Guest essay by Robert A Cook, PE
Annually, the President is required to address the nation and report on the State of the Union. Other writers here regularly report on the oceans and El Nino/ENSO conditions, the duration and status of the extended “pause” in global warming we now are enjoying, and the global average satellite temperature anomalies. Thus, let us plan on summarizing, multiplying, dividing, and discussing the status of the world’s remaining sea ice on or about the twenty-second day of each month.
In particular, for the twenty-second of each month, we will calculate and present for discussion:
- that day’s solar radiation level at top of atmosphere (TOA),
- that day’s declination angle (the tilt of the earth’s axis towards or away from the solar plane),
- that day’s average Antarctic and Arctic sea ice area and extents,
- an estimate of the latitude of the edge of that day’s Antarctic and Arctic areas,
- at the edge of the sea ice for that day, estimate the total reflected and absorbed solar radiation into open water and sea ice for a clear day. (This requires an estimate of the sea ice albedo for that day, the solar elevation of the sun for each hour of that day, an estimate of the open ocean water albedo each hour at each solar elevation angle, and an estimate of the atmosphere’s clarity that day, and the air mass attenuating the sun’s energy each hour of that day at that latitude. )
- an estimate of the average additional heat losses each hour on that day from the open ocean and from the sea ice.
Why regularly discuss sea ice area?
Well, with the “pause” now extending 18 years – 3 months, and with every other CAGW prediction regularly failing as CO2 steadily increases, Arctic sea ice loss is just about the only defense left of the CAGW’s basic predictions. It is regularly hyped and used, so you need to know the details of why they think it is important, and the limits to that assumed importance. (Certainly, the CAGW proponents will not tell you of any limitations or constraints Arctic sea ice poses to their theory of Arctic amplification!) Antarctic sea ice, on the other hand, is failing every assumed CAGW result, and is just uniformly ignored. On the other hand, because it disproves the basic CAGW predictions, you need to know the details of Antarctic sea ice, the problems it poses, and the threats it poses.
Why the twenty-second of each month?
It is a convenient and exciting (well, interesting at least) day for almost all of the changes in all areas we need to look at through the year: solar radiation levels, the earth’s declination, the Antarctic and Arctic sea ice minimums and maximum areas.
The summer and winter solstices (longest day and longest night of the year occur on or about the 22 Dec and 22 June each, the fall and spring equinox fall 90 days later on 21-22 March and 21-22 September each year.
The Antarctic sea ice maximum occurs during the two weeks after 22 Sept each year, the Arctic sea ice minimum occurs a few days earlier: now it is averaging 15-20 Sept. The Antarctic sea ice minimum occurs around 22 Feb each year, the Arctic sea ice maximum occurs a the weeks after 22 March.
Solar radiation is not quite as convenient scheduled, but it is at least completely predictable: maximum solar TOA occurs halfway between 22 Dec and Jan 22 each year, solar TOA minimum occurs 5 July, halfway between 22 June and 22 July.
Antarctica first?
I will usually mention Antarctic sea ice first for several reasons.
First, it is almost always ignored by the CAGW press agents because the Antarctic sea ice reflects badly on several of their predictions about the effects of CO2 in particular and global warming in general. As observers of the global warming debate, you need to know what is happening all over, not just what the press agents want you to know, and what they don’t want you to know.
As important as that is, you will find through the next few months just how much more important the Antarctic sea ice area actually is to the world’s heat balance: The much-hyped Arctic amplification is a very real effect. But it does NOT only occur in the limited area of the Arctic (where sea ice has been receding for several decades) but around the unlimited seas and ever-increasing sea ice surrounding the Antarctica. Down south, where the sun is always higher in the sky and the solar energy reflected back into space much greater, sea ice area really does matter. Up north? Not so much almost all of the year.
Equations.
I will not go into a lot of the equations involved in this first report – there is time for that a bit later. They need to be covered, and the constants and variables need to be looked at in detail. Few “facts” you think you know, very few of the “Wikipedia” constants and textbook assumptions about sea ice really are constant, and almost none of the facts about sea ice, albedos, and solar radiation levels that “everybody knows” are, in fact, actually facts that can stand up to close examinations.
Models and constants and equations?
Challenge any item or equation you disagree with or wish to expand upon. I will in general treat any specific equation sourced from common geometry (such as a conversion of area into latitude, or the solar elevation angle calculated for a day-of-year and hour-of-day and latitude as a specific ‘thing”. It is not a model, nor an approximation. At sea level, the sun really is exactly that high in the sky on that hour of that day of the year at that latitude on earth. If you disagree with an equation, cite your source and justify the difference.
Measured data from field research is a bit different. In general, I will not use error bars or approximations nor will I use purely theoretical data or laboratory approximations such as the Fresnel equations for the albedo of water. (Pure water, in a lab, measured in still air from still water with perfectly aligned parallel and perpendicular light waves? Those conditions do not occur around Cape Horn.)
Everywhere possible, I will quote the experimental data for actual measurements taken in the Antarctic and Arctic itself (sea ice albedo, air temperatures, water temperatures, winds and wind direction, sea ice area, cloudiness and direct/indirect radiation levels); or from the measurements of real seas and real winds and real waves in the open ocean (ocean albedo). I will often approximate experimental results (particularly x,y graphs from old pdf files and graphs) with equations and curve-fit lines. Expect this, and offer better approximations as you see fit and as you can. But the original experiment results ARE the data! You can argue with my approximations (models ?) of each experiment, but you cannot disagree with the real world. Equally, each real world experiment has its own limits and its own assumptions. Again, each source will be discussed in detail over time. Each experimental source will be cited as each detailed equation is discussed – and there will be disagreements between measured results from different sources writing in different journals at different times. Where the source article does present a specific equation or approximation of his or her own work, that equation or constant will usually be used “as-written” for that time frame or those conditions. (For example, in 2001, Dr Judith Curry measured Arctic sea ice albedo as 0.823 That value will be used for all sea ice between January and early May. Her data showed a significant decrease in Arctic sea ice albedo between May and early September, and so her reported values will be curve-fit, and used for all Arctic sea ice albedos between those dates. She has no recorded values for albedo between September and January, so the 0.823 value will be assumed valid after September.)
Solar radiation will usually be addressed pretty much as the measured source data was obtained: in terms of direct radiation only under clear skies with typical Arctic conditions at typical arctic latitudes. Diffuse radiation and cloud cover and relative humidity levels are very important, but we need to get through many other things first. Land area and sea ice area will generally use millions of square kilometers as units (abbreviated as Mkm^2) . Angles are usually in degrees.
Your additions and questions about any value are encouraged of course, but –as Willis requires, always cite exactly what item or quote you question and why you feel it needs to be corrected.
I will not take credit for the basic research results discussed here – all of the hardest field work has already been done years before by many people and many teams from many nations and many institutions, nor of the basic equations and fundamentals used each time. Others deserve that credit, and they will be credited as each detail is discussed. I do acknowledge integrating their work together, and am responsible for the results discussed each time in this series.
Enough talk – You are (probably) even less interested than I in philosophical minutia of the differences between models and equations, between predictions and presumptions and projections and forecasts.
22 January 2015, Day-of-Year (DOY) = 22
Antarctic Sea Ice Area (SIA)
The Antarctic sea ice continues to melt as the year progresses towards its summer minimum in late February. The Antarctic sea ice anomaly is still positiver (more sea ice than “normal”) for this day of year. The Antarctic sea ice anomaly is now just under 1 million square kilometers, representing an area of “excess sea ice” about half the size of Greenland. It has been more than 2 standard deviations above normal for almost 2 years now, and January 2015 only continues that trend towards more sea ice.
Cryosphere (Arctic Climate Research at the University of Illinois)
[Note: There are several other reliable labs and institutions reporting daily sea ice areas and extents. Cryosphere at the University of Illinois is unique in reporting both. All SIA and SIA values differ from each other day by day, so for consistency across both poles, I will only use Cryosphere’s values for area. (Cryosphere data is released one day after processing completes, check the day-of-year values very carefully if you download data files.)]
SIA 1979-2008, DOY 22, = 3.102 Mkm^2, Average this date
SIA 2015, DOY 22, = 4.067 Mkm^2, Actual this date
SIA Anomaly, 2015, DOY 22 = 0.965 Mkm^2, Anomaly this date
Percent increase of Antarctic SIA = 31.1% more Antarctic sea ice than normal for this date
Total Antarctic Ice = 14.0 + 1.5 + 4.1 = 19.6 Mkm^2.
Antarctica’s ice now covers a total area of 19.5 Mkm^2 = 14.0 mkm^2 of continental land ice + 1.5 Mkm^2 of permanent shelf ice plus 4.1 Mkm^2 of total sea ice.
The edge of the Antarctic sea ice is at latitude -67.5 south, very close to the Antarctic Circle at -66.5 south latitude.
General Observations: The Antarctic sea ice continues its annual retreat towards the minium sea ice area in late February. The remaining sea ice tends to be very close to the Antarctic land mass. There is a large open area (polynaya) in the Ross Sea region. This represents an area where the Antarctic sea ice creates an open area between the edge of the sea ice and the Antarctic continent mass, which is unusual. Most of the time in most years, the Antarctic sea ice lies right up close to the coastline, with the sea ice touching the coast (grounded on the beaches) called “fast ice”. (It is held fast by the land.)
Antarctic Sunlight, DOY = 22.
Solar radiation at Top of Atmosphere (TOA) = 1405 watt/m^2, this date (whole earth exposure)
Declination Angle = -0.347, Tau (the Day Angle) = 0.36
At the edge of the Antarctic sea ice, at -67.5latitude, sunrise occurs at 02:00 AM, sunset at 22:00 PM.
At noon, at -67.5 latitude, air mass = 1.482; direct sunlight on a perpendicular surface = 1104 watts/m^2
At noon today, peak radiation on the sea surface = 744 watts/m^2 at a 42.4 solar elevation angle
At noon today, Sea Ice albedo = 0.750; 186 watts are absorbed, 558 watts are reflected into space [rev, 2/3/15]
At noon today, Open ocean albedo = 0.043; 712 watts are absorbed, 32 watts are reflected.
Today, this day of year, for every “excess” meter of Antarctic sea ice, you can see that 558 watts/m^2 are reflected back into space (clear day, at noon). And “sunlight” occurs for 20 of the 24 hours down south at latitude -67.5 today.
Arctic Sea Ice Area (SIA)
22 January 2015, Day-of-Year (DOY) = 22
The Arctic sea ice continues to expand towards its spring maximum in late March. As expected, even as every individual day grows longer after the winter solstice on Dec 22, the Arctic continues to lose heat into space. This heat loss is seen as an increase every day in the Arctic sea ice area.
Today’s Arctic sea ice anomaly remains negative at -0.679 Mkm^2. This continues its decade long negative value, and this value continues the steady negative sea ice anomaly started in early 2013 and continued through all of 2014. However, today’s anomaly is significantly smaller than both 2007 and 2012’s record low sea ice anomaly, and it represents an increase in Arctic sea ice area since 2005. (Today’s sea ice area is larger than most days since 2005, though the difference (the anomaly) remains negative with respect to the 1979-2008 mean area.) Today’s Arctic sea ice anomaly remains within 2 standard deviations of the 1979-2008 mean, and that continues a trend begun in 2013 and continued through most the days since.
Today’s Arctic sea ice anomaly is negative, and represents an area of “lost sea ice” roughly half the size of Hudson’s Bay’s 1.6 Mkm^2.
Cryosphere (Arctic Climate Research at the University of Illinois)
SIA 1979-2008, = 13.131 Mkm^2, Average this date
SIA 2015, DOY 22, = 12.453 Mkm^2, Actual this date
SIA Anomaly, 2015, DOY 22 = -0.679 Mkm^2, Anomaly this date
Percent decrease of Arctic SIA = 5.1% less Arctic sea ice than normal for this date
Total Arctic Sea Ice Area = 12.453 Mkm^2
The edge of the Arctic sea ice lies approximately at latitude 72.0 north, well north of the Arctic Circle at latitude 66.5. (This assumes a circular Arctic sea ice cap, centered at the north pole. The actual Arctic sea ice is only roughly circular, and its geometric center lies closer to the Canadian coast than to the Russian coast.)
Arctic Sunlight, DOY = 22.
Solar radiation at Top of Atmosphere (TOA) = 1405 watt/m^2, this date (same as Antarctica)
Declination Angle = -0.347, Tau (the Day Angle) = 0.36 (same as Antarctica)
At the edge of the Arctic sea ice, at latitude 72.0 north, the sun never rises above the horizon.
(Further south, at latitude 70.1 north, the sun just barely nudges the horizon for a few minutes at noon.)
At noon today, air mass = infinity, solar elevation angle = -1.9 degrees
At noon today, peak radiation on the sea surface = 0 watts/m^2 at -1.9 solar elevation angle
At noon today, sea ice albedo = 0.823, but no energy is absorbed
At noon today, open ocean albedo is meaningless.
Today, this day of year, for every “lost” square meter of sea ice, the open Arctic ocean loses more energy from increased long wave radiation from the open ocean water, from increased convection and conduction losses up to the sea surface, and from increased evaporation losses. In all cases, at this latitude at all hours of the day, more energy is lost from the open Arctic Ocean water than from ice-covered Arctic waters.
Today, this day of year, less Arctic sea ice = more heat loss from the Arctic ocean.
Net Planetary Sea Ice Heat Balance (at noon, this day of year).
Arctic sea ice area anomaly x net solar energy absorbed/m^2 – Antarctic sea ice anomaly x net solar energy reflected /m^2
-.679 Mkm^2 x 0.0 watts/m^2 – 0.965 Mkm^2 x 558 watts/m^2 = -538.5 MWatts reflected back into space at noon, thus cooling the planet.
References and Boilerplate.
Arctic Ice Albedo
1. Curry, J.A. and Schramm, J.L.; Applications of SHEBA/FIRE data to evaluation of snow/ice albedo parameterizations; Journal of Geophysical Research, Vol 106, D14, July 2001.
2. Korff, H.C., Gailiun, J.J. and Vonder Haar, T.H; Radiation Measurements Over a Snowfield at an Elevated Site; Department of Atmospheric Science, Colorado State University, January, 1974.
3. Warren, S.G.; Optical properties of Snow; Review of Geophysics and Space Physics, Vol 20, No. 1; Feb 1982
4. Brandt , R.E., Warren, S.G., Worby, A.P., Grenfell, T.C.; Surface Albedo of the Antarctic Sea Ice Zone, September 2005, Link: http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3489.1
5. Perovich, D.K., Grenfell, T.C., Light, B., Hobb, P.V.; Seasonal evolution of the albedo of multiyear Arctic sea ice; Journal of Geophysical Research, Vol 107, C10, 2002.
[My thanks to reader Matt for recommending two additional references: Brandt 2005 for Antarctic sea ice albedo measurements, and a link to Perovich 2002 with additional photos and errors not available in Curry 2001. Both extend Curry’s measurements for the Arctic ice albedo measurements, but both confirm the similarities and helped eliminate an assumed albedo for the Antarctic spring and summer months on my part. Dr Warren confirmed the values used above for yearly Antarctic albedos, and for winter albedo for both poles.]
“apuse” should be “pause” methinks.
[fixed -mod]
Such typos are a sign of brilliance.
They do give one pause though.
It’s a dull, unimaginative fellow who can think of only one way to spell a werd.
Well everything I write keeps coming out wrang.
So I tend to have an over-reliance on the predictive-onions facility on my lavatory.
It should be “halt” anyway.
Ai cumpleeteley ah-gree wiv yew emmpaynter. Aiii canknot eevenn favvumm veh noushien oth standrtt spel’gn.
The lack of such typographical errors is a sign one’s mind is slower than ones fingers. I have to be careful I don’t skip whole words because my mind is so fast, how about you?.
Does not past data show that there is no such thing as a “pause” the temperature is either going up or going down , no stasis .
well at some point the time differential crosses zero, and its not getting hotter or colder. Assuming the temperature is in fact a continuous function with respect to time, and does not move on quantised leaps… 😉
Looking forward to following…and the Year End summary.
In all cases, at this latitude at all hours of the day, more energy is lost from the open Arctic Ocean water than from ice-covered Arctic waters.
Today, this day of year, increased Arctic sea ice = increased heat loss from the Arctic ocean.
Based on the penultimate sentence, shouldn’t the final sentence be “Today, this day of year, increased Arctic sea ice = decreased heat loss from the Arctic ocean”?
I would argue, that based on the actual state of the Arctic, it should read “Today, this day of year, decreased Arctic sea ice = increased heat loss from the Arctic ocean”?
Yes, your observation is correct. Thank you.
We’ve fixed it slightly differently though.
Your penultimate and final paragraphs are in opposition. I think your final paragraph is wrong/backwards. — John M Reynolds
Katherine, jmrsudbury
Good observations. Corrected.
Thank you, peer review works!
Would it be possible to include a section on sea ice volumes? See eg
http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1.png
Dr Norman Page
As you will see as the year progresses, sea ice volumes do not affect solar reflectivity.
Worse, sea ice volumes are estimates in any case.
This is because multi-year ice levels are only as good as the estimates of first year ice area, and second-third-fourth-fifth year ice areas, and first-second-third-fourth AND fifth year ice thickness estimates. There are too many ways for “interested” parties in the CAGW debate to intervene in those estimates to create the PIOMASS program. And, regularly, those interested parties DO cite sea ice volumes as proof of the problem.
Yearly Arctic sea ice anomaly plots show differently. Volumes do not matter, they do not affect the next year’s sea ice extent all all.
Lastly, there are no published Antarctic sea ice volume trends. (Almost all Antarctic sea ice melts completely each year, so the Antarctic sea ice is “all” first-year sea ice.) So, there is no point in comparing Arctic and Antarctic sea ice volumes.
Sea ice areas, sea ice albedo’s at each latitude of the edge of the sea ice at each day-of-year are all that matters in the daily heat balance.
Cryrosat2 shows the Prince Adolph Gustav sea (SW of Ellsmere Island) to be ice free. Enviroment Canada navigation maps and MODIS images show old rough fast (5-30meters) ice. So you need to take their measurements with a grain of salt.
I agree that some summarization is needed. While I have no concern about the data and explanations, I often don’t have time to read thru the details and attempt to determine how the ice is, um, “performing”. For example, is it above or below the average at this point in the year?
This could be accomplished thru graphs, like the one above, &/or thru an “executive summary” or through some other means. But please help those of us with little time &/or short attention spans &/or inability to sift through mounds of data and verbiage.
Thanks
Replying to Madman2001. Hmmn.
“The Arctic sea ice is below average for this time of year.
It doesn’t matter. There is no sunlight hitting the Arctic sea ice at this time of year.
It DOES matter, because losing this Arctic sea ice cools the planet this time of year.
The Antarctic sea ice continues to be way above average for this time of year.
It DOES matter, because the extra Antarctic sea ice this time of year is cooling the planet. A lot.”
Does that summary help? 8<)
Dr. N. Page,
I hate that PIOMASS chart! They should start at a zero baseline. But if they did that, it wouldn’t look nearly so scary. So in the interest of propaganda, they use charts like that.
Arctic ice is only about 5% below average, and Antarctic ice is around 30% above average. Total polar ice is above its 30-year average. Thus, the last alarming prediction of the alarmist crowd goes down in flames.
Whenever I discuss Antarctic ice area with a “warmer” they immediately bring up ice volume or mass and how that number has decreased. Is there any data that could be shown on ice mass at each pole? Or maybe an average ice thickness?
Check this out.
July 6, 2014
Lying with Statistics: The National Climate Assessment Falsely Hypes Ice Loss in Greenland and Antarctica
by E. Calvin Beisner and J.C. Keister
http://wattsupwiththat.com/2014/07/06/lying-with-statistics-the-national-climate-assessment-falsely-hypes-ice-loss-in-greenland-and-antarctica/
“..though the difference (the anomaly) remains negative with respect to the 1979-2008 mean area.”
Interestingly, this data narrative has an “engineering” cadence to it that one would think would be boring, but the article just slips by and its gratifying to hear the many things that we do know. Thank you Robert.
One thing that clashed with the exactitude is in the statement in parentheses. The on-going changing base of the statistical data puts everything afloat. It would be better to keep the period used for comparisons constant, or at least relate it back to the original base period used when this decline in Arctic ice became noticed. In ten years, we will probably be heralding the recovery of the ice by leaps and bounds because the average for comparison will be of the period of low ice. Presumably, once we have a long enough record (I hope I’m still tottering around with a sound mind) we can choose a more realistic average high period and average low period to see where we really are.
Gary Pearse
Thank you for the compliment, I appreciate the help of everyone’s feedback.
This is a plot of sea ice extents, not areas, over time from a different lab. But it does show the change in the three “averages” in the decades since satellite ice surveys began.
http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_v2_L.png
Notice how very, very little the Arctic sea ice maximum has changed: declining, but only from 15.5 Mkm^2 to today’s 14.5 Mkm^2 (What they call the “2000’s average”) . The Arctic sea ice minimum has dropped much more (7.3 to 5.5). Also, that 5.5 is the average of the years 2000-2010. (Maybe the years 2001 – 2011 ?)
Regardless, clearly each year since 2010 is stilllower by 1-2 std deviations the previous decade, so – They’re right! – Arctic sea ice has declined. Continues to decline.
My point is still true:
The continuing decline in Arctic sea ice area affects the planet’s heat balance two ways:
In May-June-July, the Arctic ocean waters warm up slightly.
Between August-April, the other nine months of the year, the now-open Arctic waters cool the planet.
Every month of the year, the ever-increasing Antarctic sea ice reflects more heat energy, cools the planet.
First, I’d like to see a case made as to why anyone should care – I don’t think it matters. I.e., this all presumes that sea ice matters. It doesn’t. Alarmists have set the terms of debate.
“Annually, the President is required to address the nation and report on the State of the Union.”
Not really. Article II, Section 3, Clause 1: “He shall from time to time give to the Congress information of the state of the union” is what is required. Not annually, and not to address the nation.
Yes alarmists have set the terms of debate, by manipulating politicians and the media. It is unfortunate but that is the hand we are dealt.
To a politician whether sea ice is relevant or not is irrelevant, the only relevancy is if it helps them pursue their political agenda. For the media, “if it bleeds it leads”, some scientists and a former vice-president- presidential candidate, forecasting certain catastrophe easily falls into the “it bleeds” category.
I sometimes wonder if Gore in bitter revenge at losing the presidential election, used his skills, talent, and contacts picked up from his presidential campaign to afflict the world with a fake crisis and make a 100 million dollars on nothing more than air.
Naah! Gore so the dollar sign. He is the type of politician that is there only for his own enrichement.
We are just the usefull idiots, there only to shovel money in his pocket.
No, Gore was an active warmist in the Senate in the late 1980s–and maybe earlier.
I would guess that with Al Gore, the main impetus for his CAGW stand is to maintain his perceived value to the nation and the world. He wants to maintain the image that he is at the forefront of world issues, and further that he knows the answer to the perceived problem as a true leader should.
The Gore types don,t care about money they care about control and power, money is a by product not the aim.
Sea ice cover influences albedo and heat exchange between the ocean and the atmosphere. This is why this post mentions these items. In general, we should prefer more sea ice until the Ice Age begins for real. At that point we need to cheer for less sea ice.
Another self-regulating mechanism of our earth. Increased heat—>decreased sea ice—>increased heat loss—> increased sea ice
Is it really so straightforward?
Probably not. It seems more likely that more heat is being conveyed to the Arctic via the Gulf Stream or perhaps changes in circulation of that current, hence sea ice reduction. Now the sea ice extent is recovering and probably because of natural fluctuations in such heat dynamics.
Perversely, it seems more like:
“The more Arctic sea ice lost in September, the greater the heat lost in October, and the greater the Arctic sea ice freeze that winter.
The higher the Antarctic sea ice gains, the more energy is reflected, and the longer the pause lasts.”
There is no evidence at all of any “Arctic Amplification” longer than 3-6 months. Look at the plot of arctic sea ice anomalies:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
Sept 2007. Record Arctic low sea ice minimum.
Feb-March 2008. Almost a 0.0 Arctic sea ice anomaly! Everything has re-frozen – AND THEN SOME! More sea ice at maximum 6 months later than has been seen for many years.
And the theory fails the other way as well:
March-April 2012. Near record high Arctic sea ice anomaly – Sea ice areas now frozen that have not been frozen for many years.
Sept 2012, 6 months later. Record Arctic sea ice minimum.
The next years (2013, 2014) Arctic sea ice back high again that winter, Arctic sea ice anomalies remain within 2 std deviations the next 24 months. There is no correlation the past 10 years of any kind between sea ice minimum areas and the maximum or minimum sea ice areas the following or preceding year.
Same thing happens after all of the extreme Arctic sea ice oscillations since 2005.
@RAC…look at how the max/min range drops after the 1997/98 El Nino. It then stays that way for 10 years until the 2007 season. Then an increase in max/min range runs for 6 years before the max/min returns to a tighter range from 2013 to the present time. It leaves me with the impression that the 1997/98 Grand El Nino is the reason for the start of the sea ice decline.The shift from warm trend to cool trend means that the sea ice after 2006 tries to regain more area, but it is still being affected by the movement of the extra warm oceans. That is why the max/min range increases sharply for those 6 years. After 2006, the shift year as I like to think of it, there are several more El Nino which maintains the increased max/min. The last 2+ years on the graph the max/min range has tightened up again. La Nina is starting it,s period of dominance. This should be indicating the end of the warming conditions which caused the sea ice decline. I would expect this graph to show a return to the 0 value in the next several years with the max increasing while the min gradually decreases. My best guess.
I don’t know. Something very odd happened to the two trends of Arctic and Antarctic sea ice areas the past years, and I don’t have a clean explanation for the changes.
1. Recent Arctic sea ice minimums are much later now (2006 – 2014) than the previous 36 years (1979 – 2008 average curve. Cryosphere plots the previous September Arctic sea ice minimum was a sharp 2-3 day dip on Sept 01. Last 9 years, it has become a slower more gradual 4-5 day curve with a minimum 14- 18 days later, between Sept 15 and 20.
2. The arctic sea ice anomaly curve showed a steady gradual dropping trend from 1979 through 1996, but always staying right above 0.0 – 0.5. Then it bent sharply down in 1995-1996 (before the Great El Nine ? Cause of the Great El Nino in 1998? Independent completely of the Great El Nino in 1998? ) The Arctic sea ice anomaly then began oscillating wildly 2006 – 2010 -> with peaks and drops and jumps from season to season 3-4 times as high as they have been previously! But what changed in 2006?
3. Record LOW Arctic sea ice levels in 2007 and 2012 were followed immediately by huge increases, increases large enough to push the anomaly curve back near the its near-zero values right after each record low. These positive jumps were 2-3 million square kilometers in just months.
4. But .. just as the sudden huge spikes and drops were unanticipated by theory, after 2010 the Arctic sea ice anomaly changes returned to calmer states and the Arctic sea ice anomaly began rising more steadily again between 2010 and 2015.
Coincidence or not? The Antarctic sea ice anomaly began negative (just as the Arctic sea ice anomaly began positive in 1979) and steadily dropped between 1979 and 1992. Then, the Antarctic sea ice anomaly began rising – and continued rising steadily and unspectacularly between 1992 and 2010.
But, beginning ion late 2010, the Antarctic sea ice anomaly began increasing rapidly – and has not stopped yet.
The Antarctic sea ice anomaly has been recent setting many new record HIGH SEA ICE AREAS – the latest w all-time Antarctic sea ice record was set June 2014 at 16.03 million square kilometers of sea ice. This “excess” sea ice area represents the additiona of a sudden “new” reflecting area the size of Greenland 92.16 Mkm^2!
@RAC…look at the 5+ year El Nino between 1990 and early 1995. Plus there were the 2 good sized warm events in the 1980s, also. I should have inserted from the beginning that I see the pivot point between warm and cool trends as taking place approximately every 30 years. Working backwards 2006 to 1976, 1976/1946, 1946/1916, and so on going back in time. The year 2006 thus represents the first years of a cooling trend. The MEI fits that pattern all the way back to 1870, and so do the global temperature sets. The MEI is currently showing that La Nina has been dominant since 2006. Plus the MEI shows El Nino predominance starting in 1976 and continuing to 2006. La Nina dominance is seen in the 30 years prior to that during the slight cooling between 1946 to 1976.
I also see something in the Antarctic anomaly graph, but I can not make the connections to put it to words as of yet. Also, great post. I am looking forward to your next installments on this subject.
It is seldom noted that open water in the arctic, during winter, looses more thermal energy than ice covered water. This loss of energy does not show up on the surface as a lower surface temp, it does show up as lost thermal energy below the surface. Because there are few if any temperature boyies 1000 meters below the surface of the Arctic we have little knowledge of the effect open water in the Arctic has on the oceans gain or loss of thermal energy.
It is also seldom spoken of that the wind is the main reason sea ice can get thicker than 2 meters. Multi-year sea ice is all about the wind, so is sea ice area and extent. Currently sea ice volume (arctic) is higher than it has been since 2009 even though it’s area is lower than the long term average.
kent blaker.
You are correct, open water losses increase ocean energy losses significantly, compared to ice-covered Arctic waters.
Yes, we will cover the “extra” energy losses from the Arctic open water in more detail later. Wind affects both open water albedo (reducing it) and increase heat losses due to convection, evaporation, and conduction. LW Radiation losses? Not so much. A still night has more losses than a windy night if the humidity is the same
I think all those solar energy values are Watts/m^2–not Watts.
You need to include a value for energy lost during open sky night as the deficit side of your energy accounting. A total increase or decrease in energy using the Watts/m^2 * Area anomaly would be of interest.
Adding some consideration for the change in elevation angle for the sun throughout the day and the hours of daylight will add to your complexity but make the calculated difference in the total energy for the day value more relevant.
I’ve seen this before and it always strikes me as a poor assumption; a circular pole centered arctic ice field. The maps clearly depict which regions are at a deficit, i.e. for today, Bering and Okhotsk. Since you are doing an analysis for a select day, please consider using the local Latitude for the greatest regional anomaly.
Also not 581 Watts/second, but just Watts – I assume the arithmetic “error” (cited numbers give a difference of 580) is due to rounding in a spreadsheet.
True. We will use Watts/m^2.
SORCE reports solar radiation levels at TOA in Watts/m^2, we should remain consistent with them. I was trying to emphasize the amount of the reflected energy from the Antarctic this time of year, and should not have.
Crashex
My actual spreadsheet uses the correct solar elevation angle (and thus the correct open ocean albedo, air mass, and atmospheric attenuation factor for each of the 24 hours of any given day. Added up, I do generate a useable 24-hour net “total energy.” When all losses are included, some days at some latitudes you get a net gain, some days you get a net heat loss.
See, when the sun hits any given square meter of the ocean, some of it is reflected, and some is absorbed.
When the sun hits any given square meter of a piece of sea ice, some of it is reflected and some is absorbed. So you have to compare “if it is water, how much is reflected” to “if it is sea ice, how much is reflected” every hour. And then do both again for the amount of energy absorbed. When you start playing with direct and diffuse radiation levels and albedo’s, it gets really complicated.
This time, this first article, I decided to only report the energy levels at daily noon.
The sun (obviously) highest at noon, but that single value for reflected energy is not really very useful. If one is looking at the entire day, then you really need to use the 11:30 value ( I HATE the d*mn Phoenician numbering system!!) for reflected or absorbed radiation x 60 minutes x 60 seconds to get the total value for the radiation losses at “noon'” from 11:30 to 12:30 (Did I tell you how much I hate the d*mned Phoenicians?)
Evidently, so did many other people. Note that Phoenicians are hard to find anymore.
Under the heading “Antarctica first?” you say “Down south, where the sun is always higher in the sky and the solar energy reflected back into space much greater, sea ice area really does matter. Up north? Not so much almost all of the year.” As I understand it, the sun is as high in the sky at x degrees North as it is at x degrees South 6 months later. Or is that not what you meant?
is it because the sea ice in Antactica is surrounding a continent, so is not actually so far south as the sea ice is north at the north pole (ie at a lower latitude)
The point is that the average marginal ice extent is a lot further from the South pole than it is from the North, so the marginal Southern latitude get more sunshine.
FrankH (quoting RACook)
Two parts of the effect you ask about.
Yes. Axial tilt remains the same all year long. At the same latitude, the sun will be at exactly the same solar elevation angle above the horizon at corresponding intervals of the “axial year” (Dec 22 to Dec 22) in both the southern hemisphere and northern hemisphere. But the Arctic sea ice and Antarctic sea ice are not at the same corresponding latitudes at opposite parts of the “axial tilt” solar year.
Arctic sea ice area now cycles between a minimum of 3-4 Mkm^2 (today’s avg minimum is about 3.5), and a maximum today of about 13.5 Mkm^2. (There is no doubt Arctic sea ice used to be larger: 1979-1990 minimum used to be 4.25, maximum used to be 15.0)
But Antarctic sea ice also used to cycle between a minimum of 1.75 Mkm^2 and a maximum of 15.0 Mkm^2.
today, the Antarctic sea ice cycles between a minimum of 2.5 Mkm^2 and a maximum of 16.0 Mkm^2. (Rough numbers)
A lot of people – when they look at all at the steady growth of Antarctic sea ice between 1992 and 2015 – add up the two hemispheres and compare the total of Arctic and Antarctic areas. If the total anomaly of the two hemispheres remains about the same (within a standard deviation, for example), most people would claim that arctic ice loss doesn’t matter. And, in fact, the total sea anomaly DID remain right at 0.0 from 1979 through 2005. But something change in 2005-2007. Arctic sea ice losses AND GAINS (minimums much lower – with record lows in Sept 2007 and Sept 2012) suddenly became very, very large (near zero and positive anomalies at maximum highs in 2006, 2008, 2013, 2014). Antarctic sea ice gains became strongly positive (both minimums and maximums became much larger, and continue getting larger.)
Total sea ice anomalies are positive now, and were positive for much of 2013 and 2014. Total sea ice area anomalies continue to cycle about 0.0.
but this misses the geography of the sea ice. We’ll go into it in more detail if Anthony permits with a future thread (“Sea Ice 101 – Where Is The Sea Ice and When Is It Where It Is”) but this is the (very) short version.
The Arctic sea ice is now cycling between latitudes 80.5 North (at an average minimum of 3.5 Mkm^2 in Sept) and latitude 71.3 North (at an average maximum of 13.5 Mkm^2 in late March). There are a few spots further south (Hudson Bay, Bering Sea, St Lawrence River mouth – but we’ll cover all of the exceptions and approximations later.)
But the Antarctic sea ice does NOT surround the south pole. Rather, the Antarctic sea ice surround the Antarctic continental ice (14 Mkm^2) AND the Antarctic fixed shelf ice (1.5 Mkm^2). Even if the Antarctic sea ice were exactly equal to the Arctic sea ice (or the losses in one were exactly equal to the gains in the other), the edge of the Antarctic sea ice is NOT cycling between latitudes 80 south and 71.3 south.
Rather, the Antarctic sea ice at its recent minimums sea ice area of 2.5 Mkm^2 in February is really 14.0 + 1.5 + 2.5 = 18.0 Mkm^2 at a latitude of -68.3 south.
The Antarctic sea ice at its recent maximums of sea ice area of 16.0 Mkm^2 in September is really 14.0 + 1.5 + 16.0 = 31.5 Mkm^2 at a latitude of -61.2 (Antarctic sea ice extents are even closer to the equator around latitude 58 – 59.)
At these latitudes at those times of the year (closer to the equator than the southern tip of Greenland) the Antarctic sea ice is receiving (and more importantly reflecting) much more solar energy than the Arctic sea ice receives and reflects.
But it is even worse that that!
Antarctic sea ice is facing the southern hemisphere sun at its highest point at -23.5 degrees on Dec 22 due to axial tilt.
A few days later on Jan 5, the earth is the closest it will ever be to the sun in the earth’s orbit (at this point in the Millancovich cycles at least), and the inbound solar radiation at top of atmosphere is highest at 1408 watts/m^2.
Antarctic sea ice is not yet at its minimum, but is receding towards its annual minimum in late February. So today (late January) the Antarctic sea ice reflecting the solar energy near its yearly “maximum” of TOA radiation.
But the Arctic sea ice receives NO solar energy at all.
Now, let’s look ahead a bit into early July. The Arctic sea ice will be getting 20 – 24 hours per day of sun (just like the Antarctic sea ice is now) BUT the Antarctic sea ice will still be reflecting some solar energy 4-6 hours per day. Not as many hours, but the Antarctic sea ice is still reflecting energy even in July. But in July, both Antarctic and Arctic sea ice are receiving almost 90 watt/m^2 LESS energy in July than it does today. So the yearly importance of the Arctic sea ice is much less.
RACook,
Thank you for that explanation!
Distilling your detailed explanation, I get the following:
The arctic and antarctic ice coverings are effective reflectors of incoming solar radiation. However, the total antarctic minimum ice extent is a 5X larger ‘reflector’ of incoming solar radiation than the arctic ice pack at minimum extent, when each have cycled through their respective summer maximum radiation exposures.
Bottom Line: For radiative balance and implied climate change considerations, our greater focus should be on areal changes to the ‘big solar reflector down under’.
Mac the Knife
I would prefer phrasing that just a bit more precisely:
EVERY extra square meter of antarctic sea ice extent in mid-September is a 5X larger ‘reflector’ of incoming solar radiation than ANY square meter of arctic ice pack is at its sea ice minimum on that same day.
We could lose EVERY square meter of Arctic sea ice EVERY day in September and STILL have a net loss of solar energy into space due to today’s “excess” Antarctic sea ice.
A most welcome addition and important information. I am more interested in data than the politicization of it as I see at The Great White Con and other blog sites. I find IJIS Arctic site also very valuable. WUWT’s sea ice page is also very informative but to have a monthly analysis is very welcome indeed for us interested but nonetheless non-academics. Thank you Mr Cook and Anthony
Thanks for mentioning one of my blogs on here Badgerbod. However it sounds rather like you haven’t actually looked at the data on the GWC Arctic sea ice graphs page yet? Here it is:
http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/
Try clicking a few of the links also. I think you will find there is a lot more data available to you there than here, and in actual fact a lot less “politicization” too!
BTW – I think you’ll find the number quoted above for Arctic SIA is actually for day 20, not 22.
Please provide their csv file, I used what was presented for Jan 22 from the Cryosphere plot. Now, if they are “plotting” data on their graphs one day late, or two days late, we will use the csv data. But I’ve got to read it first from Cryosphere directly.
I agree that drilling down to the original data is vital in these matters.In the case of CT area it can be found here:
http://arctic.atmos.uiuc.edu/cryosphere/timeseries.anom.1979-2008
Note that there is also this handy visualisation tool available:
http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html
If embedding an image works on here, see this closeup:
http://GreatWhiteCon.info/wp-content/uploads/2015/01/CTArea-20140126-0800.jpg
2015 is in yellow, along with 2006/12/13/14
Hi Jim, my point on politicization is that TheGreatWhiteCon whilst providing data on the Arctic (not the global situation) does attempt to interpret the data to its own agenda, whereas Sea Ice data on WUWT is purely that, the data, updated from source without comment. So I therefore find WUWT’s Sea Ice pages very useful in just looking at a record without rhetoric. Whether I am qualified to interpret the data is something else, but, with respect, I would rather have the facts then an agenda driven opinion.
Re: Badgerbod
January 26, 2015 at 1:21 am
Please show me some evidence for your assertions. As always, a link or two would be good. By way of example, where exactly does “The Great White Con interpret the data to its own agenda”?
Jim Hunt
Be careful! That data file link starts with day-of-year for January 01 2015 as 2015.000.
That puts the -0.67878 anomaly data point on Jan 21, neither Jan 20 (as you indicated) nor Jan 22 (when I first read the data when it was released Jan 23). Cryosphere has not yet returned my phone calls. I will keep trying.
But again, thank you.
My pleasure.
Have you tried hovering your mouse over the squiggly lines on the CT interactive chart yet?
I thought commonly given insolation units were watts / square meter / hour, not per second. Am I wrong?
Alan
A Watt is one Joule per second. That has two dimensions. Two Joules absorbed in two seconds is one Watt, for two seconds. Total heat is in Joules. Watts means a RATE of heat moving from one thing to another.
Thirty Watts per square meter means thirty Joules per second, and each additional second, for as long as you want. The Joules add up. The rate remains thirty per second.
A Watt hour is 60*60*1 = 3600 Joules.
A kilowatt hour is 60*60*1000 = 3,600,000 Joules
I know this is out of scope of your article, but to me the interesting things about the Arctic is why the ice varies so much over the years. Warm/cold pools of water and the resulting changes in weather patterns are the primary reasons.
The current setup with the relatively warm water off the Gulf of Alaska and the mild el Niño results in one setup while cold water off Alaska and a la Niña would result in a completely different weather pattern. The resulting winds blow warm or cold air over parts of the Arctic in the winter and ice will or will not form and the same thing happens in the summer melt season.
And the Antarctic with its isolation and own sets of currents and weather patterns is completely different.
Can we have a polar bear?
And penguins? 🙂
Here you go!
http://i34.tinypic.com/2qk8e38.jpg
Polar bears do not eat penguins!!!
They’re not eating them, they’re thawing them.
Polar bears eat meat…The reason there are no penguins in the arctic.
yeti love penguins
http://www.methodshop.com/games/play/yeti/yeti1.shtml
[288.4 feet .mod]
Polar bears do not eat penguins!!!
Has this hypothesis been tested? Given hunger and opportunity, I’m confident these climax predators will eat as many penguins as their substantial digestive systems can ‘stomach’.
Its a long way to go for a meal.
Let’s see – they don’t eat penguins but they do listen to music and watch videos while running a barbeque
humor impaired, perhaps?
It happens. See here:
http://www.sciencedaily.com/releases/2007/06/070605185637.htm
Very interesting approach in using solar radiance, and earth tilt when looking at ice behavior and effects at the 2 poles
In summary SIA grew by about 1 million square kilometers, and Arctic SIA reduced by about 700,000 square kilometers. A couple of questions come to mind:
– Is this trade off of SIA between Arctic and Antarctica just natural processes keeping a balance between the 2 poles?
– Why is 1979 the year to begin tracking Arctic and Antarctica ice behavior ?
– There are numerous types of measurement of ice. For example sea ice area, sea ice extents, land ice area, land ice extents, ice volume, ice depth and I don’t know how many more. And some of those measurements have caveats and not clear agreement in their meaning or accuracy. Anyways why is SIA the measurement picked as primary measurement in this study?
1979 first polar orbit satellite observations using microwave signature difference between water and ice. See essay Northwest Passage in ebook Blowing Smoke for details on seasonal accuracy issues. But its all we got.
See the added Note inserted above.
[Note: There are several other reliable labs and institutions reporting daily sea ice areas and extents. Cryosphere at the University of Illinois is unique in reporting both. All SIA (Sea Ice Area) and SIE (Sea Ice Extent) values from different labs differ from each other day-by-day, so for consistency across both poles, I will only use Cryosphere’s values for sea ice area. ]
Actually Cryosphere at the University of Illinois is NOT unique in that regard. By way of example please take a close look at:
http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/#Area
Understood. Yes, there are Antarctic graphics on the Great White Con site.
But, even the link on that page to https://sites.google.com/site/arcticseaicegraphs/ has no Antarctic plots nor data.
The original data on Antarctic sea ice areas and long-term trends (averages and anomalies) need to remain with at least one original source, and that single source must report both Arctic and Antarctic the same way using the same formulas and methods.
I think you actually meant “Arctic graphics” in your first paragraph?
We currently specialise in Arctic data only, but we do provide both area and extent in rather more detail than Cryosphere Today! For your purposes consistent methodology at both poles certainly seems like a prerequisite.
Arctic sea ice albedo 0.83 in January? Can you please explain. Inside the Arctic circle there is no sunlight in January.
Ah, there will always be some value for sea ice albedo. There just may not be any solar radiation coming down to reflect back off of the sea ice.
The sea ice albedo changes with day-of-year for Arctic, but remains just about the same for the Antarctic all year. (No dust, no pollen, no aerosols, no pollution, and no “dirty” second, third, or fourth year ice down there. So it remains very “clean” all year round. Then it melts almost completely.)
Today, this day of year, increased Arctic sea ice = increased heat loss from the Arctic ocean.
shouldn’ that be
“Today this day of year, decreased Artic sea ice = increased heat loss from the arctic ocean”?
Sounds logic to me: with no ice heat loss from open water is more important then with ice covered water. Ice due to it’s lesser density is a better insulator then open water. Add snow cover to this and then your ocean is even better insulated.
To me these known facts may even have more effect then the albedo effect. Note that i say “may” i found no study on this (yet) but would be an interesting one
to see the “net heat storage gain” they should considder the difference between albedo and heat absorption and heat loss due to lack of insulating. (the arctic has episodes of no sun thus no heat source) Of course CAGW fanatics forget this important (but compenating) factor
i often ask myself questions and look up
i often ask what the impact of ocean currents are on declining or increasing sea ice
i only came up with alarmism like this site (note the boldface)
http://www.whoi.edu/main/topic/arctic-ocean-circulation
This complex circulation system in the Arctic—which impacts the entire food web—is in a delicate balance. In recent years, scientists have documented changes in the Arctic system, including a dramtatic reduction in sea ice cover and a weakening of the Beaufort Gyre circulation system, that are attributed to climate change. The Arctic Ocean affects the way of life of not only the Arctic native peoples, but also those of us living “downstream,” in Europe and North America. As such, the Arctic Ocean, and the effect of changes that are taking place there, are the focus of intense study by oceanographers of all disciplines.
i wonder: PDO switched in the same time, AMo reached a max. it are current induced multidecadal variables. I wouldn’t be surprised as seen in the current chart, that these variations do also cause a multidecadal variability in the arctic ocean.
just a little two cent addition and questions to look into to add to this marvellous new topic series?
Correction made as noted. Thank you.
Yes, we will walk through through these problems each month.
Is it possible to consider emissivity and radiation into space for polar regions not in sunlight and put some numbers on it? I recall a debate with an ardent “ice is going to disappear in the Arctic” supporter, who failed to consider the effect of increased open ocean on heat radiated back to space during the winter.
We will get into that area in much more detail if Anthony permits. These come under the general problem of “Other Losses” when you consider the effect of Sea Ice on the world’s heat balance.
Problem is, they depend strongly! – almost exclusively – on the “local weather” of the water or sea ice. Local air temperature, local wind speed, local emissivity of the sea ice or open water, local Nusselt’s Number and local Reynolds’ Number number and Prandtl ‘s Number of the local air flow (and those things depend on the local air speed, local air pressure, local air temperature, local air density, local air relative humidity (which depends back on the local air wet bulb and dry bulb temperature and air pressure) and local length of the exposed water (local melt pond depth, width, length, and wind direction.)
In short, they are a real mess, and require a lot of estimates and assumptions or corrections. Now, that makes the calculations for LW radiation losses, evaporation losses, convection losses, and conduction losses no less important, but you do have to know the problems in making the estimates to find the coefficients to make the calculations to make the estimates.
Note also that ALL of these are losses. By leaving them out completely, we only make the “assumed CAGW impact” of losing Arctic sea ice even larger. By leaving them out completely, the assumed “Arctic Amplification” is artificially larger, and the assumed “Arctic Death Spiral” even greater and faster.
Robert,
Thank you for this compilation.
One thought, it may be helpful if it could be presented in tabular form. I realize this is the first instance of this series, but a tabular representation would allow an easy comparison to previous months.
Just a thought…
I really wish that somebody could grab the NEMS and SCAMS data from the 1970s if it exists. It would extend the microwave record back to 1972 from 1978.
Thanks Robert. Good work.
It might be good to develop a way to tabulate it, so to follow the monthly changes.
You need more pretty pictures 🙂
Robert: As you may already know, the real Arctic and Antarctic behave somewhat differently from what one can predict with calculations.
Firstly, almost all the SWR reaching the surface has been scattered by particles in the air and therefore doesn’t arrive on a directly line from the sun. Calculating albedo under this circumstances is challenging. (The same phenomena occurs on the rest of the planet near sunrise and sunset. Photographers prefer to take pictures at this time because the light comes from all directions and shadows are much less distinct. At twilight, the sun is just barely below the horizon and all the light from the still bright-blue sky is scattered.)
Secondly, the surface and albedo of sea ice changes with the season. In the Arctic spring, the surface of sea ice is covered with snow, which later become large melt ponds. The albedo is often far less than expected for a flat surface of pure ice.
Third, as sea ice melts, evaporation increases, as does the likelihood of clouds. So the cloud albedo increases as the surface albedo decreases, though the former doesn’t fully compensate for the latter. The radiative balance over polar sea ice and open water is continuously monitored from space.
You can find more info and literature references from a post at Tamino’s that tried to calculate the radiative forcing produced by changing sea ice. I reported some real observations that challenge his calculations.
Yes. Your observations are correct.
That is why I want EVERYBODY to be VERY SPECIFIC about their comments and calculations:
Simplest is:
Clear skies,
measured top-of-atmosphere solar radiation levels,
measured polar atmospheric transmission conditions,
measured direct radiation only (at sea levels only),
measured sea ice albedo’s for direct radiation,
measured open ocean albedo for direct radiation,
measured areas of Arctic and Antarctic sea ice.
Let’s stick with these “easy” assumptions to start with until everybody knows all of the “easy” parts of the problem. Besides, every change from the “ideal” of clearest skies, lowest humidity, highest solar elevation angle during the longest day-of-year exposure, smallest latitude/largest area, and lowest albedo only reduces the sea ice feedback on the world’s climate.
Also, because ALL measurements vary with time-of-day, latitude, day-of-year, and the current “weather” for the measurement, ALL comments and corrections need to be specific about the actual assumed conditions.
I know the real world =
Varying cloud cover percentages (with very high cloud cover in summers),
varying cloud reflections back into space,
varying humidity conditions,
varying wind speeds,
varying dust and surface particle contamination levels,
varying percentages of melt water,
varying weather conditions (which strongly control secondary heat losses (convection, evaporation, radiation),
(slightly) varying solar radiation at TOA.
I want to go into albedo’s (odd thing that: My spell check does not like ANY version of ANY spelling of the albedo but the singular!) of both open ocean albedo and sea ice albedo in much more detail. If Anthony permits, we will do that separately in “Sea Ice 101 – Reflections on Albedo” later.
As you pointed out, they are very complex. Sea ice albedo does not vary too much with incident angle of the incoming radiation, but does vary strongly with both covering (new snow, old snow, bare ice, meltwater, dust and dark particles and mixes of all of the above). I will be using Judith Curry’s 2001 paper on Arctic sea ice albedo through the year. She measured in dropping down through the Arctic summer (May, June, July, August) to as low as 0.42.
Open ocean albedo varies strongly with type of radiation (direct solar rays or diffuse – as you pointed out), very strongly solar elevation angle for direct radiation but not all with diffuse radiation, and not at all with day-of-year for either. Wind speed affects direct radiation albedo somewhat (below 10 m/sec), but not diffuse albedo. Diffuse radiation received varies very strongly with what type of clouds are present, and what height of clouds they are, and what levels of dust and aerosols are present.
As you point out, atmospheric absorption varies very strongly with solar elevation angle, strongly with latitude (which controls humidity and atmospheric density) and season of year (which also controls humidity, number of particles and clouds, and percent cloud cover/type of clouds.) If Anthony permits, we’ll cover these details in “Sea Ice 101 – Solar Radiation and Atmospheric Losses” later.
Robert: I’m glad to see you are on top of all these complications. I became familiar some of them when Tamino tried to calculate the radiative forcing (averaged over the globe) from the loss of sea ice. When he didn’t ban me immediately, I gradually discovered that such paper calculations were fairly meaningless, but that real scientists were attempting to measure these changes from satellite data.
Frank
I started researching sea ice reflections and albedo and energy totals in 2010, and have been keeping track of sea ice areas since 2006. certainly, I’m not the first to notice Antarctic sea ice levels have been increasing, but ..
Judith Curry had 779 comments on her Feb 3 2012 article “Why is there so much Antarctic Sea Ice”
http://judithcurry.com/2014/02/03/why-is-there-so-much-antarctic-sea-ice/#comments
She had 480 comments in Sept 17 2012 on her “Reflections on Arctic Sea Ice, Part II”
http://judithcurry.com/2012/09/17/reflections-on-the-arctic-sea-ice-minimum-part-ii/
She had 399 comments in Sept 16 2012 on her “Reflections on Arctic Sea Ice, Part I”
http://judithcurry.com/2012/09/16/reflections-on-the-arctic-sea-ice-minimum-part-i/
I started these calculation sets (comparing reflected energy from the increasing Antarctic sea ice against absorbed energy from the decreasing Arctic sea ice) when I noticed that NONE of these 1658 comments, and NONE worldwide on the web on ANY site ever actually calculated what the Sereze’s “Arctic Death Spiral” and its mythical “Arctic Amplification” actually was. Oh they talk about it ad nauseum, and they “arm wave” about its assumed average effects all of the time.
But they never actually calculate the absorbed and reflected net energy.
And the few times I’ve seen it calculated theoretically (see the future “Sea Ice 101 – Insolated, Insulated, Insolated Icebergs in Space, What They Teach About Arctic Amplification”) they use the wrong values, the wrong averages, and the wrong equations. In any case, when Arctic Amplification is taught (when the equations and the solutions and the lecture notes are available on-line) the increased reflectivity of the Antarctic is NEVER mentioned as a feedback, nor a solution, nor even as a possibility!
Now, I’m not going to claim I will not make errors or need corrections and reminders! CHECK MY WORK! Always. But, over the next year – if the values from 2011-2012-2013-2014 continue – we will be able to show here a constantly increasing NET NEGATIVE energy exchange from the earth back into space due to recent positive Antarctic and negative Arctic sea ice changes.
right click, add to dictionary?? albedos, even albedoes . . . works with Microsoft and here with Firefox anyway
Thanks for doing this. I have really wanted to learn and understand about sea ices. Uncle did ice core samples in Arctic for National Geodetic Survey in 60s and 70s, I recall.
They’re now at – http://www.ngs.noaa.gov/ – so I’m going to check their data and such.
Frank:
We will address the many problems of direct and diffuse radiation through the whole set of these reports.
As you suspect, they are NOT simple, but – equally – they can be addressed. But ONLY if you don’t start taking and arbitrarily assigning “yearly averages” of anything to anything else anywhere up there: areas, temperatures, latitudes, albedoes, cloud cover, water levels, or solar elevation angles or hours-of-sunlight.
The announcements of these monthly updates from RACook are very welcome.
Focus on the Antarctic is highly appropriate.
The Antarctic led the world into the Holocene and by a simple argument of symmetry,
it is likely that the Antarctic will also lead the world back to glaciation.
For the leading of Antarctic warming ~20kya up to the Holocene see the following:
Blunier et al 1997 – figure 2
http://onlinelibrary.wiley.com/doi/10.1029/97GL02658/pdf
Weaver et al 2003 – figure 5
http://rockbox.rutgers.edu/~jdwright/GlobalChange/Weaveretal_Science_2007.pdf
RA
Is there a “threshold” latitude near both poles,
above which ice cover decreases heat loss (since more heat is lost from open water, albedo less important) and below which ice cover increases heat loss (due to more insolation with the sun higher in the sky, albedo more important)?
If so what is it approximately?
Thanks.
Good question.
Obviously, we don’t know this year’s results yet, but I will add your recommendation in.
World’s Daily Net Energy Anomaly =
Antarctic sea ice anomaly (Mkm^2) x Net daily Antarctic energy balance/m^2 +
Arctic sea ice anomaly (Mkm^2) x Net daily Arctic energy balance/m^2
Looking back .. For 2014 and 2013, looking only at SW radiation energy gains/m^2
In Sept, Antarctic has 5x the Arctic’s impact.
The edge of the Antarctic sea ice at its maximum receives five times the solar energy that the edge of the Arctic sea ice at minimum does.
October-Nov-Dec-Jan-Feb-March. there are almost no Arctic solar energy gains at all in Oct and March, and zero Nov-Dec-Jan-Feb when the sun is below the horizona the entire month, regardless of Arctic sea ice extents or Arctic sea ice anomalies either positive or negative. The Antarctic dominates completely. The Arctic sea ice is almost continuously in the dark.
April. The arctic begins to dominate in midday, but loses heat overnight if the sea ice anomaly is negative.
May-June-July. The Arctic receives more solar radiation for longer periods of the day than the Antarctic does.
August. Like April, the arctic continues to dominate in midday in early August, but loses heat overnight if the sea ice anomaly is negative. By Aug 22, both Arctic and Antarctic receive the same amount of solar energy.
In the Antarctic data section, should’t ‘SEA’ be ‘SIA’?
Correct. Thank you.
SEA – Solar Elevation Angle (angle of the sun above the horizon at any given hour-of-day)
SIA – Sea Ice Area
SIE – Sea Ice Extent. (15% or more of the ocean is covered by sea ice)
By the way.
When asked directly, the NSIDC told me that they do NOT include fresh water ice (the Great Lakes and inland US rivers) in their Sea Ice Area (nor Sea Ice Extents) numbers for each day. I do not know if the other sea ice agencies (NORSEX, JAXA (Japan) or DMI (Dutch Meteorological Institution) include or exclude fresh water ice.
NSIDC does NOT include the permanent ice shelves around Antarctica or small areas north of Canada is their daily sea ice totals either.
Yes. Now corrected. Thank you.
See the abbreviations above for SEA, SIA, SIE.
An interesting Arctic science observation regarding solar energy is also mentioned here.
Each year when the solar energy drops to 200 W/m2 and below for the first time, cooling occurs suddenly in the oceans/seas.
The illustration below shows what happens over successive years around Iceland soon as 200 W/m2 are reached.
https://imageshack.us/i/0k200wm2sstscoolingp
200 W/m2 is a key ice age value, where if too much of the planets surface near the poles are absorbing equal or less, our inter-glacier climate ends.
This link should work.
Matt G
To confirm your images, if you look at the Iceland’s yearly sea ice plots for their local area, you will see that the dark blue “triangle” you show is the first region around Iceland to freeze up every year, and the last to thaw out each summer.
Both 2003 and 2004 are El Nino years on the MEI.
“The much-hyped Arctic amplification is a very real effect”
I’m possibly wrong, but isn’t (or shouldn’t) that phrase be, “polar amplification”?
Yes. But the CAGW community has to ignore the recent Antarctic sea ice gains to maintain their facade that
1. Arctic Sea Ice loss is caused by Global Warming.
2. Arctic Sea Ice loss is a proof of Global Warming.
3. Arctic Sea Ice loss will contribute to further Global Warming, or even Catastrophic Global Warming.”
The basic Polar Amplification theory (solar radiation will reflect from sea ice, and be absorbed into open ocean waters) is real phenomenon.
The SECOND half of their logic (The extra energy absorbed into the open ocean waters will heat up the water and cause more ice to melt) is NOT correct in all cases at all times of the day under all light conditions every day of the year at every latitude of the world.
See, “how much” extra solar energy is absorbed IS NOT described nor calculated by the CAGW community because it would reveal some very Inconvenient Truths about their assumptions. So we will do those calculations for one day of every month. Now, from today’s sea ice extents, Polar Amplification Theory DOES WORK.
Up north in the Arctic three months of the year.
Down south in the Antarctic latitudes for (roughly) seven months of the year.
And that ominous Antarctic sea ice is increasing every year.
Would I be right in thinking that the shape and position of the ice, as well as its area, would have an effect on albedo?
By way of illustration, would a perfect disc centred on the North Pole have the same albedo as a disc of the same area centred, say, 200 miles south of the North Pole?
Of any approximation that I’ve ever made, I dislike this assumption of a circular “beanie cap” centered over the north pole the least.
But….
Look at this animation of the Arctic sea ice several times. At minimum, that circle of latitude 80 north represents an area just smaller than the record lowest Arctic sea ice (Sept 2012) . The accepted area of the Arctic Ocean is 14.06 Mkm^2, which is also the average area of the Arctic sea ice at maximum.
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsst_nowcast_anim365d.gif
Can you think of any better approximation? A very few areas are further south (Hudson Bay, Bering Sea, that limited strip to the east of Greenland, the Denmark Strait, a little bit in the St Lawrence River mouth.) The tip of Greenland intruding into the 80th latitude circle is always ice-covered – it will freeze, melt, and reflect solar energy very much like sea ice.
The actual Arctic sea ice tends to be blown away from north Russia and over towards the north coast of Canada. Those north coast islands is the “bulge” where multi-year sea ice tends to accumulate.
So, my approximation will include a few areas where exposed “open ocean” is inside the beanie cap (north of the approximation) like that persistant “wet spot” just beside Svalsbard Island; and omits a few areas where Arctic sea ice is present at latitudes slightly further south (say 73 – 74 degrees) in the late summer when my approximation assumes the edge of the edge is at 76 or 77 degrees.
But, NO Arctic sea ice is south of 71-72 degrees in August-September-October when Arctic sea ice is at its minimum areas. ALL Arctic sea ice in the Bering Sea, Hudson Bay, Kara Sea, Chukchi Sea, south Baffin Bay and Davis Straits is entirely melted by mid-July. So, the presence (or absence) of sea ice earlier in the year does not affect any sea ice calculations later in the year. Its all water. In winter, the land within the approximation is all sea ice. Or ice-covered small islands – which will behave like sea ice in reflecting solar energy.
@RECookPE1978 animation
Wow, look at all that cold water leaking through the Bearing Straits and down the deep basin channel between Greenland and North America! It is exactly what Willis’ ARGO animation shows. The conventional wisdom is that the Bearing Strait is too shallow for that to happen. My own suspicion is that brine rejected saltwater is going down the deep Greenland channel and freshwater runoff is skating through Bearing. Pretty much a thought in progress, but the Arctic is a very “fresh” ocean.
I fully believe the mechanism of Chen and Tung whereby superhaline warm water can be carried to depth. But the reverse should also be true. Zero degree freshwater from the McKenzie river should be able to levitate two degree saltwater over the Bearing Strait.
Same old story nobody wants to hear. The ocean warms the atmosphere, not the other way around. You put an insulator (yes, ice is a solid that blocks convection and evaporation) and the ocean can transmit less energy to the atmosphere. The albedo is lunch money until the Ides anyway.
Albedo is important, but more important are the ocean currents that distribute cold water.
http://www.biomedcentral.com/1471-2148/10/203/figure/F1?highres=y
I think that it’s important to analyse the climatic revolution in the Arctic area and to see in which measure the oceans and the seas determine the climate. I suggest you to take a look here – http://www.arctic-warming.com/?page_id=17. There are many facts about the Arctic and about the warming phenomenon that happened here.
Very well done post. I’ll look forward to the monthly installments, if Anthony allows.
I am personally less interested in the sea-ice, because as far as I am concerned the entire “albedo” question has already been answered, by the behavior of the ice the past ten years. There has been no “death spiral”. There has been no feedback created, where less ice causes less ice. Instead the ice obeys the PDO and AMO, and likely depends on the strength of their cycles. What would be most interesting to study (IMHI) is how the AMO and PDO behaved during the Medieval Warm Period and the Little Ice Age.
One of the best ways for a layman to study the ice is use your own eyes. There are now a number of drifting cameras, and also the visual satellite views. The press seems to lack the time to actually watch the ice, and see what it does, and sometimes makes statements which, if you have been actually watching the ice, are obvious and atrocious balderdash. However you don’t recognize the balderdash as being balderdash unless you’ve been watching, so use your eyes.
In a couple months we will start to get splendid views due to the fact people start to venture out onto the icecap in March. The Russians set up a base where small jets can land, and wealthy explorers cross-country-ski to the Pole. Modern technology allows them post pictures onto Facebook and Twitter on a daily and even hourly basis.
The explorers tend to preach the Alarmist line, as often their funding depends on it, but if you look at their pictures and listen to their comments you can read between the lines. For example, last year the cross-polar-flow piled up huge pressure ridges north of the Canadian Archipelago, and the explorers were muttering about the mini-mountain-ranges they had to clamber over. One fellow who had done a lot of exploring on arctic ice commented “I’ve never seen such pressure ridges before”, and another nicknamed them “crazy ice”. It simply didn’t fit the narrative, which moans and groans, “It’s melting! It’s melting!”
I strongly advise checking out the various explorers, in March. Ignore their politics, because they pull off amazing feats of strength and endurance.
Please provide full study reference for Judith Curry 2001 albedo measurement. I located a 1995 report “Sea-Ice Albedo Climate Feedback Mechanism” which does show a graph indicating albedo around 0.83 derived using a model. However it should be noted that the albedo given is that which would account for snow covered sea ice in winter and may not necessarily reflect summer conditions in Antarctica. This report also shows the albedo decreases to nearly 0.5 for winter months in the Arctic.
Additionally, I located a 2002 report “Seasonal evolution of the albedo of multiyear Arctic sea ice” Perovich et al. which provides direct measurements of summer time albedo in the Arctic indicating lower albedo as expected during warmer months and may be more reflective (no pun intended) of summer conditions in the Antarctic.
Based on these two references, you may need to adjust the numbers in the calculations to better represent seasonal changes.
I noticed that you do not state the day of year 22 for the SIA 1979-2008 average. Is that indeed the average for the 22nd day of January or the average of those years as a whole? I ask only since the values provided after do state day of year. Please clarify.
matt
Valid observations, but – yes, your information is incomplete.
Arctic Ice Albedo
1. Curry, J.A. and Schramm, J.L.; Applications of SHEBA/FIRE data to evaluation of snow/ice albedo parameterizations; Journal of Geophysical Research, Vol 106, D14, July 2001.
2. Korff, H.C.’ Gailiun, J.J. and Vonder Haar, T.H; Radiation Measurements Over a snowfield at an Elevated Site; Department of Atmospheric Science, Colorado State University, January, 1974.
3. Warren, S.G.; Optical properties of Snow; Review of Geophysics and Space Physics, Vol 20, No. 1; Feb 1982.
(Curry has several other reports and articles from her year up across the Arctic sea ice during the SHEBA in-ice experiment, but No. 1 was most valuable because it did NOT require any modeling or approximations. The daily Arctic sea ice albedo was simply measured by her (her team I suppose) and plotted from April 01 through Oct 11. I used the data directly from her plot. (Ice melt started May 9-12 period, and all measurements prior to May 09 are assumed valid back to January 01 (Day-off-year 01). Refreeze was complete by Sept 18-20, and all albedo’s after Sept 21 were again back up to the first-of-year data at 0.823 (She used 0.8228 in this report, I rounded it off to 0.823.)
“Seasonal evolution of the albedo of multiyear Arctic sea ice” Perovich, 2002 reports the same SHEBA experiment that Curry performed. His report is behind a paywall, I will let them two discuss who did what when and why. I have Curry’s plots, and used her results.
[Update. Perovich et al., 2002 “Seasonal evolution of the albedo of multiyear Arctic sea ice” does report on the same SHEBA experiment data as Dr Curry, but Perovich 2002 includes Arctic albedo standard deviation information. It will be added to the reference list.]
My monthly sea ice summaries will use the correct albedo for that day-of-year as it changes through the year. The lowest albedo was 0.386 on DAY = 221 (08-12), but that was an outlier. Curve-fitting through the entire summer shows a better fit of 0.46 on that date. Likewise, she recorded 0.41 on DAY = 208 (07-27) but the smoothed albedo curve passes a little higher on that date at 0.46. (This matches well with your 0.50 for mid-summer.) She reports the melt ponds began to re-freeze on August 12, which we will show marks the beginning of the time of year when the Arctic stops gaining solar energy in open water and begins to lose more heat each day from evaporation, LW radiation, convection and conduction it gains from the sun. Curry’s plot (Figure 1) has no error bars, I will not provide any. Obviously, there are some, and we can discuss those approximations as you see fit. The other articles and references showed no substantive disagreements with Curry’s measurements.
Antarctic sea ice is unanimously reported in all of the few articles and papers that even mention it as cleaner and brighter than Arctic sea ice (no dust, no pollen, no dirt, no carbon soot or particles, no aerosols, less melt water pockets during the melt season); but equally, its albedo has never been measured out on the Antarctic sea ice pack itself. Antarctic sea ice is over 90% first-year ice, and what little sea ice remains from year to year, is trapped up next to the continental rocks in bays and alone the shore. This 5-6% remaining from year-to-year does NOT flow out towards sea, nor is it out away from the continent reflecting solar energy to any great degree. I have used Curry’s 0.823 through the entire year.
Numerically, I will use Curry’s measured sea ice albedo for (for example) day-of-year 206, the area of Arctic and Antarctic sea ice on DOY = 206, find the average latitude for that area of each sea ice pack, and calculate the solar elevation angle for every hour of DOY = 206 at that latitude. From the SEA and latitude, you get the air mass for each HOD, the atmospheric attenuation for that hour, the albedo of the open ocean water for that SEA, and thus how much direct (and indirect or diffuse) solar energy is absorbed and how much is reflected each hour. From air temperature, wet bulb temperature, and wind speed for that latitude for that day-of-year you can estimate the heat transfer film coefficients for each hour for convection and conduction, the latent heat lost through evaporation, and the LW thermal radiation losses out from the ocean surface or ice surface.
The rest is just arithmetic. 8<)
For DOY = 22 (Jan 22 2015) I simply used the data (numbers) directly from the two Cryosphere plots released on that day.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png
(Notice that the two plots above will show today’s date and data – NOT the numbers for Jan 22!)
Nothing fancy.
I have digitized their average 2-year plots for Arctic and Antarctic sea ice averages, and have curved-fit their daily average sea ice areas (and the sea ice extents from the other labs) to make it possible to calculate areas, anomalies, and altitudes (etc) for any day-of-year as it becomes convenient) but the we have to wait until the actual day-of-year to make an actual report. Oh well.
Your information is not complete either hence the comment requesting additional information. I saw the title of that Curry report during my search, so first off, thank you for citing as requested, one more PDF to add to the collection. Citation makes it easier for people to check for themselves as is what you would like your readers to do as indicated in the introduction to your post:
“Your additions and questions…are encouraged”
Perovich, no paywall, full PDF link below:
http://scholar.google.ca/scholar_url?url=ftp://ecco2.jpl.nasa.gov/data3/ATN_output/%2Btemp/%2Bseaice/Perovich_2002.pdf.gz&hl=en&sa=X&scisig=AAGBfm0vhqDjNfESZrX0h2Ev9w-mWkBKig&nossl=1&oi=scholarr&ei=nETGVNSVEIawsATy_IKwDA&ved=0CB8QgAMoAjAA
Laine, V. Antarctic Ice Albedo, Temperature and Sea Ice Concentration Trends, 1981-2000, full PDF link below:
https://www.eumetsat.int/website/wcm/idc/idcplg?IdcService=GET_FILE&dDocName=PDF_CONF_P50_S7_10_SILJAMO_P&RevisionSelectionMethod=LatestReleased&Rendition=Web
Brandt et al. Surface Albedo of the Antarctic Sea Ice Zone, September 2005, full text and PDF link on page:
http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3489.1
There were others that came up in the search but I have not had time to read them so will not discuss them.
Stated in your reply:
“Antarctic sea ice is unanimously reported in all of the few articles and papers that even mention it as cleaner and brighter than Arctic sea ice (no dust, no pollen, no dirt, no carbon soot or particles, no aerosols, less melt water pockets during the melt season); but equally, its albedo has never been measured out on the Antarctic sea ice pack itself.”
This is not entirely true with regards to both suspected cleanliness and measurements. “These impurities could be continental dust from the ice-free regions of coastal Antarctica, 83 km away, or (more likely) algae that entered the snow via seawater flooding of the snow/ice interface… There may also have been biological material from seals, penguins, and other birds” (Brandt et al, 2005).
Although Curry et al. (2001) is speaking of the Arctic, she notes in her conclusions, “Fast ice in coastal regions may be associated with lower surface albedos [e.g. Flato and Brown, 1996]. Additionally, regions in the eastern arctic may be exposed to more soot and sediment, which would lower the albedo.”
Stated in your reply:
“all measurements prior to May 09 are assumed valid back to January 01”
OK, so you have assumed that January albedo during winter in the Arctic is the same as the albedo during summer in the Antarctic. Such assumptions in your introduction and the reply are indicated to be unacceptable:
Stated in your post:
“Enough talk – You are (probably) even less interested than I in philosophical minutia of the differences between models and equations, between predictions and presumptions and projections and forecasts.”
Stated in your reply:
“most valuable because it did NOT require any modeling or approximations”
From Figure 1 of Curry et al. (2001), the roughly 0.8 albedo tends to occur prior to the melt season when dry snow cover is present on the sea ice (April-May measurements) and post melt season from freeze up onward (mid-August to end of September). Summer obviously occurred between these two time frames for which Curry took actual measurements, one of which was as low as 0.38. I did not come across any part of the study that classified that measurement as an outlier and thus, that is your opinion. It is a real measurement and just happens to be the lowest collected measurement, that is all. Since January tends to be near the middle of summer for the Antarctic, if Arctic albedo measurements are going to be used for Antarctic albedo then it would follow that mid-summer Arctic albedo measurements should be used in the calculations (ranging from 0.38 at low point to 0.77 collected during the highest melt time in early June). This posting could have been written for a day where a real data point exists rather than relying on the unknown precision of the posters processes. Another curiosity is why the graph of the curve-fitting that has been created is not provided as part of the write-up along with the data set? Anyway, you could simply just use albedo measurements collected by Brandt et al., 2005 during Antarctic summer. The 0.83 albedo also closes in on one of the highest albedos measured in Curry et al., 2001. That is called “cherry picking” data which results in misinformation. Please refrain. If you want to transfer Arctic sea ice albedo or any other data to the Antarctic, please cite references or provide links to the studies that make for such allowances.
Stated in your reply:
“most valuable because it did NOT require any modeling or approximations”
You approximated the 0.83 by using a best fit line or curve-fitting line and, as indicated by your own statement, is unacceptable. There are plenty of data points, choose an appropriate one for the time of year. Also take note of the various types of sea ice that may be present for a given time of year. These various types have different albedo measurements associated with them resulting in varying degrees of absorbed radiation. Instead of the arbitrary reasons for selecting the given day, select a day based on data collected and reported on in real studies.
Please make the necessary corrections in your post.
It should be noted that the Curry study, although they took direct measurements, the purpose was to evaluate different models for sea ice albedo. It seems that, although with margins of error as can be expected, the models are not that far off. Curry does note, “it appears that a simple albedo parameterization tuned to give appropriate results for snow-covered and melting ice can give reasonable results when used in a sea ice model”. Interesting result from the study conducted and indicates that not all models are blatantly wrong or “fudged”.
Stated in your post:
SIA 1979-2008, = 3.102 Mkm^2, Average this date
SIA 2015, DOY 22, = 4.067 Mkm^2, Actual this date
To simplify the question, why do you not state “DOY 22” for the 1979-2008 average but you state it for the value that follows. I do not question that Cryo has reported the data (along with NSIDC, &c.). More of a curiosity in the write up. I am wondering if it is that you are not sure how Cryo calculated the number and so there is a lack of confidence or perhaps some other reason? Please clarify or give reasoning and update your post to that effect so that everyone who reads is clear on the matter.
And here is a link just so that everyone is clear that no one is hiding anything, there is no conspiracy. This article states clearly that antarctic sea ice has been increasing and the arctic decreasing.
https://nsidc.org/cryosphere/sotc/sea_ice.html
More over, recent studies (not going to list them) have indicated that the science community does not completely understand the processes taking place in the Antarctic so putting words in their mouth or incorrectly interpreting studies serves only to make people look foolish and to undermine the hard work of real scientists that yes, get paid for doing their jobs just like you, me or anyone else. It should be noted that one cannot apply the same logic to both the Arctic and Antarctic for the simple reason that the Antarctic has land mass situated at its centre whereas the Arctic does not never mind the sheer size difference between the two, altitude, wind patterns, ocean currents, air, surface water and depth water temperatures and the list goes on even to include particulates ejected by volcanic eruptions for which may settle in these regions and much more.
1A. No. As stated earlier, Perovich only duplicates the data that Curry reported (though it does provide std deviation points for the albedo – which may help later efforts.) Thank you for providing the gzip file.
No. Laine’s data does have Antarctic sea ice albedo values – but they are reported only as a single average albedo for the entire spring and summer. There is no day-to-day information at all. Further, the data of every one of his plots ends in 2001, and the trend of every one of his plots was a sharp increase in Antarctic sea ice albedo – up from 0.63 in the early 1980’s to 0.76 in 2001. Thus, his information is not accurate now on a daily basis for Antarctic sea ice, particularly since the trend for all of the Antarctic sea ice albedo’s in every different region he reported on began increasing substantially in 1992. Every trend was increasing, the last values of single-point averages for albedo were 0.73 – 0.76. Also, his final albedo for 2001 is not that much different than the daily measured values of 0.823 from Curry and Perovich.
Provide measured daily Antarctic sea ice albedo measurements and I will use them. Otherwise, no. Antarctic sea ice albedo will be approximated at 0.823, with the reservations and cautions I already expressed.
2. Stated in your post:
SIA 1979-2008, = 3.102 Mkm^2, Average this date
SIA 2015, DOY 22, = 4.067 Mkm^2, Actual this date
Are you confusing or confounding the two phrases “Average this date” and “Actual this date” ?
I do not see how you can assume the average Arctic sea ice area for day 21-22 is ANYTHING except the reported Cryosphere average area for day 21 or 22. Cryosphere released their information to the public on Jan 22 with those values. You provided one file reportedly from Cryosphere with the same area and anomaly values listed, but your file had a date = 2015.055 for an anomaly of 0.679 – for the Arctic.
The values in your data file were for the ARCTIC sea ice.
The values reported were the values printed on Cryosphere’s plots on Jan 22 for the Antarctic sea ice area on Jan 22, Antarctic sea ice average area for Jan 22, and the Antarctic sea ice anomaly for Jan 22.
Cryosphere has not returned my phone calls asking about this matter. When they reply with verified information, we can decide if you want to talk about day 21 or 22 information. But please, keep the numbers for Arctic and Antarctic separate.
The equations for the solar elevation angle, axial tilt, hour angle, air mass, air attenuation, and thus energy absorbed and energy reflected from two areas of sea ice at any two latitudes across the globe are identical.
The values returned from each equation depend on hour of day and latitude.
Now, tell me why the Antarctic sea ice is going to reflect and absorb heat differently from the Arctic sea ice.
3. You appear to have great objections to sea ice albedo values, apparently assuming for some reason that I will use the same value for every day of the year.
What is your background in statistical process measurement, QA, field measurements, and data trend analysis? When measured data is changing over time, what classes and training do you have in processing and analyzing that changing data?
Keep writing, I need to figure out how better to resolve your concerns.
Brandt et al. Surface Albedo of the Antarctic Sea Ice Zone, September 2005, full text and PDF link on page:
http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3489.1
Brandt 2005 has some good points within it, and needs serious consideration as a primary source of Antarctic sea ice albedo. On the whole, it supports fully the approximation of assigning a winter-month long albedo of 0.823 for sea ice on both poles. It does not contradict Curry’s measurements of Arctic sea ice albedo of 0.823 for direct sunlight (clear Arctic/Antarctic daylight hours) for modestly thick, fully frozen sea ice (> 0.7 thick) even in the antarctic summer “freezing” months of DJF (Dec-Jan-Feb), but does justify a lower value (which is logical) for (snow-covered) Antarctic sea ice during the “melting” months of SON (Sept-Oct-Nov).
to repeat, you have made several good points, and have provided independent validation of the importance of measured sea ice albedo rather than “Wikipedi-accurate” averages. Equally, you have no invalidated the nhumbers assigned, and so we will specifically address all of them separately in Sea Ice 101 – “Reflections on the Albedo of Sea Ice.”