Guest Post by Willis Eschenbach
My examination of objects cryospherical continues. In my last post, The Size of Icy Reflections, I showed that a change of 10% in the global sea ice area translates into a global average of a 0.1 watt per square metre (W/m2) change in reflected sunlight. In this post, I’ll look at what that means given the historical changes in ice area. This will highlight the kind of the curious choices made in the analysis of climate data. To start with, here is the full data from the Hadley Ice and Sea Surface Temperature dataset (HadISST, data link below).
Figure 1. Global total ice area, computed as the sum of 1°x1° gridcell area times the percentage of each gridcell covered by ice. Areas in millions of square kilometres (Mkm^2)
I’m sure you can see the “curious choice” I mentioned before. Clearly, the recent part of the data appears valid … and clearly the early part of the data is not. Obviously, before 1900 it’s just climatological (average) data of some kind. And examining the lower edge of the data that shows the minimum extent, it is also clear that nothing before around 1970 can be trusted … so where can we start analyzing the data?
An examination of the paper explaining the dataset reveals that we have reasonable data for the Arctic sea ice since the early 20th century, but for the Antarctic the paper says the following:
Before the advent of satellite-based imagery in 1973, sea ice concentration data for the Antarctic are not available, and sea ice extent data are not readily available for individual months, seasons or years, although some visible and infrared data do exist for 1966 – 1972 [Zwally et al., 1983] and some undigitized charts reside in national archives (e.g., V. Smolyanitsky, personal communication, 2002). Readily available information was limited to two historical climatologies of sea ice extent. Therefore our sea ice concentration analysis before 1973 is derived indirectly, and does not include any interannual variability, though there are some trends resulting from the differences between climatologies for different periods.
This gives me 1974 as a reasonable starting date for what data is good enough to analyze, as that would be the first year with complete data for both poles. Figure 2 shows that valid part of the ice area data:
Figure 2. As in Figure 1, starting January 1974 and ending January 2016. Areas in millions of square kilometres (Mkm^2)
To understand the variations in the ice area it is useful to “decompose” the signal by removing the repeating seasonal component of the data. Figure 3 shows the decomposition of the same data shown in Figure 2.
Figure 3. Seasonal decomposition, HadISST global sea ice data, January 1974 – December 2015. Upper panel shows the raw data. Middle panel shows the annually repeating seasonal component of the data. Bottom panel shows the raw data minus the seasonal component. Areas in millions of square kilometres (Mkm^2)
A contemplation of this figure reveals some interesting aspects. First, there is no significant trend at all in the 40+ years of satellite data. In other words, it seems the Awful Terrible Horrible Global Sea Ice Crisis has been cancelled due to lack of evidence.
Next, remember from above that a change of 10% in the global sea ice area translates into a global average of 0.1 watt per square metre (W/m2) change in reflected sunlight. From inspection of Figure 3, the sea ice area varied by ± 1 Mkm^2 around an average of just over 20 Mkm^2. This is a change of ± 5%, and thus should be accompanied by a change of ± 0.05 W/m2 in reflected sunlight … in other words, far too small to be measured.
However, this is not the only interesting finding. We’re pretty sure that the global average surface temperature increased from the mid-1970s to about 1998 (Figure 4 below). However, we see no sign of this in the global sea ice area data (Figure 3 above). Instead, ice area remained stable throughout the 1980s and the 1990s, while temperatures climbed.
Figure 4. Global surface temperatures per the HadCRUT4 temperature dataset.
Next, we’re also pretty sure that there was no significant change in the global average temperature from about 1998 to 2015, the end of the ice data. Despite that, starting in 2000 the ice area first dipped to a low in about 2007, and since then has been climbing rapidly.
This supports a curious conclusion, which is that in modern times at least, the global sea ice area is not particularly a function of the global average surface temperature. Go figure …
Gotta love settled science.
My best regards to everyone,
w.
My Usual Request: Misunderstandings are the curse of the internet. If you disagree with me or anyone, please quote the exact words you disagree with, so we can all understand the exact nature of your objections. I can defend my own words. I cannot defend someone else’s interpretation of some unidentified words of mine.
My Other Request: If you believe that e.g. I’m using a method wrong or using the wrong dataset, please educate me and others by demonstrating the proper use of the method or the right dataset. Simply claiming I’m wrong about methods doesn’t advance the discussion unless you can point us to the right way to do it.
Data: The Hadley HadISST ice (and sea surface temperature) data is available here. I used the NetCDF file HadISST_ice.nc.gz (~15Mb) at the bottom of the page.
Willis.. you are definitely setting yourself up for a visit by the Feds on the RICO statutes.
And introducing one more acronym (ATHGSIC – Awful Terrible Horrible Global Sea Ice Crisis) to the modern lexicon in inexcusable!
On a more serious note, it will be very interesting to watch the Arctic ice growth/declines as the oceans cool over the next couple of years as well as the anticipated global cooling cycle over the next few decades. This year’s Arctic anomalous loss was centered in one particular area and as those waters cool back to normal, will another Blob form elsewhere and influence another region, or will the Arctic as a whole start to freeze over a wider area in the coming winters?
Additionally the contra-cycle of the Arctic/Antarctic polar ice totals will also be interesting to track.
And if we get a quiet Sun volcanic increase, even another item to watch.
As always, interesting stuff you put out.
THANK YOU for mentioning the ‘quiet sun / volcanic increase’ bit. Good to know I am not alone in seeing a connection.
Re Quiet Sun. I am a retired scientist, PhD [albeit biology, but experienced in analysing data]. I recollect that in the 1960s or perhaps 1970s there was an ‘International Quiet Sun Year’ [do I remember correctly?]. I was pretty busy with my specific work/family concerns so didn’t pay much attention. Can anyone provide any news on what the research on that year provided, esp. re sea ice etc.? And in fact was that year a quiet one for the Sun?
Try these 3:
International Quiet Sun Year (IQSY), the name given to a series of coordinated Sun-related observational programs performed in 1964 and 1965
The Year of the Quiet Sun: One Year at Scott Base, Antarctica: A Personal Impression, a 1968 nonfiction account by Adrian Hayter
Ulysses was launched aboard space shuttle Discovery on Oct. 6, 1990. A long term study of the Sun.
The effect on albedo depends on where the sea ice is lost. A ten percent reduction in Antarctic ice would have a much greater effect than the same loss in the Arctic, since SH ice extends farther towards the Equator.
Most of the Arctic Sea Ice is on land. There is more land North of +60 deg. Latitude , than there is south of -60 deg. latitude.
G
Wait . . . what? How can it be sea ice if it’s on land?
Most of the Arctic Sea Ice is on land
Should be Antarctic. More land but not sea ice.
latitude has a huge effect on the amount of sunlight reflected by albedo. The lower the latitude, the more reflection.
In the Arctic, most of the sea ice loss relative to the alleged mean was in the Barents Sea, east of Svalbard, ie around 80N. By contrast, Antarctic sea ice gains extend beyond 60S, as for instance into Drake Passage.
Lower latitude Antarctic sea ice thus has about five times the albedo effect of Arctic ice at its lowest, where it runs into continental land masses.
I said Arctic. That’s what I meant; NOT Antarctic.
So ok I lied it’s not SEA ice.
If you want to calculate the land / sea areas north and south of 60 degrees latitude, be my guest. I’ve already done that.
Yes of course I mean calculate both the land and sea areas.
G
Anyway as george points more of the polar ice in the NH is on land than in the SH.
Is it firmly established that sea ice always reduces warming via sunlight? At very low incidence angles (quite common near the poles) is it not possible that ice actually “catches” more light energy in broken ice areas, due to the generally flat water in such circumstances, which (it seems to me) can result in very high levels of reluctance?
. . and reflectence too ; )
Johann Wundersamer
April 6, 2016 at 2:05 pm
The vast majority of fresh water on earth, not just ice, lies atop Antarctica. Arctic ice isn’t a pimple on the a$$ of Antarctic ice.
GlotM
Anyway as george points more of the polar ice in the NH is on land than in the SH.
Think interested readers got it.
Regards – Hans
Johann Wundersamer on April 7, 2016 at 1:16 am
GlotM
Anyway as george points more of the polar ice in the NH is on land than in the SH.
Think interested readers got it.
Regards – Hans
_____________________
The argument is ALBEDO diff, the interested readers got that too.
But steps of escalation, fascinating too.
Four different things to consider, and in their own way, each of the above comments is both right … and wrong. At the same time.
The arctic sea ice plots and totals from every laboratory includes ONLY “sea ice” frozen on top of salt water: No Great Lakes ice, no river ice, no land ice. The Arctic ocean is mostly covered at spring maximum, Hudson Bay, Sea of Oskotch (off of Siberia) and Bering Sea are the only major areas not up around the arctic itself: These are about 60 degrees latitude. Arctic sea ice goes from a minimum of 3.0 Mkm^2 in September, to a maximum of about 14 Mkm^2 in late March-early April. (Today, for example.) To compare year-to-year, ONLY use sea ice area, or sea ice extents – NEVER mix the two. Best to is ONLY compare year-to-year values from the same lab. Each is a little different, but those differences do not seem to change within the lab between years.
The Antarctic sea ice surrounds the 14.0 Mkm^2 land area of the Antarctic. It also varies from a minimum of 2.5 to 3.0 Mkm^2 – and that minimum has been increasing since the satellite record began! – but the maximum is much higher 15-17.0 Mkm^2. Antarctic sea ice does NOT include Antarctic land ice, but also does NOT include the static (fixed) permanent ice shelves around Antarctica. (That rather surprised me, but, then again, the ice shelves are not melting either, so as long as they are either included in every measurement, or excluded from every measurement, the final outcome is the same.) The Antarctic land area is not a true spherical cap, the Antarctic ice shelves are not symmetric, and the Antarctic sea ice is itself not exactly symmetric either. But their total is symmetric.
Let’s simplify things just a little bit, and assume both arctic (sea ice only) and antarctic (sea ice + land ice) are “round beanie caps” centered on their respective polar spheres. The result is very good assumption for the Antarctic, somewhat less accurate for the Arctic which is actually centered slightly to the southwest of the pole. (The open ocean is closer to the pole near Iceland than the Bering Sea. The early explorers knew this, and always began their polar treks north from the islands and land nearest the pole. There is very, very little permanent arctic land ice: just a wee bit on Canada’s Ellesmere Island and a few mountain glaciers. Everything else melts out each summer and becomes mosquitoes.
By simple spherical geometry, you can then get the latitude of the edge of the Arctic and Antarctic sea ice for every day of the year.
The Arctic sea ice edge cycles between 72 degrees latitude in March up to 80 degrees latitude in September. Using the same equation, the Antarctic sea ice area cycles between 70 degrees south latitude in late February at its summer minimum, then increases towards its September maximum at 59-60 latitude.
Sea ice extents are larger than sea ice area, but the same result holds.
Knowing the latitude of interest for each day-of-year, you can calculate the sun’s position for every hour of the day at the edge of the sea ice.
Why do you need to look at the edge of the sea ice, not the averaged center of area, or the pole itself, or some assumed generic latitude? Well, first, Trenberth’s generic diagram assumes some latitude between 23.5 and 67 north. But – except for Hudson Bay, Bering Sea, Oskotch as noted above. Cycling between 59-60 south latitude and 70 degrees, the Antarctic sea ice (almost) does reflect the sun’s energy as “everybody expects”: More Antarctic sea ice => more reflected solar energy => less absorbed energy => a cooler planet. And, as “everybody knows” the Antarctic sea ice HAS BEEN increasing steadily since about 1992. Since 2000, the Antarctic sea ice anomaly has averaged above 1.0 Mkm^2 through every season of the year. Lately, it has been higher yet: averaging about 1.5 the past 4-5 years – until last year’s September-March drop towards 0.0.
Did this 20 year increase in southern sea ice cause or influence or extend “the pause” ? Maybe, maybe not. Nobody has bothered finding out. Yet.
So, the Arctic. The edge of the arctic sea ice is always at much higher latitudes than the Antarctic sea ice. It NEVER gets as much sunlight as the edge of the Antarctic sea, and even when it does get hit by the sun, the Arctic summer sun occurs at a time of year when the sun’s TOA radiation values are at their minimum on 5 July. (The Antarctic sea ice is in sunshine when the sun’s TOA values are at their maximum on 5 January.)
Result? The arctic sea ice is in shadows 7 months of the year: There is NO arctic sunlight to be reflected, only increased heat losses from longwave radiation, evaporation, convection, and conduction from the lower-than-normal Arctic sea ice areas. For five months, the Arctic ocean can heat up from increased absorbtion of solar energy, but that effect is minimized by the higher albedo of water during most of the day, and the summer’s darkening of the arctic sea ice by dust, surface melt water on the ice, and the absence of new snow and ice.
RACookPE1978 April 7, 2016 at 12:29 am
The Antarctic sea ice surrounds the 14.0 Mkm^2 land area of the Antarctic. It also varies from a minimum of 2.5 to 3.0 Mkm^2 – and that minimum has been increasing since the satellite record began!
Not exactly, the sea ice area varies from 1.3 (1993) to 2.5 (2003), 1979 it was 2.0 and 2016 it was 1.8, so yes it varies but it has not been “increasing since the satellite record began”.
No, even a simplistic linear trend of the anomalies are increasing.
Antarctic sea ice minimums are increasing, and sea ice maximums are increasing.
Phil, these are the annual averages for Antarctic Sea Ice Extent: I left out 78 and 2016 because they are incomplete.
2 1979 11.721995
3 1980 11.239044
4 1981 11.419689
5 1982 11.661588
6 1983 11.373842
7 1984 11.453191
8 1985 11.638610
9 1986 11.076098
10 1987 13.233456
11 1988 11.685172
12 1989 11.425858
13 1990 11.410397
14 1991 11.545753
15 1992 11.398822
16 1993 11.421836
17 1994 11.775888
18 1995 11.803518
19 1996 11.769273
20 1997 11.390060
21 1998 11.738332
22 1999 11.760704
23 2000 11.747383
24 2001 11.672682
25 2002 11.221603
26 2003 11.970055
27 2004 11.961500
28 2005 11.694726
29 2006 11.460912
30 2007 11.687107
31 2008 12.239407
32 2009 12.048592
33 2010 12.106792
34 2011 11.500573
35 2012 12.004437
36 2013 12.523605
37 2014 12.776126
38 2015 12.402294
Decadal:
1980s 11.62065
1990s 11.60146
2000s 11.77040
2010s 12.21897
sunshinehours1
Thank you!
Can you repeat this series for the minimum and the maximums?
RACookPE1978 April 7, 2016 at 8:32 am
Not exactly, the sea ice area varies from 1.3 (1993) to 2.5 (2003), 1979 it was 2.0 and 2016 it was 1.8, so yes it varies but it has not been “increasing since the satellite record began”.
No, even a simplistic linear trend of the anomalies are increasing.
Antarctic sea ice minimums are increasing, and sea ice maximums are increasing.
But that’s not what you said is it? The maxima appear to be bouncing around 15.2.
Here’re the CT minima:
1979 1.95
1980 1.69
1981 1.62
1982 1.72
1983 1.82
1984 1.53
1985 1.65
1986 1.78
1987 1.82
1988 1.73
1989 1.89
1990 2.05
1991 1.85
1992 1.68
1993 1.3
1994 2.13
1995 2.05
1996 1.58
1997 1.63
1998 1.7
1999 1.71
2000 1.6
2001 2.33
2002 1.69
2003 2.47
2004 2.19
2005 1.84
2006 1.72
2007 1.8
2008 2.18
2009 1.79
2010 1.96
2011 1.69
2012 1.98
2013 2.42
2014 2.46
2015 2.47
2016 1.77
I doubt whether you’ll find a statistically significant trend there.
Here’s the NSIDC Extent plot for March, clearly a not significant trend.
http://nsidc.org/data/seaice_index/images/s_plot_hires.png
words of Emily Litella; “Never mind”.
So you are telling me the ice doesn’t consult with HADCRUT or GISS prior to advancing or retreating? Who’d have thunk it.
Though it’s only anecdotal evidence, if considered there is probably little change in trend in the last 130 years. There is plenty of evidence that points to ups and downs of a considerable nature throughout that lifetime.
Nicely put together. Consider it a pill for green activists who suffer mental problems over some melting ice.
I also had a thought when I saw “HADCRUT” and the following passage in this WE post (informative and thought-provoking as always).
…or it may support the notion that “global average surface temperature” (HADCRUT, or GISS, or other land based temps) is a fictitious measure, a purely statistical construct and devoid of value in describing the globe climate?
Or when the heat goes to the arctic, it does not increase global temps as much
and when it increases global temps, it is not going to the arctic? (or both poles?)
Another possibility?
Willis, what sort of time lag would you think reasonable between lower troposphere temps and polar sea temps?
Willis, do you have the R code for this analysis posted on line?
I am a member of the Houston R User’s Group and this, dataset and time series analysis looks like a nice tight example of seasonal decomposition for use in one of our talks.
I have the equations for all of the daily TOA radiation levels over the year, the hourly solar elevation angles and atmosphere thicknesses for every day-of-year, and the latitudes of both sea ice edges. Get hold of the moderator and give him your permission, and I’ll contact you to generate an hourly heat balance for sea ice and water at both poles.
It is often the case that on a centennial to millennial scale both poles show the opposite behavior and while one is warming, the other is cooling. This anti symmetrical behavior has several causes, one being the oceanic link that gives rise to the bipolar see-saw, and another that changes in equinoxial precession are also anti symmetrical with the seasonal insolation taken from one pole given to the other.
If one pole is warming while the other is cooling the average might not show much of a trend, and ditto for sea ice. Sea ice does respond to temperatures, but seems to respond more to sea surface temperatures than air temperatures.
if there has been an oceanic warming trend it would be expected that the average ice coverage of the 2 poles would show a reduction in the total sea ice coverage of both poles. Since Willis is showing there is no reduction in the average there has either been no warming trend in the oceans or warming oceans don’t have much to do with ice coverage. Whether one pole is increase while the other is decreasing is not relevant it is the total ice coverage of the 2 that matters.
if there has been an oceanic warming trend it would be expected that the average ice coverage of the 2 poles would show a reduction in the total sea ice coverage of both poles.
Not necessarily. What matters is the surface temperature at high latitudes. Different oceans have different warming trends.
Whether one pole is increase while the other is decreasing is not relevant it is the total ice coverage of the 2 that matters.
This is absurd. What matters for what? If you want to properly describe the system you have to properly describe its components and not simply take a single metric that pleases you.
The Global metric is perhaps not the best for seaice given it consists of the sum of two out of phase oscillations. Given the current value for the Arctic is the lowest for the date it’s conceivable that the minimum this summer/fall will be a new record surpassing 2012. However, even if it all melts the global metric would only hit ~15million km^2 (CT data).
Phil;
look back at the recent past, low maximums don’t usually have much to do with low minimums. plus if you look at the north pole sea ice volume is not all that low.
Since earth is further from the sun during Antarctic Winters, than it is during Arctic Winters, and moreover spends more time there, (the equal areas bit) I can’t even imagine why anybody would expect global total ice to be constant throughout the year.
G
George , +1 .
Those are the some of the first terms which must be included in any planetary temperature model . It is underappreciated that the difference between peri- and ap-helion equilibrium gray body temperature in our orbit is about 4.6 degrees , and as you point out , we spend more time further from the Sun than closer .
Phil, there is an oft understated issue with sea ice extent. The usual metric is that if 15% of a pixel is ice, the pixel is counted as ice. DMI discontinued 30% when it changed to a finer land mask rather than recompute the historical 30% with the new mask, because it wasn’t showing Aectic sea ice deterioration for the following reason.
15% ice means an ‘ice’ pixel can be 85% open sea. Therefore how compact or dispersed the sea ice is, especially along the Atlantic edges, greatly effects extent. That is affected by winds, waves, and currents. So this year’s ‘least meximum’ probably is an artifact of the metric. The ‘warmer’ Arctic winter Serreze whined about last week was still ~ -25C accordingmto DMI. Sea ice forms at -2C.
So my expectation is that the summer minimum about first week October will show the steady recovery from the 2007 cyclic low (2012 was an unusual August Arctic cyclone issue) suggested by Akasofu in 2010, and revealed by early 20th century DMI ice maps and by Russian summer sea lane records.
phil, you wanna bet on that 🙂
ristvan
April 6, 2016 at 1:11 pm
The actual sea ice maximum hadn’t occurred when anounced by Serres. The maximum has been moving to later dates these last several years.
“””””…… Bob Armstrong
April 6, 2016 at 12:33 pm …..”””””
Bob you would think that things like Kepler’s equal orbital areas swept out in equal times, would be the stuff of 4-H club science to be contemplated while cleaning out the crap from your New Zealand White Rabbit cages. (ain’t no such critter).
I’m no expert at anything climate, but even to me it is obvious that the Antarctic Winters are quite a bit worse than the Arctic Winters.
Now I don’t think that the North Pole ever gets down to -94 deg. C like the Antarctic highlands do; but then the whole of Antarctica has an average altitude of 10,000 feet.
G
ristvan April 6, 2016 at 1:11 pm
15% ice means an ‘ice’ pixel can be 85% open sea. Therefore how compact or dispersed the sea ice is, especially along the Atlantic edges, greatly effects extent. That is affected by winds, waves, and currents. So this year’s ‘least meximum’ probably is an artifact of the metric. The ‘warmer’ Arctic winter Serreze whined about last week was still ~ -25C accordingmto DMI. Sea ice forms at -2C.
Sea ice thickness during the winter depends on the cumulative freezing degree days (~sq root of FDD), this year the FDD has been remarkably low (~1000 below the average and the lowest on record).
So my expectation is that the summer minimum about first week October will show the steady recovery from the 2007 cyclic low (2012 was an unusual August Arctic cyclone issue) suggested by Akasofu in 2010, and revealed by early 20th century DMI ice maps and by Russian summer sea lane records.
My expectation is that you will be wrong.
Bob Boder April 6, 2016 at 11:52 am
Phil;
look back at the recent past, low maximums don’t usually have much to do with low minimums. plus if you look at the north pole sea ice volume is not all that low.
I said it was ‘conceivable’, in any event there is less loss required to reach a record, the weather will determine if it happens or not. The PIOMAS volume is showing 2nd lowest in the record by a very small amount (as they say in polls, a statistical tie), is that what you call “not all that low”?
Javier, what an odd comment or perhaps wording to put at the end ..sea surface versus air temperature response. You,d think density and thermal capacity differences might be factors why this happens.
I do believe that sea ice, is actually frozen water from the sea, and not frozen air from the atmosphere. So you might be correct that sea ice would respond more to sea Temperature than air Temperature. And I think water’s thermal conductivity is much higher than for air as well.
G
Good hint – water is a better ‘Wärmeleiter’, conveyor of heat, than air.
So sea ice has no connection with temperature (or at least in the range since 1973–water still freezes at 0c).
Salt water does not freeze at 0c.
Guess again.
Sorry Tom. I should not have added those last two words.
I’ll put this here; it could go elsewhere.
This is from the National Snow and Ice Data Center (NSIDC)
Ocean water, Salinity and Brine
“Arctic temperature anomalies in the 1930s were apparently as large as
those in the 1990s and 2000s. There is still considerable discussion of the
ultimate causes of the warm anomalies in the 1920s and 1930s.” (IPCC AR5)
h/t to Dr. Judith Curry
There is that coming out of the LIA thing showing up in another graph. looks like the European ice trend has been pretty consistent since coming out of the LIA not much of a CO2 CAGW signal in that graph.
Hmmm. There’s that 60-year cycle again…
http://www.accuweather.com/en/weather-news/cold-blob-to-be-wildcard-la-nina-atlantic-hurricane-season-forecast-2016/56491288
What is the source of that figure, Anthony?
It is not in the Mahoney et al. 2008 article:
http://seaice.alaska.edu/gi/publications/mahoney/Mahoney_2008_JGR_20thC_RSI.pdf
It seems labelled in Russian
Another chart showing the 1930’s as being hotter than subsequent years.
“…the global sea ice area is not particularly a function of the global average surface temperature.”
The recovery of the past decade does seem to fit with the ‘terrible horrible Pause crisis’ that the control knobs are trying to erase of late, though. One can see that when we fiddle a part of the picture – temperatures, that other parts stubbornly stand in contrast.
Note that Antarctic ice extent has gone up in 5 years “bounces”. We just completed a bounce and it looks like we are taking off on a new 5 year cycle. Look to Antarctic ice expanded robustly over the next few years to new highs.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
correlects ENSO ?
If the Antarctic sea ice anomaly did correlate with the EL Nino oscillation, then a low (or negative) Antarctic sea ice anomaly should cause more solar energy to be absorbed down south, then the slightly warmer water should flow north along the Peru-Chile coast, then turn and spread westward towards Australia-Polynesian Islands.
The timing of 2010-2011 Antarctic sea ice “negatives” and this latest 2015’s negative do match El Nino’s, but the 1997-1998 El Nino matches a near-zero Antarctic sea ice anomaly. The 2011-2011 monthly-daily anomalies don’t exactly line up given the time for a patch of warm water to actually move that far north with the surface currents, nor does the Sept 2015-March 2016 dates match that delay.
Unless something else is going on, it doesn’t transfer times very well. But earlier El Nino’s ?? Don’t know.
The data is gridded, and so there’s Arctic data since 1973. Should be able to plot and see if the beginning of the satellite era (1979) was an (un)lucky year to start…
Been done. IPCC FAR WG1 figure 7.20 on page 224. 1979 was the highest ice year 1973-1990. 1974 was ~2 million km^2 lower. The ice specific (microwave) satellite measurements started in 1979, but optical ice sat obs go back to 1973 as you point out. A coincidence that 1979 was peak. But not a coincidence that the warmunists ignore the quasiperiodic ~60 year cycle evident in other Arctic ice records. Their Arctic ice disappears and polar bears drown meme served IPCC well for 25 years through AR5. Now it is turning around to discredit them strongly.
And here is the plot containing that early 1970s data.
In broad terms (within margins of measurement error) we have about the same amount of Arctic Ice as that observed in 1974.
Next, remember from above that a change of 10% in the global sea ice area translates into a global average of 0.1 watt per square metre (W/m2) change in reflected sunlight.
_________________________________
Are you sure about that, Willis?
Your 0.1 Wm2 figure was derived in part from an assumption that ice extent is greatest in the winter, when there is no insolation, and melts in the summer. So the high ice-albedo season is nullified by there being no winter insolation, and so albedo has a much reduced effect.
However, if the winter ice stays all summer then the influence of the ice albedo will be much greater, and possibly significant in terms of regional cooling. And possibly vice versa too, if all the ice suddenly disappears in summer.
R
ralfellis April 6, 2016 at 1:18 pm
Thanks, Ralph. In fact, the 0.1W/m2 figure was calculated directly from the observations. My claim that when there was more ice there was less sun an attempt to explain the observations, not a method of calculation.
Regards,
w.
ralfellis
l think its when this extending of the snow and ice in the Hudson Bay area is what is a key factor to NH cooling. Because when the NE North America’s climate cools. Then its effects can extend across the northern Atlantic and towards europe.
Willis,
Comparing your Figure 3 with the global sea ice anomaly graph on Anthony’s sea ice page (the black one), I can’t help but see a clearly different trend. Any idea on how to explain this difference?
Frank
They are from different sources. I’m using the HadISST dataset.
w.
Any idea why they are so different from each other, and which one (if either) is more likely to be correct?
The Cryosphere Today graphs showed Global Sea Ice at an all-time low (yes – OK, since 1979), at this year’s minimum at the end of January
This is because Antarctic sea ice does not follow the global average surface temperature, however Arctic sea ice does follow the global average surface temperature.
Source: https://diablobanquisa.wordpress.com/2013/10/04/estimando-la-extension-de-la-banquisa-artica-entre-1880-y-2011/
Exactly.
Er…. I might point out that in 1880 large parts of the Arctic hadn’t ever been visited by humans, so how can there be any information about ice conditions there?
The following areas for example were unknown in 1880: the whole Central Arctic Basin, all of Severnaya Zemlya, all of the Sverdrup Archipelago, most of the east and north coasts of Greenland, most of Franz Josephs land most of Wrangel’s land. There were plenty of smaller blank spots too.
The only areas regularily visited at that time were Hudson Bay and Baffins Bay, the waters off Western Greenland and Spitzbergen, Barent’s sea and the waters immediately north of Berings Strait.
The data from 1900 can be trusted a lot more. There is quite good data since then from the European Arctic that includes about 77% of the Arctic. These are the reconstructions from Zakharov and Alekseev (2000, 2005). There is also the Vinje reconstruction for the Nordic seas.
The data prior to 1900 is from Chapman and Walsh whole Arctic reconstruction. It does not appear to be as good as the Russian and Nordic ones.
Sources given by https://diablobanquisa.wordpress.com/2010/03/26/banquisa-artico-siglo-xx/
Variations of Arctic sea ice extent in the 20th century from dataset based on available Russian observations
Johannessen, O.M. et al. (2004), Arctic climate change: observed and modeled temperature and sea-ice variability, Tellus A 56 (5)
Walsh and Chapman Northern Hemisphere Sea Ice Data Set
ftp://pscftp.apl.washington.edu/incoming/PolarFridays/2-walsh_2001.pdf
Cryosphere Today
Monthly figures for ice cover
The old data comes mainly from ship logs. If you know where the sea ice reaches, you know its extent. A painstaking job to get all those logs into data. It is surprising that after doing it, it follows so closely the inverse of the temperature. But it is what one would expect after all. In a warming planet, well behaved sea ice melts.
I don’t understand why Willis Eschenbach writes here about a so-called ‘Awful Terrible Horrible Global Sea Ice Crisis’.
Is this the actual focus in the discussion, or is this his personal view on it?
We have
– arctic sea ice decline, best documented by PIOMAS’ sea ice volume data:
http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1.png
– antarctic sea ice increase, by far more important than the arctic decline, due to the huge size of the Antarctic continent.
Wether or not there is a link between the sea ice info above and the temperature info below: who knows?
http://pamola.um.maine.edu/fcst_frames/GFS-025deg/ARC-LEA/T2_anom/01.png
And the beautifully idealized plot from ‘Mahoney and al. 2008’ does not seem me to have so much in common with the 72×36 grid data I downloaded from Japans JMA:
http://fs5.directupload.net/images/160406/fmf9v9xn.jpg
Sorry: I forgot
– to mention that JMA’s data has been normalised wrt UAH’s baseline (1981-2010)
– to inform about JMA’s data source:
http://ds.data.jma.go.jp/tcc/tcc/products/gwp/temp/map/grid/gst_mon_1891_last.gz
You do see the ice thickness marching back upwards over the past 4 or 5 years in your PIOMASS graph, don’t you. Wouldn’t this in your mind be a very unrealistic departure from a crisis warming projected for the next century and beyond? Wouldn’t this at least cause you to say, hmm… an ever decreasing trend in ice thickness is not in the cards? Falsification is falsification. Now it could thin again for a while, but the linear decline we now know to be a gross overstatement. Hmm…I wonder if the temperature and sea level prognostications should also be cut back from the scenarios recently projected? Don’t argue now that this is expected and not a falsification after a better “expert” than you (Dr. Viner with UK Met Office) told us in 2002 that in a few years, children are just not going to know what snow is!
But what is awful about this?
Surely it would be a god send if we were to revert to conditions seen during the Holocene Optimum. It is not easy to think of any significant negatives to the loss of Arctic Sea Ice.
For a normal person, opening up of the Arctic for shipping, fishing, and development of natural resources would be a huge benefit. To a warmist, they are staunchly opposed to capitalism, trade, and development of natural resources, so it is a huge disadvantage.
I interpreted it as tongue-in-cheek, a bit of a mocking tease, if you will.
Bindidin
The map of temperatures you are showing is very interesting as it clearly shows that any cooling of NE America can then extend its effect across the northern Atlantic and towards europe.
As mentioned before during other discussions at this website, the PIOMAS data is derived from a model at the Univeristy of Washington, and I do not know how closely it resembles reality.
PIOMASS_Total_volume = (Piomass_Area_1 x Piomass_Assumed_Thickness_1) + (Piomass_Area_2 x Piomass_Assumed_Thickness_2) + (Piomass_Area_3 x Piomass_Assumed_Thickness_3) + (Piomass_Area_4 x Piomass_Assumed_Thickness_4) + ( …) to as many assumed thicknesses and areas as they wish to assume.
A linear trend in PIOMASS is only as good as their assumptions about ice thickness, ice age (which usually relates to thickness) and ice area of each thickness.
A linear trend in PIOMASS is only as good as your assumption is for a linear trend (extrapolation) of the Arctic sea ice as a whole. If the Arctic sea ice aea/extent does follow the AMO 36-40 year oscillation, then a 6 year increase in PIOMASS ice mass DOES indicate a significant reverse of an apparent decline since 1979. Indeed, the first 10 years since 1979 DO show a shallow, near zero slope. Then we see a faster decline until 2006-2007, then a steady Arctic sea ice area since 2006-2007 low spot.
Which DOES look like a oscillation, NOT a linear trend.
So, will the Arctic sea ice go back upwards towards the high of 1979-1980? The only thing we can say for certain is “Maybe. “
Hmm. See the arc of really, really cold across northern Canada? That is where the ice sheet will begin. Watch for that area to retain snow year-to-year.
“….± 0.05 W/m2 in reflected sunlight … in other words, far too small to be measured.”
So what is large enough to be measured? 10 W/m^2? 1 W/m^2? 0.1 W/m^2?
Incoming at ToA is 340 W/m^2. 0.5% uncertainty = 1.7 W/m^2, the RF of 261 year’s worth of CO2 increase and lost in the noise.
Actually incoming at TOA is 1366 W / m^2; well averaged over the whole earth year cycle.
G
Correct. This is why solar quiescence could be so impactful – over an 11-year solar cycle the TOA drops by approximately 1.1 W/m^2 so if at the peak the output declines by even a fraction of that, it has a much greater effect overall on the climate than admitted to by the so-called climate scientists.
AZ1971 April 6, 2016 at 8:29 pm
Thanks, AZ, but there are a few problems with your claims.
First, the 24/7 global average is only a quarter of your 1.1 W/m2 variation, or about 0.28 W/m2 over the ~ 11-year sunspot cycle.
Next, thats 11-year variation is LARGER than the variation between times of active sun and times of quiet sun.
Next, the 24/7 global average downwelling radiation at the surface is about half a kilowatt per square metre … compared to which a variation of 0.28 W/m2 is lost in the noise.
Here’s the part most people don’t seem to get. A peak-to-peak variation of 1.1 W/m2 out of 1362 W/m2 is a change of only EIGHT HUNDREDTHS OF ONE PERCENT … like I said … lost in the noise.
Best wishes,
w.
george e. smith
The actual TOA radiation values for any day-of-year (DOY, in Excel format) is
TOA=1362.36+46.142*(COS(0.0167299*(DOY)+0.03150896))
George, the 1366 W/m^2 was the “old number” based on the solar measurements between 1960’s through 1996-1998. Leif Svalgaard reports the “corrected” solar TOA average over the year is now down to 1362.36 W/M^2 and ALL earlier values were incorrectly reported “high” based on bad sensors.
Thus, of course, that also means ALL theoretical global energy balances made by ANY global circulation model (and ANY assumptions or other calculation made before the revised solar TSI values were issued by his group) were ALSO “too high”.
Nobody has ever explained why these old NASA/IPCC/RS/GISS results have never been challenged: A drop in inbound TOA radiation of 4 W/m^2 is greater than the “multiplied” effect of all CGAW projected between today’s CO2 levels and 2150’s values. Sure, you could argue that the “actual” TOA radiation did not fall, only the measured radiation was reduced by the instrument re-calibration. But the GCM models START with their assigned (assumed) TOA radiation values. Artificially INCREASING the modelled inbound TOA radiation by 4.5 watts while “calibrating the model” using ground-based records for the same period creates a false +4.5 watt/m^2 heating effect.
NS, you cite the surface estimate, not the TOA estimate. TOA is reasonably certain. Surface is not. Clouds are just one problem.
What’s the trigger to send the NH into cooling.?
Well its looking like that the next 7 days of weather has given me a answer. lt starts in the mid Pacific where area’s of high pressure form west of the Hawaii Islands. These form kinks in the jet stream which allow high pressure to ridge up towards NW America. This sends the jet stream up towards and into the
Arctic. Where once clear of these highs it sends the jet and cold air down across NE America, where areas of low pressure form in the dip as the jet stream bottoms out. Now here is a key part of the story. When this pattern forms over America in would then send the jet NE towards europe, drawing warm air along with it. But what would stop this from happening is if huge Omega blocks formed over the northern Atlantic and pushed up into Greenland. So sending the warm air up towards Greenland instead. While over in Europe instead of this warm air flow. These Omega blocks would instead be sending cold air down across northern europe from the north or across from the east. Along with this there is a other important effect these Omega blocks would cause and that is they would stall areas of low pressure over both NE America and over or near europe. Allowing large amounts of snowfall with which to build up the ice sheets over these areas. This is what l now believe is the basic set up which sends the Atlantic side of the NH into an ice age.
Should have added its when this set up becomes a long term trend is when it leads to cooling in the NH.
“… into an ice age.
Many consider the terms “ice age”, “glacial advance” (aka glacial period), and “interglacial” …
https://en.wikipedia.org/wiki/Interglacial
… to be well defined. In this context, what you wrote is not what you meant.
Sorry for the poor coding — it’s late. Off to bed now.
taxed, I think you are correct about the jetstream. The jetstream arcs farther north in these situations, which allows it to interact with cold polar air and bring it south on the east side of the jestream arc.
This is similar to the hot weather pattern that sets up over the central U.S. during the summer time. A large high pressure system will form over the central U.S. which will route the polar jetstream up and over it, bringing mild, wet weather to Canada, and dry, hot weather to the central U.S. The hottest area being whereever the center of the high pressure system is located. If the high pressure area is large enough, Canada also gets hot and dry weather.
What I wonder about is, what happens to the atmospheric circulation in the NH when this huge high pressure system sits practically stationary over the U.S. for year after year, as was the case during the the very hot decade of the 1930’s?
According to anecdotal data, the entire NH (and SH) were involved in this 1930’s heatwave, with Europe, Russia, and China reporting extremely hot temperatures during this time period.
It seems to me if there was a huge high pressure system stalled over the U.S. for several years during the 1930’s, and there was extreme heat reported around the NH, then there must have been stalled high pressure systems over Europe, Russia and China, at the very same time. You don’t get these kinds of extreme heatwaves any other way than under a persistent high pressure system.
What did NH atmospheric circulation look like in the 1930’s due to all the stalled high pressure systems?
Also, if California has experienced several bouts of drought that lasted, in one case, about 200 years straight, what kind of weather pattern has to set up to create this condition? Does a high pressure system sit over California for 200 years straight?
You mean, stalling the precession of the Rossby Waves?
” …the global sea ice area is not particularly a function of the global average surface temperature. ”
… or it suggests that either the claimed temperature trend or ice coverage measurement is incorrect
… or it suggests that apparent changes in global temperature and/or sea ice are just random measurement errors.
Arctic sea ice has varied millions of square kilometers over the last few decades. No one died. Few people know which year was the highest, and which was the lowest. It affects no one. Truth be told, less sea ice would be better than more.
Reporting sea ice as anomaly exaggerates the relevance of variability. The base is over 15 millions square kilometers. Tell someone the max went from 23 Mkm^2 to 25 Mkm^2 and see if they care.
There are about 3,600 weather stations in the USA catering to 9.857 million sq. km. There are 16 weather stations in the Antarctic, mainly in the ‘West’ Antarctic which caters for 14 million sq. km. The Arctic is monitored mainly from Greenland, Russia, Alaska, Canada and Norway. This means that there is very little information about the place where there is most sea ice. One cannot expect to be getting a lot of sense out of such a sparse coverage.
@Willis
if I take a frozen beef joint out of the freezer, will it thaw quicker if I leave it on the side, or will it thaw quicker i I put it in a bowl of water ?
EternalOptimist April 6, 2016 at 5:43 pm
Sorry, my optimistic amigo, but I’m terrible at the Socratic method. How about if you state your point as clearly and simply as possible, and we can discuss it?
w.
I am thinking about the atmosphere melting the ice (by contact) as opposed to the ocean. I was thinking of avoiding the radiation aspect. The beef joint would make it easier for an ignoramus like me to understand.
The water.
It’s SH is 4x greater.
I am not really sure what his point is: But the Arctic and Antarctic sea ice melts two very different ways.
The Arctic sea ice melts from above, with the surface melting into “meltwater ponds” of still water sitting a about a 1/2 meter ABOVE the sea level ON TOP of the sea ice. The meltwater ponds are very still (because they have very little “”fetch” or open lengths to get blown by the wind, very shallow (6 to 18 inches), and disappear when the sea ice cracks below them. The melted water then runs down through the cracks into the sea. The Arctic water does melt the sea ice continuously from below, but the ice as a whole melts from the top down. The dark meltwater and the region’s dust (and now soot from China!) darkens the Artic sea ice much more through the summer period than the rather pristine Antarctic sea ice. Through the summer, very, very little snow accumulates on the Arctic sea ice.
From Curry’s measured Arctic sea ice albedoes, an adequate definition is
DOY 280 Albedo_Ice_Arctic = 0.83
(The average through the summer melt period really does follow a sinusoid.)
The Antarctic sea ice melts from below, and stays solid until the bottom melts out and the whole local floe goes away. Because the top of the sea ice is NOT dirty, and does not have meltwater ponds, it does accumulate what snow falls on it, and so has a significantly higher albedo than northern sea ice over more months of the year. (The summer months around Antarctica have lower sea ice albedo (Sep-Oct-Nov-Dec-Jan-Feb) than do the fall re-freeze, winter and spring warming, but the Antarctic summer albedo is much brighter than the Arctic summer albedo.
March – Sept = Antarctic_Sea_Ice_Albedo = 0.83
Sept-Oct-Nov = 0.81
Dec-Jan-Feb = 0.75
I argued this a couple days ago on another website regarding the hot spot melting Greenland’s ice underneath the ice cap — that because of matter phases, it’s far easier and quicker to melt something when in direct contact with same matter phases (solid:solid) than two phases away (solid:gas). I was told to prove it, because the fundamental physics and 3rd grade science was so obvious as to undermine the tool’s reasoning that AGW is primarily the cause of mass budget decline.
I understand that the SH is greater and I understand the matter phase point. The air (atmosphere) would also be kept constant due to the central heating and that would also keep the water warming up.
It struck me that I could collect the various ideas here, then test it next Sunday.
Oh….. horseshit.
Gorbal Warming, AGW, climate change whatever you wish to call it is a hoax, the sole purpose of which is to advance one world government.
When asked what is the purpose of the IPCC’s Climate Change agenda, the U.N’s Climate Chief, Christina Figueres replied “Our goal is to change the economic development model that has been reigning for at least 150 years, since the industrial revolution.” In other words, destroy capitalism and free markets. “The whole aim of practical politics is to keep the populace alarmed, and hence clamorous to be led to safety, by menacing it with an endless series of hobgoblins, all of them imaginary.” H. L. Mencken
“The welfare of humanity is always the alibi of tyrants.” Albert Camus
Since the AGW hoax is skating on very thin ice, we now have the Zika Virus to replace it. Just in case. Well, you know.
You scoffers can laugh all you want. I am making steady payments on my kayak, and I am now hunting on Priceline for flights.
I will kayak straight to that North Pole this year. Just you watch me. The REAL North Pole. Not the “magnetic” North Pole, or the “Traditionally Observed North Pole,” or any other pole.
I am sure at most I will have to use one of those Bear Grylls camping axes to break up what lingering ice there might be this summer.
Take care, there are a lot of cruise ships and unemployed ice-breakers churning around up there looking for icebergs these days … in fact, why not ditch the canoe lark and get a cabin on the poop deck?
(I have no idea how it got that name … though I have my suspicions)
Typo in Figure 3. bottom panel Y axis, “blue line is loess” … should be ‘loses’?
Oh, and email an excerpt of that graph, but from 2005 to present, to Al Gore and Barry, and other profligate jet-setters / trend-setter worriers.
I don’t think I’d take the time to mail those two a graph. They seem not to be at all bothered by all the CO2 they personally spew into the atmosphere. The Obamas’ took two planes to Argentina because they wanted to fly into an area that did not have an airfield where AirForce One could land. They took two planes to LA because Michelle did not want to take the time to stop over at a Veteran’s Hospital in Phoenix with Obama during the VA scandal.
If they really believe in AGW, CC or whatever they call it today, they would not do such things. They and the likes of Gore would lead by example. Fat chance of that happening.
As it is, their behavior would be like Martin Luther King jr. accepting membership into an all-white country club but just for him and no other black during the Civil Rights struggle of the 50’s and 60’s. Lying hypocrites.
Typo in Figure 3. bottom panel Y axis, “blue line is loess” … should be ‘loses’?
No Loess refers to a statistical technique to remove seasonal effects.
http://www.astrostatistics.psu.edu/su07/R/html/stats/html/stl.html
Interesting uptick. So the follow up is to look at NH, SH differences and what contribution they each make.
I did look at this by estimating the length of melting/freezing season. I did this by detecting the turning point having used all the available daily data and using a low-pass filter to take out the weather driven wobbles.
This is far more informative that the usual obsession with spotting the one single daily data point that is max or min for the year. Melting seasons vary by just a few days whereas the single day extrema jump about by two or three weeks, mostly masking whatever is going on in irrelevant weather noise.
Of course alarmist love climate noise. It’s what they’re good at.
There is often talk of a “polar see-saw”: one goes up while the other goes down. Willis shows the global sum and we see that there is some residual up and down, ie it is not well balance see-saw.
I noted that there were a couple of notable spikes in both hemispheres but they occured in different years. This inspired to look at this in terms of north-south lag. I found the biggest excursions lined up with NH leading by three years.
There is quite a lot of similarity in the length of melting season across the record with this lag.
ttps://climategrog.files.wordpress.com/2014/06/ant_arctic_melting_season_lag.png
https://climategrog.wordpress.com/ant_arctic_melting_season_lag/
At the end of that graph we see both hemispheres moving towards shorter melting seasons. This matches the up tick is Willis graph.
So, what was the “turning point” (shoulder) for the Arctic that you calculated?
Judith Curry reports the arctic sea ice meltwater ponds (the melted water sitting on top of the arctic sea ice) began re-freezing each night beginning 12 August at latitude 78 north. From that night onwards, the meltwater froze just a little deeper, accumulated more fresh snow when it fell, and stayed longer each morning, and appeared earlier each evening. It did melt away through the daylight sun, which of course, was still up each day. (Report from her SHEBA arctic expedition 1998.)
Spring melt began about 1 May.
oops, lost a bit of my URL
What this analysis suggests is that rather than being opposing swings, they are moving in the same direction but with a three year lag. Changes are seen first in the NH ice and it takes 3y to propagate to Antarctica.
Willis,
When you eventually run out of things to look at, try checking the effect of a thin layer of oil and surfactant on the oceans, Don’t forget albedo change, evaporation decrease and reduced aerosol production.
I’d be very interested to see the numbers.
JF
Dear Willis,
Nice article, but I don’t think it is a ” curious conclusion that in modern times sea ice extent is not a function of average global surface temperature”. The thermal capacity of the oceans is a thousand times greater than that of the atmosphere and you don’t see many gnats on a dogs back that can influence the direction of travel. The AGW crowd have got the relationship the wrong way round.
The heat engine of ocean oscillations that transports tropical warmth to the poles takes decades to play out and undersea volcanic activity is ignored by the AGW crowd.
Regarding the cooling oceans as solar activity declines and the inevitable reduction of atmospheric CO2 levels caused by increased solubility, I am speculating that the AGW crowd will claim that western decarbonisation of industry has indeed been a fantastic success. Apologies if I have stated the obvious.
Add to that the areas of deep water under sea vents, waters are 500c degrees and above due to not being able to boil off under pressure. There are sea floor radiators pumping heat into the oceans, apparently it is irrelevant, because if it throws doubt on AGW then.. it is ignored, like natural CO2 for example.
In looking at the >80N temp graphs, it seems that all the Arctic’s “unprecedented” surface temp readings result from “warmer winters” rather than warmer summers. Albedo can’t have much to do with warmer winters. The Arctic sea ice will return to higher levels of coverage when the AMO goes cold – not before.
R2Dtoo
True. If you combine all of the DMI Arctic daily temperature forecasts (they are not really measurements specifically) for 80 north latitude since 1959, you will find a very slight decrease (less than -0.05 degrees) in summertime temperatures, and a notable 8-10 degree increase in winter temperatures. Winter temperatures oscillate strongly, varying greatly day-by-day. Summertime temps do not change at all.
The yearly average, of course, moves as the CAGW crowd demands by their theory: Averaging winter temperatures (when the sky is dark and their is no solar heating!) with a static summer temperature will, indeed, give a rising average. Which is all they publicize.
As long as there is ice present there will be no increase above freezing, once it is gone there can be a significant temperature rise.
Sea ice is a reflector, but also an insulator. Decreased sea ice causes more sunlight to be absorbed in daytime, and more ocean heat to be radiated to space in the nighttime. One is a positive feedback, while the other is a negative feedback. It is far from clear which side dominates. Many have noted an apparent regime change in the year-to-year Arctic sea ice anomaly variability beginning around 2007, which may represent the tug-of-war between these competing warming and cooling feedbacks.