Jump to content
Thunder?
Local
Radar
Pollen
IGNORED

Arctic Ice 2009


J10

Recommended Posts

This is the thread to discuss the summer melt season, remember to RESPECT others opinions, and if we can try to be objective, this will help the quality and tone of debate.

Moving on, I have attached the first update for the Summer Season, there has been quite a change this week on the IJIS figures, with large rises and falls, averaging at a drop of around 55,000sqkm per day. This has dropped the overall total below the average for the year for the first time in months, albeit only by around 10000sqkm, this is the 4th highest figures ( of 7), of interest we are now 75000 below 2008, and 95000 above 2007.

Latest Update and this years ice extent is continuing to drop closer to the average at this time of year, being just over 95,000sqkm above the average at this time of year, and this equates to the second highest, slightly below the corresponding figure in 2003, the current ice loss is now around 60,000sqkm per day.

Arctic_Ice_Spring_2009.xls

Arctic_Ice_Summer_2009.xls

Link to comment
Share on other sites

  • Replies 630
  • Created
  • Last Reply
Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......
    of interest we are now 75000 below 2008, and 95000 above 2007.

    Arctic_Ice_Summer_2009.xls

    Thanks for the new thread J1! :D

    We must remember when we compare figures that the makeup of the pack is different for each year (never mind the conditions across the melt season).

    As we all saw last year even an 'average' season will now melt out a large portion of the pack over the coarse of the melt season. This year we have even less 'stable' perennial in place and the old 'Strongholds' for the perennial are no more leaving a thin pack from the East Canadian sector through to Barrents.

    I do not like the steepness of the IJIS plot now the summer 'recalibrations' are over. The closeness of all 7 years on the plot would suggest that a continued ablation at current rates would pretty rapidly have extent at the lowest of the 7 years on the plot. In reality one would expect melt to start speeding up as we enter the 4 weeks around solstace.

    Another point is the breakup of the pack beyond 75n (as the C.T. site hints at).

    Link to comment
    Share on other sites

    Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

    Yup , pretty avarage so far.Gone from near the 79'-2000 average to under last years figure for the same time (and beyond looking at the IJIS figures).

    MODIS gives a good view (cloud willing) of just how fragmented the central pack is now confirming the C.T. images of the high arctic and this just as the melt is accellerating.

    The East coast of Greenland is already seeing some 'traffic' from large plates of ice and Bergs seeing as it's clear waters to the north of there through to Svalbard and beyond.

    Even the NW Passage is showing signs of an earlier clearence the the past two years with both ends breaking up now.

    I wonder how long it takes for things to become 'Average'? 2 years maybe??? LOL

    Link to comment
    Share on other sites

    Posted
  • Location: hertfordshire
  • Location: hertfordshire

    Again nothing of any significance to report and with a normal melt season forcast things looking very, very,very positive.

    Link to comment
    Share on other sites

    Posted
  • Location: Lincoln, Lincolnshire
  • Weather Preferences: Sunshine, convective precipitation, snow, thunderstorms, "episodic" months.
  • Location: Lincoln, Lincolnshire

    Tundra, I get a strong sense of you looking for what you want to see and fitting confirmation bias around it, rather than looking objectively (this also goes for the "the globe is cooling open your eyes" jibe in the previous thread). The 2007 melt was certainly not "normal"!

    I see a fair bit to be concerned about with the current melt now close to the record-breaking 2007 melt. Again we cannot read too much into this because it could be that melt doesn't accelerate in the summer like it did in 2007- indeed it could stall quite early in the season as per 2006. But the last month's trend is not positive.

    Link to comment
    Share on other sites

    Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......
    Tundra, I get a strong sense of you looking for what you want to see and fitting confirmation bias around it, rather than looking objectively (this also goes for the "the globe is cooling open your eyes" jibe in the previous thread). The 2007 melt was certainly not "normal"!

    I see a fair bit to be concerned about with the current melt now close to the record-breaking 2007 melt. Again we cannot read too much into this because it could be that melt doesn't accelerate in the summer like it did in 2007- indeed it could stall quite early in the season as per 2006. But the last month's trend is not positive.

    Not quite 'model watching' but we should still try to compare 'like for like' I feel and ,seeing as we have very low perennial volumes and high single year ice volumes, it is difficult to find other 'likes' .

    Only 07' and 08' come close but we are in poorer shape than either of those years.

    Yes, a lot depends on the synoptics over summer but as we found last year even 'average summers' can bring about record low ice extents/volumes/% perenial left.

    I do expect a steep drop-off of ice levels to start as early as mid-July as the dark water increases (already many areas have plenty of water surrounding the now rounded flows).

    Link to comment
    Share on other sites

    Posted
  • Location: Aberdeen
  • Location: Aberdeen

    Yup , pretty avarage so far.Gone from near the 79'-2000 average to under last years figure for the same time (and beyond looking at the IJIS figures).

    MODIS gives a good view (cloud willing) of just how fragmented the central pack is now confirming the C.T. images of the high arctic and this just as the melt is accellerating.

    The East coast of Greenland is already seeing some 'traffic' from large plates of ice and Bergs seeing as it's clear waters to the north of there through to Svalbard and beyond.

    Even the NW Passage is showing signs of an earlier clearence the the past two years with both ends breaking up now.

    I wonder how long it takes for things to become 'Average'? 2 years maybe??? LOL

    Talk about facetious! If you had read that link, which is the foremost authority on the issue of Arctic ice seasonal predictions, you will see that they don't expect the NW passage to be navigable this year. Let's take it one step at a time shall we. Things look as if they could go either way.

    Enough premature extrapolation :D

    Link to comment
    Share on other sites

    Posted
  • Location: Napton on the Hill Warwickshire 500ft
  • Weather Preferences: Snow and heatwave
  • Location: Napton on the Hill Warwickshire 500ft
    Again nothing of any significance to report and with a normal melt season forcast things looking very, very,very positive.

    Best post so far.

    Objective and correct ie nothing as yet to be alarmed about.

    Will have another look in a month.

    Link to comment
    Share on other sites

    Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk

    i agree also nothing dramatic to report but i do get the feeling sometimes that the ice melt scenario gets over hyped we gain lots of ice infact near the 79 average.

    but then then the melt season takes effect then the drama unfolds even though not alot is going on,

    and i myself expect this years melt to be around average in terms of melt after seeing a exciting arctic comeback in 08/09 but anything is possible but unlikely this year.

    even with a weak el nino. :D:D

    and if all goes good then 09/10 will be even better around the arctic so no need to be alarmed just yet.

    ofcoarse im sure some will have different idears but i often wonder wether focus is just on the ice melt and not the ice gain. :)

    Link to comment
    Share on other sites

    Latest IJIS figures, shows a slow down of the ice loss, and a climb back above 2008 figure and also above the 2003-08 average, however at this time, 2007 was also doing quite well in fact above 2008, so no real picture is emerging yet.

    Link to comment
    Share on other sites

    Posted
  • Location: Lincoln, Lincolnshire
  • Weather Preferences: Sunshine, convective precipitation, snow, thunderstorms, "episodic" months.
  • Location: Lincoln, Lincolnshire
    Best post so far.

    Objective and correct ie nothing as yet to be alarmed about.

    Will have another look in a month.

    That's the opposite of what Gray-Wolf was accused of- saying something is objective and correct, presumably because it supports your view rather than because of the objective reality. The objective reality is that nobody is "right" yet as the melt could still go either way. A cool cloudy summer up in the Arctic could give us another fairly significant recovery and we could be onto something good. But a warm sunny summer with frequent warm plumes could plunge us into a similar ice minimum to what we had in 2007.

    Link to comment
    Share on other sites

    It's much too early to say anything. Look back at the IJIS plots for the last few years and see where the 2007 and 2008 melts broke away from the pack. Neither of them appeared out of the ordinary at this stage.

    2007 broke away during July, due to extremely favourable conditions promoting the melt. It is reasonable to assume this will happen again if this year is similarly conducive to melt. If it's not, then as in 2008 the melt will appear comparatively unexceptional through June and July.

    2008 didn't break away from the rest of the data curves until August. In this case the break away was due to "melting out" of vast amounts of thin first-year ice - thin because of the 2007 record melt. This meant that the melt season was prolonged well beyond the time when it normally tails off. It's important to point out that the thin first-year ice melted out even in what was a fairly normal year for melt conditions. Given that this summer has a similar proportion of first-year ice in place, it is reasonable to assume that this year will show a similarly prolonged melt season, with strong losses continuing through August.

    What does this mean for this thread? It means there's very little point faffing around pointing at individual days' results! By mid-July it will be clear whether we're following the "normal" 2000-2006 pattern or the catastrophic 2007 pattern. And we won't know until mid-August whether the extreme late-season melt of 2008 will repeat itself. If both these potential disasters are evaded, we could see a return to ~2005 levels of ice (still well down from the 70s and 80s!). If either comes to pass, we'll be looking at another very bad year, while if both come to pass, we'll see a new record low.

    Link to comment
    Share on other sites

    Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk
    It's much too early to say anything. Look back at the IJIS plots for the last few years and see where the 2007 and 2008 melts broke away from the pack. Neither of them appeared out of the ordinary at this stage.

    2007 broke away during July, due to extremely favourable conditions promoting the melt. It is reasonable to assume this will happen again if this year is similarly conducive to melt. If it's not, then as in 2008 the melt will appear comparatively unexceptional through June and July.

    2008 didn't break away from the rest of the data curves until August. In this case the break away was due to "melting out" of vast amounts of thin first-year ice - thin because of the 2007 record melt. This meant that the melt season was prolonged well beyond the time when it normally tails off. It's important to point out that the thin first-year ice melted out even in what was a fairly normal year for melt conditions. Given that this summer has a similar proportion of first-year ice in place, it is reasonable to assume that this year will show a similarly prolonged melt season, with strong losses continuing through August.

    What does this mean for this thread? It means there's very little point faffing around pointing at individual days' results! By mid-July it will be clear whether we're following the "normal" 2000-2006 pattern or the catastrophic 2007 pattern. And we won't know until mid-August whether the extreme late-season melt of 2008 will repeat itself. If both these potential disasters are evaded, we could see a return to ~2005 levels of ice (still well down from the 70s and 80s!). If either comes to pass, we'll be looking at another very bad year, while if both come to pass, we'll see a new record low.

    i see nothing to suggest 2007 repeat,

    we made a good recovery 08/09 and if it where to happen so what next ?

    nothing i expect because it will come back even with a 2007 melt,

    if it dont melt then maybe where have to talk about the arctic recovery.

    dont get me wrong its great to talk about the arctic ice but its the drama the way it pushed apon us really gets my back up i hold my hands up and well if it happens what the hell am i soposed to do what next.

    nothing because no one will be able to do anything :)

    Link to comment
    Share on other sites

    Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

    For those wondering about the 'difference in ice loss I'd suggest a look at the leach off of the perennial pack over the last 5 years. Sub evidence would have it that the Arctic basin has been melting down since at least the late 50's but the real proof is when that chunk of perennial is not just thinning (from below) but melted out completely. 3/4 of the perennial we used to measure is now gone. Much of that was situated at lower latitudes effectively 'blocking' ice flow into warmer waters. Today the Arctic Gyre runs without hindrance and ,what's more the SST's are so high we see no berg's entering the Atlantic from the east coast of Greenland (check out the +ve anom there) as we did in the past.

    I'd agree that mid-July is the point to start seeing how things are progressing but the majority thin ice will melt out because of it's 'thinness' and not purely the weather conditions on the ground (it all sits on fluid water y'see). :(

    Link to comment
    Share on other sites

    Posted
  • Location: Aberdeen
  • Location: Aberdeen
    Today the Arctic Gyre runs without hindrance and ,what's more the SST's are so high

    Presumably you mean soley to the E of Greenland as there are more extensive negaitve anomalies in other parts, notably W of Alaska.

    Link to comment
    Share on other sites

    Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......
    Presumably you mean soley to the E of Greenland as there are more extensive negaitve anomalies in other parts, notably W of Alaska.

    I think the patch you speak of is more than compensated by the other +ve anoms across the arctic :rolleyes:

    As we see off Ross in Antarctica each summer patches of cold melt run off do influence (short term) areas of ocean.

    Watch the west coast of Greenland over the summer months for such patches as the glaciers and ice sheet pour of into the channel between Canada and Greenland. :)

    Link to comment
    Share on other sites

    Posted
  • Location: Aberdeen
  • Location: Aberdeen
    I think the patch you speak of is more than compensated by the other +ve anoms across the arctic :doh:

    As we see off Ross in Antarctica each summer patches of cold melt run off do influence (short term) areas of ocean.

    Watch the west coast of Greenland over the summer months for such patches as the glaciers and ice sheet pour of into the channel between Canada and Greenland. :cray:

    OK, let me get this straight...

    Warmer than average SSTs mean the ice is going to melt.

    Colder than average SSTs mean the ice has melted.

    :doh:

    Link to comment
    Share on other sites

    Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......
    OK, let me get this straight...

    Warmer than average SST's mean the ice is going to melt.

    Colder than average SST's mean the ice has melted.

    :D

    Water is water and unless under immense pressure is only fluid above 0c (as I understand things). :)

    Link to comment
    Share on other sites

    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey
    Latest IJIS figures, shows a slow down of the ice loss, and a climb back above 2008 figure and also above the 2003-08 average, however at this time, 2007 was also doing quite well in fact above 2008, so no real picture is emerging yet.

    This is the non cherry picked, informative post. Thanks for that Jackone

    BFTP

    Link to comment
    Share on other sites

    Posted
  • Location: Lincoln, Lincolnshire
  • Weather Preferences: Sunshine, convective precipitation, snow, thunderstorms, "episodic" months.
  • Location: Lincoln, Lincolnshire

    Agreed.

    I'm watching a pool of 20C 850hPa air that looks set to move into the east Asian side of the Arctic over the next few days. Could be quite a significant Siberian melt if that warm pool gets far north enough.

    Link to comment
    Share on other sites

    This is the non cherry picked, informative post. Thanks for that Jackone.

    BFTP

    It's informative to be sure, and it's not deliberately cherry-picked. However you need to be really cautious when looking only to the IJIS figures for evidence of recovery, since they only go back as far as 2000 - which means they cover the eight worst years on record! Values around the average of the IJIS data set are NOT a sustained recovery, they're evidence that things are still very bad indeed.

    For a more realistic comparison, you need to look at the figures on the NSIDC website, or on Cryosphere today, which will show you how the current ice pack is holding up relative to the 1979-2000 average. To save you the bother, I'll tell you today's figures: they're a million square kilometers lower than they should be.

    http://arctic.atmos.uiuc.edu/cryosphere/

    http://nsidc.org/arcticseaicenews/

    For what it's worth, my prediction for this year is "No better than 2008". We started the year with the same amount of ice as 2008, there's a similar proportion of first year / multi-year ice, and the conditions in 2008 were not particularly favourable or unfavourable for melt. Thus, if this year's conditions are similarly average, we should expect a similar melt. If we do tip into an El Nino and see greater melt earlier in the season, then the 2007 record is in danger. The truly worrying factor is that given an average melt season and average winter, 2008 saw no recovery in multi-year ice. We seem to have lost the conditions for creating it (and, more importantly, preventing it being flushed out by Arctic currents). Thus, for it to recover will require unusually cold winters, every year, for decades.

    Link to comment
    Share on other sites

    It's informative to be sure, and it's not deliberately cherry-picked. However you need to be really cautious when looking only to the IJIS figures for evidence of recovery, since they only go back as far as 2000 - which means they cover the eight worst years on record! Values around the average of the IJIS data set are NOT a sustained recovery, they're evidence that things are still very bad indeed.

    For a more realistic comparison, you need to look at the figures on the NSIDC website, or on Cryosphere today, which will show you how the current ice pack is holding up relative to the 1979-2000 average. To save you the bother, I'll tell you today's figures: they're a million square kilometers lower than they should be.

    If the figures from NSIDC were available in a numerical format, going back to 1979, I would use them, unfortunately they do not appear to supply this data, which makes a comparison of the type you describe impossible. The thought that the figures are remotely cherry picked which you are insinuating is absolute nonsense, and you now it, provide the NSIDC figures in a daily format, and I wil provide these figures in the same way a I do with the IJIS figures.

    The figures I use are always shown in comparison to the recent years, and no other comparison is ever intended, I never say how they compare as an example to 1979-2000 averages as an example.

    I supply figures as independently as possible and at a fixed item, to ensure fairness of comparison, and will continue to do this throughout the melt season regardless of how the good/bad the figures are. If you want to criticise the lack of use of NSIC figures, blame NSIDC for nor supplying the figures.

    I also consider the IJIS figures a useful benchmark, if this years out turn is the highest in past 8 years, I think nearly everyone would consider that a good recovery, while below 2007 would clearly be bad results.

    Link to comment
    Share on other sites

    Posted
  • Location: Napton on the Hill Warwickshire 500ft
  • Weather Preferences: Snow and heatwave
  • Location: Napton on the Hill Warwickshire 500ft
    That's the opposite of what Gray-Wolf was accused of- saying something is objective and correct, presumably because it supports your view rather than because of the objective reality. The objective reality is that nobody is "right" yet as the melt could still go either way. A cool cloudy summer up in the Arctic could give us another fairly significant recovery and we could be onto something good. But a warm sunny summer with frequent warm plumes could plunge us into a similar ice minimum to what we had in 2007.

    You miss the point it wasnt my 'view' on what could happen ,it was a comment on what is actually happening now. ie NOW (June 12) all is good.

    On the previous thread someone mention by cira Nov 2009 ways of measuring the volume of ice rather then just area, are we any nearer that.?

    Link to comment
    Share on other sites

    If the figures from NSIDC were available in a numerical format, going back to 1979, I would use them, unfortunately they do not appear to supply this data, which makes a comparison of the type you describe impossible. The thought that the figures are remotely cherry picked which you are insinuating is absolute nonsense

    I'm sorry you took that inference from my post: I thought the phrase "NOT deliberately cherry-picked" was sufficiently unambiguous.

    provide the NSIDC figures in a daily format, and I wil provide these figures in the same way a I do with the IJIS figures.

    They're not available in a daily format, however the monthly data is available - see links below. I recommend graphing the extent figures rather than the area figures for two reasons: (a) it will be more consistent with the IJIS figures, and ( :D if you graph extent, you have to decide what to do with the "polar hole".

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...n/N_01_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...b/N_02_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...r/N_03_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...r/N_04_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...y/N_05_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...n/N_06_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...l/N_07_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...g/N_08_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...p/N_09_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...t/N_10_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...v/N_11_area.txt

    ftp://sidads.colorado.edu/DATASETS/NOAA/G...c/N_12_area.txt

    The full raw daily satellite data is also available linked from ftp://sidads.colorado.edu/pub/DATASETS/se...near-real-time/ - however in this case you need to have programs available to perform the extent calculation yourself (i.e. sum over the image and count all pixels >15% ice , with due regard to the projection from sphere to flat image). Certainly not something I personally know how to do!

    The figures I use are always shown in comparison to the recent years, and no other comparison is ever intended, I never say how they compare as an example to 1979-2000 averages as an example.

    That is unfortunate, because it really obscures the wider picture. If anyone wants to claim there has been a recovery of Arctic ice towards the historical average, they need to know what that average is! Otherwise they're in the position of one who sees a redwood get cut down and gleefully cheers at the mushrooms growing on the stump. I intend no disrespect you personally in pointing this out, which is why I carefully said your graphs are not deliberately cherry-picked. However they do not tell anything like the full story, and it's important not to read any more into them than they will bear.

    I supply figures as independently as possible and at a fixed item, to ensure fairness of comparison, and will continue to do this throughout the melt season regardless of how the good/bad the figures are. If you want to criticise the lack of use of NSIC figures, blame NSIDC for nor supplying the figures.

    The figures are supplied, at least on a monthly basis, and took me all of five minutes to find by following the links from the NSIDC front page.

    Link to comment
    Share on other sites

    Archived

    This topic is now archived and is closed to further replies.

    Guest
    This topic is now closed to further replies.
    ×
    ×
    • Create New...