Weather pattern changes over Greenland may account for melting, storms in Europe

From the UNIVERSITY OF SHEFFIELD and the “weather, not climate department” comes this paper that basically says it has discovered the Greenland Block all over again. See image below, which isn’t part of the original article:

thegreenlandblock

The jet stream pattern with the Greenland Blocking High pressure zone. Image: The Weather Channel

Climate change and extreme weather linked to high pressure over Greenland 

  • Climate change and extreme weather – including unusually wet summers in the UK – linked to high pressure weather systems over Greenland
  • Study finds increase in atmospheric high pressure systems since 1980s throughout all seasons
  • High pressure weather systems drag unusually warm air over Greenland’s Ice Sheet

Greenland is one of the fastest-warming regions of the world, according to climate change experts at the University of Sheffield.

New research, led by Professor Edward Hanna from the University’s Department of Geography, has identified changes in weather systems over Greenland that have dragged unusually warm air up over the western flank of Greenland’s Ice Sheet.

These weather systems are also linked to extreme weather patterns over northwest Europe, such as the unusually wet conditions in the UK in the summers of 2007 and 2012.

The study analysed changes in weather systems over Greenland since 1851, using a measure called the Greenland Blocking Index (GBI). The index measures the occurrence and strength of atmospheric high pressure systems, which tend to remain stationary when they occur, causing long runs of relatively stable and calm weather conditions. The high pressure also blocks storm systems from moving in on the region. The previous available version of the GBI only extended back to 1948.

Professor Hanna and his team have found an increase in the occurrence of atmospheric high pressure ‘blocking’ systems over Greenland since the 1980s throughout all seasons, which relates to a significantly strong warming of the Greenland and wider Arctic region compared with the rest of the world.

The Sheffield-led team also found an especially strong recent increase in the occurrence of Greenland ‘blocking’ weather systems in summer, which is linked to a more northward-meandering branch of the atmospheric jet stream. This has resulted in warmer air more often moving north into the region in recent years.

Professor Hanna said: “Our research has found an increase in the incidence of high pressure weather systems remaining stationary over Greenland since the 1980s, which is having a significant impact on extreme weather and climate change in the region.

“These weather systems are occurring in the area more often because of strong Arctic warming and changes in the atmospheric jet stream in recent years.

“This is resulting in an increase in the occurrence of warm air in the region and it is also affecting weather systems downstream of Greenland, such as over the UK. The unusually wet weather seen in the UK in the summers of 2007 and 2012, for instance, is linked to these stationary high pressure systems over Greenland.”

The research team, which also includes a climate scientist John Cappelen from the Danish Meteorological Institute in Copenhagen, Denmark, found that Greenland ‘blocking’ pressure systems have become much more variable from year to year in December in recent decades. This reflects an increasing destabilisation of atmospheric weather systems in late autumn and early winter, which the team believe may be related, at least in part, to dramatic declines in sea-ice coverage in the Arctic region.

“Sea-ice coverage throughout the Arctic has significantly reduced in recent years, which we already know is having an amplifying effect on warming in the region. What this study now tells us is that changes in stationary high pressure over Greenland are adding to the change in polar climate,” Professor Hanna added.

This research has more than doubled the timespan of data analysed on Greenland ‘blocking’ weather systems and is a useful measure of changes in North Atlantic atmospheric circulation. The results can enable an improved understanding of the links between mid-latitude and high-latitude climate change when combined with other climatological studies.

Findings from the research are published in the International Journal of Climatology on 27 April 2016

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81 thoughts on “Weather pattern changes over Greenland may account for melting, storms in Europe

    • Maybe over in Detroit it was dry but it certainly was not here in the UK.
      This blocking pattern was a large part of the cause of the very wet weather we had in April 2012 in the UK. Plus this sort of blocking pattern lead to the very cold December in 2010 in the UK. Also its very likely this weather pattern lead to the european “year without a summer” in 1816.

  1. What the U. of Sheffield does not state is how they are measuring meterological highs over Greenland as far back as 1850. Proxies? Redescovered old met records?

    • Co-author Cappelin compiled DMI Greenland records from 1873 to 2012. DMI TR 13-04. There is one location that pushes back to 1851. Temp, barometric pressure, wind, precipitation, daily and monthly. Although early records are all below lat 80N, basically the lower 40% of Greenland. Available on line. I was wondering also, so googled the question. Sufficient, I suppose, to identify a blocking high over the island.

      • Thanks for posting that, Vuk. Their Greenland pressure graph is simply following the AMO.

        But you will have to explain your NAP plot. What is that? Even Google is not familiar with that one. And why would the AMO be following tectonic activity?

        R

      • Vuk,
        Could you please elaborate on what the “North Atlantic Precursor / Tectonic records” means & what is the scale for this data is?

        Also, would you care to elaborate on how & why it is tied to the AMO ?

        Thanks

      • Word ‘tectonic’ is derived from the old Greek word ‘tecton’ for stone mason.
        Iceland is still in the process of being built, slowly but steadily, but events doing the building could pass un-noticed or be very violent.
        This process regulates the Icelandic low pressure system, moving cold westerly winds, further south or north. The winds take heat energy (several hundred watts/m sq) from warm salty N. Atlantic drift current, now devoid of its heat it sinks deep into N. Atlantic ( AMOC ) powering the ocean’s conveyor belt the ocean’s conveyor belt pulling more warm water northwards.
        Most of scientists on both sides of the argument ‘agree’ that AMOC and the AMO are directly linked.

  2. I wonder if any discernable long-term trends in Greenland blocking is associated with AMO fluctuations?

      • Not saying you’re wrong, Vuk but you just introduced a new parameter called “NAP” that nobody’s ever heard of. What is it? Where does the data come from? Also, showing an apparent correlation is a good start, but it is just a start. After explaining what a NAP is, you need to posit a theory as to how a NAP might influence SST. And why the 7-year lag is necessary to make the cycles match. And your theory needs to explain why NAP influences SST and not the other way round.

        OK, that’s criticism of your presentation. Now. Making a not unreasonable inference that your NAP is an index of seismic activity on the Mid-Atlantic Ridge, which is of course intimately related to magmatic activity along the ridge (of which we don’t know nearly as much as we should), it is not beyond the bounds of possibility that increased discharge of magma along the ridge might warm enough ocean water to change the mode of the AMO. Inferentially, this may be where you’re going. It sounds a bit thin, and there seems to be a decided lack of observational data to support it, but don’t let lack of data get in the way of a good theory. Theories are what start you looking for observations. You would probably have to create a model (models are fine as long as they lead to testable hypotheses) to show how you visualize it working.

        Vukcevic, it seems as if you’ve got a fertile imagination and are not bound by conventional or generally accepted theories. This is good. Keep it up, but try and be a bit clearer in your comments if you can, please. I do enjoy your ideas. They are stimulating.

      • “Not saying you’re wrong, Vuk ….”
        You might as well, just to be on safe side, everyone else does, or at least they think so.

        As I said further above I hope to publish (non peer review ! ) in few months. The data is all collected from the web, from the most respectable sources available.
        a) I do not think that magma vents and volcanic sub-marine activity provide enough energy to raise the SST (btw annual AMO varies by 4C, while multi-decadal by les than 1C).
        b) Magnetic data doesn’t provide the evidence but does support it.
        c) Solar activity is also within the range, but it is unlikely to be the main driver.
        d) The strongest corroboration comes from the CET.

        Precise mechanism can never be defined more than with a reasonable certainty, but I think in the final analysis it has to be down to the ocean currents, one of the main suspects could be the little known north Icelandic jet current.

    • According to Cappelin in TR 13-04, it is meridional circumpolar jet stream. The high is usually lower and over Canada, to the SW. Its gets shifted NE to over Greenland. He did not mention AMO at all in his general climatology/weather patterns section.

      • Stole my thunder, Rud. Wait until we get to a fully negative AMO. We can already see cooling in the northern Atlantic SSTAs, as well as the north Pacific of recent. Rather sudden, actually, if one is paying attention.
        I suspect melting won’t be an issue in 5 years…

  3. Layman’s Lament:

    As I am a non-scientist: If both events are happening at the same time, how did the researcher determine that less ice caused more Greenland Blocking rather than more Greenland Blocking caused less ice?

    Or, how does the researcher know that there was not another factor that caused both events?

    • You made a good point; macro-focusing on cause/effect relationships among observed phenomena can easily exclude investigation of an external component which actually drives the process.

      • And another excellent point! You have, I believe, identified the main weakness of the Global-warm-mongers’ approach to “climate science”- namely, the refusal to admit ignorance of all the factors that might affect the weather/climate.

        Well done, Pop!

  4. Climate change and extreme weather linked to high pressure over Greenland

    Or Climate change and extreme weather linked to low pressure over Norwegian sea.

    Why does blocking suddenly increase in times of lowering global temps. Horse – cart : Cart – Horse

    • Blocking makes it sound like it is not natural.

      Colder pockets are more dense and block warmer less dense weather systems i think, but do research it rather than take my word for it

  5. Prof. Hanna mentions Climate Change (CC). Is this the Global Warming CC or Natural CC? No mention of CO2 causing the Greenland Blocking (H).

    Clear as mud.

    • Bit like black holes, no one ever says which type they are talking about, because like Hanna, they dont know what the truth is

    • Different paper, and suspect. Published 2016, yet data stops in 2006 rather than 2014 or 2015. Reason is likely that surface mass balance (paper metric) has been increasing since except for 2012. And NSIDC summary says Greenland net ice sheet mass (including iceberg calving, not just summer melt) was stable in 2014 and gained in 2015.

    • So the world is burning up but Europe is cooling.

      These people just cannot even keep their story straight.

      We have come full circle to the nonsense of Day After Tomorrow.

  6. Soooo, weather that causes Catastrophic damage is CLIMATE..But, Climate that is beneficial to Humans is weather ?? I’m so confused !! /sarc……

    • Aren’t you Canadian, Marcus? Money you borrow for stuff you need is bad. Money the government borrows for stuff you don’t need is good. Sorry, that’s as close an explanation as I could make up!

      • ..Actually John, I’m a half American living in Southern Canada freezing my nuts off at the end of April AFTER living for 18 years in Daytona Beach, Florida !! That’s why I’m confused ~! LOL

    • Marcus when you break down many scientific theories and their claims and break them down into language and apply logic, they fail. Climate science, Particle physics and Astrophysics all suffer this problem.

      Which is why they like such obfuscating language to hide the illogical nonsense they come up with

  7. Hmm … The annual GBI may have increased since the 1980’s simply because it decreased before then. The trend from 1948 to 2014 is .0004 PERCENT of it average value per year. The change over the whole 67 year period, of the public data, is (roughly) from 99.9% of its average value in 1948 to 100.1% of it average value in 2014 [according to the fitted trend line].

  8. The above graphic of the ‘Greenland Block’ shows a strong warm Azores High pushing poleward so as to put part of southern Greenland south of the distorted jet stream so that Greenland is warmer than average. That is what often happened during the late 20th century warming spell.

    The true ‘Greenland Block’ should actually show a cold High Pressure cell over Greenland distorting the jets southward so that cold air from the Arctic and the Siberian High can flow westwards across Western Europe against the usual zonal westerly flow. That has been happening more often since about 2000.

    • Stephen the above graphic is a Omega block which does send warm air into Greenland when it forms. So it does explain better what this report is saying. The fact this weather pattern does send warm air into Greenland is a key factor into understanding why there were such big temperature swings in Greenland during the ice age. Because during the ice age am convinced that there was persistent Omega blocking over the northern Atlantic/Greenland as well as blocking over Greenland/northern europe. And it was the change in how often one of these blocking highs were turning up. ls the reason for the big swings in temps over Greenland during the ice age.

      • It doesn’t need to be such an Omega block to send warmer air up along the West Coast of Greenland.

        That also happens when the block is in the cold air north of the jets because the easterly flow to the south of the cold block then turns poleward up along the Greenland west coast causing warmer Atlantic air to arrive there.

        Generally, one sees the warm Azores block south of the jets when the globe is warming and the cold Greenland Block north of the jets when the globe is cooling.

        In ice ages I would expect to see the cold block firmly in place north of the jets with frequent and persistent warmer southerly flows up the west coast of Greenland.

      • Stephen yes you are right that such a blocking high can send warm air into Greenland.
        But a key factor with the a Omega block in the northern Atlantic is the effect it has on the weather patterns over North America and europe. This Omega blocking not only sends cold air down across North America and europe. lt also forces areas of low pressure to stall over these areas. Which would lead to the heavy snowfalls needed to build up the ice sheets. lts this fact and the big swings in temp over Greenland. Which convinces me that this Omega blocking over northern Atlantic was a persistent weather pattern during the ice age.

      • Both types of block occur and the Omega block does produce lots of snow as you say but it is a consequence of the Azores High pushing poleward into cold air whereas the Greenland Block pushes cold air equatorward into warmer air.

        The true Greenland Block is a high pressure cell over Greenland to the north (not south) of the main jet stream track.

        In reality both types fight with each other over time. The cold Greenland Block dominates when the sun is quiet and the warm Azores Block dominates when the oceans are in energy releasing mode such as El Nino events.

  9. Well if there right in their claim that this weather pattern is increasing due to CO2 and global warming. Then they may have find the cause of what is the trigger into pushing the NH into a ice age. Now ain’t that going to make a few AGW science heads explode.:)

  10. As l have been posting on WUWT over the last 3 years, its the weather where you need to be looking for the causes of major climate change. Recently l have been pointing out that this weather pattern is a key factor in ice age formation in the NH. Because should this pattern become persistent over the long term. Then it will be a key driver into climate cooling in North America and europe. They are right when they say it drives warm air up into Greenland as shown by the recent Omega block over the northern Atlantic.
    And l am convinced it was this ery pattern that leand to the big swings in temps in Greenland during the ice age.

    • Something weird has been happening in the SH and BoM acknowledges that the Subtropical Ridge has intensified over recent years. Producing out of season balmy weather in Oz as we speak.

      The cause of course is global warming, but I’m convinced it has something to do with a positive SAM and global cooling. This is an uneducated guess.

      • ironicman
        During the last ice age it seems that a area of the southern Pacific extending from the eastern coast of Oz was very warm. lf you google CLIMAP you will be able to see what l mean. Don’t know lf that has any link to the weather pattern you are taking about.

      • taxed I have heard that but its probably unrelated to the situation now because it was at the LGM.

        My feeling is that its more like entering a cool spell, so we should be able to see similar mechanisms as when we came down from the MWP in the 13th century.

        At the moment the Southern Annular Mode is positive and I’m linking it to the increasing extent of Antarctic sea ice and dry winters in Oz.

      • ‘In 2014, Dr Nerilie Abram used a network of temperature-sensitive ice core and tree growth records to reconstruct a 1000-year history of the Southern Annular Mode. This work suggests that the Southern Annular Mode is currently in its most extreme positive phase over at least the last 1000 years, and that recent positive trends in the SAM are attributed to increasing greenhouse gas levels and later stratospheric ozone depletion.’

        wiki

  11. uugh, given the trend of claims and reactions when they fall flat, the analysis clearly shows that in 60 years from now we will still be getting the same old tired lines spewed out, and the previous 90 years of clams will go the way of the clams of an ice age in the 70s (it never happened)

    Most of us will be too dead to protest :D

    • Mark
      When this weather pattern starts turning up, then the very cold December 2010 shows just how quickly things can change. Am also convinced that it was just this sort of weather pattern that lead to the european “year without a summer” in 1816.

  12. Basically a near permanent Greenland block occurs all year round for many decades/centuries, once Ice Age conditions have been triggered. In ice cores Greenland becomes very dry because of this. The trigger is unknown, but warm air not moving from the Atlantic ocean at all would have the same influence as the blocking shown with warmer air circulating around Greenland instead of Europe. The Greenland block prevents warmer air from reaching most of North America and most of Europe via the North Atlantic Ocean.

    The weather pattern with this block remaining in place is not difficult to see how much colder conditions develop consistently around North America and Europe. These conditions would be ideal in helping build up glaciers, especially in more northern regions at first. The Arctic is cold enough for snow now to cause an Ice age, what is needed is a consistent supply of warmer moist air around Greenland to give it the extra snow that is needed.

    The Greenland block has become stronger through the year, once the solar activity become quieter this century.

  13. It’s the Sun, stupid.

    “”Reduced solar activity could lead to colder winters in Northern Europe. This is because the sun’s UV radiation affects the atmospheric circulation. Interestingly, the same processes lead to warmer winters in Greenland, with greater snowfall and more storms.” said Dr said Raimund Muscheler, Lecturer in Quaternary Geology at Lund University. “The study also shows that the various solar processes need to be included in climate models in order to better predict future global and regional climate change.”

    Further to their theory, the researchers believe that changes in wind patterns resulted from alterations in received temperatures, suggesting that a top-down solar influence increased oceanic feedback and may have acted as an additional amplification mechanism. In other words, variations in solar radiation affected the atmosphere, altering the barometric pressure which, in turn, changed the prevailing wind patterns in the upper atmosphere.

    In atmospheric physics parlance, these winds are known as eddy-driven jets and a high-pressure increase over the North Atlantic (as evidenced in today’s climate) is often accompanied by a displacement to the south of these winds. This results in a negative effect on the North Atlantic Oscillation (the atmospheric pressure difference at sea level between the Icelandic low and the Azores high), which can produce colder winds and higher levels of snowfall.”
    http://www.gizmag.com/suns-activity-influences-natural-climate-change/33409/

  14. Since it is difficult to go back to the 1930-1940 during the dust bowl. The same weather pattern happened from 2006-and should end most areas after 7 years and the remaining about 11 years. This is per what happened during the dust bowl. If there are any weather issues that are similar during the dust bowl that UK had may shed light on the change in jet stream patterns during these two periods. By the way, this appears to be inline with a 60-66 years cycle that would need more time to visualize. Anthony, what do you think or may have on this? Grant money anyone?

  15. I find it surprising and laughable, that most “climate scientists” or “geographers” and such I meet at meetings like the AGU and EGU and others, unfortunately, today do not know or realize that the Greenland Ice Sheet is a mountain! The elevation of Summit, yes it is a summit, 3216 meters currently and that will change though very slowly, elevation above mean sea level. Far easier for the surface wind fields to bend around to the north and then down to the south around the mass of ice and this produces a localized high pressure zone in the atmosphere (vertical direction). Do our fine and “brainy” [ha ha] chaps with GRACE realize a correction needed by way of the Bouguer Gradient and Topography Gradient? No! Sad for them! [They do not win the prize! And that is GOOD! Ha Ha] Next time you are traveling in a A330 or such might want to check the temperature outside at 3000+ meters above mean sea level. It’s DAMN COLD! And at that surface temperature any amount of “carbon” on the surface means nothing, nothing at all! Completely irreverent!

    Ha ha

    Lesson for the day. ;-)

  16. ”Climate change and extreme weather – including unusually wet summers in the UK – linked to high pressure weather systems over Greenland”

    How ”unusual” is a wet summer in the U.k.?

    Eamon.

  17. It’s all a yawn. Someone should do some real homework to reconstruct North Atlantic (and other) weather/climate.

    I understand that at least since the late 18th Century (and I think its a lot farther back than that), the Admiralty has kept the logbooks of its ships. The RN between ca 1700 and 1945 made the USN of today look paltry (no disrespect intended – the USN is magnificent), but the fact is it was a different age.

    The point is there is a wealth of very accurate record – much of which will have to be accepted as anecdotal because the kit used to collect the data was relatively primitive – of climate and weather conditions, wind, sea temperature, ice cover, cloud cover etc just waiting to be tapped.

    I had heard that there was a project afoot to do the exercise, but its gone very quiet. Anyone know anything?

    Equally the records of the British Merchant Marine must make for fascinating reading…and just wait til someone gets on top of the Imperial Chinese records which must surely exist somewhere. They’ll likely go back at least 2000 years.

  18. “The results can enable an improved understanding of the links between mid-latitude and high-latitude climate change when combined with other climatological studies.”
    It could have been said with any change of the Greenland and Arctic region.
    If it had cooled it would also be a sort of climate change. It is a pity that all studies must be connected to the “climate change” meme no matter what.
    It is anyway an old wisdom, that the weather around Greenland and northern Europe is connected.
    Just ask the Germans why they wanted a weather station on Greenland during WW2.
    It was not to invade Greenland i can tell you.

  19. “This is resulting in an increase in the occurrence of warm air in the region and it is also affecting weather systems downstream of Greenland, such as over the UK. The unusually wet weather seen in the UK in the summers of 2007 and 2012, for instance, is linked to these stationary high pressure systems over Greenland.”

    2007 and 2012 also had the lowest summer Arctic ice minima – reinforcing the interpretation that these minima were primarily wind and weather phenomena.

  20. Off topic, but what’s up with the sea ice page? Are there any alternate data collection satellites/etc. that have updated reliable information? There hasn’t been any new data for about a month now.

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