Sea Ice News: NSIDC’s Dr. Walt Meier on this Arctic ice season

Guest post by Dr. Walt Meier, National Snow and Ice Data Center

Winds, Temperatures, and Arctic Sea Ice Extent

As the summer sea ice melt season gets into high gear, I thought I’d do a post on sea ice processes and other tidbits about sea ice that may be useful as people watch the seasonal sea ice extent decline. My thanks to Anthony for the opportunity to share this information.

Often, much of the focus in the news is on the effect of warming air temperatures on observed decline in Arctic sea ice extent, such as in the The Economist article. Others have suggested, such as in last Saturday’s post, that winds are the key to understanding the extent decline. These are not competing viewpoints, but reflect complementary contributions to changes in sea ice extent. For a full description of how sea ice changes – day-by-day, month-by-month, and over the years and decades – both wind and air temperatures (along with other factors, e.g., the oceans) need to be considered.

Winds and daily variations in extent

Winds primarily affect sea ice extent by pushing ice around, either spreading the ice out over larger area (increasing extent) or compressing it into a smaller area (decreasing extent). Often, day-to-day changes in sea ice extent are primarily due to changes in winds and not freezing or melting. The winds can also open areas of water within the ice-pack, called leads, if they push floes of ice apart. Thus, even during winter, there are open water areas or areas of thin ice (as leads begin to re-freeze) throughout the ice-pack. It is this feature that has allowed submarines to surface at the North Pole since the 1950s, even though the overall sea ice thickness was much greater in the 1950s compared to today. (In other words, surfacing subs at the North Pole are not an indicator of Arctic sea ice conditions.)

Winds and interannual changes in extent

Winds are variable, blowing at different directions and speeds. Thus over time, the effect of the winds settles into an average pattern and their net effect on extent is smaller relative to temperatures. However, average wind patterns can themselves vary over longer periods of time due to large-scale climate oscillations, most notably for the Arctic Oscillation (AO). During the late 1980s and early 1990s, the AO was often in a positive mode that favors the motion of older, thicker sea ice out of the Arctic. The remaining younger, thinner ice cover was more easily melted completely in the subsequent summers. This contributed to some of the summer extent decline during that period, as was noted in papers by Rigor and Wallace (2004) and Rigor et al. (2002). However, in recent years, this relationship appears to have broken down. After very strongly negative AO winters in 2009-2010 and 2010-2011, the summer sea ice again reached low levels (Stroeve et al., 2011).

Winds and summer extent

Even over a season, variation in the winds can play an important role. They were a key factor in the record low extent of 2007, as noted for example by Ogi and Wallace (2012) and Zhang et al. (2008) , who found that ~30% of the record low extent could be attributed to unusual ice motion (driven by the winds). According to Ogi et al. (2010), 50% of the year-to-year variation in extent can be explained by the variation in winds. Ogi and Wallace (2012) noted that if the wind patterns were similar to 2007, the minimum extent during 2010 and 2011 would have likely been as low as or lower than 2007.

Effects of winds and temperature on long-term changes in sea ice

Winds can also influence the long-term trend in extent. Ogi et al. (2010) estimated that up to 33% of the trend for 1979-2009 could be explained by winds. One mechanism for this long-term influence is via long-term changes in the winds, which have been noted by Ogi et al. (2010) and Smedsrud et al. (2009). Another effect on extent due to winds is in how effective winds are pushing the ice around. Spreen et al. (2011) noted that while some increase in wind speed is observed (in agreement with the Ogi and Smedsrud papers), the speed of the ice increased much more. In other words, the winds are becoming more effective at pushing the ice around.

The motion of sea ice is affected not only by winds (and other smaller factors), but also by the ice itself. Thinner ice is more easily pushed around by the winds than thicker ice (Haas et al., 2008). And the sea ice cover has been getting substantially thinner through the loss of older, thicker ice (e.g., Maslanik et al., 2011; Kwok and Rothrock, 2009). Zhang et al. (2008) found that thinner ice cover was a crucial factor in the 2007 ice loss and if the ice pack were thicker, a record low would not have occurred under the same winds. As mentioned above, some of this loss can be ascribed to the positive AO of a couple decades ago. However, since then the AO has been in a mostly neutral or negative mode and yet older ice has continued to be lost. For those interested, a nice animation of changes in ice age can be seen at the NOAA Climate Watch website.

Thus, the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures. Thick ice still moves out of the Arctic (or melts within the Arctic), but the additional energy in the Arctic prevents the replenishment of thicker ice at the same pace. The system is out of equilibrium and older, thicker ice continues to decline (though with some year-to-year variability). The additional energy is not always indicated by warmer local air temperatures though, especially in ice-covered areas. The Danish Meteorological Institute (DMI) air temperature estimates for north of 80° N, shows summer temperatures just above freezing during summer and there is little or no trend. This is because the additional energy is used to melt the surface of the ice and not warm the atmosphere, which stays near the melting point through the summer.

Conclusion

So, overall, the long-term decline in sea ice is mostly due to increasing temperatures leading to thinner ice cover that is more easily melted completely during summer. Winds accelerate or slow the long-term decline through the motion of thick ice out of the Arctic for period of up to a few years. The effects of winds may have longer-term consequences because their effect on ice motion increases as ice thins. The interplay between the two factors – wind and temperature – is perhaps best exemplified by the estimates for September sea ice extent in the recently released Sea Ice Outlook. There is a wide spread between different outlooks – about 500,000 square kilometers; even the uncertainties of a single method are on the same order of magnitude. That 500,000 square kilometer uncertainty reflects uncertainty in how the winds will vary this summer. However, all of the outlook contributions are more than 1.5 million square kilometers below normal, which demonstrates the effect of the long-term warming trend.

References

Haas, C., A. Pfaffling, S. Hendriks, L. Rabenstein, J.-L. Etienne, and I. Rigor (2008), Reduced ice thickness in Arctic Transpolar Drift favors rapid ice retreat, Geophys. Res. Lett., 35, L17501, doi:10.1029/2008GL034457.

Kwok, R., and D. A. Rothrock (2009), Decline in Arctic sea ice thickness from submarine and ICESat records: 1958–2008, Geophys. Res. Lett., 36, L15501, doi:10.1029/2009GL039035.

Maslanik, J., J. Stroeve, C. Fowler, and W. Emery (2011), Distribution and trends in Arctic sea ice age through spring 2011, Geophys. Res. Lett., 38, L13502, doi:10.1029/2011GL047735.

Ogi, M., K. Yamazaki, and J. M. Wallace (2010), Influence of winter and summer surface wind anomalies on summer Arctic sea ice extent, Geophys. Res. Lett., 37, L07701, doi:10.1029/2009GL042356.

Ogi, M. and J. M. Wallace (2012), The role of summer surface wind anomalies in the summer Arctic sea ice extent in 2010 and 2011, Geophys. Res. Lett., 39, L09704, doi:10.1029/2012GL051330.

Rigor, I.G. and J.M. Wallace (2004), Variations in the Age of Sea Ice and Summer Sea Ice Extent, Geophys. Res. Lett., v. 31, doi:10.1029/2004GL019492.

Rigor, I.G., J.M. Wallace, and R.L. Colony (2002), Response of Sea Ice to the Arctic Oscillation, J. Climate, v. 15, no. 18, pp. 2648 – 2668.

Smedsrud, L. H., Sirevaag, A., Kloster, K., Sorteberg, A., and Sandven, S. (2011), Recent wind driven high sea ice area export in the Fram Strait contributes to Arctic sea ice decline, The Cryosphere, 5, 821-829, doi:10.5194/tc-5-821-2011.

Spreen, G., R. Kwok, and D. Menemenlis (2011), Trends in Arctic sea ice drift and role of wind forcing: 1992–2009, Geophys. Res. Lett., 38, L19501, doi:10.1029/2011GL048970.

Stroeve, J. C., J. Maslanik, M. C. Serreze, I. Rigor, W. Meier, and C. Fowler (2011), Sea ice response to an extreme negative phase of the Arctic Oscillation during winter 2009/2010, Geophys. Res. Lett., 38, L02502, doi:10.1029/2010GL045662.

Zhang, J., R. Lindsay, M. Steele, and A. Schweiger (2008), What drove the dramatic retreat of arctic sea ice during summer 2007?, Geophys. Res. Lett., 35, L11505, doi:10.1029/2008GL034005.

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88 Responses to Sea Ice News: NSIDC’s Dr. Walt Meier on this Arctic ice season

  1. Stephen Wilde says:

    What about melting from below as a consequence of the high sea surface temperatures over the last few decades (from stronger El Ninos) flowing past Spitzbergen into the Arctic Ocean ?

  2. “Thus, the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures.”

    I was with you until this point. What is the basis for this statement?

    The primary driver of the long-term thinning trend appears to be that thicker multi-year ice has been transported through the Fram Strait, i.e.;

    In this 2011 paper “Recent wind driven high sea ice export in the Fram Strait contributes to Arctic sea ice decline” by L. H. Smedsrud, et al. used;

    “geostrophic winds derived from reanalysis data to calculate the Fram Strait ice area export back to 1957, finding that the sea ice area export recently is about 25% larger than during the 1960’s.”

    In this 2001 paper, “Fram Strait Ice Fluxes and Atmospheric Circulation: 1950–2000” by Torgny Vinje found that:

    “Due to an increasing rate in the ice drainage through the Fram Strait during the 1990s, this decade is characterized by a state of decreasing ice thickness in the Arctic Ocean.”

    How can you conclude that “overall, the long-term decline in sea ice is mostly due to increasing temperatures leading to thinner ice cover” when you have provided no citations to support this conclusion?

  3. Ric Werme says:

    One thing that many critics of WUWT miss is that this is a really good forum to reach a lot of people. Often more people than might read one’s own site. I’ve appreciated Dr. Meier’s responses on sea ice subjects and and am glad to see these “proactive” comments as we move into both peak sea ice melt and peak sea ice hype season.

    As for me, I leave ice predictions to you guys!

  4. Wayne says:

    Anthony,

    I love your blog, and I just reblogged this post.

    Keep up your work putting out the lies of the opposition.

    Wayne

    [REPLY: Wayne, Dr. Meier has been very forthcoming and one of the few to engage here and knows he has a tough audience. If you have a substantive objection to make, please engage. -REP}

  5. RobW says:

    “Below normal”

    Excuse me. Normal according to what time frame? I have, for years wondered about the thirty year ice “normal”. If I am not mistaken the start of that thirty year “normal” was after a thirty year cold spell (40’s-70’s) so unless the ice did not increase during those thirty years of colder than ‘normal’ the thirty year average has to be biased towards a larger “normal” than we see today.

    OK that’s just one scientists opinion but where did I make a logic mistake?

  6. Manfred says:

    “Winds can also influence the long-term trend in extent. Ogi et al. (2010) estimated that up to 33% of the trend for 1979-2009 could be explained by winds…
    Thus, the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures.”

    Even if the 33% is true, the rest is not well founded. The main reason for the temperature increase is the positive AMO phase and this is not global warming. Temperatures in the arctic are not very different from the last peak 60 or 70 years ago. Soot is another issue.

  7. RobertInAz says:

    “What is the basis for this statement? The primary driver of the long-term thinning trend appears to be that thicker multi-year ice has been transported through the Fram Strait”

    Dr Meier said
    “Winds can also influence the long-term trend in extent. Ogi et al. (2010) estimated that up to 33% of the trend for 1979-2009 could be explained by winds.”

    So one might conclude that his educated opinion based on his life work is that wind accounts for 33% of the sea ice loss leaving the rest to increased energy uptake.

  8. Ian H says:

    Clearly ice has declined recently. And all other things being equal, warming will result in less ice.

    The only quibble I have with any of this is the use of the word “normal”. We don’t have good enough long-term data in my opinion to say what is usual with regard to ice coverage in the arctic or understand the full extent of its natural variation. Furthermore the word “normal” carries the implication that this level is in some sense ideal and that deviations from it are “abnormal” and potentially problematic. I have yet to see any evidence that recent declines in ice are causing, have caused, or are likely to cause any kind of problem.

  9. Thus, the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures.

    I’d like to see a plausible mechanism which allows warmer air temperatures to melt thicker older multi-year ice faster than thinner perennial new ice, before I accept your ‘thus’.

    http://wattsupwiththat.com/2012/03/01/nasa-and-multi-year-arctic-ice-and-historical-context/

    BTW, the likely mechanism is an increase in solar insolation and more embedded particulates (soot) accumulating on the surface of older ice decreasing its albedo.

    Which also means melting ice is a significant cause of warming Arctic atmospheric temperatures, as it insulates the ocean from heat loss.

    Apologies if this is double posted, but WordPress seems to have lost the first attempt.

  10. P.F. says:

    Any sea ice study that bases a conclusion on observations between 1979 and 2010 is no more valuable than predicting the temperature at midnight based on the trend from 8:00am to 5:00pm.

  11. Manfred says:

    Dr. Meier, is there any interest in an update of the historic sea ice estimations over the last century. I think, this data is based on a paper you co-authored. The pre-satellite data appears not to match with a multitude of historical reports and additionally there appear to be downward steps where datasets have been combined.

    Links to historical data

    http://www.real-science.com/new-giss-data-set-heating-arctic

  12. Craig Schleuniger says:

    Thank you, Dr Meier for taking the time to privide your insight. I see many references cited regarding wind as well as ice thickness studies for this article.

    However, your explanation of the many drivers of ice extent relies heavily on the existence of warming temperatures in the Arctic. Yet any references to studies of the number of above freezing hours or higher daily temperatures in the various weather stations in the Arctic are not listed. Would it be possible to get unadjusted temperature references for support?

  13. David Falkner says:

    Hello Dr. Meier,

    First, I think a thank you is in order for offering a post here. Hopefully the comments stay gracious enough to encourage continued posts. It is good to see.

    Second, I want to present my major issue here. Your conclusion is that increasing Arctic temperatures are the main driver of ice decrease, yet the major swings in Arctic temperature are during the colder months according to the Denmark Institute temperatures. It is readily apparent to anyone with an understanding of the mechanics of statistics that the temperatures are wildly variable in the other seasons, but in melt season they are remarkably consistent. This can be seen by comparing the DMI actuals (red line) to the DMI averages (green line) in the WUWT Sea Ice tab (click your way through the years, readers). I wondered if you, or anyone else could quantify the effect of CO2 on this temperature variability?

    Regards,

    David Falkner

  14. Tom Harley says:

    Let’s just hope it stays ‘warmer’ as the benefits of warming are far better than ‘coldening’ (as Tim Blair often describes it).

  15. TomRude says:

    “So, overall, the long-term decline in sea ice is mostly due to increasing temperatures leading to thinner ice cover that is more easily melted completely during summer”

    If so Dr. Meier how do you explain that 1) chartered maps in the 1930s (Danish) showing the same extent than during the 2000s, i.e. during a period of rapid mode of circulation high pressure anticyclones -Dust Bowl- not at all warming? 2) if as you claim global temperature rise influences arctic sea ice melt, how do you explain the increase dynamics observed remobilizing ice and stronger winds, higher waves documented in the Atlantic that cannot be associated with a diminishing poles/equator gradient? 3) If arctic ice state was a novelty, unprecedented interrupting a state of perennial stability how do you explain the absence of 100y old ice, 50 y old ice in the 1980s? 4) Since you wish to minimize modes of atmospheric circulation to the role of 0.8 C global temperature rise (on land, if we can trust HadCrut etc…) how come the shape of summer arctic sea ice is always the same? 5) How do you explain that during the global LIA, Arctic sea ice extent was in fact reduced as per a recent paper by a Canadian researcher? Is it that in fact, Arctic sea ice is no reliable proxy for Global Warming and that transitional periods toward cooling produce increased dynamics that for short periods can reduce arctic sea ice extent? Are you aware that during the onset of the last glaciation the Svalbard islands enjoyed a warming trend that finally was interrupted when the glaciation reached these islands (quoted in Leroux Dynamic Analysis of Weather and Climate 2010 Springer/Praxis)?

  16. ferd berple says:

    We are in the middle of the most rapid change in the earth’s magnetic field in recorded history. Most notably in the Arctic. We know from the fossil records that major climate change and species extinction are related to magnetic field changes.

    The Antarctic is cooling, not warming as the south magnetic pole moves away from the geographic pole. The Arctic is warming as the magnetic pole moves towards the geographic pole. CO2 cannot explain this. Charged particles enter the earth’s atmosphere from the sun in fantastic quantities at the magnetic poles. As the magnetic poles move, so does the location of entry of these particles.

    Completely ignored by the high priests of science in their quest to solve society’s problems through human sacrifice. Be it virgins or carbon tax, the solution is always the same, as are the result. More suffering and no benefit to anyone except the priests.

  17. Rhys Jaggar says:

    A thoughtful article, well written. Thank you Dr Meier.

    One question which of course arises from your analysis is this: if the warming in arctic temperatures is due to six or so cycles of high solar activity, what would be the effect of 25 years of much lower activity?

    We are about to have a most interesting period in climate science, if cycles 24 and 25 are much lower than the previous ones.

    After all, if it has taken 30 – 50 years to bring summer ice extent down to where it now is, it wouldn’t take Einstein to predict that to return it to 1950s levels will take an equally long time……

    It is therefore entirely likely that summer sea ice extent will remain relatively low until at least 2025.

    The key outcome will be whether it shows a slow (or even accelerating) rise, stays static or continues on a downward trend toward little if any summer sea ice.

  18. ferd berple says:

    David Falkner says:
    June 20, 2012 at 10:24 pm
    the major swings in Arctic temperature are during the colder months according to the Denmark Institute temperatures.
    ==========
    The same effect is found in the Canadian records. It is the low temperatures that are getting warmer. The high temperatures are unchanged. The same effect is found generally all over the world. The climate is becoming less extreme, not more extreme.

    High temperatures are not getting any higher, which suggests there is strong negative feedback in the system as temperatures increase, which prevents high temperatures from rising higher. Only low temperatures are showing signs of increase, which suggests that feedback is not constant, that feedback varies as temperature.

    Which suggests that averaging is masking what is actually going on with the climate. That climate science, in its fascination with using averaged data, is working against developing an understanding of climate.

  19. AndyG55 says:

    Seems to me that temperatures higher than the 40 year average over the colder months

    would have lead to less build up of thick ice, so of course it is now disappearing quicker.
    Again, the fact that we are still climbing out of the little ice age (I hope we haven’t reached the peak yet), and that we don’t seem to have much reliable data going back much before than 40 year average (or it just not used because it is inconvenient?), makes the use of terms such as “normal” and “average” pretty much pointless terminology in a historical sense.

  20. AndyG55 says:

    ferd,
    “The climate is becoming less extreme, not more extreme. ”

    yes, that does seem to be what the real life data is telling us. Sort of makes you wander how NICE the climate was during the MWP and Roman times. Must have been a pretty nice times weather-wise, I reckon. Barmy summer type days in Autumn and Winter.. yummm !! Plants must have luvved it !!! And now with the extra CO2 as well……. flourishing !!!!!

  21. tonyb says:

    Dr Meier

    Thanks for your article.

    Can you tell me the range of tides in the Arctic?

    Living next to the sea here in the UK (with a total tidal range of up to 5 metres locally) it is very noticeable that high tides- combined with strong winds- have a dramatic impact on shaping our beaches and moving sand dunes around. Similarly low tides, whilst helping to deposit sand would presumably have a bg impact in the arctic in helping to put pressure on ice as the water levels fall?

    As a skier I am also aware of the dramatic impact of sun on snow/ice and whilst appreciating the diffrence in angles any increase in sun hours over a long term average would presumably have some impact?

    tonyb

  22. mfo says:

    All the many graphs and data are neatly collated here, as many WUWT readers will know:

    https://sites.google.com/site/arcticseaicegraphs/

  23. Arfur Bryant says:

    [David Falkner says:
    June 20, 2012 at 10:24 pm]…

    An excellent post. Simply comparing the earliest (1958) with the latest (2011) demonstrates the remarkable consistency of summer air temperatures in the Arctic.

  24. Good to read. My issue Dr Meir is with your use of the word “normal”. As we have less than 40 years reliable data, and lots of mostly ignored anecdotal evidence of similar melt in the 1920’s, please explain why you consider we have enough to define “normal”.

  25. Eugene WR Gallun says:

    As I understand it — many years ago when they first reached agreement on how to divide up Colorado River water they used collected data for past river volumes to determine average overall volume — divding that amount up among the participating groups. No sooner was the ink dry on the treaty then the Colorado River returned to what was its historically normal and much lower flow rate. The [snip . . kbmod] has been hitting the fan ever since.
    Until you start writing papers that include information about historic assessments of Artic sea ice extent you can’t be taken seriously. Certainly reports by scientists and explorers and sea captains about artic sea ice extent are better proxies than are the tree rings that are used as proxies for past global temperatures. I mean human beings were there — they saw things with their own eyes and reported what they saw.
    Such reports might be as inconvenient for your ideas about the cause of artic sea ice loss as Dr. Mann found the Medieval Warm Period to be for his ideas about current temperatures. But I don’t know. Maybe such old data will support your ideas. Don’t you think it is worth your time to look? Or do you, employing some sixth sense that seems to have evolved among the new breed of climatologists, instincttively shy away from data that might refute your beliefs — consigning such to the memory hole?
    I am not a scientist but just a casual reader of the things on this site — but obviously you are reaching conclusions using only part of the data available. You are not giving us the full picture and thus what you say is highly suspect. Your paper is just about as viable as that old Colorado River water treaty.

    Eugene WR Gallun

  26. Warm says:

    @David Falkner
    “Second, I want to present my major issue here. Your conclusion is that increasing Arctic temperatures are the main driver of ice decrease, yet the major swings in Arctic temperature are during the colder months according to the Denmark Institute temperatures. It is readily apparent to anyone with an understanding of the mechanics of statistics that the temperatures are wildly variable in the other seasons, but in melt season they are remarkably consistent. This can be seen by comparing the DMI actuals (red line) to the DMI averages (green line) in the WUWT Sea Ice tab (click your way through the years, readers). I wondered if you, or anyone else could quantify the effect of CO2 on this temperature variability? ”

    Dr Meier addressed this issue:

    “The additional energy is not always indicated by warmer local air temperatures though, especially in ice-covered areas. The Danish Meteorological Institute (DMI) air temperature estimates for north of 80° N, shows summer temperatures just above freezing during summer and there is little or no trend. This is because the additional energy is used to melt the surface of the ice and not warm the atmosphere, which stays near the melting point through the summer.”

  27. Ron Manley says:

    First of all thanks to Dr Meier for his article – I learnt from it. I hope he manages to filter out valid questions from the comments of those who would never ever believe him.

    It seems to me that the central problem of attribution is that we only have accurate data from 1979 to the present when the trend was mainly in one direction. It would help to resolve the issue if we had a consistent data set going back over 100 years or more. (Manfred made a similar point.) This of course would mean sitting down with dusty archive records in Russian, Icelandic, Finnish etc and trying to make consistent sense out of them. Not half as much fun as jetting off to Rio with people who share your eschatological view of humanity’s future.

  28. AndyG55 says:

    Note also that the current temp is slap bang on the 40 year average, so how can only really say increased temperature is the cause.

  29. Don K says:

    While I’m far from convinced that the position Dr Meier sets forth is entirely correct, at least it is clearly and intelligently set forth — which is a refreshing change from the usual climate-crap, dubious math, worse logic, cherry-picking, blatant manipulation of appallingly bad data, ad hominem attacks on dissent, etc that afflicts so many climate discussions. And he does address issues like the lack of dramatic atmospheric warming in the high Arctic. I would like to see a bit more about assertion that energy is going into ice melt rather than warming. It’s plausible. And I haven’t encountered it before. But some evidence would be nice. (Where is the energy coming from? The sun hasn’t brightened? The mid latitudes haven’t warmed much? Has cloud cover changed?) Anyway, something is clearly going on in the Arctic and has been for a decade. This is the best discussion I’ve seen of the situation.

    Thanks to you and Dr Meier for presenting it.

  30. RACookPE1978 says:

    I will remind all readers, and the good Dr Meier himself – that it was this WUWT group that first plotted all of the historic DMI daily temperatures at 80 north latitude since 1958.

    And, the results of that plot of daily temperatures during the melting season?

    Since 1958, summer temperatures in the actual Arctic Ocean where all of the sea ice actually is have declined since 1958, and the recent rate of decline is increasing!

    Since summer temperatures immediately above the ice match the only time of year when solar radiation can actually reach the ice surface, the greenhouse gas feedback/effect of CO2 on re-radiated radiation from the ice cannot be true: At 4.5 million km^2, the Arctic ice extents reflect a “cap” that can be approximated as that region between latitude 79.5 and the pole. Or, in round numbers, 80 north to the pole.

    So his excuse that some kind of “summer heat increase” is melting ice rather than increasing the temperature of the air is incorrect. There is NO summer heat increase that is actually measured at the place where the ice is!

  31. kadaka (KD Knoebel) says:

    I was wondering what effect the regional changes in salinity were having on the Arctic sea ice.

    Ref, January 04, 2012: http://www.jpl.nasa.gov/news/news.cfm?release=2012-002
    NASA Finds Russian Runoff Freshening Canadian Arctic

    A strengthening of the west-east Arctic Oscillation has made an ocean circulation pattern go the other way. Historically the Russian river runoff flowed westward, ending up in the Eurasian basin between Russia and Greenland. Now it goes eastward to the Beaufort Sea (near western Canada and Alaska).

    (Arctic reference map showing the assorted seas for the other people who wonder where the hell they all are.)

    The stronger Arctic Oscillation is associated with two decades of reduced atmospheric pressure over the Russian side of the Arctic.

    The Canada Basin (see large version of salinity change map from NASA article) has freshened considerably.

    Between 2003 and 2008, the resulting redistribution of freshwater was equivalent to adding 10 feet (3 meters) of freshwater over the central Beaufort Sea.

    Kwok said on whole, Arctic Ocean salinity is similar to what it was in the past, but the Eurasian Basin has become more saline, and the Canada Basin has freshened. In the Beaufort Sea, the water is the freshest it’s been in 50 years of record keeping, with only a tiny fraction of that freshwater originating from melting ice and the vast majority coming from Russian river water.

    As the freezing point of water drops as salinity increases, I commonly find -2°C cited for “average” seawater, this should lead to greater extent in the Beaufort Sea and Canada Basin regions as ice would be formed when the water is warmer than would have historically supported ice growth. Offhand I guess the main difference would be additional thin ice at the end of the freeze-up season, prone to breakup by winds.

    The reverse should also hold true. As noted on the large salinity change map, the area around the Laptev Sea has seen significant increases in salinity.

    As mentioned in the Alfred Wegener Institute press release in a recent WUWT post, SMOS Satellite imagery suggests NE passage to open soon – ‘primarily attributable to the wind’, about the Laptev Sea:

    … Amongs experts the shelf sea is known as an “ice factory” of Arctic sea ice. At the end of last winter the researchers discovered large areas of thin ice not being thick enough to withstand the summer melt.

    The increase in salinity would lead to a decrease in ice production, as has been noted.

    The strengthening of the Arctic Oscillation appears to be primarily influencing the decreases in extent and multi-year ice, with more breakup from stronger winds and changes in ocean circulation. As Julienne Stroeve noted in March:

    … Given the positive AO throughout most of this winter, there was good export of multi-year ice out of Fram Strait, such that this winter there was a larger amount of 3+ year old ice exported than in the last 4 winters (the amount was similar to the amount exported during the 2006/2007 winter). This helps to precondition the Arctic Basin to ice loss, since thinner ice melts out easier.

    With the winds of the predominantly-positive AO having grown strong enough to reverse a longstanding ocean current, I would expect this has lead to stronger west-to-east ocean currents around Greenland, where the multi-year sea ice likes to hang out, thus leading to increased amounts of multi-year ice being flushed out of the Fram Strait to the east of Greenland, and the decline of the Arctic sea ice.

    So one question would be, since the energy for winds normally comes from temperature differences and ice is a source of coldness, will the sea ice decline lead to the AO weakening, to where either an equilibrium or a reversal of the decline occurs?

    One other question would be, as I wondered at the beginning of this thought train, how much has the changes in salinity affected the sea ice? And if it is significant, if the AO weakens, the Arctic Ocean currents weaken and that freshwater starts flowing back to the Eurasian Basin and the salinity reasserts the historical distributions, won’t that yield a quick whipsawing back to increasing ice?

  32. Warm says:

    “I would like to see a bit more about assertion that energy is going into ice melt rather than warming. It’s plausible. And I haven’t encountered it before. But some evidence would be nice. ”

    It is widely reported in the litterature. See for instance:

    Variations in Surface Air Temperature Observations in the Arctic, 1979–97

    http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/Rigor.pdf

    The authors state (p 907)
    “The ice and snow masses in the polar regions interact
    with the global climate system in a myriad of complex
    ways. During most seasons, SAT [Surface Air Temperature] trends can be studied
    by simple statistical methods, but during summer, because
    these masses hold the SAT to the melting point
    of sea ice, detection of changes in SAT must rely on
    other, less direct indicators such as the length of the
    melt season.”

    other source:

    Vertical structure of recent Arctic warming

    http://ic.ucsc.edu/~acr/BeringResources/Articles%20of%20interest/Central%20Artic/Graversen%20et%20al%202008.pdf

    The authors state (p 54)
    “We note that the lack of amplification near the surface in summer is
    consistent with expectations because surface air temperatures over
    the Arctic Ocean are constrained to be close to the freezing point
    owing to the melting of sea ice”

  33. Perry says:

    Dr. Meier,

    You wrote: “Thus, the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures.”

    I draw your attention to the “models versus observations 1958 – 2011″ graph, posted at WUWT on June 15th and ask to know the authority by which you assert your statement?

    http://wattsupwiththat.com/2012/06/15/james-hansens-climate-forecast-of-1988-a-whopping-150-wrong/

    Steve Goddard has also commented on the meaning of Hansen’s 1988 scenarios.

    http://stevengoddard.wordpress.com/2012/06/15/clarifying-hansens-scenarios-worse-than-it-seems/

  34. Slabadang says:

    So compered with the warmingperiod leading to the MWP…whats the difference?

  35. Jens Bagh says:

    Given that the summer temperatures in the Arctic have not risen it should be clear that little heat is transferred from the air to the ice. The ocean must supply the heat and changes in the ocean current flow must be responsible. What are the present and past flow rates in and out of the arctic ocean. Comparing the specific heat of ice, water and air it should be clear that ice would have a large moderating influence on temperature excursions during the summer and open water during the winter.

  36. tonyb says:

    Ron Manley said;

    “It seems to me that the central problem of attribution is that we only have accurate data from 1979 to the present when the trend was mainly in one direction. It would help to resolve the issue if we had a consistent data set going back over 100 years or more. (Manfred made a similar point.) This of course would mean sitting down with dusty archive records in Russian, Icelandic, Finnish etc and trying to make consistent sense out of them.”

    I did that back in 2009 in this article carried here

    http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/

    I am currently working on the period from 1940 backwards to the start of the Hoocene. The melting of the arctic in the 1920-1939 doesnt seem a whole lot different to today, which is one of seven substantial periods of melt we can trace back several thousand years.
    tonyb

  37. PezdePlata says:

    “will the sea ice decline lead to the AO weakening,”

    The temperature diference inside and outside the arctic air is less than used to be weaking jet stream and therefore weather that the Jet stream carries about. On a ‘normal’ June it would be over UK or above Scotland… http://squall.sfsu.edu/gif/jetstream_atl_init_00.gif
    currently it’s over Spain http://squall.sfsu.edu/gif/jetstream_atl_init_00.gif
    Jet Stream displacement seems to be happening more frequently. I’d say AO is already too weak.

  38. RobertInAz says: June 20, 2012 at 9:43 pm

    “What is the basis for this statement? The primary driver of the long-term thinning trend appears to be that thicker multi-year ice has been transported through the Fram Strait”

    Dr Meier said
    “Winds can also influence the long-term trend in extent. Ogi et al. (2010) estimated that up to 33% of the trend for 1979-2009 could be explained by winds.”

    So one might conclude that his educated opinion based on his life work is that wind accounts for 33% of the sea ice loss leaving the rest to increased energy uptake.

    You are comparing two different things here, i.e. I am challenging Walt’s assertion as it relates to sea ice thickness/thinning, whereas the quote and paper you’ve cited only addresses sea ice extent, i.e.:

    Based on a statistical analysis incorporating 925-hPa wind fields from the NCEP/NCAR Reanalyses, it is shown that the combined effect of winter and summer wind forcing accounts for 50% of the variance of the change in September Arctic sea ice extent from one year to the next (ΔSIE) and it also explains roughly 1/3 of the downward linear trend of SIE over the past 31 years.

    http://www.agu.org/pubs/crossref/2010/2009GL042356.shtml

  39. Craig Schleuniger says: June 20, 2012 at 10:17 pm

    However, your explanation of the many drivers of ice extent relies heavily on the existence of warming temperatures in the Arctic. Yet any references to studies of the number of above freezing hours or higher daily temperatures in the various weather stations in the Arctic are not listed. Would it be possible to get unadjusted temperature references for support?

    It has definitely gotten warmer in the Arctic over the last 30 years, i.e. RSS Northern Polar Temperature Lower Troposphere(TLT) Brightness Temperature Anomaly;

    Remote Sensing Systems (RSS) – Microwave Sounding Units (MSU) – Click the pic to view at source

    shows a .337 K/C per decade increase.

    However, some of this warming may be related to the Arctic Oscillation, i.e.;

    A dominant mode of Arctic variability is the Arctic Oscillation (AO), and its strong positive phase during the 1990s may account for much of the recent decrease in Arctic ice extent. The AO explains more than half of the surface air temperature trends over much of the Arctic [Rigor et al., 2000].
    http://www.atmos.umd.edu/~kostya/Pdf/Seaice.30yrs.GRL.pdf

    versus the change in global temperatures, i.e. RSS Global Temperature Lower Troposphere (TLT) – Brightness Temperature Anomaly- 1979 to Present;

    Remote Sensing Systems (RSS) – Microwave Sounding Units (MSU) – Click the pic to view at source

    which have only increased by .134 K/C per decade.

    Regardless of source of the warming, undoubtedly arctic atmospheric temperatures have increased during the last 30 years. The key question is how much atmospheric warming has influenced the thinning of Arctic sea ice, as compared to wind and currents transporting multi-year sea ice into warmer waters, changes in sea surface temperatures, increases in soot, increased ship traffic and icebreaking, etc.

  40. David Gould says:

    I am not sure why some people are saying that the Arctic has not warmed. UAH data show a strong warming trend over the Arctic Ocean for their period of record.

    http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt

    Surface warming will, of course, not be the same as that detected by the satellites, but still …

  41. wayne Job says:

    In a previous life I did a lot of rowing when the wind refused to blow. In our Viking long boat we traversed much of the area now rather severely ice bound. The hide covering on our long boat suffered not from ice as we explored the far north and travelled west then south. We turned north again and travelled back to a friendly welcome as the natives we met were a tad aggressive.
    It was not long after our exploration that the cold set in and our farmers and communities suffered starvation, as the cold and advancing ice killed crops and live stock. The advent of the sea ice prevented us from fishing and those that could escaped to sea did, it was a bad time.

    My question is, what is the problem, in my days the ice was not there, and it was a good time of plenty. WUWT {sarc}

  42. sceptical says:

    Interesting article. Thanks for posting it Mr. Watts. Seems we were told just a little over 2 weeks ago on this very site that “In fact, as the NSIDC points out, the extent of Arctic sea ice is very close to the average for the last three decades” How quickly things change.

  43. Don K says:

    Warm says:
    June 21, 2012 at 2:29 am

    “I would like to see a bit more about assertion that energy is going into ice melt rather than warming. It’s plausible. And I haven’t encountered it before. But some evidence would be nice. ”

    It is widely reported in the litterature. See for instance:

    ——–

    Thanks, but what you have cited is evidence that Arctic temperatures probably would not increase much while ice is melting. Yeah, I’ll buy that. I forget the heat of fusion for water, but it is substantial.

    However, what I’m looking for is evidence that additional energy is actually present to melt the ice as well as some thoughts on where that energy is coming from.

  44. Many ice ridges form over winter, with stronger winds, even with the thicker ice. So wind action does not need thin ice alone.

  45. Dave says:

    One thing not discussed by Dr. Walt is the role that ocean currents, which over time vary both in intensity and location, has upon the sea ice. Furthermore, the current that flows through the Bearing Strait into the Arctic Ocean is likely affected by the Pacific Decadal Oscillation, and thus has funneled warm water to the arctic since the PDO flipped to the warm state back in the late 70’s.

    The heat capacity of water far exceeds that of air and since we know that temperatures during the melt season have varied little over the years, then I find it plausible that ocean currents play a major role in the degree at which ice melts from season to season.

  46. Dr. Deanster says:

    It would seem to me that the winds effect on sea ice would an accelerating effect. If 5 year old ice is blown out of the arctic, it will result in the formation of more new ice, which is more easily moved around and blown out of the arctic as well. Common sense tells you that such a process would result in an acceleration of ice exit through the Fram Strait.

    Thicker, older ice will take a much longer period to replace, and its formation itself will be dependent on the wind, and its residency in the arctic over multiple years. IMO, it will take a prolonged period of decreased ice exit through the Fram Strait, thus allowing thicker, less mobil ice to form. I’m not seeing that at the moment in the wind graph on the sea ice page.

  47. John says:

    It makes sense that the Arctic is warmer, and that ice is therefore melting more quickly. Let’s accept and get past that, to other questions:

    1. What is the relative contribution of black carbon, vs. other emissions (CO2, methane, tropospheric ozone)? If people want to reduce warming in the Arctic, black carbon (mainly from older diesels, or newer diesels without the pollution controls diesels now have in the US) can be reduced much more quickly and cheaply than can CO2. The health of people in China would certainly be improved if they reduced diesel emissions.

    2. What are the effects of less sea ice in the Arctic? We’ve already learned that the Arctic was largely ice free at summer peak at what used to be called the “Holocene optimum” about 6,000 to 8,000 years ago. We’ve also learned recently that polar bears can swim over 400 miles, and even cubs can swim over 100. The notion that polar bears will die out when there is less ice is now looking more than a little shaky. Even more so when you realize that the last interglacial, 110,000 years ago, was warmer than today, with sea levels 7 feet higher, but polar bears survived that as well.

    I take warming seriously, but we need to understand concrete effects, we need to understand timing, and we need to know why we have to act precipitously NOW, putting people out of work and increasing our national indebtedness even more, rather than waiting a decade or so for solar energy to be competitive and with no need for subsidies. When that day comes, CO2 can be dealt with much more easily.

  48. Jim Cripwell says:

    An excellent paper. What I always hope is that when people like Walt seem to have such an excellent grasp on a situation, in this case Arctic sea ice extent, they dont use this knowledge to forecast what will happen in the near future. Canadian Ice Services has, for two years, put in a forecast to ARCUS for minimum Arctic sea ice extent. One wonders why NSIDC is absent from the list of ARCUS forecasters. Surely their knowledge should be second to none, and their forecasts amongst the most accurate.

  49. Jimbo says:

    Hi Walter,
    you say:

    Conclusion
    So, overall, the long-term decline in sea ice is mostly due to increasing temperatures leading to thinner ice cover that is more easily melted completely during summer.

    In your opinion what part does soot have to play in these “increasing temperatures” as you say?

    References:

    http://www.pnas.org/content/101/2/423.long

    http://www.agu.org/pubs/crossref/2005…/2004JD005296.shtml

    http://www.sciencedirect.com/science/article/pii/0004698181903437

    http://www.sciencedirect.com/science/article/pii/S1352231005002165

    http://www.agu.org/pubs/crossref/2010/2009JD013795.shtml

  50. John says:

    To Jimbo at 7:08 am:

    Exactly! Let’s get to the specifics of what is causing the warming, and what reductions can be done quickly and effectively.

  51. Bill says:

    From Dr. Meiers article and from a number of the comments that correctly point out dozens of other factors that influence sea ice, it is quite clear that even something as seemingly simple as ice melting, is, in fact, extremely complex. Very difficult to model or come up with a complete understanding. Given that we only have 30 years of data, it is obviously impossible to say at this point that we know what the cause or future trends will be. Very large error bars should be assigned. With another 15 years of study, however, we will be in a much better position to determine the causes and to make predictions. As a scientist myself, I want to see more data before I come to a conclusion. That’s really the only responsible position to take.

  52. Richard M says:

    Thank you, Dr Meier. Your description matches almost perfectly with what I have been thinking. I also appreciate your use of the term “global warming” rather than AGW. Most of us accept that the planet was, in fact, warming for most of the satellite data period up to around 2006. This, no doubt, led to some thinning of the ice that allowed winds to be more effective than they would have been otherwise.

    I have personally predicted that we will not see a recovery of the ice until 2020 at best even with the current leveling off of temperatures. It will take a long time to replenish the ice when it can so easily be moved around. I’m sure I’ll be watching it closely when I’m not spending time doing my other equally exciting hobby … watching grass grow.

  53. Harold Ambler says:

    I also appreciate Walt’s willingness to engage here. I find the phrase “long-term decline” tough to swallow, nonetheless. Why? Because waves striking the shores of northern Greenland have been shown to have been generated by a mostly open Arctic Ocean during the Holocene Climatic Optimum. These same waves are not currently striking northern Greenland, because the Arctic Ocean is too clogged with ice to allow them to form. So, unfortunately, a few decades’ worth of satellite imagery is taken as indicative of “climate change” when we know perfectly well that the entire system has been in flux for millions of years, including during the remarkably stable Holocene. Walt and I have corresponded enough for me to know that he is utterly convinced that the three decades’ worth of evidence is proof of a human fingerprint, worrisome, and probably unique. I respectfully disagree on all three counts.

  54. Jim Steele says:

    Dr Meier, I don’t understand your quantum leap in attribution. You wrote well about the impacts of winds, and then suddenly make the statement: “Thus, the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures” You invoke dubious subtraction to imply greenhouse warming by ignoring the warmer waters that lie below the surface which are pumped into the Arctic. The volume of warm water entering the Arctic has been demonstrated by moorings to have increased in accord with a positive PDO and NAO. Now that the PDO has gone negative that source of warm water entering through the Bering Sea has slowed and cooled, and accordingly we also see tremendous growth of ice in the Bering Sea. As demonstrated by Shimada’s 2006 paper “Pacific Ocean inflow: Influence on catastrophic reduction of sea ice cover in the Arctic Ocean”, the loss of sea ice allows the winds to couple the surface withe deeper warmer layers. Despite the cooling of upstream waters from the Bering, there was continued sea ice loss as wind turbulence brought warmer waters to the surface. Likewise the great loss of sea ice in the Barents Sea is due to warm Atlantic intrusions that similarly generated the similarly warm temperatures in the 1930’s. (See BENGTSSON 2004) Despite the changes in the wind that initiated the ice loss, the winds are still churning the open waters and heat is being brought to the surface and vented. This process would create higher temperatures in the winter ice seaon.The lack of a summer trend of rising temperatures is further testimony that high Arctic temperatures are due to heat ventilation due to less ice, not as you imply that less ice due to more heat. That ventilation also suggests a deeper cooling has been taken place and predicts that thicker sea ice will soon return.

  55. aharris says:

    Pardon me if I sound ignorant on this because I’m by no means an expert on oceanography, but it seems to me that you are missing part of your equation. The atmosphere above the ice is important I’m sure, but wouldn’t the effects of the sea under and around the ice be just as important to understanding what’s really going on? I would think it would be premature to conclude that the temperature is warming and that’s causing the sea ice to shrink without being able to rule out any possible negative effects from the currents themselves, and they can take decades or centuries to turn over, so 40 years of data wouldn’t really help you to establish a pattern there.

  56. Jim Clarke says:

    “The Danish Meteorological Institute (DMI) air temperature estimates for north of 80° N, shows summer temperatures just above freezing during summer and there is little or no trend. This is because the additional energy is used to melt the surface of the ice and not warm the atmosphere, which stays near the melting point through the summer.”

    I have always had a problem with this concept. The same thing has been argued about the oceans absorbing the heat energy that increasing CO2 is generating and that is why the air temperatures are not warming.

    Doesn’t the whole process start with a warming atmosphere? How can the additional energy be “used to melt the surface of the ice and not warm the atmosphere” when the additional energy (as heat) is in the atmosphere? That is like having a pot of boiling water on the stove that is heated to exactly 100 degrees C. Dr. Meier and others appear to be arguing that it is possible to make the water boil faster by adding heat to the pot, but not have the pot get any hotter, just the water inside the pot. Seems to me, if the pot isn’t getting any hotter, neither is the water inside of it.

    Am I missing something?

  57. PezdePlata says:

    Warmer Atlantic waters are reaching deeper into the Arctic Ocean which could in the future keep the Arctic ice free even in the dark winter. New species will move in. Open water means erosion of coastal areas which were previously protected by coastal ice. The much feared melt of permafrost which seems now inevitable and the consequent scape of CH4. There is far too much going on and nothing to stop it. The Siberian tundra has again paid the price of a massive temperature anomaly which has been over the area for the last 2 months… this has now resulted in massive Tundra fires which are dwarfing those in 2010.

  58. David Falkner says:

    Warm says:
    June 21, 2012 at 12:53 am

    Dr Meier addressed this issue:

    “The additional energy is not always indicated by warmer local air temperatures though, especially in ice-covered areas. The Danish Meteorological Institute (DMI) air temperature estimates for north of 80° N, shows summer temperatures just above freezing during summer and there is little or no trend. This is because the additional energy is used to melt the surface of the ice and not warm the atmosphere, which stays near the melting point through the summer.”
    ==============================
    Thank you for pointing this out Warm, but I did see that. The question I was asking is what effect CO2 will have on the variability of temperatures. They should become more uniform as they push upwards, yes? Since there should be warming occurring, wouldn’t one logical conclusion of that warming be more uniform temperatures as the melt season should begin sooner, expanding the length of time the less variable temperature exerts its influence on the record? Otherwise it sounds like, “It’s warming when it’s not.” which is kind of redundant.

  59. vukcevic says:

    Dr. Walt Meier (or anyone else) interested in the Arctic temperatures may find useful to know what NASA’s Jet Propulsion Laboratory has to say

    http://www.vukcevic.talktalk.net/Arctic.htm

  60. Jimbo says:

    PezdePlata says:
    June 21, 2012 at 10:15 am

    Warmer Atlantic waters are reaching deeper into the Arctic Ocean which could in the future keep the Arctic ice free even in the dark winter. New species will move in………………..

    We are doooommmmed!!!! References would be nice next time. ;-)

    By the way your Russian fire link says it is mostly man-made with a little help from above.

    According to Russian authorities, many of the fires started when people lost control of agricultural fires and campfires. However, lightning sparked some of the blazes as well.

  61. Louis Hooffstetter says:

    Thank you for your post Dr. Meier! One small comment on “…surfacing subs at the North Pole are not an indicator of Arctic sea ice conditions”:

    Most of us understand that ice free conditions at the North Pole don’t necessarily mean much. Kindly pass this information on to Dr. Serreze, the IPCC, and the media.

  62. geo says:

    I’m always happy to see Dr. Walt here. I don’t always agree with him, but he plays fair, supports his arguments well and in detail, is genuinely interested in having a respectful dialogue, and doesn’t get overly excited (unlike some of his colleagues) in extrapolating short term trends.

  63. David A. Evans says:

    Thank you for your calm assessment Dr. Meier.

    I have long maintained that receding Arctic sea ice is a negative feedback with the albedo decrease being far exceeded by ocean energy loss by the open water losing energy to the atmosphere and thence to space.
    It’s natures way of cooling the oceans.

    DaveE.

  64. Kip Hansen says:

    ‘The Danish Meteorological Institute (DMI) air temperature estimates for north of 80° N, shows summer temperatures just above freezing during summer and there is little or no trend. This is because the additional energy is used to melt the surface of the ice and not warm the atmosphere, which stays near the melting point through the summer.

    Does anyone else feel that this last bit is just thrown in there? Is there any OBSERVATIONAL data that shows surface melting of the ice in the Arctic at those ‘just above freezing’ temperatures?

    My experience with ice melting is rivers and streams in upstate NY…it generally doesn’t actually melt from above, usually the water below the ice increases (because it is not freezing when it falls, and the comparatively warm earth melts snow from below), warms up (it is almost always already above freezing), the slowly eats the ice from below. Only when Spring temps reach the high forties (F) does are temp begin to affect the thick winter ice.

    Anyone else know anything about this? Any Arctic experts here at WUWT?

  65. Kip Hansen says:

    The DMI site shows, using the old eye=o-meter, that the last five years or so summer air temps have been a bit below the 40 yr average.

  66. Phil. says:

    TomRude says:
    June 20, 2012 at 10:54 pm
    “So, overall, the long-term decline in sea ice is mostly due to increasing temperatures leading to thinner ice cover that is more easily melted completely during summer”

    3) If arctic ice state was a novelty, unprecedented interrupting a state of perennial stability how do you explain the absence of 100y old ice, 50 y old ice in the 1980s?

    It wasn’t absent just substantially diminished, e.g. the Ayles Ice sheet has recently broken and is a shadow of its former self.

    4) Since you wish to minimize modes of atmospheric circulation to the role of 0.8 C global temperature rise (on land, if we can trust HadCrut etc…) how come the shape of summer arctic sea ice is always the same?

    It isn’t! See here for example: http://nsidc.org/data/google_earth/index.html#sea_ice_index_sept

  67. Jim Steele says:

    Kip Hansen,

    Your exactly right and your intuitive sense is being confirmed. Most of the melting is coming from below due to warm water intrusions associated with positive PDO and NAO. A 2011 paper “Fate of Early 2000s Arctic Warm Water Pulse” by Igor V. Polyakov et al wrote :

    These recent observations show the warm pulse of Atlantic Water (AW) that entered the Arctic Ocean in the early 1990s finally reached the Canada Basin during the 2000s. The second warm pulse that entered the Arctic Ocean in the mid-2000s has moved through the Eurasian Basin and is en route downstream. One of the most intriguing results of these observations is the realization of the possibility of uptake of anomalous AW heat by overlying layers, with possible implications
    for an already-reduced Arctic ice cover.

    from several cross-isobath sections spanning 43° to 185°E show consistently higher temperatures in the OL (overlying layer) in eastern sections than in the western sections. Since the AW layer is the closest source of heat, this leads us to suggest significant upward heat flux from the AW to the OL during the transit along the slope.

  68. Phil. says:

    Jim Cripwell says:
    June 21, 2012 at 6:23 am
    An excellent paper. What I always hope is that when people like Walt seem to have such an excellent grasp on a situation, in this case Arctic sea ice extent, they dont use this knowledge to forecast what will happen in the near future. Canadian Ice Services has, for two years, put in a forecast to ARCUS for minimum Arctic sea ice extent. One wonders why NSIDC is absent from the list of ARCUS forecasters. Surely their knowledge should be second to none, and their forecasts amongst the most accurate.

    They have indeed submitted a forecast, authored by Julienne Stroeve, Walt Meier, Mark Serreze, Ted Scambos, & Mark Tschudi, their average predicted extent is 4.59. Their June 2011 forecast was pretty much bang on.

  69. climatebeagle says:

    Thanks for writing the article Dr Meier.
    “the long-term thinning trend is primarily a reflection of additional energy from globally warming temperatures”

    What is really being meant here when you say “globally warming temperatures”, temperature of what exactly? You go onto say the local air temperature is not increasing, so is it:
    a) additional radiant energy from GHG (CO2) in the atmosphere above the ice.
    b) additional energy due to warmer sea temperatures in the Arctic.
    c) additional energy due to warmer temperatures elsewhere (but how is this energy transported to the Arctic?)
    d) something else?

    Maybe I’m just missing something obvious.

  70. phlogiston says:

    This post 3 years ago shows data published by Levitus et al on an exact corellation between Barents sea temperatures and the AMO.

    http://wattsupwiththat.com/2009/10/08/new-paper-barents-sea-temperature-correlated-to-the-amo-as-much-as-4%C2%B0c/

    If – as Dr Meier states, Arctic ice decline is not from cooling air temperatures (current DMI arctic temps are normal or just below) then maybe the decline of recent decades is simply the upswing of the AMO pushing more north Atlantic drift water up to the Arctic. It looks due for an overturn to a downward slope.

  71. Don K says:

    Kip Hansen says:
    June 21, 2012 at 1:13 pm

    My experience with ice melting is rivers and streams in upstate NY…it generally doesn’t actually melt from above, usually the water below the ice increases (because it is not freezing when it falls, and the comparatively warm earth melts snow from below), warms up (it is almost always already above freezing), the slowly eats the ice from below. Only when Spring temps reach the high forties (F) does are temp begin to affect the thick winter ice.
    ======
    After thinking about it, It crossed my mind that the proposed melting mechanism doesn’t match what we see here in the Champlain Valley either. Many years, we enter March with anywhere from 50cm to a meter of snow on the ground and the lakes frozen. As the sun gets higher in the sky and temperatures rise, we start to lose frozen moisture directly to the air (sublimation). As the days get longer and warmer, there is direct melting. But what doesn’t happen is a noticable tendency for daytime temperatures to hold at freezing (because energy is sucked from the air to melt snow and ice). Of course things might be different in the Arctic where sun angles are much lower than they are at 44 degrees North.

  72. PezdePlata says:

    @ Jimbo

    Nevermind the fact that the snow cover is dissapearing earlier and the Tundra is losing its permafrost. TheTundra is catching fire because as its exposed to sun radiation for longer (that snow cover melts earlier now, remember?) its vegetation of mainly dwarf shrubs, sedges and grasses, mosses, and lichensis is dry like tinder.

    http://www.arctic.noaa.gov/report10/ocean.html

    Notice this is from 2010 and that it talks of historical record warm water. I’d expect that if the ice melts this year as much as in 2007, the same will occur.

    All the best.

  73. Steven Mosher says:

    has the ocean temperature warmed in the arctic since 1979?

    I dunno ask Tisdale

    Does anyone here think that warmer water will create more ice?

    A nice depiction of air temperatures from a typical buoy. As it warms the air temperature is thresholded at around 0C.. guess why

    http://imb.crrel.usace.army.mil/2011J.htm

    http://imb.crrel.usace.army.mil/2011M.htm

    http://imb.crrel.usace.army.mil/2012E.htm

    More stuff here

    http://nsidc.org/noaa/moored_uls/index.html

  74. Dave Wendt says:

    Rigor and Wallace 2004 noted a dramatic decline in old sea ice which occurred at the end of the 80s as a result of a paradigm shift in the Beaufort Gyre and the TransPolar Drift. During the 80s the BG was large and covered most of the Arctic between the Pole and the Bering Strait. Old ice circulated within it for up to a decade or more. The TPD ran mostly parallel to the Lomonosov Ridge. At the end of the 80s the BG contracted and shifted toward North America and the TPD moved to track that followed almost exactly along the prime meridian and tangential to the tighter BG circulation. The old ice that through the 80s had remained west of the pole at minimum and was 80% of the total was broken up and flushed out through the Fram and in only a couple seasons old ice was down too 30% and max age had changed from 10+ yrs to 3-4 yrs.
    That circulation pattern remained mostly the same for nearly two decades

    http://iabp.apl.washington.edu/pdfs/RigorWallace2004.pdf

    At this point it’s probably doubtful that much ice is enduring for even 4 years. In the last couple years the BG seems to be quite variable and although it might return to its 80s pattern the Arctic drift maps don’t seem to indicate a consistent pattern yet, at least to my eye. Unless or until the BG does go back to what it was in the 80s, we will probably continue to see variations around the new baseline that was established in the early 90s and, although temps will undoubtedly have some effect, the end results will continue to be dominated by circulation patterns driven by winds, currents, and pressure fronts which, from what I’ve seen, are mostly unrelated to anything anthropogenic.

  75. Jim Steele says:

    Dr Meier, Hopefully, since you will be responding to this thread there is a question about a comment you made in a 2008 CNN interview that was hyping shrinking ice and polar bear cannibalism, that has long troubled me. You said, “That warming is going to spread to the lower latitudes, to the United States, and it’s going to affect storm systems and storm tracks, the jet stream; that’s going to affect crops and all sorts of things,”

    My understanding is excess heat from the tropics is redistributed towards the poles due to the temperature gradient. Your suggestion that heat will accumulate in the poles and then flow back towards the equator against that gradient appears to defy the law of physics. Polar air masses that move south are always colder. So could you explain why a scientist would suggest such a thing?.

  76. Ed Barbar says:

    I’m confused, as usual. I was under the impression the models predict the poles cool down and the tropics warm up due to global warming (err, Climate change).

    Please help me to understand this, and if the poles are supposed to cool down, then you have to take away the idea it’s on account of heat, as you are saying here.

    Or do you think the models are wrong? Or do you think there is less ice when things cool down?

    Really in a spin,

    Regards,

    Ed

  77. SteveSadlov says:

    Has anyone ever succeeded in definitively mapping thickness across the entire broad swath of Arctic Sea Ice and done so in a way to create meanigful time series of such mappings? And the follow on question, what would be the earliest reliable baseline mapping assuming any acceptable mapping even exists or has ever existed?

  78. David Gould says:

    Ed Barbar,

    Climate models predict that there will be more warming at the poles than at tropical latitudes.

  79. Craig Schleuniger says:

    Just The Facts says

    It has definitely gotten warmer in the Arctic over the last 30 years, i.e. RSS Northern Polar Temperature Lower Troposphere(TLT) Brightness Temperature Anomaly;

    Thanks for the point out. I do understand that both you and myself can find a source or two for a short period arctic temperature trend. However, I was looking for the reason that Dr Meier did not list a reference for temperature data and it’s effect on ice melt.

  80. PezdePlata says:

    @Jimbo

    “Water temperature and salinity

    Maximum upper ocean temperatures in summer 2009 continued to decline since the historical extreme in summer 2007 (Fig. O.2). This tendency is strongly linked to changes in the characteristics (e.g., pace and location) of the summer sea ice retreat and their effect on local atmospheric warming (Steele et al. 2010, manuscript submitted to J. Geophys. Res.). Surface warming and sea ice reduction in the Canada Basin has also been accompanied by the widespread appearance of a near-surface temperature maximum at 25–35 m depth due to penetrating solar radiation (Jackson et al. 2010). As described in the Arctic atmosphere section, the heat accumulated in the surface and near-surface layers of the ocean can be released back into the atmosphere in the fall—a cycle that is likely to influence sea ice conditions in the future.

    Extract from the link I posted earlier.

  81. spen says:

    Any author who knows the difference between complementary and complimentary registers confidence in me. Well done Dr Meier

  82. atheok says:

    Dr. Meier: Thank you for posting. That said, I have a difficult time reading your science, well prepared and articulate presentation, and accepting your leaps in logic. The leaps in logic are either based on somebody else’s science (and I assume their conclusions) or behind paywalled research and again their conclusions.

    ‘…The additional energy is not always indicated by warmer local air temperatures though, especially in ice-covered areas. The Danish Meteorological Institute (DMI) air temperature estimates for north of 80° N, shows summer temperatures just above freezing during summer and there is little or no trend. This is because the additional energy is used to melt the surface of the ice and not warm the atmosphere, which stays near the melting point through the summer…”

    Unexplained, yet explained away by possibles assumption. That is, plausible conclusions are maybe used as conclusions and citations to the work drop the maybes. No long term historical research, No existing climate or circulation cycles verified, no defined laboratory experiments/tests confirming assumptions then verified by direct observations of the identified processes in the field. It seems that climate science no longer is based on repeatable tests confirmed by larger yet still repeatable experiments in the field.

    When people fantasize theories and then confirm them with programs and models designed to provide confirmation, it bears little difference both in result and method from preschoolers involved in make-believe plays. Nothing of this process resembles reality except through sheer chance.

    Your science is excellent. Keep performing your science and expect others in the climate science world to perform with equal rigor and standards. When faced with a leap in logic, look explicitly for the data that validates and confirms the steps towards the conclusion. All too often we are being handed conclusions and refused any information that might prove a supposition.

    Coincidence is not causation! Yet we are being handed conclusions that depend on accepting causes without proof that current trend are more than coincidence. A science lesson every climate scientist existing must understand is that climate is based on natural cycles (often very long ones)until PROVED otherwise. Your science is wonderful. Your acceptance of other’s statements of causation when proof is lacking is puzzling. What about climate science is so secret that you accept their proofs, but we are not allowed to see/read/analyze those proofs. Are we so unclean?

    Think about it. If you were to look at long long climate cycles and you accept there are ice ages and warmer periods in-between, what are your expectations for how this cycle proceeds? Just what steps have you taken to ensure any atmospheric science you observe are truly outside of normal boundaries? This is even before we get into historical concepts of warmer or cooler episodes of climate, e.g. Roman warm period, medieval warm period. And we haven’t even reached back to deeper time climate cycles, yet; such as, when can we expect a return to weather the dinosaurs experienced? If not, exactly whynot? I’ll lay odds that it’s not because of CO2 or CFCs, (CFCs have been postulated recently by warmers trying to explain why CO2 is on vacation as a greenhouse gas the last decade).

  83. Ed Barbar says:

    “Using all different ranges of greenhouse gasses that occurred during the early Eocene, models were unable to produce the warming that was found at the poles and the reduced seasonality that occurs with winters at the poles being substantially warmer. The models, while accurately predicting the tropics, tend to produce significantly cooler temperatures of up to 20 °C (36 °F) underneath the actual determined temperature at the poles.[14] This error has been classified as the “equable climate problem”. To solve this problem, the solution would involve finding a process to warm the poles without warming the tropics. Some hypotheses and tests in attempt to find the process are below.”

    http://en.wikipedia.org/wiki/Eocene

  84. John Daly gave a good reason to take Atlantic and Pacific ocean circulation into consideration.
    After all, more floating ice melts from the bottom than from the top. Here is one of his illustrations

    Seems to me, Dr Meier falls a bit short in acknowledging the influence of the respective oceanic oscillations.

  85. Pamela Gray says:

    I prefer to look at all sources of additional heat energy. Greenhouse gas sourced higher air temperatures are one source, but a distant cousin compared to what really has the power to warm us or chill us. The author has failed to rule out the first encountered pathology – Oceanic current temperatures going in and out of the bowl. In NE Oregon, we are hog-tied to the temperature of the pond to the west of us. And not just the overall temperature, but the temperature and placement of different pools of warm versus cold water in that big pond. As the on-shore flow and jet stream pick up these “pond” signals we get warm and dry, warm and wet, cold and dry, or cold and wet, depending on where these ponds are and what temperature they are. What’s worse, we get to experience these wonderful results over multiple years, because the offending pools of water tend to oscillate noisily in and out of these conditions over multiple years and sometimes over multiple decades.

    The Arctic is filled with currents going this way and that, and run the gamut of temperatures. This also means the Arctic has its fair share of pools. It makes sense to see what is happening with these current and pool temperatures before looking at CO2. The proper analysis should have included such an obvious and well known source and store of heat energy variations, oscillations, and trends.

  86. HR says:

    If you take a look at the warming trends in the NH air temperature outside of the arctic (eg 0oN-60oN) you’ll see that there has been zero warming over the past decade.

    There has also been zero warming in the Atlantic waters entering into the arctic seas for the past 5 years.

    How long can internal feedback processes continue to warm the arctic and melt more ice without an increase in energy avected from outside the arctic?

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