reallocated to someone on the winning side of the battle. I am sure my side of the family would of keep all the trees on their former lands so I’ll call the the families carbon footprint even if that ok with you.
@RGates
P.S. Go to KNMI and look up ocean heat content for the North Atlantic. In fact, look up OHC for any region affecting the Arctic, including the Arctic region itself.
The paper you linked to appears as another rendition of a treemometer. Other research (including Archaeological evidence) does not support it.
Mr Gates,
As you know Steve Goddard is documenting the ice buildup from pip2s:
http://stevengoddard.wordpress.com/2011/03/25/huge-increase-in-thick-ice-over-the-last-three-years/
The buildup correlates with the negative NAO:
http://ioc3.unesco.org/oopc/state_of_the_ocean/atm/nao.php
I think it is interesting that the negative NAO and estimate sea ice volume buildup in the 1960’s was also associated with a decline in solar sunspot number. It is looking more and more like arctic sea ice volume and arctic ocean heat content are controlled by a top down solar forcing that determines the NAM phase.
“”””” Werner Brozek says:
March 24, 2011 at 6:47 pm
“George E. Smith says:
March 24, 2011 at 3:12 pm
Well, the temperature in the Arctic is about 21 K below freezing.
Are you sure you don’t mean -21 deg C ?”
What is the difference? Suppose the temperature is 98 deg C or 371 K. Would I not be equally correct to say this is either 2 K below boiling or 2 deg C below boiling? “””””
Well words have a meaning. The usual idea of communication is to use words that carry the meaning you intended to communicate.
Other words; have other meaning, so you should not use other words; just those that convey the meaning you intended.
The “Kelvin” Temperature scale is an absolute Temperature scale. xyz Kelvins is a specific Temperature; not how much hotter or colder than your coffee something is.
So 21 K is way below the freezing point of both Nitrogen and Oxygen.
98 deg C is certainly 371 K, actually 371.15 , and it certainly is 2 deg C below the BP of water (at standard pressure) but it is not 2 K below the BP of water; 2 K is below the BP of Hydrogen.
The Celsius scale is also a “Centigrade” scale, in that it divides the temperature range between the BP and the FP of water (at standard pressure) into exactly one hundred equal increments or “degrees”
The Kelvin scale is defined so that the triple point of water; which occurs at about 0.01 deg C (at the triple point pressure); is exactly 273.16 Kelvins, and the difference between two Kelvin Temperatures, is identical to the difference in those two Temperatures in Degrees Celsuis. So the standard freezing point of water is 273.15 Kelvins, and the standard boiling point is 373.15 Kelvins.
It is hard enough for scientific experts to keep their terminology correct, so that they can communicate ideas correctly among themselves; it is much more destructive when they use loose language when talking to lay or non science experts. No wonder so much miscommunication occurs.
So the brief answer to your bottom line question is “no” for a more explanatory answer try “Hell no!”
gaya hap says:
patterns to continue and worsen throughout this decade and beyond. And so will its effects and repercussions such as crop loss, escalating food prices, and eventually social unrest.
So the basic answer to your question, “. . . why I should care what the ice extent is?” is:
“Because you like to eat.”
—————————
Yes I like to eat, so I should hope for a warming world. Because, you see, warmth nurtures, cold kills.
What I find curious is the fact that NSDIC’s opening statement (below) in the press release has these words: “Arctic sea ice extent” but if you look at the NSIDC provided plot above, you’ll note that they include normal lines (in orange) for areas that are outside of the Arctic circle. While perhaps a small point, it does speak to accuracy in reporting. For example, I really don’t see how sea ice off the north coast of Newfoundland can be considered “Arctic” when it doesn’t even come close to being within the Arctic Circle.
One could argue that the circle is named after the Arctic not the other way round. In fact a common definition of Arctic is as follows:
“Arctic, the northernmost area of the earth, centered on the North Pole. The arctic regions are not coextensive with the area enclosed by the Arctic Circle (lat. 66°30′N) but are usually defined by the irregular and shifting 50°F (10°C) July isotherm that closely corresponds to the northern limit of tree growth and that varies both N and S of the Arctic Circle. The regions therefore include the Arctic Ocean; the northern reaches of Canada, Alaska, Russia, Norway, and the Atlantic Ocean; Svalbard; most of Iceland; Greenland; and the Bering Sea.”
Columbia Encyclopedia
Or:
“In climatology the Arctic is defined in terms of the treeless zone of tundra and of the regions of permafrost in the Northern Hemisphere.”
Geographical Dictionary
martin brumby says:
“There are always lots of hyperthermalist trolls who show up every time Arctic ice gets a mention.”
That’s because out of the literally hudreds of events predicted by the CAGW believers, only the Arctic region is going in the direction of their predictions. All their other predictions have been falsified by the planet. So they cling to declining Arctic ice like a drowning man clings to a twig.
But it’s only natural variability in action; CO2 has nothing to do with it, or every glacier on earth would be receding. The fact that Arctic ice is declining, even though this N.H. winter was the coldest in six years, is convincing evidence that the decline is due to the ocean, not to a minor trace gas in the air.
And @Mike:
Your Skeptical Pseudo-Science link claims that the official land temperatures are accurate, and that satellite temperatures are showing too much cooling. Doesn’t the fact that the official temperature record is always “adjusted” to show greater warming tell you what the record keepers are doing??
Skeptical Pseudo-Science is just passing on their lie, like they lied about Prof Ross McKittrick’s peer reviewed finding that the models were dead wrong in their predictions of a tropospheric hot spot – the supposed “fingerprint of AGW.”
Since the atmosphere isn’t warming as predicted, it must be that all the satellites are wrong, eh? Just like the ARGO buoy network is wrong to show ocean cooling. Your global warming religion just can’t accept scientific observations, can it?
Andrew30 says:
March 24, 2011 at 3:22 pm
Here is my forecast
2011 Minimum Extent:
September 17th 2011.
6.23 M km^2 (JAXA’s AMSR-E 15%)
———————————–
Andrew30 is one of the first brave souls to put a number down. One that is quite a bit higher than the Goddard minimum of 5.5 million, so he is very brave indeed.
So who else wants to get their forecast on record? If you don’t have an exact number just say if you think it will be over or under the Goddard minimum.
I expect it to be under.
Operation ice bridge has started up again.
http://www.iewy.com/20083-wheels-up-for-nasa-missions-most-extensive-arctic-ice-survey-2.html
It should be documenting the sea ice volume buildup since the missions began in 2009. The silence is deafening. If the volume was shrinking I think we would hear about it.
Gneiss says:
March 24, 2011 at 4:03 pm
Luther Wu writes,
“Just looking at the AMSRE (IJIS) graphic, the extent is apparently > 2005 and 2007 while above the extent for 2006.”
That is correct, if you mean that IJIS max this year is *below* 2005 and 2007, while still above 2006.
______________
Right- hit the wrong key. PIMF<
R. Gates, mind posting a link to the clam stick graph? Do you suppose they applied a well-known statistical maneuver to link both clams and observed temperatures together? If you use a proxy, you must show overlapping temperature correlations (or not) across the entire proxy. I would like to see that graph.
But as to your contention regarding warm water invasion, look no further than the AO which has slipped into negative and now somewhat neutral positive territory. That pressure system does a fine job of keeping warm air out or inviting it in (that includes changes in the Atlantic incoming current), depending on the pressure gradient, something you are well aware of.
You attribute changes in the AO to CO2 (but correct me if I’m wrong). At first AGW scientists were convinced that CO2 caused the AO to go positive and but then had to back peddle and say it the other way around. What are your thoughts on the AO now, since I assume you convict the CO2 driven AO for allowing warm water in?
Or are you saying that long wave radiation warmed the water elsewhere and it then traveled to the Arctic Circle where it was let in or not by the AO, whichever condition it is in? If you believe it to be CO2-warmed water, you will have to determine where that water was as it warmed, and how long it took to get to the Arctic.
Your theory is full of holes me thinks.
I find it curious that there is so much discussion about what defines the Arctic. NSIDC tracks the sea ice, and as you can tell from the spatial maps, it extends well outside of the Arctic circle during the winter. The orange line is simply the mean winter ice extent on that date based on all data from 1979 to 2000.
Last winter when the ice extent was approaching the 1979-2000 mean, WUWT was making a big deal out of it, and alluding to the fact that this meant a significant recovery for the 2010 September ice cover. This of course didn’t happen. The southerly extent of winter ice is very thin and melts out every summer, and has little impact on the summer minimum.
But what the data are showing is that the ice extent during winter is also declining, albeit at a much slower rate.
In response to the posting below:
As you know Steve Goddard is documenting the ice buildup from pip2s:
http://stevengoddard.wordpress.com/2011/03/25/huge-increase-in-thick-ice-over-the-last-three-years/
The buildup correlates with the negative NAO:
http://ioc3.unesco.org/oopc/state_of_the_ocean/atm/nao.php
I think it is interesting that the negative NAO and estimate sea ice volume buildup in the 1960′s was also associated with a decline in solar sunspot number. It is looking more and more like arctic sea ice volume and arctic ocean heat content are controlled by a top down solar forcing that determines the NAM phase.
We have a recent paper published in GRL (Stroeve et al., 2011) that details the impact the extreme negative AO phase from winter 2009/2010 had on the ice cover (the simple statistics that Goddard is using doesn’t quite work).
For those who cannot access the paper I give our conclusions:
Typically, the negative phase of the winter AO is associated with a strong Beaufort Gyre that sequesters sea ice in the Canada Basin where it can thicken and survive summer melt [e.g. Proshutinsky and Johnson, 1997]. The winter of 2009/2010 had the most extreme negative phase of the AO since at least 1951. Nevertheless, the September 2010 sea ice extent minimum ended up only 40,000 km2 above the minimum observed in 2008. Part of the explanation lies in pronounced differences in atmospheric circulation during winter 2009/2010 compared to the mean anomaly pattern based on past negative AO events. In particular, the wind field drove older ice directly across the Beaufort into the Chukchi Sea as opposed to curving northward in the western Beaufort While lending credence to arguments that the character of the AO may be changing [e.g., Wang et al., 2008; Overland et al., 2008], one must also recognize that the AO only explains roughly 50% of the SLP variability [Rigor et al., 2002]. Furthermore, ice conditions can be sensitive to slight shifts in the position of high and low pressure centers [e.g., Maslanik et al., 2006] that are not captured by EOF loading patterns.
The character of the sea ice is also changing. The spring ice cover is thinner than it was in the 1980s, with less old, thick MYI and a greater fraction of thinner first-year ice that is vulnerable to melting out in summer [Lindsay and Zhang, 2005; Maslanik et al., 2007]. Given that PIOMAS suggests a record low ice volume starting the 2010 melt season, it is perhaps not surprising that September 2010 ice extent was third lowest on record, despite atmospheric circulation less favorable to summer ice loss than observed in 2007 (record low September ice extent) and more MYI than seen in 2008 (second lowest) and 2009 (fourth lowest).
In the 1980s, winds associated with the strong Beaufort Gyre during negative AO winters would carry older, thicker sea ice from the Canadian Arctic towards the Eurasian Arctic, and older, thicker ice in the Eurasian Arctic towards the Canadian/central Arctic. However, during the last several years, most of this ice has melted out in summer before being able to re-circulate back to the Canadian Arctic [Maslanik et al., 2007]. Indeed, while the winter of 2009/2010 saw a substantial transport of the Arctic’s remaining store of old, thick ice into the Beaufort and Chukchi seas, the majority of this ice did not survive the summer melt season. This suggests that in the present warmer climate state, the tendency for a negative winter AO pattern to promote increased transport of ice into the western Beaufort/Chukchi Sea actually enhances summer ice loss. In our view, events of 2009/2010 did little to delay the Arctic Ocean’s ongoing transition to a seasonally ice-free state.
Since sea ice extent has only been measured since 1979 I suggest we use arctic ocean heat content as a proxy.
http://i51.tinypic.com/2eb5t39.jpg
Based on this I would then use 1990 as the mean.
This is close to where Cryosphere today has the mean.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
Based on how fast the the arctic OHC is dropping we should reach the mean in 5 more years.
@george E. Smith says:
March 24, 2011 at 3:22 pm
Uhhhh…when did you go to school, when they taught that a celestial lion from the zodiac menagerie runs around the earth? Did you study under Archimedes, Plato or……? It must have been earlier, I don’t think they bought into that myth either.