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Posted
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
  • Weather Preferences: Northeasterly Blizzard and sub zero temperatures.
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK

    Here we go. Will the loss of summer ice be greater than last year ? A close run thing seems likely. How long will first year ice last and how thick is it ?

    Russian submarines cruises and surface coring missions provide the most accuarate results. Latest results, based on sea ice motion data indicate ice thickness in the higher latitudes of the Arctic has slightly increased since the Mid-90s, whereas the volume of sea ice has not increased.

    Some great posts on this thread during the Spring with a lot of emotion and passion about the latest reports. This summers results are going to be crucial.

    C

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    Posted
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
  • Weather Preferences: Northeasterly Blizzard and sub zero temperatures.
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
    Here we go. Will the loss of summer ice be greater than last year ? A close run thing seems likely. How long will first year ice last and how thick is it ?

    Russian submarines cruises and surface coring missions provide the most accuarate results. Latest results, based on sea ice motion data indicate ice thickness in the higher latitudes of the Arctic has slightly increased since the Mid-90s, whereas the volume of sea ice has not increased.

    Some great posts on this thread during the Spring with a lot of emotion and passion about the latest reports. This summers results are going to be crucial.

    C

    Evening all,

    A combination of higher shortwave radition levels and advection of heat plumes into the Arctic contributed to last years record summer loss of sea ice, particularly in the Siberian Sectors. Positive mode AO usually produces greater cloud cover in the summer months with a resultant lowering of incoming radiation levels and lower temperatures. If the North Atlantic high pressure wind divides continues in its present state, warm plumes seem less likely this summer into the high Arctic with extensions of continental lows of North America and Siberia likely to rule.

    C

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

    C'mon. you can make it easier that ....

    Don't spoil it with a load of :D

    I think, to try and paraphrase, the story so far is this;

    Lots less multiyear ice. A bit more winter ice (than of late) but not (generally) of an average, or above average, thickness.

    Most polar agencies appear to be 'running to keep up' with their hind cast/forcast of the Polar ice situation but most now appear to agree that a repeat,or worse, of last years melt is the favoured outcome of this spring/summers melt.

    I am well out of my depth here and so the rest is a purely personal opinion (built from 28 odd year of watching and studying) but I feel we are well beyond the polar 'tipping point' and ,in a world of continued forced heating (above and beyond natural cyclical warming/cooling events), we needed to have protect at least 70% of the 1979 levels of multiyear ice to hold onto any hope of helping nature restore her 'balance' (of sorts).

    Do not be fooled into thinking this is all about Ice, Polar Bears and Walrus's.

    It , to me at least, is about the exposure of the majority of frozen Cathrite deposits, held in the northern permafrosts, to temps above -4c. We all know about the impact of methane (super Greenhouse gas) on the 'warming' we are experiencing/predicted to experience.

    The 'floating' of the remaining 'multiyear ice' from their anchorage on the shelf sea beds in the Polar regions would tend to indicate a rise in the temp of ,not only, the surrounding waters, but also the underlying sea bed/coast.

    The Polar Year's teams witnessing of the solufluction of, until then , solid permafrost hills down to their bedrock ( in the Canadian/Alaskan Arctic) last year shows that the process is up and running and only the grounding of the other major portion of remnant multiyear pack (and the sealing of the 'Eastern Passage') delayed similar ,widescale melting, in Siberia/Eurasia.

    The 'Eastern Passage' is expected to open this summer (along with the NW Passage) and so the grounding event is either not expected to happen again this year or the multiyear pack is expected to melt (or both!) with the inevitable impacts on the permafrost.

    The loss of the multiyear to the north of Greenland would also impact the ice loss on the Greenland ice sheet ( already increased Berg activity is being reported from the Greenland glaciers this year).

    The planting of National flags on the arctic seabed shows little or no global intention to restrict/limit our use of fossil fuels (nor did the Polar Bear dispute in the Chuki sea over Oil exploration!) so we must expect a B.A.U. scenario insofar as our global CO2 outputs are concerned .I feel that we can expect our human efforts to introduce CO2 into the ecosystem will be doubled by the impact of the planets release of it's northern Cathrite deposits over the next 5 years.

    The loss of summer ice in the arctic is no longer the issue ( nor is the loss of our winter snow!!!). The underestimation of the planets response to our forced warming (by the bodies looking at the impacts we are causing), in the form of super greenhouse gas releases, truely is.

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    Posted
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
  • Weather Preferences: Northeasterly Blizzard and sub zero temperatures.
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
    :):D:):doh::doh:

    C'mon. you can make it easier that ....

    Don't spoil it with a load of :D

    Thankyou for your enlighten contribution to my last post. Sorry you find it a load of old ...rubbish..

    To shed a bit more light on my thinking, pressure patterns so far are more influent to produce less sunlight and cooler conditions to prevail in the High Arctic this summer compared to last year.Hope this helps.

    C

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    Posted
  • Location: Worthing West Sussex
  • Location: Worthing West Sussex
    I think, to try and paraphrase, the story so far is this;

    Lots less multiyear ice. A bit more winter ice (than of late) but not (generally) of an average, or above average, thickness.

    Most polar agencies appear to be 'running to keep up' with their hind cast/forcast of the Polar ice situation but most now appear to agree that a repeat,or worse, of last years melt is the favoured outcome of this spring/summers melt.

    I am well out of my depth here and so the rest is a purely personal opinion (built from 28 odd year of watching and studying) but I feel we are well beyond the polar 'tipping point' and ,in a world of continued forced heating (above and beyond natural cyclical warming/cooling events), we needed to have protect at least 70% of the 1979 levels of multiyear ice to hold onto any hope of helping nature restore her 'balance' (of sorts).

    Do not be fooled into thinking this is all about Ice, Polar Bears and Walrus's.

    It , to me at least, is about the exposure of the majority of frozen Cathrite deposits, held in the northern permafrosts, to temps above -4c. We all know about the impact of methane (super Greenhouse gas) on the 'warming' we are experiencing/predicted to experience.

    The 'floating' of the remaining 'multiyear ice' from their anchorage on the shelf sea beds in the Polar regions would tend to indicate a rise in the temp of ,not only, the surrounding waters, but also the underlying sea bed/coast.

    The Polar Year's teams witnessing of the solufluction of, until then , solid permafrost hills down to their bedrock ( in the Canadian/Alaskan Arctic) last year shows that the process is up and running and only the grounding of the other major portion of remnant multiyear pack (and the sealing of the 'Eastern Passage') delayed similar ,widescale melting, in Siberia/Eurasia.

    The 'Eastern Passage' is expected to open this summer (along with the NW Passage) and so the grounding event is either not expected to happen again this year or the multiyear pack is expected to melt (or both!) with the inevitable impacts on the permafrost.

    The loss of the multiyear to the north of Greenland would also impact the ice loss on the Greenland ice sheet ( already increased Berg activity is being reported from the Greenland glaciers this year).

    The planting of National flags on the arctic seabed shows little or no global intention to restrict/limit our use of fossil fuels (nor did the Polar Bear dispute in the Chuki sea over Oil exploration!) so we must expect a B.A.U. scenario insofar as our global CO2 outputs are concerned .I feel that we can expect our human efforts to introduce CO2 into the ecosystem will be doubled by the impact of the planets release of it's northern Cathrite deposits over the next 5 years.

    The loss of summer ice in the arctic is no longer the issue ( nor is the loss of our winter snow!!!). The underestimation of the planets response to our forced warming (by the bodies looking at the impacts we are causing), in the form of super greenhouse gas releases, truely is.

    I take the opposite viewpoint - repeated loss of sea-ice over several summers will result in an increased rate of global cooling, increase of permafrost depth and area, increased world ocean cooling, and then a rapid reestablishment of the northern polar ice to record extents. The annual melt may be extreme for perhaps another 8 years, maybe less time than that, and the refreeze sets in for the following 10-15 years.

    Why? The open polar ocean not only absorbs sunlight - it emits long wave radiation much more effectively than ice does. It absorbs CO2 much more effectively than ice covered water, CO2 which is efficiently sequestered by the extremely productive biological processes in the northern ocean. Open polar ocean results in higher humidity of the continental sub-polar air - leading to increased winter precipitation as we saw last year - thus extending the cool period, and encouraging wetter spring and summer conditions.

    Northern deep oceans cool.

    A cooling Northern hemisphere increases Southern polar cooling, and Antarctic precipitation.

    Southern deep oceans cool.

    ENSO shifts to predominantly La Nina conditions, with increasing precipitation at tropical and subtropical latitudes.

    Atmospheric CO2 falls.

    Everything cools.

    We have been seeing this for several years, but have been blinded by the forcefulness of AGW propaganda.

    Has this situation I have laid out above been predicted by climatologists? Ewing and Donn, for instance in the 1950s:

    "Our current epoch of ice ages, Ewing and Donn argued, had begun when the North Pole wandered into the Arctic Ocean basin. The ocean, cooling but still free of ice, had evaporated moisture and promoted a pattern of severe weather. Heavy snows fell all around the Arctic, building continental ice sheets. That withdrew water from the world's oceans, and the sea level dropped. This blocked the shallow channels through which warm currents flowed into the Arctic Ocean, so the ocean froze over. That meant the continental ice sheets were deprived of storms bringing moisture evaporated from the Arctic Ocean, so the sheets began to dwindle. The seas rose, warm currents spilled back into the Arctic Ocean, and its ice cover melted. And so, in a great tangle of feedbacks, a new cycle began."

    (From Spencer Weart's excellent treatise on global Warming at www.aip.org)

    http://www.aip.org/history/climate/simple.htm#M_48_

    What's the weather likely to do in the next week at the pole?

    Watch this space: Rhavn841.gif

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    Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

    Chris and Carinthian: How do you both see the knock on effect in this country? Do you think it will effect weather patterns here, if so how? Will we see a period of wet, cool Springs followed by cooler winters or do you think the effects here will be one of warming? Was last summer's high rainfall connected in any way to the ice loss?

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

    Hi Chris!

    a very novel take on things but I have never come across any research that would back up your scenario. Most all of the agencies dealing with the cryosphere are singing from the same hymn sheet and all are alarmed at the recent rapidity of ice loss in the arctic.

    Time will tell?

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    Posted
  • Location: Worthing West Sussex
  • Location: Worthing West Sussex
    Chris and Carinthian: How do you both see the knock on effect in this country? Do you think it will effect weather patterns here, if so how? Will we see a period of wet, cool Springs followed by cooler winters or do you think the effects here will be one of warming? Was last summer's high rainfall connected in any way to the ice loss?

    Almost certainly Jethro - the SSTs over the Central North Atlantic last summer showed a pool of anomalously cold surface water in the same region as the stable Azores High over the period during which we experienced the wet summer weather - due to cool meltwater moving south along the Eastern seabord of N America and then eastwards overriding the North Atlantic drift. When the melt stopped, the North Atlantic warmed in the area, due to the influence of the southerly current, and we experienced the warm dry autumn. I think we shall see something similar this year, perhaps with a shorter period of warm dry weather in the autumn in the UK. We may even start to get some cold winters soon.

    This indicates the situation in late June last year:

    anomnight.6.25.2007.gif

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    Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

    Thanks for that Chris; I'm trying to put together a 10 - 50 year game plan for an estate at the moment, likely weather patterns in this country are a crucial part of it, sifting alarm from facts is tremendously difficult.

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    Posted
  • Location: Worthing West Sussex
  • Location: Worthing West Sussex
    Hi Chris!

    a very novel take on things but I have never come across any research that would back up your scenario. Most all of the agencies dealing with the cryosphere are singing from the same hymn sheet and all are alarmed at the recent rapidity of ice loss in the arctic.

    Time will tell?

    Hi GW, it is a new experience for all of us, including the experts!

    The ice loss (thickness, concentration) has been going on for years, but the open Arctic is new, but think about it - the refreeze was amazing - yet we are both certain it will all go again this summer - representing two years unprecedented cold, less salty water flowing into the Atlantic and Pacific at the northern latitudes.

    The Antarctic maintains its 1M sq Km anomaly, over and above last year's record high minimum levels.

    Phenomenal amounts of snow fell on the northern continents last winter (except Western Europe!) - the albedo of the NH after the winter was higher than for many years until about a month ago, when much of the remaining snow melted, for the usual seasonal reasons.

    Temperatures in the atmosphere at all levels from the ground to the stratosphere are cooler than last year - at cloud top levels, record low temperatures below the 20 year minimum are being experienced, a degree below the 20 year mean.

    gallery_7302_418_81936.jpg

    On the Milankovich orbital eccentricity cycle, the most highly correlated with iceages, we are due to cool anytime soon:

    gallery_7302_418_54416.jpg

    Compare with 40,000 years ago. There is a simple significant theme existing since the northern hemisphere became dominated by land and the SH by oceans - as the annual difference in solar heating between the hemispheres becomes less pronounced - the current 90 W/m2 extra radiation experienced by the southern hemisphere in January over the northern hemisphere in July will become less as the earth's orbit becomes more circular, aided by precession of the equinoxes over a period of the next 21,000 years, and the obliquity cycle of 41,000y, both on the downturn.

    Why? The oceans are the biggest heat sink, and control climate on decadal terms. The southern oceans offer a much larger area than the northern counterparts. Land in the north warms and cools annually, to levels maintained by the heat pool of the oceans. The cryosphere is the key to sudden change, the tipping point, if you will, but in a counterintuitive direction.

    The atmosphere and weather follows, in its chaotic variability, and following annual cycles. The weather is not getting hotter, it is staying less cool, both diurnally and seasonally, in the northern hemisphere. This last winter has marked a downturn, more will follow.

    The 150 odd years between the mini iceages of the last 400years has also come around, and it has nothing to do with solar cycles or sunspots, but coincidentally with the rather irregular solar weather cycles.

    I am not saying this is the beginning of the next iceage, just that we are near the end of the current interglacial, and it has nothing to do with weather, or atmospheric greenhouse gas composition - they are just indicators of the changes that have been happening in the oceans over the last century or so.

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    Posted
  • Location: Zurich Switzerland
  • Location: Zurich Switzerland

    lol no wonder there is much confusion... i can see GWs point and also Chris's. i guess there will be data to back up either scenario. the proof of course will be in the pudding. For the short term at least we are more than likely to see sea ice levels continue to drop, with perhaps one or two years subject to variations in this theme. I do hope though that this isnt the end and that indeed sometime in the not too distant future we will start to see a recovery of sea ice and maybe even the good old fashioned winters we always see in the movies but never in reality.

    il continue to read the arguments with great anticipation.

    just a few bits of current data...

    quite a strong artic high forecast over the next week or so.. not sure about radiation levels.. has anyone got a link for this kinf of data for the Arctic?

    2m temp anomolies..

    sfctmpmer_01b.fnl.gif

    for today at least some negative anomolies.. this is likely to change over the next few days though..

    current reports of -5 degrees in places - from buoy informaton

    sea ice thickness still 30-200cms in most places...

    n080526.gif

    SSTS

    unisys - lots of negative anomolies.. not suprisingly!

    sst_anom.gif

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    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey
    .

    I am well out of my depth here and so the rest is a purely personal opinion (built from 28 odd year of watching and studying) but I feel we are well beyond the polar 'tipping point' and ,in a world of continued forced heating (above and beyond natural cyclical warming/cooling events), we needed to have protect at least 70% of the 1979 levels of multiyear ice to hold onto any hope of helping nature restore her 'balance' (of sorts).

    The loss of summer ice in the arctic is no longer the issue ( nor is the loss of our winter snow!!!). The underestimation of the planets response to our forced warming (by the bodies looking at the impacts we are causing), in the form of super greenhouse gas releases, truely is.

    GW

    From your previous post the following is the MOST important sentence of all

    But the down side to the retreat of the Arctic's thin ice cover is a 50-50 chance that the North Pole will become ice-free this September - for the first time in more than 100,000 years.

    So we've been there and done that. What followed that type of global change?

    Re methane - well contrary to all alarmism Methane levels have been falling since early 90s and continue to do so - so that supergreenhouse appears to bear no threat currently [if indeed it is a threat].

    Chris

    I am sort of there with you.....arctic being ice free has according to theory by Simpson preceeds an iceage...every time.

    Now re La Nina....we ahve already entered the perturbation cycle in Feb 07 so that is already upon us. The ice minina certainly 'seemed' to do nothing regarding the temps up there...it was a very cold arctic winter in general with huge amounts of widespread cold outbreaks surging southward. Are we to see more....you bet we are.

    The Unisys SST shows a classic cold phase PDO with the reverse C in the Pacific of cold water. This is important because the La Nina phase and PDO cold phase have converged together and will run fo about 20-30 years together. Hence why NASA now say there may be 20-30 years of cooling.

    To chuck it in too re milankovitch cycle...part of it is to do with the tilt of the earth.....will a bottom heavy planet assist in a 'wobble' and change the tilt? . We know the tilt ranges from 22.5 to 24.5deg and we also know it is on the move currently away form the 'ideal' angle.

    Solar cycle 24 is very much on target now to be a quiet cycle [much quieter than some expected] and we could be heading towards a Dalton equivalent minima by 2030.

    To finish though as mentioned before I may lean on other side of fence to GW but I share his concerns as there are bound to be some strong knock on effects out of this one way or another.

    BFTP

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    Posted
  • Location: Thame, Oxfordshire
  • Location: Thame, Oxfordshire
    Thankyou for your enlighten contribution to my last post. Sorry you find it a load of old ...rubbish..

    To shed a bit more light on my thinking, pressure patterns so far are more influent to produce less sunlight and cooler conditions to prevail in the High Arctic this summer compared to last year.Hope this helps.

    C

    Carinthian,

    I look forward to your excellent posts bringing us all back into line when needed...

    Your comments regarding conditions up there are why I don't think the 2007 minimum will be beaten this year, and will herald the recovery in multiyear ice as the planet cools in subsequent years.

    Why? The open polar ocean not only absorbs sunlight - it emits long wave radiation much more effectively than ice does. It absorbs CO2 much more effectively than ice covered water, CO2 which is efficiently sequestered by the extremely productive biological processes in the northern ocean.

    Watch this space: Rhavn841.gif

    Chris

    you make a very important point there, one that ( even) I had not seen ;)

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    I take the opposite viewpoint - repeated loss of sea-ice over several summers will result in an increased rate of global cooling, increase of permafrost depth and area, increased world ocean cooling, and then a rapid reestablishment of the northern polar ice to record extents. The annual melt may be extreme for perhaps another 8 years, maybe less time than that, and the refreeze sets in for the following 10-15 years.

    Why? The open polar ocean not only absorbs sunlight - it emits long wave radiation much more effectively than ice does. It absorbs CO2 much more effectively than ice covered water, CO2 which is efficiently sequestered by the extremely productive biological processes in the northern ocean. Open polar ocean results in higher humidity of the continental sub-polar air - leading to increased winter precipitation as we saw last year - thus extending the cool period, and encouraging wetter spring and summer conditions.

    Northern deep oceans cool.

    A cooling Northern hemisphere increases Southern polar cooling, and Antarctic precipitation.

    Southern deep oceans cool.

    ENSO shifts to predominantly La Nina conditions, with increasing precipitation at tropical and subtropical latitudes.

    Atmospheric CO2 falls.

    Everything cools.

    We have been seeing this for several years, but have been blinded by the forcefulness of AGW propaganda.

    Has this situation I have laid out above been predicted by climatologists? Ewing and Donn, for instance in the 1950s:

    "Our current epoch of ice ages, Ewing and Donn argued, had begun when the North Pole wandered into the Arctic Ocean basin. The ocean, cooling but still free of ice, had evaporated moisture and promoted a pattern of severe weather. Heavy snows fell all around the Arctic, building continental ice sheets. That withdrew water from the world's oceans, and the sea level dropped. This blocked the shallow channels through which warm currents flowed into the Arctic Ocean, so the ocean froze over. That meant the continental ice sheets were deprived of storms bringing moisture evaporated from the Arctic Ocean, so the sheets began to dwindle. The seas rose, warm currents spilled back into the Arctic Ocean, and its ice cover melted. And so, in a great tangle of feedbacks, a new cycle began."

    (From Spencer Weart's excellent treatise on global Warming at www.aip.org)

    http://www.aip.org/history/climate/simple.htm#M_48_

    What's the weather likely to do in the next week at the pole?

    Interesting, but largely inaccurate. Deep oceans won't cool any further than they are already because of the stratification of water as it cools due to its varying density. 90% of ocean water is below the depth of the thermocline - the layers affected by temperature differences - and is already between 0 - 3 degC.

    And in the arctic this is even more irrelevant because there is little or no thermocline and the ocean is equally cold throughout its depth.

    edited to remove image repost

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    Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......
    Re methane - well contrary to all alarmism Methane levels have been falling since early 90s and continue to do so - so that supergreenhouse appears to bear no threat currently [if indeed it is a threat].

    BFTP

    Sorry to disabuse you of your notions BFTP but it would seem you are a little behind the times;

    Carbon dioxide, methane levels rise sharply in 2007

    mongabay.com

    April 23, 2008

    Atmospheric concentrations of carbon dioxide and methane — potent greehouse gases — rose sharply in 2007, according to NOAA.

    The U.S. weather agency said that global levels of carbon dioxide, the primary driver of global climate change, climbed by 0.6 percent, or 19 billion tons in 2007. Methane levels increased by 27 million tons after nearly a decade with little or no increase.

    NOAA said that atmospheric CO2 levels currently stand at 385 parts-per-million, or about 38 percent higher than pre-industrial levels. It noted that the rise in CO2 concentrations has been accelerating since the 1980s when annual increases were around 1.5 ppm per year. Last year the increase was 2.4 ppm.

    On the other hand, the increase in methane levels is a relatively new trend. Emissions had been flat since 1998.

    0423methanetrend.jpg

    Global methane (CO4) concentrations rose in 2007. The red line shows the trend together with seasonal variations. The black line indicates the trend that emerges when the seasonal cycle has been removed. (Credit: NOAA) NOAA attributed the rise in methane emissions to rapid industrialization in Asia and higher emissions from peatlands in the Arctic and the tropics.

    Methane is produced by both human activities and natural causes. About one-third of methane emissions come from oceans, wetlands, wildfires, and termites, while two-thirds from the production of oil and natural gas, mining, sewage and decomposition of garbage, changes in land use and deforestation, and livestock.

    Billions of tons of methane are locked up in Arctic tundra and as frozen hydrate deposits in the deep oceans. Researchers are concerned that as the planet warms, these deposits could destabilize, releasing large methane emissions.

    "We're on the lookout for the first sign of a methane release from thawing Arctic permafrost," said Ed Dlugokencky, a scientists with NOAA's Earth System Research Laboratory. "It's too soon to tell whether last year's spike in emissions includes the start of such a trend."

    0423methaneglobal.jpg

    The 2007 rise in global carbon dioxide (CO2) concentrations is tied with 2005 as the third highest since atmospheric measurements began in 1958. The red line shows the trend together with seasonal variations. The black line indicates the trend that emerges when the seasonal cycle has been removed. (Credit: NOAA) Scientists say hydrate deposits may have played an important role in past climate change by causing fluctuations in atmospheric concentrations of greenhouse gases. For example, the rapid decomposition of frozen methane hydrate deposits, possibly a result of higher ocean temperatures, may have been responsible for the sharp spike in atmospheric concentrations of greenhouse gases during the Palaeocene/Eocene thermal maximum (PETM) -- a period of rapid, extreme global warming about 55 million years ago. The methane released during melting would have reacted with oxygen to produce huge amounts of carbon dioxide. The warming caused a mass extinction among marine animals and helped usher in the "Age of Mammals."

    Most methane emissions never reach the atmosphere -- they are broken down by ultraviolet radiation. For methane that does reach the atmosphere, the gas has a lifetime of about eight years. In contrast, carbon dioxide can last a century in the atmosphere. As such, atmospheric methane levels can be quickly reduced, while carbon dioxide accumulates and presents a long-term problem. Still, methane levels have more than doubled since the beginning of the Industrial Revolution in the 18th century. With twenty five times more heat-trapping potential than carbon dioxide, methane's overall climate impact is nearly half that of carbon dioxide despite atmospheric concentrations of around 1,800 parts-per-billion.

    Meanwhile at 385 ppm, present carbon dioxide levels may be significantly higher than at any point in the last 650,000 years, according to research published in 2005 in the journal Science. The Intergovernmental Panel on Climate Change (IPCC) projects that atmospheric carbon dioxide levels could reach 450-550 ppm by 2050, resulting in higher temperatures and rising sea levels.

    Environmenalists have recently launched a campaign targeting a global CO2 concentration of 350 ppm, a level which they say will avoid the worst impacts of global warming.

    -----------------------------------------------------

    Now I wonder where all that extra methane came from?....................

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    Posted
  • Location: Thame, Oxfordshire
  • Location: Thame, Oxfordshire
    Interesting, but largely inaccurate. Deep oceans won't cool any further than they are already because of the stratification of water as it cools due to its varying density. 90% of ocean water is below the depth of the thermocline - the layers affected by temperature differences - and is already between 0 - 3 degC.

    And in the arctic this is even more irrelevant because there is little or no thermocline and the ocean is equally cold throughout its depth.

    edited to remove image repost

    But the other 95% of what he said could be right ? ;)

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    Posted
  • Location: Worthing West Sussex
  • Location: Worthing West Sussex
    Interesting, but largely inaccurate. Deep oceans won't cool any further than they are already because of the stratification of water as it cools due to its varying density. 90% of ocean water is below the depth of the thermocline - the layers affected by temperature differences - and is already between 0 - 3 degC.

    And in the arctic this is even more irrelevant because there is little or no thermocline and the ocean is equally cold throughout its depth.

    edited to remove image repost

    Thanks for pointing this out Interitus, perhaps, I should retract the word "deep". It is misleading and not what I meant, certainly giving the impression of cooler deep water than already exists, which would be unlikely, in the short term at least. I meant cooler surface water in the respective deep oceans. Apologies.

    However, in the last year of ice melt, the less dense, less saline surface waters of the newly exposed Arctic waters transferred, with the melting ice, largely southwards, on either side of Greenland, primarily down the Fram Strait as various animations posted elsewhere in this forum have graphically illustrated. So what replaced the less saline, less dense surface water from the Arctic that ended up in the Atlantic - the Arctic water levels did not change significantly, or else it would have been widely reported - either warmer, more saline Atlantic water drawn from the northern end of the north Atlantic drift (and Pacific water via the Bering Straits?) , or denser more saline, cold Arctic water from below, or, of course, both?. We certainly see that upwelling in the frozen Arctic causes polynias and other ice features, and that ice drift patterns follow tidal patterns, pressure and weather systems, so the more fluid open waters of the summer Arctic could permit more mixing and heat exchange with the arctic summer air above. In fact, up to 4 degrees Centigrade was reported, so it cannot be considered equally cold throughout it's depth any more.

    20071211_pid38532_aid38531_warmarcticwaters_w800.jpg

    Graphic credit required: Applied Physics Laboratory/University of Washington News

    A comparison of 2000 and 2007 shows how the ice edge has retreated as the ice cap has shrunk and how surface waters have warmed compared to the 100-year average. For example, parts of the Bering Strait and Chukchi Sea were 3 and 3.5 degrees warmer than the historical average. The spot that was 5 degrees above average was found at the center of the 4 degree area of water north of the Chukchi Sea.

    link

    In an open Arctic Ocean, likely to be repeated this summer, and possibly for several years in the future, some stratification of the Arctic Ocean temperatures could be expected, possibly with a dense saline warmer band at some depth, with cooler less dense, less saline water above and cooler more dense water below.

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    Posted
  • Location: Redhill, Surrey
  • Weather Preferences: Southerly tracking LPs, heavy snow. Also 25c and calm
  • Location: Redhill, Surrey
    Sorry to disabuse you of your notions BFTP but it would seem you are a little behind the times;

    Carbon dioxide, methane levels rise sharply in 2007

    mongabay.com

    April 23, 2008

    -----------------------------------------------------

    Now I wonder where all that extra methane came from?....................

    GW

    Ta re methane levels. I'll double check my source and post it but I won't argue too much about that. Re CO2 yep upwards and onwards....pity about the warming though :D

    BFTP

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    Posted
  • Location: Worthing West Sussex
  • Location: Worthing West Sussex
    Most methane emissions never reach the atmosphere -- they are broken down by ultraviolet radiation.

    ...........

    Now I wonder where all that extra methane came from?....................

    Probably the same place all that mysterious ultraviolet radiation came from. :D

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

    Lets leave this thread for reports and take our debates down below where they belong eh?

    Sorry Carinthian, we got a bit carried away.

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    Posted
  • Location: Coventry,Warwickshire
  • Location: Coventry,Warwickshire

    Yes we should probably leave most of the conjecture to the climate thread but i do have to correct a slight misunderstanding about radiation budgets. You can not look at outgoing long wave radiation in isolation away from short wave radiation. The link below explains how although outgoing long wave radiation increases short wave radiation is substantially reduced.

    Radiation Balance

    Actually it is a lot more complex than that in reality with cloud fractions as a result of particular synoptic patterns playing a key role.

    Lower Atmosphere radiation budget

    Disruption of the ocean conveyor and disappearance of deep water formation gyres could lead to increased ice coverage as a result of an initial ice melt as explained in the link below.

    Nasa A chilling posibility

    I am not sure I agree with this philosophy or more specifically I think the conclusion may be correct but for different reasons. Namely that the ice melt changes the artic oscilation signal more positive which in term causes fresh water transport from the Arctic capping the Nordbukta region and preventing deep-water convection which in turn slows the coean conveyor.

    What drives greenland deep sea water convection

    Enough of that though and back to actual conditions. Here is a nice report in the following link from Emily Davenport about recent conditions in the arctic.

    Nearing the end of our adventure

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    Posted
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK
  • Weather Preferences: Northeasterly Blizzard and sub zero temperatures.
  • Location: Ski Amade / Pongau Region. Somtimes Skipton UK

    Back on the topic of latest reports. This latest pictures shows a worrying loss of first year ice in the upper Greenland Sea. Normally the open area off the NE coast of Greenland maintains "old ice " for much of the year. The break up of the main polar ice front is the main cause for the fast ice along the coastline of the Greenland Sea. On a more positive note,the ice sheet remains locked into Northern coastline of Spitsbergen, where the amount of early summer ice is above last years level.

    C

    post-3489-1212513998_thumb.png

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    Posted
  • Location: Zurich Switzerland
  • Location: Zurich Switzerland

    nh12.gif

    carinth, might be the source.. i find all the grpahical sites have one or two off days.. from the above you can see that the loss isnt that bad.. then again this source could also be wrong...

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    Yes we should probably leave most of the conjecture to the climate thread but i do have to correct a slight misunderstanding about radiation budgets. You can not look at outgoing long wave radiation in isolation away from short wave radiation. The link below explains how although outgoing long wave radiation increases short wave radiation is substantially reduced.

    Radiation Balance

    Actually it is a lot more complex than that in reality with cloud fractions as a result of particular synoptic patterns playing a key role.

    Lower Atmosphere radiation budget

    The latest update from the NSIDC released today touches upon this very subject

    http://nsidc.org/arcticseaicenews/index.html

    A new record minimum is looking quite likely now.

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