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    Around The Arctic June 2013
    By Patrick Lockerby | June 14th 2013 04:09 PM | 22 comments | Print | E-mail | Track Comments
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    Retired engineer, 60+ years young. Computer builder and programmer. Linguist specialising in language acquisition and computational linguistics....

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    Around The Arctic June 2013


    The Arctic is currently primed for rapid and extensive ice loss, unless we see some very unusual weather conditions this Summer.

    The state of the ice can be seen in the following series of satellite images from NASA's Earth Observing System Data and Information System - EOSDIS.  EOSDIS produces near real-time data and makes images such as the Arctic mosaic and the Near Real Time (Orbit Swath) Images available on the web.

    The Arctic mosaic is made up of panels arranged as six rows and six columns.  Any panel can be viewed in higher resolution by clicking on it.  In single panel view, other resolutions are available up to 250 meters per pixel.

    Using images from the Arctic mosaic since June 10 2013 - except where clearly noted - I have compiled a 'June 2013 tour around the Arctic'.  The 'itinerary' is marked on the image below.



    Arctic Mosaic, annotated.


    A - Bering Sea and Chukchi Sea


    Arctic Mosaic Bering Straits June 2013

    The annotations show the regions in the zoomed images below.  The satellite images show large areas of open water and of dispersed ice.  This is confirmed in the current ice chart from the National Weather Forecast Office, Anchorage Alaska.



    Sea ice analysis June 13 2013

    The next image is part of the NSIDC ice extent chart for June 14 2013.  It demonstrates the difficulties of using software in determining what is ice and what is not.  It also demonstrates that the chart should not be used to report on current ice conditions.  It does not discriminate between thick or thin, tightly-packed or loosely-dispersed ice.  Comparing the chart with the satellite images shows this clearly.



    NSIDC ice extent chart.

    Much of what appears to be ice in the NSIDC chart is ice smoke - water vapor coming from the melting ice.



    Region 1

    Where there is continuous ice, it is breaking up and melting in situ.  The ice smoke obscures some ice, but indicates melting.



    Region 2

    The pack is in motion.  Agitation promotes melting of this predominantly 1st year ice, as does tidal current penetration under the ice.



    Region 3


    Along the Siberian coast in this region is an open lead with broken ice.  Less ice smoke indicates slower melting than on the Alaskan side.  But it is melting.



    Region 4

    News from Alaska -
    Summer ice melt
    Warming Alaska, Canada glaciers send 100 gigatons of ice into ocean each year



    B - Beaufort Sea

    The ice in the Beaufort sea retreats from the coast most years, allowing navigation along the coast.  Currently extent is a little above average.  However, due to persistent losses of multi-year ice the volume is lower than was once normal.  The loss of thermal mass will be reflected in a rapid drop in extent as the Arctic continues to warm in the Summer.

    Thermal mass is what kept an ice-box cool before the fridge was invented.  Ice can absorb heat withoout melting until its sub-zero temperature is raised to zero.  The greater the thermal mass, the more heat can be absorbed.  The lower the temperature, the mopre heat can be absorbed without melting.  When the Winter temperature drop of sea ice is exceeded by the Summer rise, it malts.  When the mass is too little to absorb all of the Summer heat, it melts.  If we knew the ice volume and temperature we could predict with a great deal of certainty the effect of a normal Summer in reducing the volume.

    In the image below we see two polynas.  There is meltwater on the shorefast ice.


    Meltwater on ice in the Beaufort Sea.

    In the image below we can see loose, mobile pack.  The lighter colored lines in the shorefast ice, running mostly parallel to the coast are likely to be heavy ridges formed by 'ice shove' as the pack is forced against the shorefast ice.


    Pack ice and shorefast ice, Beaufort Sea.


    C - Beaufort Sea and Canadian Archipelago

    In the next image, from June 15 2013, ice in the Beaufort sea adjacent to the North West Passage is breaking up and dispersing.


    Meltwater and ice breakup in NWP


    Ice breaking up NWP - detail



    D - Canadian Archipelago

    As all Arctic aficionados know, most of the (remaining) multiyear ice is pressed up against the shores of the Canadian Archipelago and Greenland.
    ...
    Up till now that multiyear ice that was pressed against the Canadian Archipelago had something to press up to. But as we saw in the first half of August [2010] (check the animation) all of the ice in those channels started breaking up and multiyear ice was transported from the Arctic Basin to lower latitudes where a lot of it melted out. Some of it froze up in the Northwest Passage, which could be a reason the passage is a bit slower in breaking up than it was last year.
    Neven, Arctic Sea Ice Blog 2011

    Throughout the Canadian Archipelago, floes of older ice are glued together by first-year ice.  The volume of older ice has reduced over the past decade or so, meaning that the region has a reduced thermal mass.  This means that an ordinary Summer is sufficient to cause the ice to break up rapidly into mobile floes.  The images below show regions of particular interest.


    The Canadian Archipelago.



    Region 5 - McClure Strait

    The ice is breaking into huge floes, but they are held in place by sea ice and land.  Further melt in the area will permit motion, with consequent greater breakup and melting of these floes.


    Region 6 - Dundas Peninsula

    Where pressure ridges might be expected we see a narrow - circa 250m - crack.  As tidal currents run under the ice they subject the ice to both flexing strains and bottom warming.  This "tidal injection" bottom-warming mechanism is often overlooked.  This weak point in the CA ice cover will most likely form a seed point for ice breakup, hastening the July melt.



    Region 7 - Gulf of Boothia

    The rate of breakup here is about normal for the season.  The Bellot Strait contains a persistent polyna.  (See link below next image.)


    Region 8 - Grinell Peninsula region


    This area contains many persistent polynas.  They are described in Polynas and Tidal currents, Hannah, which is the source of the image below.




    Region 9 - Lancaster Sound

    Lancaster Sound is joined to Baffin Bay.  Explorers in the days of sail would attempt to enter this sound after a dash around the Baffin ice in late Summer.

    A page of resources concerning CA ice flow.


    E - Baffin Bay

    Baffin Bay was first entered by John Davis in 1585.  William Baffin, after whom the bay is named, explored it in 1616.  It was about 200 years before any other explorer could enter Baffin Bay.  These days there is little sea ice left there by the end of July.


    Baffin Bay June 2013

    In the North of Baffin Bay is Nares Strait, which links to the Lincoln Sea.  Melt is proceeding there at what is now considered to be a normal pace.  In the past such a pace of melt might have been considered normal for July.


    Nares Strait

    Petermann fjord is located in Nares Strait.  The Petermann glacier is in retreat.  Since the massive 2010 and 2012 calvings the rate of calving appears to have slowed somewhat.  The ice tongue is being pushed into a narrowing fjord.  I predict that once the glacier has retreated to a point where the fjord is more nearly parallel the rate of calving will increase from this year's levels.  The image below shows the calving front as it was on August 26 2012.


    Petermann glacier August 26 2012

    In the same region E marked on the top image lies the last remnant of the Ward Hunt ice shelf.  It is shown in this image from August 26 2012.


    Ward Hunt ice shelf August 26 2012.

    The ice shelf remnant has probably persisted because it is anchored at each end to an ice cap.  That remnant of the The Oldest Arctic Ice cannot persist long in a warming Arctic, even though that coastal region is still one of the coldest places in the Canadian Archipelago.  Even though anchored to ice caps there is nothing to prevent the ice shelf breaking in the middle, after which the ice islands will move out.


    F - Disko and Jakobshavn

    Disko, or Qeqertarsuaq, is a large island in Baffin Bay.  In most years since the region was first explored by Europeans - probably including the Vikings - the sea ice has melted out, making Disko an ideal base for expeditions further North.

    Signs that the region may be warming include earlier melt of sea ice and early formation of melt pools on the edges of the Greenland ice sheet.


    Disko, Jakobshavn and melt pools



    Jakobshavn glacier

    Jakobshavn glacier has retreated substantially since about 1850 and is still retreating.  In the image above the arrows point to a white area which indicates calving restrained by sea ice.


    G - Scoresby Sund

    Scoresby Sund is named for William Scoresby, who first explored and mapped the area in 1822.  Prior to his explorations the area had been unreachable due to the persistent Greenland ice barrier.   For a long time after Scoresby, areas North of the region could only be mapped by sledging parties.  The North East coast of Greenland is now one of the fastest warming areas in the Northern hemisphere.

    Our tendency is to lump the Greenland Ice Sheet into one category impacted similarly by each of the dynamic forces that impact flow. This is akin to saying banks, credit unions and savings and loan institutions are impacted similarly by all the economic forces. In the case of a recession there is a shared signal, just as with global warming there is a shared signal among Greenland glaciers. This is a simplification that does not work.

    Greenland Ice Sheet Index

    Scoresby Sund

    The arrow points to Warming Island.  The blue melt pools and the extensive swirls of ice smoke show that the ice here is melting out.


    H - North East Greenland

    The land-fast sea ice along Greenland's NE coast is subject to cycles of melt and re-formation.  Over the past few years this cycle, which used to last many years, seems likely to have switched to an annual cycle of mainly first-year ice.  I covered this in a recent article -  Glacier Changes In NE Greenland.


    North East Greenland

    The shorefast ice is breaking up and there are extensive melt pools.


    I - Greenland Sea and Svalbard

    Svalbard has the distinction of being home to the world's most Northern railway, albeit derelict. 


    Locomotive on Spitzbergen
    See link above for full image.

    In the past it was most unusual for Svalbard to be entirely surrounded by open water in late Summer, but this has now become the norm in early to mid-Summer.  Last year there was substantial open water North of Svalbard by July 07.  This year the same open water extent will likely be reached earlier.


    Svalbard July 07 2012

    Research shows that the glaciers in Svalbard are melting and getting smaller. This is taking place because the climate has become generally warmer in the past 100 years. Higher air temperatures have brought a more rapid retreat in the last 10 years.

    A glacier gets smaller because it loses more mass during the summer than it adds in the winter. It is mainly temperature and precipitation that control this relationship. Measurements of the mass balance in three glaciers in Svalbard show that two of them, which are in the lowlands, had a negative mass balance from 1967 to today, whereas the third, which is situated higher up, had a positive mass balance until 2000, but it, too, has had a negative trend since then.

    Glaciers are getting smaller and are retreating


    J - Barents Sea and Franz Josef Land

    A recent study by the Institute of Marine Research, the University of Bergen and the Bjerknes Centre for Climate Research in Norway shows that the northwest Barents Sea warmed substantially during the last decades. The temperature of the subsurface Atlantic Water in the northern Barents Sea increased rapidly during the late 1990s.
    Science News, September 05 2010

    Barents Sea June 2013

    Cape Fligely is the Northernmost point of Franz Josef Land.  Julius Payer, a lieutenant in the Austrian army on the ship "Tegetthof", discovered Cape Fligely in 1874. He was a member of the Austro-Hungarian North Pole Expedition of 1872–74.  Their ship, the Tegetthoff became ice-bound in 1872.  She was abandoned in 1874 and the crew returned home over the ice.
    In June 1899 H.R.H. the duke of Abruzzi started from Christiania in his yacht, the "Stella Polare," to make the first attempt to force a ship into the newly discovered ocean north of Franz Josef Land. The "Stella Polare" succeeded in making her way through the British Channel to Crown Prince Rudolf Land, and wintered in Teplitz Bay, in 81° 33' N. lat. The ship was nearly wrecked in the autumn, and the party had to spend most of the winter on shore, the duke of Abruzzi suffering severely from frost-bite. In March 1900 a sledge party of thirteen, under Captain Cagni, started northwards. They found no trace of Petermann Land, but with great difficulty crossed the ice to 86° 33' N. lat., 20 m. beyond Nansen's farthest, and 240 m. from the Pole. The party, with the exception of three, returned to the ship after an absence of 104 days, and the "Stella Polare" returned to Tromso in September 1900.

    Encyclopedia Britannica 1911

    Since those times the ice has become ever less of a hazard to navigation.  There has often been open water around the islands which have now been well explored.  The region is clearly warming.
    "We have explored 42 of the archipelago's 191 islands and concluded a reduction of the ice sheet from the last Soviet expeditions in 1957," said head of the expedition Maria Gavrilo, an ornithologist.
    Space Daily, November 21 2012


    K - Kara Sea and Laptev Sea

    The Kara Sea was formerly a major obstacle to navigation.  It was not until 1878 that a ship was able to pass from the Atlantic to the Pacific via the Kara Sea.  Finnish explorer Adolf Erik Nordenskiöld achieved this feat of navigation and exploration by over-wintering in the Chukchi Sea.

    Because of the perennial thick ice it was necessary to build icebreakers so that freight could be shipped through the Baltic and Kara seas beyond the brief Summer season.
    The Ermack was designed especially for ice-breaking in the Baltic and Kara seas, for the purpose of keeping open the northern ports of  Russia  either  during the whole winter or for a longer period than they would otherwise be  navigable, ...
    Vice-Admiral Makaroff
    The Icebreaker Yermak

    L - Laptev Sea and East Siberian Sea




    Laptev Sea and East Siberia Sea June 16 2013

    Britain's Daily Mail, which has all too often published opinion pieces denying that global warming is a problem, seems to be more inclined to report actual science these days.

    The Laptev Sea had an excess of carbon dioxide during the late summer of 2008 that was of the same order of magnitude as the western East Siberian Sea, probably caused by the breakdown of organic matter from the land.

    The results [of the study] suggest that the Laptev Sea has changed from being a sink for atmospheric carbon dioxide to become a source of carbon dioxide during the late summer.

    Miss Wåhlström's work is the latest to suggest that changes in the Arctic climate have the potential to play havoc with the Earth's delicate ecosystem.
    Global warming is changing Arctic seas from where CO2 is absorbed to where it is produced, new study warns
    Daily Mail June 19 2012


    This concludes our 2013 tour of the Arctic.


    Some points to ponder

    The thermal mass of land and sea ice is the crucial core of the Arctic's thermodynamic cooling mechanism.
    The Arctic ice pack is governed by two processes: thermodynamics and dynamics. The mass balance of sea ice is a straightforward thermodynamic concept. It is simply the balance of how much the ice grows in the winter and melts in the summer.
    Mass Balance: What is it ?
    A basic element in studies focused on thermodynamics is the mass balance of the ice cover. The ice mass balance is the great thermodynamic integrator. If there is net warming over time, then there will be thinning of the ice.
    Mass Balance
    There is growing recognition that reductions in Arctic sea ice levels will influence patterns of atmospheric circulation both within and beyond the Arctic. New research in the International Journal of Climatology explores the impact of 2007 ice conditions, the second lowest Arctic sea ice extent in the satellite era, on atmospheric circulation and surface temperatures.
    ...
    "This suggests the sea ice conditions in the months preceding and during the summer of 2007 were not responsible for contributing to a circulation pattern which favored the large observed sea ice loss in that year. The circulation during autumn and winter which was more similar between the model simulations and the observed circulation suggests that the reduced sea ice in 2007 was in part responsible for the observed atmospheric circulation during autumn and winter of that year."
    Study explores atmospheric impact of declining Arctic sea ice, May 28, 2013

    Although the Arctic regions are now well mapped and explored, science still has much to learn.  We can look forward to new discoveries in this new Arctic.
    .

    Comments

    rholley
    Here at Reading the Meteorology department is looking at similar processes in the Antarctic.

    Here also, if you have a few minutes, is something you might like.  At 15:20 on this week’s Countryfile:

    http://www.bbc.co.uk/iplayer/episode/b02zc981/hd/Countryfile_N_Wales_Woo...

    there is an item about reef-building worms on the North Wales coast.  There should as of now be 6 days left to watch.
     
     
     
    Robert H. Olley / Quondam Physics Department / University of Reading / England
    MikeCrow
    I think this is the key statement:
    The temperature of the subsurface Atlantic Water in the northern Barents Sea increased rapidly during the late 1990s.

    I know that the PDO is switching into it's "cold" cycle, and my weather this year (NE Ohio,US) has been on the cold side, the other night I could see my breath. Lots of Canadian air this year. So, I think Pacific waters will be cooling.


    And surface waters


    And the La Nina Polar Jet stream


    I also wonder how much of Climate warming is just due to the area north of the polar jet stream, during the AMO and PDO warm/cold cycles.

    Oh, I'm not sure if I shared this paper with you on Albedo of water at high latitudes.
    Never is a long time.
    logicman
    Mi Cro, sorry I missed your contribution until now.

    Regarding albedo: if errors in calculating the albedo of ice and of water are of the same order and operate in the same direction then we can safely ignore them.  What matters is the ratio of the one to the other.  Over any given area of ocean, less ice is the other side of the 'more water' coin.  Whatever the exact figures, we know as a fact of physics that albedo change is an amplifier of Arctic warming.  What normally keeps ice loss in check is the volume and temperature of the ice, i.e. the Arctic ice's thermal mass.  It does not matter if air and / or water temperatures are above 0 degrees C if the negative temperature of the ice exceeds that amount.  But when the average "store of cold" of the ice in Winter is outweighed by even a fraction of a degree  by the average warming of the ice in Summer, then the ice will inevitably reduce in average volume.  That is what we are seeing.

    Regarding your other points: we are currently experiencing an unusually cold Summer here in the UK.  This is not surprising given that the ever increasing Summer melt of Arctic ice appears to have had an effect on the Gulf stream.
    Researchers on a scientific expedition in the Atlantic Ocean measured the strength of the current between Africa and the east coast of America and found that the circulation has slowed by 30% since a previous expedition 12 years ago.
    The Guardian, December 2005
    The 'oddball' weather patterns currently being experienced in the UK were the topic of a recent get-together of climate scientists.  They observed the cyclic nature of UK weather patterns.

    The scientists must now address what "dynamical drivers" are causing this cycle, Belcher said. The meeting debated a range of possible interconnected reasons for the unusual weather of recent years, including this year's cold spring and the freezing winter of 2010/11. The most likely cause for the wet summers, he said, was the Atlantic multi-decadal oscillation, or AMO, a natural pattern of long-term changes to ocean currents.

    Other candidate causes that could be "loading the dice", as Belcher described it, include a shift in the jet stream, solar variability and fast-retreating Arctic sea ice. Aggravating all of these factors could be the influence of anthropogenic greenhouse gases entering the atmosphere.

    The Guardian, June 19 2013
    My purely anecdotal evidence, from 60 plus years of memories, is that extremes which used to affect the occasional season or year are now affecting 2, 3 or more years in a row.  Something strange is happening to our once predictable weather patterns.  Natural cycles are not sufficient to explain the current changes in UK weather patterns.
    MikeCrow
    I'm not quite sure I followed your comment on albedo, so let me paraphrase what I took from the paper: at high latitudes, open water has an albedo much closer to ice than water.

    This would reduce (not eliminate) the warming from the Sun during summer to a more ice like amount. But let's not forget surface waters would (still) be radiating straight up to a very cold sky, even on warm days. And they radiate far more heat than ice would. And as the DMI charts show, I don't think the current melting is unheard of.

    As for your weather, this summer reminds me of the cool summers of my childhood and teens, so far. Most of the warm days are in the 70's, and a lot of nights dropping into the high 50's. We've had some hot days, but not many. I'll have to see what July and August do.

    The PDO might be entering it's cold cycle. Decadal Oscillations
    Never is a long time.
    logicman
    I'm not quite sure I followed your comment on albedo, so let me paraphrase what I took from the paper: at high latitudes, open water has an albedo much closer to ice than water.
    That is not correct.

    You can get a very good first impression of albedo by checking the relative brightness values in an Arctic mosaic.  Albedo ranges from 0, black to 1, white.  RGB values range from 0,0,0 for pure black to 255,255,255 for pure white.  You can thus use any RGB satellite image to estimate albedo and compare that with published values.  From the NSIDC page on albedo:

    Sea ice has a much higher albedo compared to other earth surfaces, such as the surrounding ocean. A typical ocean albedo is approximately 0.06, while bare sea ice varies from approximately 0.5 to 0.7. This means that the ocean reflects only 6 percent of the incoming solar radiation and absorbs the rest, while sea ice reflects 50 to 70 percent of the incoming energy. The sea ice absorbs less solar energy and keeps the surface cooler.

    Snow has an even higher albedo than sea ice, and so thick sea ice covered with snow reflects as much as 90 percent of the incoming solar radiation. This serves to insulate the sea ice, maintaining cold temperatures and delaying ice melt in the summer. After the snow does begin to melt, and because shallow melt ponds have an albedo of approximately 0.2 to 0.4, the surface albedo drops to about 0.75. As melt ponds grow and deepen, the surface albedo can drop to 0.15. As a result, melt ponds are associated with higher energy absorption and a more rapid ice melt.

    Extensive melt ponds indicate areas where the ice is most likely to decline rapidly in extent due to the local lowering of albedo.  Given the vast extent of melt pools, it is reasonable to expect a rapid drop in ice extent .

    Here is a more recent - 2004 - paper on ocean albedo and its determination by direct measurement:

    http://snowdog.larc.nasa.gov/jin/LUT_OcnAlbedo/2004GL021180.pdf

    MikeCrow
    Did you look at the paper?

    The problem with your mosaic suggestion is that is an over head view of the ice and water. Have you ever looked at a low hanging Sun over water and have to shield your eyes from the glare? At low angles light reflects off water.
    My playstation has a global earth screen saver when music is playing on it, this shows the effect quite well, a large glaring reflection the size of a continent over the oceans.
    Depending on the angle, and froth this greatly reduces the albedo. So even during summer while the surface longitude in line with the Sun might have only a 25-30% increased albedo compared to tropical water with the Sun over head, off to the sides of that it looks to be increased much more.
    Never is a long time.
    logicman
    Albedo is a mathematical expression of that proportion of incident radiation which is absorbed by a surface.  It does not matter if the unabsorbed part is reflected or scattered or whatever.  Glare is either the effect of extreme scattering in multiple directions as seen by a single observer from a single direction or the low angle reflection of the Sun.  Since scattering and reflection are due to light or heat not absorbed, they are already allowed for in mathematical expressions derived from direct observations of albedo as absorption.

    The image in the mosaic is formed of scattered  light, but since the Sun is never in the field of vision of the detecting instruments, nor immediately behind them,  there can be no glare.  In this situation the comparison of brightness levels across the image is a very good - but admittedly imperfect - measure of the relative albedos of snow, ice, water, land etc.  From the angle of incident radiation we know that the light 'seen' by the Aqua and Terra satellites must be scattered light.   Also, if ever reflected light could be detected near the poles, we would see the same glare that is seen in more equatorial regions imaged by these two polar orbiting satellites.  We never see this at the poles.  What we do see during the dawn and dusk of the Arctic's and Antarctic's 6 month long days is that green tinge which is the inverse of the red tinge seen by any observer at ground level.  This confirms that the Arctic and Antarctic images are the result of only scattered light.

    The albedo difference between ice and water remains substantial whether one looks only at reflection or only at scattering.  That is because scattering occurs when incident light is reflected from a multiplicity of very small surfaces at different angles to the incident radiation.  In effect, scattering is a special kind of reflection.

    Anyone who has ever looked across a mixture of ice and water knows that the glare from the ice - especially when covered in snow - is much greater than the glare from the sea.  The glare from desert sand - especially white sand - can also be stronger than that from rivers, lakes, oases etc.  Such has been my experience, at least.

    Unless there is a gale of such strength as to blow spume across the sea, I know of no circumstance in which the albedo of the sea can approach anywhere near that of ice.  Even then, under such conditions there is likely to be substantial cloud cover which will mask any albedo change at the sea surface.
    Ok, so I was wrong with my terminology. Albedo is the % of incident reflected. To my point, and what the paper measured, polar water because there is no incident sun light even in summer has a much higher effective albedo.
    The point is that far less light is absorbed than would be suggested by the albedo of water at say the equator.
    Secondly, warm water will radiate far more heat to space than ice, regardless of the temp as long as It's clear.

    Open arctic waters are the earths cooling system.

    logicman
    Mi Cro, I clearly need to write an article on albedo.  Many people seem to have difficulty with the concept, especially within an Arctic context.
    there is no incident sun light even in summer
    This is clearly wrong.

    Explanations of albedo can range from the excessively simple to the excessively complex: at either end of that spectrum the reader may come away with mistaken ideas - as I did when I first came across the term 'albedo'.

    The English term 'albedo' is from the Latin word meaning 'whiteness'.  The degree of whiteness of an object can only lie in a range from 0% to 100%: physics renders this as a dimensionless number between 0 and 1.

    The English term 'incident' used as an adjective means 'falling upon'.  For as long as light falls upon any surface there is incident light: it is inherent in the meaning of the words used.

    The apparent whiteness of any object made visible by the light which it scatters is independent of the angle at which radiation strikes its surface - the angle of incidence - over a very wide range of angles.

    As more and more light is reflected rather than scattered the surface in question behaves more and more like a mirror.  In the extreme case the object itself would become invisible, an observer would see only reflections of other objects and the invisible mirror.  Since a mirror can have no whiteness value the concept of albedo here becomes irrelevant.

    Contrarily, as more and more radiation is absorbed a surface is seen as ever more black.  It cannot reach an albedo of zero since it would then become a black body: a radiant body to which the term 'albedo' has no meaningful application.

    Disregarding polarization, except for angles of incidence approaching zero or 90 degrees - which exceptions are not relevant to the polar images produced from downward looking instruments - relative albedos can be determined with reasonable accuracy by measuring the amount of light scattered by various surfaces which are subject to the incidence of light at the same angle.

    The Arctic mosaic images are composed of elements such that each part is seen in its own polar projection.  The images are composed from data received during the course of 24 hours.  This means that the image must contain a mix of angles of incidence of sunlight, but over a relatively small range of angles.  The mosaic affords a rough guide to albedo but with quite large error bars.  That said, according to the laws of physics an estimate of albedo in the Arctic made from an Aqua or Terra Arctic image can never be entirely or even substantially wrong.  Within that specific context it can never be argued from a rational perspective that black is 'really' white or that white is 'really' black.

    I will leave the matters of polarization and of total internal or external reflection until I find time to write an article on this very interesting topic.
    Ah the misguided economy of a few words when replying by smartphone.
    I don't need a lesson on albedo.
    There is no normal incident, ie 0 degree solar incident light in the arctic. When the sun is over the equator, at the north pole the incident angle is 90, parallel to the ground.
    As the paper points out, at latitudes over 80 there is a significant reduction of energy falling on each sq meter. The overhead image defines a maximum, the sun is never directly overhead.

    logicman
    When the sun is over the equator, at the north pole the incident angle is 90, parallel to the ground.
    Yes, but on two days a year only.
    As the paper points out, at latitudes over 80 there is a significant reduction of energy falling on each sq meter.
    I do not dispute that point.  However, the key word is energy, not albedo.  Albedo is a property of a surface no matter where it may be located.  Just as insolation angle is responsible for the distribution of insolation aka heat over the globe's zones of latitude, so albedo is responsible for apportioning each latitude's heat between different types of material according to their powers of absorption of light and heat.   Insolation and albedo are two entirely separate concepts.
    But the type of surface, and It's latitude alter the energy absorbed. The absorption of water changes with latitude, in effect It's albedo is no t constant, at large incident angles it becomes more mirror like. Even in late summer east and west of what ever longitude the sun is aligned with, it also becomes more mirror like. And this effect is on top of the geometry changes reduce the solar flux per sq meter.

    I believe all of this is accounted for in the paper.

    It all reduces the amount of absorbed energy by polar water.

    Thor Russell
    Note sure you understand Mikes point.
    I hope this graph helps, its simpler than the paper referenced.
    http://en.wikipedia.org/wiki/File:Water_reflectivity.jpg

    When the sun is at an extremely low angle, little heat will be absorbed by the water as a lot more of it will be reflected back. Not sure what difference this makes because firstly the albedo is still way more than ice when then angle is as high as 75% and I expect the climate models to use knowledge to some extent. Also it seems like most light will be reflected back when there is low insolation anyway so even if this effect is not fully taken into account, I don't see it making huge difference. The most heat will be absorbed when the sun is highish in the sky because of high insolation and the albedo concern hardly applies then.
    Here is another source that may be interesting
    http://journals.ametsoc.org/doi/pdf/10.1175/1520-0493(1979)107%3C0775%3ATAOWAA%3E2.0.CO%3B2



    Thor Russell
    MikeCrow
    Hey Thor,
    The second link is the same paper I was referencing (but it is interesting).
    If you look at table 1, it shows the reduction in solar radiation by latitude, as well as elevation of the Sun at those latitudes, which show a large reduction in incoming radiation.
    Tables 3-6 show the effective albedo due to incident angle.

    What all this means is that open water north of about 70 Latitude absorbs a small fraction of the energy that open water at the equator would absorbs.

    And, if the sky is clear, this same open water will be radiating large amounts of heat to space, even during the day. I measured the temp of a clear sky on a 35F day as ~-40F. Water at 33F will radiate over 12 MJ/sq meter per day to a -40F sky. 4500MJ/sq meter per year, and @70 degree solar radiation is 6100 MJ/sq meter per year, but absorbed energy is a fraction of this amount, so it looks like open water radiates more energy into space than it receives from the Sun, at least on average.

    Not sure what difference this makes because firstly the albedo is still way more than ice when then angle is as high as 75% and I expect the climate models to use knowledge to some extent.
    At summer solstice, the Sun is about 23 degree's north. At 70 Lat, the Sun has an elevation of 42 degrees (calculator), it will never get to 75 degree that far north.
    Never is a long time.
    Thor Russell
    There has been some confusion about 75 degrees. In the wikipedia graph it is incident angle from normal, that is 75 degrees means 15 degrees in your definition. It is only when the elevation is below 15 degrees elevation that reflection matters according to that graph 
    Thor Russell
    MikeCrow
    Ok, glad you clarified this.

    As you're picturing a low hanging Sun in the Arctic (which will only be a maximum of 43 degrees for a few days a year), remember east and west of the "noon" longitude the angle also drops rapidly.
    Never is a long time.
    How soon can I expect some relief here in Minnesota??

    The vast, complex chaotic climate system you have such wonderful pictures of is NOT susceptible to mankind's behavior. You remind me of monks of the Dark Ages, flagellating themselves.

    logicman
    How soon can I expect some relief here in Minnesota??

    I am not a weather forecaster.

    The vast, complex chaotic climate system ... is NOT susceptible to mankind's behavior.
    What is it that scientists have missed and which you have discovered in support of that assertion ?

    The revolutions of the seasons, with their alternations of temperature and of length of day and night, the climates of different zones, and the general conditions and movements of the atmosphere and the seas, depend upon causes for the most part cosmical, and, of course, wholly beyond our control. The elevation, configuration, and composition of the great masses of terrestrial surface, and the relative extent and distribution of land and water, are determined by geological influences equally remote from our jurisdiction. It would hence seem that the physical adaptation of different portions of the earth to the use and enjoyment of man is a matter so strictly belonging to mightier than human powers, that we can only accept geographical nature as we find her, and be content with such soils and such skies as she spontaneously offers.

    But it is certain that man has reacted upon organized and inorganic nature, and thereby modified, if not determined, the material structure of his earthly home.

    [my emphasis]
    George Perkins Marsh, The Earth as Modified by Human Action, 1874, citing over 200 sources.
    rholley
    You remind me of monks of the Dark Ages, flagellating themselves.
    Scientifically, Patrick is more than capable of defending himself.

    However, the comparison you make suggests that you have blindly followed a narrative contributed to by people such as Washington Irving (may his memory be execrated) who propagated the idea that Christopher Columbus was opposed by the Inquisition for suggesting that the Earth is spherical.
    Robert H. Olley / Quondam Physics Department / University of Reading / England
    http://www.bjerknes.uib.no/pages.asp?kat=2&id=2111&lang=2

    Just out of curiosity I looked for funding for this research that is solely based on the premise that mankind is a danger to the planet. I see that the gravy-train continues.

    How many trillions of dollars can academics consume? And all while there are real people suffering throughout the world.

    In one hundred years, historians will look back in wonder at how an entire generation could so delude themselves and others.

    logicman
    The scientific investigation of human influence on weather and climate began with the Ancient Greeks.  What evidence do you have that these early philosophers were funded by anyone at all?

    How many trillions of dollars can academics consume?
    I wish I had the opportunity to find out.  Unfortunately, the few dollars a month which I earn from writing here are greatly outweighed by my costs.  I write, not to make money but from my love of science, language, law, logic and their history.

    In one hundred years, historians will look back in wonder at how an entire generation could so delude themselves and others.
    Not an entire generation.  Fortunately there are some of us who refuse to be deluded by anti-science propaganda.
    Wow, what an article
    I'm wondering if having Artic passage opened for shipping wil be considered as a new 'Panama Canal' in lowering costs and time for trade

    To P Lockerby,
    Sorry about you having to spend effort on responses to Teacher comments
    I do wonder tho if we have a proper solution for warming
    Mostly I hear that we need to return to temps and Co2 pre-industrial age or so; when I ask if we're sure that previous temp is better for earth, I don't get satisfying answer

    What is correct temp and Co2 for our Earth?
    Warmer temps are good for vegetation (in general) and higher Co2 is also better
    What's good for vegetation is good for all life that feeds on vegetation and in turn is better for the life that feeds on animals
    I'm not convinced that warming is problem that needs solving
    I live near Palm Springs, CA (Summer temps of 115 F common) so I don't want more warming for me and my family but I think warming will benefit far more than harm the earth