From #AGU14 – satellites detect albedo change in the Arctic, resulting in more absorbed solar radiation

This press session at AGU conference today had quite a lot to say. Personally, I think the issue of carbon soot forcing is one of the strongest drivers of this, as WUWT previously covered here: In the Arctic, nearby soot may be a larger forcing than CO2
NASA Satellites Measure Increase of Sun’s Energy Absorbed in the Arctic (video follows)

NASA satellite instruments have observed a marked increase in solar radiation absorbed in the Arctic since the year 2000 – a trend that aligns with the steady decrease in Arctic sea ice during the same period.

While sea ice is mostly white and reflects the sun’s rays, ocean water is dark and absorbs the sun’s energy at a higher rate. A decline in the region’s albedo – its reflectivity, in effect – has been a key concern among scientists since the summer Arctic sea ice cover began shrinking in recent decades. As more of the sun’s energy is absorbed by the climate system, it enhances ongoing warming in the region, which is more pronounced than anywhere else on the planet.

Since the year 2000, the rate of absorbed solar radiation in the Arctic in June, July and August has increased by five percent, said Norman Loeb, of NASA’s Langley Research Center, Hampton, Virginia. The measurement is made by NASA’s Clouds and the Earth’s Radiant Energy System (CERES) instruments, which fly on multiple satellites.

sea_ice_fraction_change_and_absorbed_solar_radiation_change[1]

The Arctic Ocean is absorbing more of the sun’s energy in recent years as white, reflective sea ice melts and darker ocean waters are exposed. The increased darker surface area during the Arctic summer is responsible for a 5 percent increase in absorbed solar radiation since 2000. Image Credit: NASA Goddard’s Scientific Visualization Studio/Lori Perkins

While a five percent increase may not seem like much, consider that the rate globally has remained essentially flat during that same time. No other region on Earth shows a trend of potential long-term change.

When averaged over the entire Arctic Ocean, the increase in the rate of absorbed solar radiation is about 10 Watts per square meter. This is equivalent to an extra 10-watt light bulb shining continuously over every 10.76 square feet of Arctic Ocean for the entire summer.

Regionally, the increase is even greater, Loeb said. Areas such as the Beaufort Sea, which has experienced the some of the most pronounced decreases in sea-ice coverage, show a 50 watts per square meter increase in the rate of absorbed solar radiation.

“Advances in our understanding of Arctic climate change and the underlying processes that influence it will depend critically upon high quality observations like these from CERES,” Loeb said.As a region, the Arctic is showing more dramatic signs of climate change than any other spot on the planet. These include a warming of air temperatures at a rate two to three times greater than the rest of the planet and the loss of September sea ice extent at a rate of 13 percent per decade.

While these CERES measurements could ultimately become another of those signs of dramatic climate change, right now scientists say they have obtained the bare minimum of a data record needed to discern what’s happening over the long term.

Getting data beyond 15 years will allow scientists to better assess if recent trend falls outside the realm of natural variability, said Jennifer Kay, an atmospheric scientist at the Cooperative Institute for Research and Environmental Science at the University of Colorado.

“We need long time series to detect climate change signals over the internal variability.  For example, observed sea ice loss over the last 30 years cannot be explained by natural variability alone.” Kay said. “Fifteen years is long, but climate is often defined as the average over 30 years – so we are only half-way there with the CERES observations.”

Kay and colleagues have also analyzed satellite observations of Arctic clouds during this same 15-year period. Kay’s research shows summer cloud amounts and vertical structure are not being affected by summer sea ice loss. While surprising, the observations show that the bright sea ice surface is not automatically replaced by bright clouds. Indeed, sea ice loss, not clouds, explain the increases in absorbed solar radiation measured by CERES.

Increasing absorbed solar radiation is causing multiple changes in the sea ice cover, said Walt Meier, a sea ice scientist from NASA’s Goddard Space Flight Center, Greenbelt, Maryland. Two of those changes include the timing of the beginning of the melt season each year and the loss of older, thicker sea ice.

The onset of the melt season in the high Arctic is now on average seven days earlier than it was in 1982, Meier said. Earlier melting can lead to increased solar radiation absorption. This is one step in a potential feedback cycle of warming leading to melting, melting leading to increased solar radiation absorption, and increased absorption leading to enhanced warming.

Since 2000, the Arctic has lost 1.4 million square kilometers (541,000 square miles) of older ice that is more than 3 meters thick, which during winter has essentially been replaced by ice that is less than 2 meters thick, according to data provided by Mark Tschudi at the University of Colorado. Once again, Meier said, this trend is a step in a feedback cycle.

“Having younger and thus thinner ice during winter makes the system more vulnerable to ice loss during the summer melt season,” Meier said.

CERES instruments are currently flying on the Terra, Aqua and Suomi-NPP satellites. The Terra satellite launched Dec. 18, 1999, and CERES first started collecting Arctic data in 2000 so 2015 will mark 15 continuous years of CERES measurements over the Arctic.

The instruments include three radiometers – one measuring solar radiation reflected by Earth (shortwave), one measuring thermal infrared radiation emitted by Earth (longwave), and one measuring all outgoing radiation, whether emitted or reflected.

For more information about NASA AGU presentations, visit:

www.nasa.gov/agu

Advertisements

76 thoughts on “From #AGU14 – satellites detect albedo change in the Arctic, resulting in more absorbed solar radiation

  1. A typical climate dilemma: we have measured an increased absorption of heat, and also an increasing ice cover. Uncertainties prevail.

    • Nothing much is new. Herodotus wrote about the Persian invasion (480 BC) where their fleet was wrecked against the coast of northern Greece by a great storm, and the Persian priets and magi prayed and sacrificed three days until the wrath of the gods was stilled, -or maybe, he writes, maybe the storm just stopped by itself.
      So, we also have priests and magi and they offer enormous sacrifices to the gods of climate (paid for, like all sacrifices, by us) to stop the disaster, or maybe, maybe….

    • And yesterday we had this from WUWT.
      “Good news from #AGU14 ‘Arctic sea ice is holding up to global warming better than expected’
      ….Arctic sea ice volumes in the autumn of 2014 are above the average set over the last five years and sharply up on the lows seen in 2011 and 2012, according to the latest satellite data….”
      Since the September minimum of 2012 Arctic sea ice extent was up in 2013 and stayed at about the same extent in 2014.
      http://ocean.dmi.dk/arctic/plots/icecover/icecover_current_new.png

  2. Intresting stuff.
    I have a question.
    Would not an aggregation of soot (volcanic or otherwise) not melt a hole through the ice eventually?
    Self cleaning, if you will….

  3. so its the increased albebdo of the sea ice that is the trigger which is then driving the September minimum. Not the sunlight fueled residual OHC from the daylight months as the ice sheet returns to near normal levels.
    CO2 is absolved once again.

  4. Open waters also radiate more heat outward to space. I wonder why they ignored this part of the total energy balance. Isn’t the total balance important?
    They also ignored Antarctica which should see a big increase in albedo. Why is this not mentioned? Isn’t the issue global?

    • the dynamics of the Southern Ocean sea ice are entirely different.
      One is a cold polar ocean mostly surrounded by land.
      The other is a cold polar continent surrounded by an ocean.
      The common threads are physical processe common to freezing seawater and seasonal light-dark stretches.. That is that colder water can freeze faster, but warmer water can provide much more evaporated moisture to make more snow as a negative feedback to soot-albedo effects, which are minimal anyway in winter darkness.. Sea ice forms during dark hours and clear skies. But it melts by both warmer water and by surface incident sunlight.

    • It’s global when concentrated locally and it’s local I.e just weather when something non alarmist happens globally. You need to employ Orwellian doublethink when dealing with these issues. Just as the surest sign of warming is cooling. And so on and so forth. It’s like mental illness has a PhD.

    • Richard M,

      Open waters also radiate more heat outward to space. I wonder why they ignored this part of the total energy balance. Isn’t the total balance important?

      Yes. You know these things in the first place because they haven’t been ignoring them.

      They also ignored Antarctica which should see a big increase in albedo. Why is this not mentioned? Isn’t the issue global?

      Yes the issue is global, but both press sessions and Anthony’s coverage of them will be necessarily incomplete due to time and space restraints.

      • what happens when the sun don’t shine? Open water radiates between 50 and 100 times the energy that is radiated by sea ice…..when the sun don’t shine.

        • Open water radiates between 50 and 100 times the energy that is radiated by sea ice…..when the sun don’t shine.

          Actually it does it 100% of the time, but during the 4-6 hours per day the Sun’s angle of incident is less than 75-80% it also collects solar energy.
          Hey, anyone have a simple way to calculate the incident angle of the Sun During Summer at 70-85 Latitude for a 24 hour period? I’d like to know exactly how long during the day the Sun matters in the Summer.

      • kent blaker,

        what happens when the sun don’t shine? Open water radiates between 50 and 100 times the energy that is radiated by sea ice…..when the sun don’t shine.

        My instinct is that it’s not very relevant since at present the Arctic Ocean completely re-ices in winter as per “normal”. If the past million years of interglacials are any guide, it’s what happens in NH summer near the Arctic circle which is the strongest indicator of global climate, mainly due to the exact sort of albedo feedbacks we may now be inducing with black carbon emissions more than GHG forcing.

      • Mi Cro
        December 18, 2014 at 6:25 am
        Hey, anyone have a simple way to calculate the incident angle of the Sun During Summer at 70-85 Latitude for a 24 hour period? I’d like to know exactly how long during the day the Sun matters in the Summer.

        Assume you have excel available.
        in a convenient place, define the following and declare the variable names
        Define DOY in a cell                       =DOY      (Day of Year, Julian number)
        Define Lat in a cell in degrees.           =LAT_D
        Calculate TOA Radiation for that DOY       =TOA       =1362.36+46.142*(COS(0.0167299*(DOY)+0.03150896))
        Define attenuation factor for  the air     =ATF      (use 0.85 for the Arctic, 0.66 for temperate latitudes)
        =RADIANS(LAT_D)                           = LAT      (Got to translate your latitude into radians for excel)
        =2*3.1415*(DOY-1)/365                     = TAU      (Defines Tau Angle for that DOY )
        =0.006918-0.399912*COS(TAU)+0.070257*SIN(TAU)-0.006758*COS(2*(TAU))+0.000907*SIN(2*(TAU))-0.002697*COS(3*(TAU))+0.00148*SIN(3*(TAU))
                                    That whole thing defines the Declination Angle in radians for that DOY = DECL_RAD
        now choose a cell, let's use D11.
        That cell defines hour of day, it and all the others below will be duplicated for the rest of the equations.
        hour                               D11 =0
        hour_angle, in radians             E11 =(RADIANS(D11-12)*15)
        SEA_Radians                        F11 =ASIN(  (SIN(DECL_Rad)*SIN(LAT)) +(COS(DECL_Rad)*COS(LAT)*COS(E11))    )
        SEA_Degrees                        G11 =DEGREES(F11)
        Air_Mass                           H11 =IF(G11<0,0,(1/(COS(3.14159/2-F11)+0.50572*(6.07995+G11)^-1.6364)))
        Attenuation                        I11 =IF(G11<0,0,(ATF)^((H11)))
        Direct Radiation on that day       J11 =TOA*I11
        Dir_radiation on a flat surface    K11 =J11*SIN(F11)
        

        So, now that you the Direct Solar Radiation for that latitude on that day-of-year for hour = 0 duplicate the entire row, and change the hour to 1. Copy that entire row to the next row, and change hour angle to 2 …
        Rinse, wash, repeat until you have all 24 hours. (0 to 23, or 1 to 24)
        If you are going to "add solar radiation over time”, do NOT use 0 to 24. That will give you 25 values.
        Note a few of the Excel logic points.
        If SEA (Solar Elevation Angle) is < 0., the sun is below the horizon, and air mass = 0.0.
        If SEA < 0, then attenuation = 0.0
        you can add a column for horizontal solar angle, but I'm not interested in that value

        Hour	HRA	SEA_Rad	SEA_Deg	Air_Mass  DIR_ATT	DIR_Rad DIR_Rad Mu0 Ocean_Albedo  Ocean_Abs Ocean_Refl   Ice_Abs  Ice_Refl
        0.0	-3.1416	-0.0515	 -2.9	 0.000	  0.000	        0	0	-0.051	 0.000	  0	   0	         0	  0
        1.0	-2.8798	-0.0428	 -2.5	 0.000	  0.000	        0	0	-0.043	 0.000	  0	   0	         0	  0
        3.0	-2.3562	 0.0227	  1.3	23.873	  0.021	       27	1	 0.023	 0.917	  0	   1	         0	  0
        5.0	-1.8326	 0.1366	  7.8	 6.995	  0.321	      427	58	 0.136 	 0.433	 33	  25             25	 33
        7.0	-1.3090	 0.2705	 15.5	 3.697	  0.548	      730	195	 0.267	 0.200	156	  39	         83	112
        9.0	-0.7854	 0.3905	 22.4	 2.613	  0.654	      870	331	 0.381	 0.121	291	  40	        140	191
        11.0	-0.2618	 0.4625	 26.5	 2.233	  0.696	      925	413	 0.446	 0.094	374	  39	        175	238
        12.0	0.0000	 0.4721	 27.1	 2.191	  0.700	      932	424	 0.455	 0.091	385	  39	        180	244
        13.0	0.2618	 0.4625	 26.5	 2.233	  0.696	      925	413	 0.446	 0.094	374	  39	        175	238
        15.0	0.7854	 0.3905	 22.4	 2.613	  0.654	      870	331	 0.381	 0.121	291	  40	        140	191
        17.0	1.3090	 0.2705	 15.5	 3.697	  0.548	      730	195	 0.267	 0.200	156	  39	         83	112
        19.0	1.8326	 0.1366	  7.8	 6.995	  0.321	      427	58	 0.136	 0.433	 33	  25	         25	 33
        21.0	2.3562	 0.0227	  1.3	 23.873	  0.021	       27	1	 0.023	0.917	  0	   1	          0	  0
        23.0	2.8798	-0.0428	 -2.5	 0.000	  0.000	        0	0	-0.043	0.000	  0	   0	          0	  0
        24.0	3.1416	-0.0515	 -2.9	 0.000	  0.000	        0	0	-0.051	0.000	  0	   0	          0	  0
        
    • Open waters also radiate more heat outward to space [?]

      Compared to what?
      Richard, this may seem intuitively correct, but it is in fact wrong.
      The surface of the planet emits in the infrared region and, whilst it’s true that the ocean approximates to a blackbody at infrared wavelengths, this is also true of snow of ice (and most land mass). In fact, snow and ice are almost perfect blackbody emitters around 10 microns.
      http://scienceofdoom.com/2010/07/31/the-amazing-case-of-back-radiation-part-three/
      So the ice will radiate as much, if not more, than open water.
      The important differences are in absorption with respect to incoming solar radiation, where the reflectivity (albedo) is different.

      • So the ice will radiate as much, if not more, than open water.

        Probably not, as the water always is ~31F or warmer, ice and snow not so much.

      • I was basing my claim on peer reviewed research that claimed the recovery in Arctic sea ice in 2013 (and 2008) was due to excessive cooling of the open waters due to the low ice levels the previous years. Maybe you can explain why this research is wrong.

      • You overlook the fact that open water can also lose substantial heat through convective transport (think Lake effect snow). But as soon as that first millimeter of surface ice forms, evaporation stops.
        Once that first millimeter of ice forms, heat transport from the freezing interface is now conducted to the ice surface (ice-air interface), energy then radiates away as IR into the even colder air. If the air is above freezing, this transport stops, and further freezing at the ice-water interface stops. Melting from below can begin if upwelling water is warmer, and the air above stays right at freezing. Of course the marine surface air layer has to be below T(freezing) for the net loss of IR energy away from the ice surface to keep the cooling, and thus freezing, going at the ice-water interface to thicken the ice. As the ice thickens, the conduction of heat upward to the cold air slows just a little with each additional mm.

    • To dissenters….
      I do not know what research you are referring to, since you don’t provide any reference.
      Of course, if the ice is at a much lower temperature than the water then you are correct that it will radiate less.
      But, ice and snow comprise fresh water which has a higher freezing point than the salty sea water, so this is not necessarily the case.
      But I take your point(s). I could be wrong. [copy this, I’m not wrong often]

      • MikeB
        But, ice and snow comprise fresh water which has a higher freezing point than the salty sea water, so this is not necessarily the case.

        If you are going to make this point, do the math.
        What is the salinity of the Arctic ocean? What is the freezing point of salt water at that salinity? You have made the claim, provide the value.
        Open water loses much more heat than ice-covered water. This heat loss is through greater:
        1) LW radiation from the surface of the open water at 0-4 degrees C, compared to the upper surface of the ice at air temperatures of -4 deg C to -25 degree C. Both are radiating from surfaces with nearly the same emissivity, and into the same mass of air and the same relative humidity.
        2) Greater evaporation: Ice covered water evaporates continues into the air, removing heat from the water.
        3) Greater forced convection losses from 2-4 deg C open water into air compared to ice at -4 to -25 deg C into the same air. The 1-3 meter-thick ice covering the water below reduces the surface of the ice compared to the surface temperature of the ice.
        Give me your assumed air conditions above the ice or the salt water: 2 meter air temperature, pressure, wet bulb temperature, and wind speed are needed. Show us your claim is corrct.

        • @RACookPE1978
          “Give me your assumed air conditions above the ice or the salt water:”
          For radiative cooling, what matters is the IR temp for the surface the ground radiate to, the sky, which is much colder than air temp. With a 8-14u ir thermometer I’ve measured over 100F colder zenith temps. You still need to add the ghg dwir to that, but it’s still cold.

      • MiCro (replying to RACookPE1978)
        “Give me your assumed air conditions above the ice or the salt water:”
        For radiative cooling, what matters is the IR temp for the surface the ground radiate to, the sky, which is much colder than air temp. With a 8-14u ir thermometer I’ve measured over 100F colder zenith temps. You still need to add the ghg dwir to that, but it’s still cold.

        True, true. For “theoretical” black body radiation losses, you need only the two surface temperatures and the two surface emissivities – which, for open water and sea ice, are not really very close together.
        Note! Read the references, these are NOT the usual “Table of Emissivities” you find in Wikipedia.
        Open ocean = 0.980 (http://modis.gsfc.nasa.gov/sci_team/meetings/200503/posters/ocean/minnett1.pdf
        Sea ice = 0.86 – 0.88 (http://www.curry.eas.gatech.edu/currydoc/Haggerty_JGR106.pdf)
        As was pointed out above, the most important values for LW radiation losses are Tsky (what the surface is emitted into) and the surface temperature. But, here the papers differ. If you find ANY authority calibrated against MEASURED DATA for the Arctic, speak up.
        Some assume Tsky = Tair, but add a fudge factor based on relative humidity
        Others assume a “clear sky” temperature of -40C for example) then add a cloudy fudge factor.
        Others ignore factors and assign a “arctic fudge factor” of 0.75 regardless of humidity or clouds
        Convective heat losses change by air temperature, wind speed, air pressure, and surface temperature. (You need to run a bunch of little equations, but all require some assignment of the “weather” to even start. So, pick a condition, and we’ll go from there.)
        Evaporation heat losses vary by paper to paper to paper. I have found no measured paper giving consistent values for the Arctic conditions, but several for evaporation losses in the high deserts of Colorado and New Mexico, very in the Andes mountains, one in southern Spain, and two in the very humid lower south US. two others use ponds in Kansas on still evenings. One uses roof ponds in south Florida. None are really good assumptions for the Arctic.

        • I’m at 41N 81W , and clear sky temps average 75 – 80 F colder than air temp, humidity matters, day time doesn’t. I’ve read as low as -80F.
          But it does seem that if you watch cooling and relative humidity, when rel humidity gets over 80-85, cooling slows from over 5F/hr to a degree or two per hour near dawn.

          • As I said, if you can find ANY measured, credible source for LW radiation losses in the Arctic – Let me know.
            I’ve worked overnight on shifts in clear skies, in cloudy skies, under rain and snow, and under cold and clear … I KNOW the low-level atmosphere conditions – “the weather” – matters, and I KNOW the high atmosphere conditions matter. Now, give me an equation and the plots SHOWING what the factors are for a open ocean surface in the Arctic (or even Antarctic!) into the “sky” under real conditions!
            Endless repeats of classic “Blackbody theory” of hollow black spheres in space in a vacuum are useless.
            Shape factors for both surfaces are ignored.
            Surface emissivities are ignored.
            Surface emissivities changes over time, dirt, pressure, and temperature are ignored..
            Transmission efficiency is ignored.
            Transmission effect at various altitudes are ignored.

          • I think the rel humidity feedback on nightly cooling could regulate cooling in a way that would negate an increase in dwir, it would just push the transition point from high cooling rate to limited cooling till a little later in the night.
            Your albedo Measurements have to be take pointed down for the rest of the planet, can’t imagine they do something different in the arctic.

  5. Uhm… do these numbers make sense?
    The first claim is that absorption goes up by 5% which later they quantify as about 10 w/m2. That would give an absorbed insolation on the order of 200 w/m2. The average surface energy flux for the entire earth is roughly 240 w/m2, with equatorial regions getting on the order of 4 times that. There is no way that the arctic region gets anywhere near 200 w/m2 in the first place!
    In fact, a quick glance at ERBE shows absorbed radiation in the arctic region to be on the order of between 80 and 140 w/m2 on an annual basis:
    http://eos.atmos.washington.edu/erbe/
    So, either the 5% number is wrong, or the 10 w/m2 number is wrong.
    Then there is the claim that the Beaufort sea is up by fifty w/m2. That would be gigantic! If we start with the high end of the estimate (since the Beaufort Sea is toward the southern reaches of the arctic) that would take it from 140 w/m2 to 190 w/m2 aborbed. It doesn’t get 190 w/m2 to absorb in the first place!
    I will freely admit that I didn’t do the math, not even a back of the envelope calc, I just rattled the numbers through my head and they do not make sense. These must be “peak” numbers, not averages, or some other unexplained mystery as to how they were calculated.
    Further, I saw nothing in the article about changes in LW radiated back out. It isn’t about how much is absorbed, it is how much is absorbed less how much is radiated back out. What’s the net? If there is THAT much more water absorbing THAT much more insolation, then the water is itself warmer than the ice that would otherwise have been there and there should be a corresponding increase in LW radiated out, PARTICULARLY in a region that has a dearth of water vapour (the dominant GHG) due to the low temps.
    If they’d said on the order of 2 or 3 w/m2 I would have thought it interesting. But 50? In the Beaufort Sea? 5% on average which means the arctic gets almost the earth average? No, that’s not interesting, that’s a reason to ask some tough questions as to how they got these numbers.

    • It is interesting that that they pick June, July, and August
      OK, I missed that. I thought it was an average for the year. Makes more sense now. But 50 w/m2 in the Beaufort Sea still seems out of whack.

  6. Since the year 2000, the rate of absorbed solar radiation in the Arctic in June, July and August has increased by five percent, said Norman Loeb

    It is interesting that that they pick June, July, and August – odd that he skipped May actually – because every other month of the year there is so little solar radiation falling on the Arctic sea ice edge that increased Sea ice loss from today’s levels only serve to INCREASE heat loss from the newly exposed Arctic Ocean.
    The increased loss of heat by evaporation, convection, and radiation from the open ocean is higher from 22 August through early April than the little heat gain by solar radiation at the very low solar elevation angles, high air mass losses, and very high cloud cover reflectivity allows. Nice theory if you have an insolated, isolated, insulated exposed iceberg in space …. But not a real area of pack ice in the Arctic at sea level, behind clouds, below 12 and 13 air masses exposed to the sun at only 6-8-10 and 12 degrees above the horizon..
    By the way, their albedo scheme and its approximation ARE CORRECT, but ONLY for the steadily rising Antarctic sea ice. Which has been increasing since 1992, and has been above the 2 std deviation line for 15 of the past 17 months. (November saw it drop down a bit, but it is back above 2 std dev above normal.) Again. And Antarctic sea ice set a new all-time record high sea ice extents in June at 2.06 million “excess” kilometers of sea ice. As much as the entire ice cap of Greenland (2.16 Mkm^2)

    • “It is interesting that that they pick June, July, and August – odd that he skipped May actually . . . .”
      Those are the months that constitute meteorological summer. That’s probably why.

    • odd that he skipped May actually
      I think that’s part of how he juiced the numbers up. In May, insolation is high, but so is sea ice, because it has only started melting, and the divergence from 2000’s is low, so one would not expect a lot of difference due to sea ice area/extent. The divergence doesn’t show up in a big way until June:
      http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_v2_L.png
      Then he cuts it off in August, because even though divergence in area from the mean in still high in Sept, angle of incidence is by then so low that the albedo of open water increases dramatically, number of hours of sunshine in the day is way down, and so is the w/m2 incident in the first place. This is cherry picking of the highest order.
      Averaged over the course of a year, this would come down to a much smaller number. And the corresponding LW radiated out would also be expected to be much higher, and THAT ought to go right into October or so when the ice area starts to climb again. I suspect the NET over the course of a year is mice nuts.

      • davidmhoffer
        Averaged over the course of a year, this would come down to a much smaller number. And the corresponding LW radiated out would also be expected to be much higher, and THAT ought to go right into October or so when the ice area starts to climb again. I suspect the NET over the course of a year is mice nuts.

        Actually, I have the equations and constants available if you want to calculate the direct solar exposure to the edge of the Arctic and Antarctic sea ice for any hour of the day, any day of the year.
        But it is worse than you think. From mid October through mid-March, there is NO solar exposure at all to the sun any hour of the day to any part of the Arctic Ocean Sea ice. (Hudson Bay gets a little bit, the Bering Sea gets a few hours of exposure – both at very low solar angles as you suggest.) No part of the Arctic Ocean sea ice is below the Arctic Circle (66.5 latitude) ANY day of the year.
        The edge of the Antarctic sea ice on the other hand, DOES get exposed to direct and indirect (diffuse) solar radiation EVERY DAY of the year.
        The Antarctic sea ice, on average, never retreats past 67 degrees latitude (the Antarctic Circle) any day if the year. It ALWAYS is exposed to the sun, and that sunlight is much, much higher in the sky evry hour of the day. In fact, by September 22 on the equinox when both poles are exposed to the same levels of solar radiation, when the Antarctic sea ice is nearing its maximum extents and the Arctic sea ice is at its yearly minimum extents, the Antarctic sea ice is reflecting FIVE TIMES the solar energy energy per sq meter that the Arctic sea ice is receiving! But back in March 22, again when both poles are receiving the same solar radiation for the same number of hours per day, the Arctic sea ice extent at its maximum extent is only approaches 70 north, but the Antarctic sea ice extents as it increases from its yearly minimum is still closer to the equator at 66.8 south.

    • RACookPE1978

      than the little heat gain by solar radiation at the very low solar elevation angles,

      I was also going to point this out as well
      See http://www.iwu.edu/~gpouch/Climate/RawData/WaterAlbedo001.pdf
      I’ve done a number of rough calculations based on different Tsky values, all lose more energy that they gain, some by very large amounts.
      I also wonder if they’re taking Albedo measurements from directly over head, as opposed to albedo measurements from the same angle the Sun is, because they will be drastically different, and while overhead does give the correct albedo, what matters to climate is albedo from the same angle as the Sun.

      • Mi Cro
        I also wonder if they’re taking Albedo measurements from directly over head, as opposed to albedo measurements from the same angle the Sun is, because they will be drastically different, and while overhead does give the correct albedo, what matters to climate is albedo from the same angle as the Sun.

        We don’t really know – which is by itself very, very telling.
        Two things are very important – and BOTH vary significantly from “average” Wikipedia values. I have NEVER found ANY Sereze quote or paper that admits to eitehr however!
        Judith Curry has measured Arctic sea ice several times from several different platforms: She reports that Arctic sea ice albedo does not very very strongly with SEA (solar elevation angle) nor with direct or diffuse radiation, but DOES vary strongly by date (Day-of-Year)
        Curry, 2001 reports Arctic sea ice albedo begins the winter season Oct 6 at 0.8228
        Arctic sea ice albedo stays at 0.823 until May 6, then begins dropping down to mid-summer low of 0.46
        Arctic sea ice albedo then recovers through the rest of the melt season (August and September) back to its winter high of 0.823
        Open Ocean Albedo of DIRECT Solar Radiation varies VERY STRONGLY with Solar Elevation Angle, and slightly with high wind speeds.
        Open Ocean Albedo of DIFFUSE Solar Radiation does NOT vary with Solar Elevation angle, nor with wind speed. However, high winds are almost always associated with cloudy skies and heavier wetter clouds, so the amount of time you see both very clear skies (little diffuse radiation) and high winds AND direct solar radiation is actually very, very little.
        Classically, you will find the albedo of ocean water is 0.06.
        That is true ONLY for diffuse radiation, when clouds are present. However, when clouds are present, they reflect 75 – 80 percent of the available solar radiation from top of the clouds, so the amount that actually gets down to the surface 9after attenuation) is a small fraction of people assume is present at top-of-atmosphere.
        See Payne for his open ocean measurements from the Chesapeake Bay platforms, and Pegau 2006 for wind speed corrections;
        At low SEA angles, measured open ocean albedo is
        0.40 below 5 degrees SEA,
        0.25 – 0.35 between 5 degrees SEA and 10 degrees
        0.15 to 0.25 above 10 degrees SEA.
        Above 30 degrees SEA, open ocean albedo of direct radiation continues down towards the assumed nominal value of 0.06
        Formulas: If Mu =SIN(SEA) for cell G11 = SEA (in radians) and WIND = knots
        Albedo =IF(SEA<0,0, (0.026/(Mu^1.7 +(-0.0002*WIND^2+0.0076*WIND+0.0266))+0.15*(Mu-0.1)*(Mu-0.5)*(Mu-1)))

  7. You see that “little” area of Greenland up there in his “graphically red” alarm propaganda images?
    This past June, just the “excess” Antarctic sea ice anomaly of 2.06 Mkm^2 was equal to that entire ice cap under Greenland.
    Sure, that was a record. But today? The “excess” Antarctic sea ice is “only” 1.236 Mkm^2 .. about 2/3 the size of Greenland. And the Antarctic sea ice is at latitude 58-66 south. Closer to the equator than ANY Arctic sea ice but Hudson Bay.

  8. Just a reminder, or new information for many, that the exact same amount of sunlight hits the arctic during all of spring as it does during all of summer. In other words, the same quantities of sunlight is equal for spring as it is for summer. I have seen far too many comments showing that people don’t seem to realize this.
    The same holds true for winter. Fall, or autumn has the same amount of sunlight in the arctic as winter does.
    Same for the Antarctic as well.

    • garymount
      Just a reminder, or new information for many, that the exact same amount of sunlight hits the arctic during all of spring as it does during all of summer. In other words, the same quantities of sunlight is equal for spring as it is for summer. I have seen far too many comments showing that people don’t seem to realize this.
      The same holds true for winter. Fall, or autumn has the same amount of sunlight in the arctic as winter does.
      Same for the Antarctic as well.

      No. Your statements are wrong.
      Show me your calculations justifying your statement: None are valid at either Top-of-Atmosphere TOA nor at the Arctic or Antarctic Circles, nor at the latitude of the edge of the Antarctic or Arctic sea ice.
      TOA solar radiation varies cyclically from a maximum of 1407 on January 5 down to a minimum of 1315 on July 5 due to the elliptical orbit: close in January but faster, and further away in July, but slower.
      each day-of-year, the tilt of the earth’s rotation means that any given latitude receives more or less radiation, and each hour of each day-of-year, that solar radiation has to penetrate a greater or lesser amount of atmosphere (air mass) causing more or less losses. Since the sum is higher or lower in the sky at hour-of-day, its radiation on to a flat surface is even further spread out by a second cosine function of solar elevation angle.

      • Thank you David. Note, I was only referring to the angle of the sun and not the distance from the sun due to the annual elliptical or whatever shape it is orbit. Is it elliptical ? Elliptical seems to imply there would be two periods of both being closer and further away from the sun each year, but we only have one of each per year.
        I have done a fair amount of studies on elliptical equations, and I see after a few seconds of internet searching that my mistake was to assume the sun was in the center of the elliptic geometry, but it is at a foci instead.

      • Mpainter

        You are right. Gary should take a trip up to the North Pole, on December 21st and a second trip on June 21st and see if there is a difference in the amount of sunlight there.

      • mpainter December 17, 2014 at 11:39 pm
        But, Hoffer, the chart shows him incorrect, it is obvious. The curve for 90°N is a parabola.
        >>>>>>>>>>>>>>>>>>>
        Yes. And spring is the 90 days prior to the peak of the parabola, and summer is 90 days following the peak of the parabola.

      • garymount;
        Is it elliptical ?
        >>>>>>>>>>>>>>
        Yes it is. NH is actually closer to sun in winter than it is in summer. You can see that the chart I posted isn’t quite symmetrical, so technically your statement isn’t 100% accurate, but for the point you were trying to make… close enough in my books.

      • I would like to see mpainter’s derivation for the curve being parabolic at 90 deg. north latitude.
        As in y = ax^2 + bx + c
        And I’ll even accept that the earth is a sphere for the purpose of simplifying the derivation.

    • So garymount, if you have done a “fair amount of studies of elliptical equations” and not learned that the center of mass of the two orbiting bodies is at one focus of the ellipse (roughly); then just WHAT was it that you learned about ellipses in those studies ??

  9. It is interesting that that they pick June, July, and August
    OK, I missed that. I thought it was an average for the year. Makes more sense now. But 50 w/m2 in the Beaufort Sea still seems out of whack.

  10. observed sea ice loss over the last 30 years cannot be explained by natural variability alone
    ==============
    explain why the arctic was ice free for a thousand years about 8000 year ago. explain why we see huge swings in greenland paleo temps over periods as short as ten years. what caused such large and rapid climate change in the past? climate science doesn’t know, but it is certain it can’t be the same mechanism today, because well it can’t be, because we say so.

  11. Interesting. We have supposedly a couple of W/m^2 from ‘enhanced GHG’s’, now another 10W/m^2 from albedo feedback, so around 12W/m^2 of ‘forcing’!!!
    However, according to PIOMAS, the energy imbalance to melt the Arctic sea ice at the ‘measured’ rate is around 0.4W/m^2. With the recent increases in sea ice extent and volume the recent energy imbalance must be sign inverted! Perhaps it’s just a simple mathematical error?!!
    Methinks, more funding is required.

  12. I’m a bit sceptic towards the importance of soot. There’s a much low clouds over the Arctic ocean during summer [and during the less cloudy in winter, there’s little sunlight]. Also, the surface of the ice is quite dynamic and the albedo changes anyway, so how does one detect the soot component?

  13. Sorry jmorpuss, not much help there, but I did read your link and met with a request for funding.
    Then I read this…
    “”Black carbon stays in the atmosphere for only several days to weeks, whereas carbon dioxide (CO
    2) has an atmospheric lifetime of more than 100 years.[2]””
    Why don’t those people ask for funds from the governments, after all that is the propaganda they are pushing,

  14. Global dimming has changed to global brightening thus increased the solar input and the cloud cover.
    In Denmark and Sweden we have an increase of 10-15% since 1980s [W/m^2].
    Partly as an effect of less black carbon in the air.
    The surface of a snow cover will accumulate all winters downfall in spring. On a glacier this means many years accumulation only disturbed by flowing water.

  15. Antarctic ice is at record highs and has been for years. Presumably, the growth of sea ice in the Antarctic, and the increasing albedo, will offset any loss in the Artic. So, globally, no warming effect.

  16. Sigh. So how does this all fit in with the fact that Arctic sea ice has been increasing during the past year or two? There are too many variables, too many competing theories, too many computer models and too many people who are ready to believe that human issued CO2 is causing climate to change. It all grows tedious and nonsensical. Time to shut down taxpayer funding for climate science.

  17. Reblogged this on Centinel2012 and commented:
    It would interesting to see if the Increased use of coal for generating electricity in China could be the reason. I’m not familiar with the air movement in that area , someone should study that!

  18. They just can’t let go of the arctic death spiral idea. Well, I guess with the heat vanishing somewhere into the deep oceans the past 18+ years, they need to latch onto something.

  19. I am amazed at the level of ignorance and stupidity from this press release.
    “The instruments include three radiometers – one measuring solar radiation reflected by Earth (shortwave), one measuring thermal infrared radiation emitted by Earth (longwave), and one measuring all outgoing radiation, whether emitted or reflected.”
    They are neglecting to mention or measure the extra latent heat lost by the open ocean which dwarfs the radiant heat lost by the ocean. Or the fact that the angle of incidence of the suns rays puts the extra absorbed radiation into the Fairy Fart range.
    I thought I had lost the ability to be surprised by the audacity of the warmers bold faced lies, now surely, they have reached the pinnacle. But no, while it beggars the imagination, I am sure they will come up with a whopper to surpass this one.

  20. So-called “green” policies discouraging the use of fossil fuels are responsible for much of the soot. Irony, but the warmunists also get a two-fer with whatever increased warming and ice-melting that results in the Arctic.

  21. I wonder how our human produced soot in the Arctic compares to a large volcanic event that would deposit soot over the same region? Over the long term history of the earth the human component may be insignificant in terms of albedo. Lets work with the engineers in developing countries and help them get scrubbers installed on their coal plants.

  22. One possible explanation of why such a large percentage of the global warming measured since 1979, assuming the measurements are correct, is in the northern half of the Northern Hemisphere, and so little of the warming is in the Southern Hemisphere: Dark soot on the Arctic ice and snow continuously deposited by burning coal and wood in the Northern Hemisphere, especially in China.
    .
    That might explain “local warming” (in the Arctic since 1979 — I know there has been cooling there for a few years, but the overall trend since 1979 is warming), while the average temperature in Antarctica is not increasing at all.
    .
    There could be other explanations for why we seem to have “local Arctic warming”,and no Antarctica warming … but greenhouse gasses would not be one of them.
    .

  23. Surprise, the arctic albedo is irrelevant when turned away from the Sun in winter. And now that the climateers are promising us *more* snowfall than before due to global warming, that means more albedo too. It’s all a nonsense.

  24. The most important fact about snow and ice albedo feedbacks is their strong directional asymmetry. From current initial conditions they are much stronger in the cooling direction (as snow and ice descend to latitudes that encompass ever larger swaths of the planet’s surface where solar incidence is also steeper) than in the warming direction (where snow and ice retreat to latitudes of shrinking area where solar incidence is also declining).
    If these researchers can work themselves into a state of alarm when looking in the warming direction they should be terrified looking in the cooling direction, but it seems they never do.
    Question for Anthony: any mention at this AGU session of the directional asymmetry in snow and ice albedo feedbacks?

    • Alec Rawls
      The most important fact about snow and ice albedo feedbacks is their strong directional asymmetry. From current initial conditions they are much stronger in the cooling direction (as snow and ice descend to latitudes that encompass ever larger swaths of the planet’s surface where solar incidence is also steeper) than in the warming direction (where snow and ice retreat to latitudes of shrinking area where solar incidence is also declining).

      Good observation.
      Like this steady increase in the Antarctic sea ice since 1992, and its very rapid increase towards this year’s record breaking HIGH Antarctic sea ice extents in June? Like the very fast continuous rise of Antarctic sea ice anomaly every season since Jan 2011?
      http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
      Today’s “so-so, average, nothing unusual, nobody notices” Antarctic sea ice “excess” anomaly of “only” 1.319 million sq kilometers was never even seen before 2007-2008! Now, an Antarctic sea ice anomaly of “only” 1.3 million sq kilometers is so common that nobody notices – because it is so much smaller than recent high Antarctic records.
      Today’s “excess” sea ice around Antarctica – just the “excess” sea ice mind you! – is half the area of the ENTIRE remaining Arctic sea ice in September 2012. And, if ALL of the Arctic sea ice were lost – down to “0.0” some September, today’s “excess” Antarctic sea would reflect five times more energy than the entire remaining Arctic sea ice would have on that hypothetical September day.
      That “excess” Antarctic sea ice anomaly today is “only” 2/3 the size of Greenland’s entire ice cap. And it is at a latitude far, far closer to the equator than Greenland.

Comments are closed.