Northern Winter Nights

Guest Post by Willis Eschenbach 

[See Addendum at the bottom.] [See Second Addendum at the bottom]

I got to thinking about the distribution of the so-called “global” warming. I’d heard that a good chunk of it was due to increasing nighttime minimum temperatures. So I grabbed the Berkeley Earth land-only temperature dataset. It has its problems, and I suspect the overall warming trend is exaggerated, but at least it is internally complete and consistent. I wanted to know both where and when the warming is strongest, and where and when it is weakest. I used the post-1900 data because prior to that the error bars get pretty wide, but the choice of starting point doesn’t make much difference.

For my first subdivision in time and space, I looked at the daytime maximum and the nighttime minimum temperatures by hemisphere. Figure 1 shows the result:

berkeley earth min max hemisphericFigure 1. Maximum daytime temperatures (orange/red) and minimum nighttime temperatures (dark/light blue) by hemisphere. Data goes from 1900 through 2014.

This shows that as a hemispheric average, the nighttime minimum temperatures are rising faster than the daytime maximums, and that the northern hemisphere nights are warming the fastest of the four groups.

(I note in passing that while both the northern and southern hemisphere daytime temperatures dropped strongly from about 1945 to 1975, the corresponding drop in the nighttime temperatures is nowhere near as large. No idea why … always more questions than answers, gotta love that, but I digress …)

However, that wasn’t quite what I was looking for. I wanted to know more details about exactly where and when the warming was going on. So I made a couple of movies. Since the fastest warming is in the night-time, here are the century-plus nighttime minimum temperature trends, on a 1°x1° gridcell basis:

Minimum temperature trend animationFigure 2. Berkeley Earth month-by-month average minimum nighttime temperature trends, in degrees C per decade. 

This is what I was looking for, the details of the location and timing of the warming. The Northern Hemisphere nighttime temperatures are increasing the most during the winter in Siberia and Canada. And similarly, in the Southern Hemisphere the nighttime warming is greatest in the winter, although it is more evenly distributed spatially. Meanwhile, there is little trend change month-over-month in the tropics.

Now, call me crazy, but I don’t recall anyone ever saying “Boy, I sure wish that the February nights in the Yukon were colder” …

What about the daytime maximum temperatures? Figure 3 below shows the days:

Maximum temperature trend animationFigure 3. Berkeley Earth month-by-month average maximum daytime temperature trends, in degrees C per decade. 

Curiously, or perhaps not curiously, this daytime view shows the same pattern as the nighttime temperatures. The warming is concentrated in the extratropics in the winter.

Conclusions? Well, the most obvious conclusion is that the “global” warming is not global at all. Instead, it is strongest at night in the winter in Siberia and Canada. I’m pretty sure the poor people in Murmansk are not complaining about that …

In addition, there are large regions of the earth where for one or more months of the year, over more than a century the temperatures have actually cooled … the entire southeastern US, for example, is now colder in January than it was a century ago, both during the day and at night. If nothing else, this highlights the complex nature of the climate.

That’s what I see so far, but there’s much more to learn in the movies …

Clear weather today. I’m off to build an outdoor viewing tower so our cat can survey its domain … got to take my shirt off and saw up some wood in the sunshine, we melanin-deficient folks need to get our Vitamin D.

Best wishes to you all, whether you are in sunshine or rain,


Addendum: I was accused in the comments of suffering from  hypo-Europhilia, as evidenced by my Pacific-centered movies. Hey, I’m a tropical South Pacific boy, guilty as charged, so here’s the new movie:

Minimum temperature trend animation atlantic

Second Addendum: A commenter asked how well the climate models do at reproducing the patterns shown above. Here are a comparison of four different months (Feb, May, Aug, Nov) of one single GISS-E2-R model run from the KNMI dataset:

minimum temps berkeley earth and giss febminimum temps berkeley earth and giss mayminimum temps berkeley earth and giss augminimum temps berkeley earth and giss nov

I don’t find the agreement particularly compelling, but YMMV.

Data: I got the Berkeley Earth temperature data from the marvelous KNMI site. Click the link entitled e.g. “1833-now: Berkeley 1°” and look down at the bottom of the resulting page for the gridded NetCDF dataset.

PS: I am reliably informed that it is no longer politically correct to refer to so-called “white” people as being “melanin-deficient”, as it implies that something is wrong with them. The new politically approved term is “melanin-challenged”.

My Usual Request: If you disagree with me or anyone, please quote the exact words you disagree with. I can defend my own words. I cannot defend someone else’s interpretation of my words.

My Other Request: If you think that e.g. I’m using the wrong method on the wrong dataset, please educate me and others by demonstrating the proper use of the right method on the right dataset. Simply claiming I’m wrong doesn’t advance the discussion.

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Barclay E MacDonald
February 23, 2016 12:43 pm

Interesting post as always Willis, but we are still talking temperature changes within 1 degree C with significant range of error. Do we really know anything? What a lucky cat:)

Reply to  Barclay E MacDonald
February 24, 2016 12:33 am

Cats are amazing family members, they love being “observers’ we are planning a “Cat Walk” along the ceiling they already have a climbing post with a landing but they have told us they want a loft!

February 23, 2016 12:44 pm

As always Willis, concise and very interesting. As usual though, the data is suspect. Can you do the same with just the satellite data (if it is available). Would be very interesting to see what it shows for the past 35 years or so as it is more believable.

Reply to  rbabcock
February 23, 2016 4:42 pm

No You cant do it with Satellite data.
1. UAH does not publish temperatures
2. RSS does
HOWEVER, satelllites DONT measure the temperature at the same time every place on the globe
so they have to adjust the data.
RSS adjusts the data to LOCAL NOON. it does this adjustment using a GCM
This is one reason why people who compare surface and satellite, by simply looking at anomalies dont know what they are doing
Oh ya, Radiosond data is reported in UTC time… so if you want to use that you have more adjusting to do

Bob Boder
Reply to  Steven Mosher
February 24, 2016 5:18 am

The largest temperature changes are happening in the areas that are the least populated. What would be the most likely reason for that?

Reply to  Steven Mosher
February 25, 2016 9:45 am

What would be the most likely reason for that?

The temperatures at those areas are pretty harsh. So most warming over land has happened where there was very cold to start with.

Reply to  rbabcock
February 23, 2016 4:53 pm
Reply to  Steven Mosher
February 23, 2016 6:07 pm

Undaunted Courage by Ambrose is a terrific chronicle of their expedition.

Reply to  rbabcock
February 23, 2016 10:25 pm

i suspect that would take down the scope of the article it handles about a century. (starting in 1900) Satellite data is only available since 1979 which is too short for this…
i would be more interested to see where the urbanization did grow significantly or where the land use has changed dramatically to see the similarities…. sure that it would folow pretty close with the warming hotspots….

February 23, 2016 12:47 pm

Let me see if I understand this right. The areas that are more sensitive to climate change are experiencing a bit more marked climate change than the areas that are less sensitive….. Were we supposed to have stable climate? I missed that memo.
I think I understand that what you have presented: in a warming world, the areas where it is colder will warm much faster than the ones where it is warmer, has more humidity, thus more resilient to changes.
Unfortunately, your observations will fall on deaf ears to those that want us to be the culprit for the new normal… or is it worse than the new normal?

Reply to  Francisco
February 23, 2016 3:08 pm

“the areas that have the least witnesses to climate change are experiencing a bit more marked climate change”
…strange how climate change is effecting the least populated places on the planet

Reply to  Latitude
February 24, 2016 9:17 am

Strikes me planet land surface is warming most where it is coldest. Human distribution is inverse. This means the equilibrium functions are working well. Westerlies are evident in the progression of NH hot and cold blobs.
Since they are working well the result will be the same regardless the source of the warming.
Now, if we could only figure out why it is warming…
This is a great piece of work, Willis.

Michael Carter
February 23, 2016 12:47 pm

Nice work but pray tell me the number and distribution of locations where minimum nighttime temperature was recorded prior to (say) 1960? Global records? Yea right!

Reply to  Michael Carter
February 23, 2016 4:51 pm

Its actually NOT minimum nightime. Its the minimum during the 24 period whenever that occurs.
Daily records go back to the early 1800’s
Even Lewis and clark recorded daily temps.. They “calibrated” their thermometers as well using the boil and freeze method

Reply to  Steven Mosher
February 23, 2016 5:29 pm

Steven Mosher

Even Lewis and Clark recorded daily temps.. They “calibrated” their thermometers as well using the boil and freeze method

Did Lewis and Clark use an elevation/atmospheric correction for their freeze/boil checks? They did not know the altitude of the mountains they were passing through, only the atmospheric pressure. And no calibration elevation until they got back to near- sea level in Oregon the second winter.

Reply to  Steven Mosher
February 24, 2016 12:39 am

That’s correct. minimum temperatures typically occur shortly after dawn when warming from incoming solar radiation exceeds cooling from OLWR.
It’s my contention that a significant part of minimum temperature warming results from increased solar radiation at the surface in the early morning resulting from decreased air pollution and lowlevel aerosol seeded clouds, from decreased vehicle pollution, crop residue burning, domestic burning of wood and coal, etc. This effect would be strongest at mid to high latitudes in winter due to the low angle of early morning sunlight at this time. And note the same cause would account for the 1945 to 1975 daytime cooling.
Australian BoM temperature data taken at fixed times supports this explanation with most warming occurring between the last night time measurement and and the first daytime measurement. Although with some warming in the afternoon, consistent with a general increase in solar radiation at the surface.

Reply to  Steven Mosher
February 24, 2016 12:46 am

The Min Max mercury thermometer (the Six’s Thermometer) was invented in 1780 and in widespread use by the early 1800s, and until electronic thermometers came along. You only need to read and reset it once a day.

Reply to  Steven Mosher
February 24, 2016 10:20 am

Good reply Mosh. Appreciate your comments. They often provide pondering material. Some of us remember calibrating thermometers in our old physics classes 50 years ago. Wonder if they still do that? Probably not. Interesting lesson in applying offsets WITHIN known boundaries and knowing your measurements could be precise but not accurate.

Steve Fraser
Reply to  Michael Carter
February 24, 2016 2:48 pm

@RACook: boiling point varies by atmospheric pressure. Pressure varies by altitude, but it’s not necessary to know the altitude… Only the pressure.

Lucius von Steinkaninchen
February 23, 2016 12:48 pm

It is interesting that in the movies Antarctica shows “strong” tendencies for both heating *and* cooling, depending on the month observed. Maybe that has some relation with the observed overall Antarctic ice increase?

February 23, 2016 12:52 pm

Conclusions? Well, the most obvious conclusion is that the “global” warming is not global at all. Instead, it is strongest at night in the winter in Siberia and Canada. I’m pretty sure the poor people in Murmansk are not complaining about that …
Another hypothesis is that the “global” warming is strongest where there are the fewest thermometers.
Nothing like homogenizing across 500 km to put your thumb strongly on the scale. A slice here, a dice there, and “What difference will it make?”
I am disappointed you went to Berkley Earth at all. I have viewed their scalpel method with theoretical disdain from Day One based upon what happens in the Fourier Domain.
(with links to other references)
Did you ever get a satisfactory answer from Zeke and others at BEST to the question you posed here?

Reply to  Stephen Rasey
February 23, 2016 2:15 pm

Another hypothesis is that the “global” warming is strongest where there are the fewest thermometers.

In North America the greatest warming was in the northern states and prairie provinces. This area has lots (hundreds) of airports and therefore met stations.

Reply to  commieBob
February 23, 2016 3:46 pm

[Even] In North America the greatest warming was in the northern states and prairie provinces.
You see? The fewest (i.e. lowest density) thermometers will be found in the Northern States and prairie provinces.
See the maps here:
Do not overlook the change in coverage from 1985 to 2005.
(Even if it is just missing location data in 2005, how can that be?)

Reply to  commieBob
February 23, 2016 4:33 pm

Stephen Rasey says:
February 23, 2016 at 3:46 pm

This makes no sense. The maps you link show almost no temperatures for the Canadian prairies. On the other hand, if you google metar saskatchewan you see about 40 airports for which local met data is available. Similarly, if you go to a map of Environment Canada Active Weather Stations at link you see a bunch. I didn’t check them all, it looks like more active weather stations than there are airports. WUWT?

Reply to  commieBob
February 23, 2016 4:59 pm

“You see? The fewest (i.e. lowest density) thermometers will be found in the Northern States and prairie provinces.”
Dont use GHCN data from 2008 as the post on climate audit did.
big piles of data are missing from GHCN old versions

Reply to  commieBob
February 23, 2016 8:47 pm

Typical Mosher, Drive by… leave no links.
Would have been so easy to provided a link to a better set of maps.. but Noooooo.
Some expert.

Reply to  commieBob
February 24, 2016 2:24 am

Stephen Rasey says:
February 23, 2016 at 8:47 pm

It would have been better if Steven Mosher had provided a link but at least he deals with the problem. Saskatchewan is full of official government thermometers. Are they being ignored or are the maps on ClimateAudit wrong?

Reply to  commieBob
February 24, 2016 8:08 am

Saskatchewan is full of official government thermometers. Are they being ignored or are the maps on ClimateAudit wrong?
I would bet on Both.
The maps linked to on ClimateAudit ARE wrong.
“Not only is it easy to lie with maps, it is essential!” — Opening line in “How to Lie with Maps.”
The real question is how wrong are they? Until I see better maps I’ll use what I have.
Also, a safe bet is that not all official thermometers in Saskatchewan are used. The “Great Dying of Thermometers” is no myth. There are official thermometers that are not being used.
Some were being used and are now estimated.

Reply to  commieBob
February 24, 2016 11:26 am

Map concentration of temperature stations – I would think it is a relative issue. Remember the Canadian population is 1/10 the US. Note also how the temperature stations have a perceived limit that runs on a SE to NW line that probably corresponds to the Canadian Shield. As you move west, there are more northerly stations.
I know that there are stations in places like Wollaston Lake, Stony Rapids and Uranium City, Cumberland House and so on but they are so disperse and some have somewhat discontinuous records. The old records from the Hudson Bay Company and the North West Company are probably more reliable. (I have used some of that kind of information in engineering work up there – though it was 25 to 30 years ago so maybe some of the new stations are better. )
This is a log HOUSE with a canvass flap for a door in Sandy Bay, Saskatchewan at about 35 below in the winter of 1978 next to the community’s water treatment plant that I was up there looking at. (see next post- browser has locked up) Consider how lucky we are to live in our insulated heated houses. The School or the HBC store frequently looked after temperature recordings in the north, or in this case there was the nearby Island Lake hydro-electric facility. I don’t know how official their records were but we got them for engineering purposes (and proofed with field work). The dam was built in 1920 and weather records were kept there – and still are through an automated station installed by EC in 2004. Previous records don’t show but they exist. I suspect that is the case for many locations. Record High for Sandy Bay – July 21, 1929 at 40C, record low for Sandy Bay January 15, 1930 at -46.1C. Interesting that the record High and the record low were within 6 months of each other.
A long winded reply to say that there is a lot more information out there than you will find on an official government site. Though the quality might not be good enough for climate, it is good enough for engineering.

Reply to  commieBob
February 24, 2016 12:17 pm

For Commie Bob – Sandy Bay house. To twist a phrase: “When you are up to your a$$ in snow, it is hard to remember you came to measure the temperature.”comment image?dl=0

Reply to  commieBob
February 24, 2016 2:58 pm

Wayne Delbeke says:
February 24, 2016 at 12:17 pm
… Sandy Bay house. …

The wiki article on Sandy Bay raises more questions than it answers. The situation in northern communities and on reserves is often really crappy and there are no easy answers.
Notwithstanding the above, a well chinked log cabin can be pretty cozy.

February 23, 2016 12:52 pm

I cannot reconcile mainly nightime increases in temperature and the CO2 causing warming models. Presumably, given the assumptions of the models, the increase should be general.

Reply to  Tom Halla
February 23, 2016 3:40 pm

CO2 warming occurs in the tropical troposphere. That has to be the place, because it is where CO2 intercepts the most outgoing IR. From there, the warmer CO2 itself emits IR which warms the tropical surface. From the tropics, the heat then spreads to the rest of the world. Now look at Willis’ globe : There is no warming at the tropics. So not only do we not have a tropical troposphere ‘hot spot’ but we also do not have any tropical heating of any kind. In any other branch of science, a failure like that would terminate the hypothesis.

Reply to  Mike Jonas
February 25, 2016 9:58 am

You don’t understand, though Al Gore said it is so simple?
For real, (C)AGW has never and nowhere been explained; and no-one will because the doom is only predicted with a model run, not with understanding directly the mechanisms in Nature.

Richard M
Reply to  Tom Halla
February 23, 2016 5:24 pm

If you accept negative feedback the answer is quite simple. During the day the warming increases convection which leads to more clouds and decreased high altitude water vapor. Both of these cool. At night the clouds have nothing to reflect (they warm) and convection usually decreases at night.
This maps in the summer warming because there is more day and winter cooling because there is more night. The bottom line is CO2 warms exactly when it helps the most and doesn’t warm when warming would be a problem.

Reply to  Richard M
February 23, 2016 6:24 pm

I am under the impression the IPCC models assume positive, not negative, feedback regarding CO2.

Reply to  Richard M
February 23, 2016 7:21 pm

My understanding is that water vapor is by far the most significant greenhouse gas. When water vapor is present in high enough concentrations it masks much of the radiative forcing effect of CO2. There is very little water vapor in very cold air so we would expect more CO2 warming.

Reply to  Tom Halla
February 24, 2016 1:09 am

The CO2 theory would predict most warming in the afternoon as maximum OLWR occurs then and hence maximum warming from DLWR per the theory.

February 23, 2016 1:00 pm

Thanks for a great post. A similar thing is happening with monthly minimum maximums that I have plotted, both in terms of extreme min/max and median mean max for western Canada from 49 N to 82 N – which of course are derived from the daily temperatures so not a big surprise.
Your plots are excellent and show anomalies a number of people have commented on before but your plots really show extremely well.
Thanks. I have filed this one away for future reference.
Now I’ve got to get back to cutting birch trees for firewood as I have burned through almost 4 cords of wood already this year. Get a start on next year’s during our current heat wave. It’s plus 2 C outside. 😉
February 23, 2016 1:02 pm

Lucius, I wouldn’t read too much into the Antarctic data. The trends you’re noticing are almost certainly artifacts from poor data coverage. In the early part of the period, explorers struggled to even survive on the continent. Automatic weather stations weren’t deployed until the 1970’s, but, even now, spatial coverage is so low that any trends are largely dependent on the validity of interpolations across wide expanses of unsampled ice sheet.

DD More
Reply to
February 24, 2016 11:16 am

Let Mosher speak from the past.
Steven Mosher | June 28, 2014 at 12:16 pm | [ Reply to the ” ” prior post – spelling in the original ]
“One example of one of the problems can be seen on the BEST site at station 166900–not somempoorly sited USCHN starion, rather the Amundsen research base at the south pole, where 26 lows were ‘corrected up to regional climatology’ ( which could only mean the coastal Antarctic research stations or a model) creating a slight warming trend at the south pole when the actual data shows none-as computed by BEST and posted as part of the station record.”
The lows are not Corrected UP to the regional climatology.
There are two data sets. your are free to use either.
You can use the raw data
You can use the EXPECTED data.
See how easy it is.
If a fully automated, staffed by research Or just call it something else.
Which reminds me – Willis did you use the ‘RAW’ data or the ‘EXPECTED’ data?

February 23, 2016 1:02 pm

Oops – “median mean max for western Canada” should say median min/max.

February 23, 2016 1:10 pm

After reviewing you analysis, all I can say is that if current trends continue, in the future children will not know what quilts are.

February 23, 2016 1:12 pm

The only thing i object to in this essay is:
“Conclusions? Well, the most obvious conclusion is that the “global” warming is not global at all. Instead, it is strongest at night in the winter in Siberia and Canada. I’m pretty sure the poor people in Murmansk are not complaining about that”
Actually Murmansk is on the Kola Coast and has a maritime climate only moderately cold and strongly influenced by the Gulf Stream and hasn’t experienced any appreciable warming, nighttime or otherwise. Change to “Yakutsk” instead, and You will be spot on.

Reply to  tty
February 25, 2016 10:00 am

If there is anyone here from Yakutsk, I sure they won’t object some warming. Like, -50C => -30C can only be an improvement.

February 23, 2016 1:16 pm

Thanks, Willis.

February 23, 2016 1:18 pm

People have been talking for years about the anomalous warming in Siberia. The best explanation is that in the Soviet era, heating fuel was distributed according to local temperature, and in remote Siberia the local authorities would exaggerate the cold (change the temperature data) to get better resources. When the Soviet Union collapsed there was no longer any incentive to do this, so they reported the real temperatures. Voila, instant warming!

Reply to  braddles
February 23, 2016 1:27 pm
Reply to  Tony
February 24, 2016 6:16 am

Thanks Tony, thats a useful resource.

Mike Macray
Reply to  braddles
February 23, 2016 4:34 pm

Well said Braddles, having spent some weeks in Siberia (Jan/feb 1992) your explanation matches my experience there. The ‘gaming’ of the system was staggering during the Soviet era!

Reply to  Mike Macray
February 25, 2016 10:04 am

Right, sounds overly probable in the Soviet system. But there has to someone who knows this if it is true.

Reply to  Mike Macray
February 28, 2016 2:57 am

“Right, sounds overly probable in the Soviet system. But there has to someone who knows this if it is true.”
Someone should apply for a grant to interview old-timers there. It would be amusing to see what reason the NSF gave for rejecting it.

charles nelson
February 23, 2016 1:38 pm

Because water vapour is the principle energy transporting substance on the planet. (atmosphere)
If we believe their data, then we can conclude that there is more water vapour reaching these frozen deserts, much of which will turn to ice or snow.

Dick McNider
February 23, 2016 1:38 pm

Nice post! Asymmetrical nighttime warming over day time warming has never been a signal that climate models produced. They always had Tmin rising at nearly the same rate as Tmax. So we are left with the biggest observed signal of global warming being unpredicted by the CO2 warming models. See McNider et al. 2012 JGR and a post here back in 2012. Also, models greatly under predict the high latitude warming. I suspect the model problem is too much mixing in the stable boundary layer so that they are not sensitive as they should be to land use changes or radiative forcing changes. My personal belief is that the high latitude warming in the NH is due to radiative forcing by aerosols that are destabilizing the stable boundary layers and producing warmer surface temperatures by a redistribution of heat not an accumulation of heat. At high latitudes in aerosols can be et warmers since the dimming effect is reduced by the low sun angles.

Reply to  Dick McNider
February 23, 2016 3:38 pm

See Bob Tisdale’s book: Tisdale – On Global Warming and the Illusion of Control – Part 1 – pages 270 to 286. The discrepancy between the models and “measured” is covered.
Though I am still wondering what is doing what. And as shown in Willis’ graphic, there appears to be circulation and geographic influences that don’t work bunching data into a pure north-south analysis. Seems pretty clear that the atmosphere, oceans, land, and geography influence what happens. Why it happens is another unanswered question for me.
I do know that I don’t know.
But I have been wrong once or twice before.

john harmsworth
Reply to  Wayne Delbeke
February 24, 2016 2:53 pm

Further to this, I read your comment regarding the records of 1929 being within 6 months of each other. As you are no doubt aware, both winter low temps and summer high temps occur during episodes of high pressure systems. I couldn’t say whether or why that time period would be predominated by highs but the 30’s in Western Canada were of course drought years and also show many of the record winter lows. Possibly even a few hardy souls at that time homesteading and living in sod huts. Hard to believe! Curious that intense highs would occur within 6 months of each other but dry conditions may have exacerbated that- with the lack of moisture resulting from patterns of North to South weather patterns as winds from the West tend to predominate but bring Pacific moisture and more moderate temps. I will also try to check my theory against these records as I believe that high pressure systems in this region are associated with full moon phase. Or perhaps I just howl at the moon more when it’s hot or cold.

Reply to  Dick McNider
February 25, 2016 5:39 pm

High latitude northern hemisphere warming since the mid 1990’s was driven by increased negative North Atlantic Oscillation. That is the opposite of what increased GHG’s should do to the NAO.

Dick McNider
February 23, 2016 1:40 pm

In the last sentence above should be – At high latitudes aerosols can be net warmers since the dimming effect is reduced by the low sun angles.

Alan Watt, Climate Denialist Level 7
February 23, 2016 1:42 pm

I prefer the term “melanin optimized”. I have exactly the amount of melanin my body requires — no more, no less. YMMV.

Reply to  Alan Watt, Climate Denialist Level 7
February 23, 2016 2:05 pm

That is fantastic.

Brett Keane
Reply to  Alan Watt, Climate Denialist Level 7
February 23, 2016 4:25 pm

That’d be right. Not many Tropics in the USA.

John M. Ware
Reply to  Alan Watt, Climate Denialist Level 7
February 23, 2016 5:25 pm

Indeed. I, mine own self, am neither melanin deficient nor melanin challenged. I’m merely an old white guy, tired of politically correct language, thought, and action.
I enjoyed the article greatly. It makes a lot of sense and brings together some of the stats I’ve seen in separate places over the past few years.

February 23, 2016 1:42 pm

Is there a relationship to the CO2 fluctuations in these regions during these seasonal time periods?

Reply to  Erik
February 23, 2016 8:09 pm

That’s a joke, right ?

February 23, 2016 1:44 pm

These patterns were generally forecast in Arrhenius’ 1896 paper.
“By means of these values, I have calculated the mean alteration of temperature that would follow if the quantity of carbonic acid varied from its present mean value … This calculation is made for every tenth parallel, and separately for the four seasons of the year. The variation is given in Table VII.
“A glance at this Table shows that the influence is nearly the same over the whole earth. The influence has a minimum near the equator, and increases from this to a flat maximum that lies further from the equator the higher the quantity of carbonic acid in the air … The influence is in general greater in the winter than in the summer … On account of the nebulosity of the Southern hemisphere, the effect will be less there than in the Northern hemisphere. An increase in the quantity of carbonic acid will of course diminish the difference in temperature between day and night.”

Reply to  Brian
February 23, 2016 2:03 pm

Hey, wait. Arrghenius says “carbonic acid.” According to Wankerpedia, carbonic acid is “a chemical compound with the chemical formula H₂CO₃ (equivalently OC(OH)₂).” This is not the same as CO₂. You can’t have carbonic acid without water present. Arrhenius must have known that. Was gibt?

Reply to  jorgekafkazar
February 23, 2016 2:32 pm

It’s an archaic term for CO2, along with “fixed air”.

Gard R. Rise
Reply to  jorgekafkazar
February 23, 2016 3:44 pm

Yep, Arr(g)henius uses the word “kolsyra”. (Lit. “coal/carbon acid”). As Brian says, when referring to carbon dioxide, the usage of the word is archaic. It is still frequently used about the fizzy bubbly stuff in your regular can of carbonated soft drink, though. I sometimes like to refer to carbon dioxide as “kolsyra” for fun; it tends to remove some of the scariness behind the supposedly planet-devastating CO2. (“Varför är ni rädda för kolsyra?/Why are you afraid of carbonic acid?”)

Gil Dewart
Reply to  Brian
February 23, 2016 3:05 pm

There are, of course, many other factors involved, but this is what would be expected on the basis of the radiative absorption spectrum of carbon dioxide.

Owen in GA
Reply to  Gil Dewart
February 23, 2016 5:23 pm

It is also precisely what would be expected from poor station siting and UHI.

Gil Dewart
Reply to  Gil Dewart
February 24, 2016 11:40 am

Of course, “other factors” could also include deliberate falsification, not unknown, for example, during wartime (is there any other?).

February 23, 2016 1:48 pm

So most of the warming is in places where there are very few stations and the interpolation is high? *feigning surprise*
I always say this when discussing regional warming/cooling patterns, but based on Mann’s logic when analyzing paleoclimate (Manngic?), modern climate change is modest at most and not global in scope.

February 23, 2016 1:50 pm

I’m wondering what the output would look like if you used temperatures instead of anomalies. . .

Bill Illis
February 23, 2016 1:53 pm

Night-time winter temperature increasing substantially in more polar locales would be mostly caused by increased cloud cover at night one would think.
I don’t think CO2 by itself would cause this much of a change (especially, nighttime versus daytime). [But also remember there is a polar amplification effect whereby the poles might react by up to 2X to what the global average is reacting – this is in part due to the fact that 1.0 W/m2 of increased forcing will have a greater temperature impact in areas that are colder simply due to the Stephan Boltzmann equations – which are correct equations].
So is there evidence for increased cloudiness (and/or at night).

February 23, 2016 2:00 pm

Maximum and minimum temp trends in the US; what’s not to like? Though it looks like Florida could stand to be a little warmer in January so someone please change the setting on the atmospheric temp control knob.

Curious George
February 23, 2016 2:09 pm

Just nitpicking on terminology. A northern winter night can last up to 180 days. The meaning of a daytime/nighttime temperature should be defined better.

Reply to  Curious George
February 23, 2016 2:34 pm

Only north of the Arctic circle.

Reply to  Curious George
February 23, 2016 2:41 pm

Actually the 6 month night only occurs at the pole itself. As you move from the pole to the equator the length of the longest night decreases.

February 23, 2016 2:31 pm

Looks to me like warming is greatest in those areas that you would expect to be both cold and dry.
Humid areas aren’t seeing much warming, which you would expect because water vapor is such a strong greenhouse gas.
What was surprising to me was that a hot and dry area like the Sahara should so little warming.

Reply to  MarkW
February 23, 2016 7:25 pm

There is far more water vapor in the air on a hot day in the Sahara than a cold night in the arctic. The shores of the Red Sea and the Persian Gulf have the highest absolute humidity levels of anywhere in the world.

Reply to  Thomas
February 23, 2016 9:47 pm

This has been bugging me ever since I passed through the Suez canal several times. 102 degrees in the shade,high humidity and still. Why doesn’t it rain?

Reply to  Thomas
February 23, 2016 11:35 pm

Hadley Cells …
And no mountains.

Reply to  Thomas
February 24, 2016 5:30 am

Siamiam, there are two important measures of humidity. Absolute humidity and relative humidity. Absolute humidity is the water content of the atmosphere. The relative humidity is the water content of the atmosphere respect to maximum water content, and maximum water content increases greatly with temperature. The poles have low absolute humidity and high relative humidity. When relative humidity goes above saturation rain is possible if nucleation particles are present. Hot deserts have high absolute humidity and low relative humidity. Water content, albeit higher, never goes above saturation point.

Reply to  Thomas
February 24, 2016 10:31 am

siamiam, the high humidity there exists only in the very thin surface layer. A short ways up, it’s very dry…..

Reply to  MarkW
February 24, 2016 5:22 am

More warming in cold dry areas is what you would expect from increased CO2, as in those areas CO2 has less competition from water vapor.

February 23, 2016 2:38 pm

I got to thinking about the distribution of the so-called “global” warming.

My impression of that excellent visualisation is to see a 0.1C trend and a bunch of natural variation.

James at 48
February 23, 2016 2:47 pm

Forced air central heating became much more common during the mid 20th century. Prior to that gravity fed systems (or worse) were much more the norm for most of the built environment. Other sources of energy flux at or near the ground have obviously grown exponentially since mid century.

Mark from the Midwest
February 23, 2016 2:59 pm

I suspect that global warming is strongest in Siberia and Canada due simply to human activity on the ground, when you open up 3000 acres for strip mining things tend to warm up, (urban heat islands aren’t the only kinds of heat islands). We also tend to measure temperature closer to where humans are active, rather than in remote/isolated areas.
I, for one, can attest to the differences attributable to a black asphalt driveway as opposed to a gray concrete drive here on the 45th parallel. Small changes can make a huge difference.

Reply to  Mark from the Midwest
February 23, 2016 3:57 pm

I don’t think so Mark. I think the effects are much bigger than the small contribution from humans.
I have looked at Environment Canada (EC) data from Alert (82N) to Eureka to Igloolik to Rankin Inlet to the Canadian border (49N). The same signal is in most locations. In fact, what I see in many cases is DECLINING maximum temperatures and LESS cold temperatures – so a convergence (In many but not all). In addition, geography, lake effects, ocean effects, elevation, etc, etc, etc all have influences. The Rocky Mountains cause a huge effect on what happens in British Columbia versus Alberta and as you move east the influence of Hudson’s Bay and the Canadian Shield appears to have a large effect. That’s weather of course , but isn’t long term weather climate? I have been alive long enough to have seen more than two 30 year “climates”. There is no way that I would consider the period 1980 to 2010 to be “CLIMATE” in my region.
My engineering studies told me to get the longest available record, and then go out in the field to proof it in case there was evidence that the data record was insufficient. And often the field proofing showed the data to be inadequate. For example, stream flow records and evidence of past flooding – usually the past flooding evidence was the real indicator.
My great grandmother was born the same year Canada was born – 1867. I trust her recollections of the climate in our region from when she was young a lot more than the last 30 year forecast from EC.
Bob Tisdale covered a lot of this in his book – On Global Warming and the Illusion of Control. Not promoting his book. However his section on DTR struck a cord with me as does Willis’ presentation.

February 23, 2016 3:19 pm

One of the first holes I saw in GHG “science” was the lack of any discussion of change in temperature variance as opposed to mean . It’s one thing to change a mean , but quite another to change the variance , that is , the inertia . Increasing CO2’s coupling of surface heat to the atmosphere could change the inertia , but only changing our spectrum as seen from outside can change the mean .

David L. Hagen
February 23, 2016 4:03 pm

Curious if the “Cold war”/fall of the USSR had a significant impact on apparent global warming. vis
Jason Calley commented:

Apparently, many of the cities in the northern Siberian region of the USSR were allocated coal and oil based on their climatic needs, i.e., on “how cold does it get there each winter?” The colder the city, the more coal and oil it got….so what do you think happened to their temperature measurements? Yup…outright fraudulently low records. Once the Soviets fell in the early 1990s, the reported temperatures became untied from resource allocations and there was a remarkable, uh, “warming” in the reports.

I have not seen any official reports either way on this though I have heard of the hardship caused by coal fired heat not being turned on until a prescribed date regardless of the temperature.

Reply to  David L. Hagen
February 23, 2016 6:22 pm

If true, terrific story. Nothing I would ever have thought of. Humans have a way of adapting.

February 23, 2016 4:17 pm

Honestly, I think it’s from all the persistent contrails acting as a heat blanket. Remember how temperatures at night went down after the 9/11 no fly time?

February 23, 2016 4:38 pm

ls it possible there has been a decrease in the amount of blocking highs present in these areas over the long term. With this happening it would likely lead to warmer nights.With a decrease in cold clear nights and a increase in cloudy and windy nights. This would also explain the lack of warming in daytime temps during the summer months, eg a decrease in hot sunny weather and a increase in cloudy cooler weather. What is also interesting is the cooling during Oct/Nov. This may suggest that during these months there has been a increase in high pressure. So allowing the cold to set in more early

February 23, 2016 5:01 pm

I’m confused. I thought the general standard for recording temps was max and min for the day. I assume there are some sites that may record more but what is the distribution of those sites? Just wondering where and how Berkley got the data.

John Harmsworth
February 23, 2016 5:35 pm

I live in Saskatchewan, in the middle of the illustrated max warming zone in western Canada. A number of issues come to mind that I think may be relevant. This area was quite sparsely populated in the early twentieth century. I wonder about the accuracy of readings taken in the middle of the night, in the middle of winter, at small stations. If those guys had to go out to check temps in the middle of the night, in the middle of winter, what is the probability that they caught the ovenight minimum? Not a chance. And doing it for joe stalin in siberia? Go ahead, shoot me!I have personally seen temps below minus fourty in DEC., Jan., and Feb. Not sure what they think in Murmansk but we would be OK with some global warming

Paul Coppin
Reply to  John Harmsworth
February 24, 2016 5:20 am

The guys who used to record the temps at the DEW line stations are on record as having said that many a night in the winter especially, readings were taken by the nose-out-the-door method that by actually bundling up and trudging out to the thermometer. This came out in the late 60s during some renewed interest in arctic and sub-arctic ecology. My own, “uncalibrated” anecdotal and semi-scientific observations from many years of field assessments of mammalian ecology leads me to easily conclude that the margins of error for temp readings is much, much higher than physicists and some mets would have you believe. There are so many uncontrolled situational variables to the site network that haven’t been adequately characterised, that while the data may show a trend increase in temperature, what has not been evaluated is the actual, rather than statistical, margins of error. in the network.
There is nowhere near enough discussion on the factors that perturbate the temp readings, and way too much emphasis on the temps themselves. We can show a trend increase in temperature. Whoop-tee-do. At this point, the discussion begins to fail dramatically. The physicists and climate alarmists fall back on simplistic textbook discussions that mumble about CO2, and other single cause excuses. At this point the response to an upward temp trend, in and of itself, should be no more than “so what?”. There is so much very big, very difficult, very expensive research to be done on the perturbers of the temps, rather the actual temps themselves, that an upward temp trend remains little more than a curiosity.

Paul Coppin
Reply to  Paul Coppin
February 24, 2016 5:23 am

That should have been “factors that perturb”. “factors that perturbate” somehow sounds un-social even if it more closely reflects what has been done to the data…

john harmsworth
Reply to  Paul Coppin
February 24, 2016 8:57 am

Exactly! Nowadays, these readings are taken remotely and logged by a computer so it’s no skin off anybody’s nose ( literally) or any other body parts

February 23, 2016 5:48 pm

Surely you recall E.M. Smith’s work on the great thermometer die off in Siberia about 5 years ago. The rising temps in that region are quite possibly due to substantial reductions in stations by latitude as the more northerly stations were eliminated from the GHCN. Even the Russians complained at the time.

Reply to  Fred Ohr
February 24, 2016 7:23 am

The satellite data also show that “global” warming was mostly in the North for the past 37 years.

Reply to  Willis Eschenbach
February 24, 2016 1:31 am

Willis thanks for the reply.
lts what has happened during Oct/Nov in Russia is what is the biggest clue for me that this maybe the case,
Because had there been a increase in blocking during this time. Then l would expect there to be cooling in northern Russia but warming in southern Russia. Due to the difference in how long the days are and how high the sun is.

Smart Rock
February 23, 2016 5:50 pm

This is good stuff but it’s not really news to those of us who spend a lot of time in northern Canada. You can’t really talk about warming, but you can say that (anecdotally and based on personal experience) the winters have been getting “a bit less cold” since the 1970’s. Except in the last few years (before the current El Niño) there seemed to be a bit of a reversal, with maybe a cooling trend emerging, e.g. more -40°C mornings than we’ve seen for a long time, Lake Superior freezing over two winters in a row.
All the above unsubstantiated by instrumental measurements!! Maybe I can get a job as a climate scientist!!

john harmsworth
Reply to  Smart Rock
February 24, 2016 9:03 am

Saskatchewan here and certainly I remember more severe winter storms when I was a kid in the 60’s. Lots of snow and flooding in the 70’s, hot and dry in the 80’s, back to cold and snowy in the 90’s, pretty decent winter weather through most of the 2000’s and finally- 2012 was one of the worst winters I have ever experienced and 2013 was very snowy and a little less cold and we had serious flooding again- to the extent that we have a few new shallow lakes that have persisted for 3-4 years now where no one ever identified lakes before in over 100 years.

john harmsworth
Reply to  john harmsworth
February 24, 2016 9:05 am

Very warm winter now with the current el nino. Next couple of years might be tough

Reply to  john harmsworth
February 24, 2016 12:26 pm

John – another Saskatchewan moment: do you remember the panic when Old Wives Lake was shrinking from a lake to a pool and people were panicking over “Global Warming”? Then they discovered tree stumps in the bottom of the lake indicating the lake bed had previously been dry for enough years to support trees – at least what passes for trees in that part of Saskatchewan. Remember the Palliser Triangle? What is old is new again.

john harmsworth
Reply to  john harmsworth
February 24, 2016 3:01 pm

Yes Wayne, and now Old Wives’ is risen to the point that roads are cut off in the area and local farmers are pleading for compensation to offset the many thousands of acres of land flooded out. Hang on though, help is on the way in the form of an incredibly long and snowless winter which may lead to a much drier 2016. Smart farmers around here just throw the dice every spring. Takes a real climate genius to spot the pattern here

February 23, 2016 5:53 pm

Surely you recall the work done by E.M. Smith on the thermometer dropout from the GHCN in Siberia. Many of the most northerly stations were eliminated. This may be the cause of the regional warming you have identified. Even the Russians complained at the time.

February 23, 2016 6:07 pm

Willis, you said “I got to thinking”. This has got to stop, you hear! Might upset the “conventional warmist vision”. Can’t have that. Enjoy your posts. Always interesting. -E

Reply to  ECK
February 23, 2016 6:09 pm

I meant, “conventional warmist wisdom”.

John Harmsworth
February 23, 2016 6:09 pm

Also, the historic high for our province was 47C or 115F in 1937. For those who think we live in igloos. Hot and dry in the thirties as well as the 80’s_ 1880’s and 1980’s. Post major el nino periods I would guess. Expecting hot and dry now that this el nino is disintegrating. I’m also wondering if the historical record supports the existence of a prior pattern of major el Nikos as per the sequence 1980, 1997, 2015

John Harmsworth
February 23, 2016 6:15 pm

El Ninos, sorry. Major el Niko is just a guy I served under in the Greek army.

Reply to  John Harmsworth
February 23, 2016 7:48 pm

Johb Harmsworth: I worked in Northern Saskatchewan for about 13 years, 4 in Prince Albert. I experienced many many winter days of minus 40 C in the late 70’s.

Prince Albert experiences a humid continental climate (Köppen climate classification Dfb). The coldest month on average is January with an average low of −25.2 °C, and July is the hottest month with an average high of 23.9 °C. The highest temperature ever recorded in Prince Albert was 39.4 °C on July 19, 1941. The coldest temperature ever recorded in Prince Albert was −56.7 °C on February 1, 1893.[22] With the fourth warmest month of September’s daily mean of 10.5 °C (50.9 °F) – 0.5 °C over the threshold for being subarctic, the Prince Albert climate is very cold for this climate type. Winter lasts five months of the year with January daily means of −17.3 °C (0.9 °F), causing a great temperature amplitude in comparison to the 18 °C (64 °F) mean temperature of July. The variability of the climate is further demonstrated by the brief transition zones with April recording both above and below 32 °C (90 °F) and −33 °C (−27 °F) respectively.

The late 1800’s were very cold in Alberta and Saskatchewan. I have old records for a number of places along with the old exploration records from the Yukon at that time. People were tough back then as they didn’t have fossil fuels to heat their houses or even insulation in the walls. I remember days on the farm when things froze inside the house and frost grew on the inside of the logs.
I have experienced 50 below C. I have nearly frozen to death on several occasions and bear the scars. I’d be happy not to experience it again. A couple of degrees warmer – big deal.
The old joke of Canada having two seasons isn’t too far from wrong:
“6 months of winter and 6 months of bad sledding.”
Go Riders.

john harmsworth
Reply to  Wayne Delbeke
February 24, 2016 9:16 am

Interesting to a fellow rider fan, wayne. thank you. The guy who said winter lasts 5 months was what we call an optimist. However, I have read that years with high snowfall levels actually tend to bring an earlier melt, as the ground temperature stays warmer throughout the winter. Snowfall levels in Southern sask are pretty variable but most years, what falls-stays, until spring melt. So some years we may get -30 temps with little snow on the ground and frost may penetrate 6′, whereas other years we get snow early and frost doesn’t get deeper than 3′. This has a significant effect on snow melt and ground thaw in the spring. Tricky phrase around here but-negative feedback! Tough winter means early spring- at least to some extent. Different farther north in the boreal forest as well. And- go riders!

Reply to  Wayne Delbeke
February 24, 2016 12:31 pm

John – many great memories of snow in Saskatchewan. When I lived in Regina we used to say we got the same snow 6 times a years. It blew in from Medicine Hat 3 times a year and then it blew back from Winnipeg another 3 times a year. Talk about albedo effects. Prairie Schooners was an apt name for those of who have seen the waves carved into prairie snow and tried to drive up a remote country road through those “waves”.

Pamela Gray
February 23, 2016 6:21 pm

I wonder if the start of extensive ice sheets is the presence of abnormal warmth? Did the Medieval Warm Period actually serve as the beginning stages of a plunge into an ice sheet growth? Does the blob’s presence help set this up? Does the pattern of warming nights actually tell us we have ice sheets coming? I know it seems to be an oxymoron that warm means cold but when it comes to a loopy jet stream warming parts of the Earth and colding other parts in a pattern eerily similar to the extent pattern of ice age ice sheets, it does make me go “hmmmmmmm”. My imaginative mind can see continued episodic El Nino waters that end up accumulating in the North Pacific Gyre causing that blob to be a fairly permanent part of the coastline, setting up a long term loopy polar vortex that buries the Eastern half of the US in a very cold and very deep ice sheet.
Basically then, is it the western warmth that heralds the eastern cold of growing ice sheet behavior?

James at 48
Reply to  Pamela Gray
February 23, 2016 6:31 pm

There may be something to this. Consider this. Looking at the West Coast, I don’t see much evidence that the Cascadian flora ever extended much beyond where they are now found. I also don’t see evidence of the California open and semi closed hardwood having extended much beyond where they are now. From this, I must wonder if in fact, during the Pleistocene, we were actually drier than now. Perhaps colder, yes, but also, perhaps, drier. And the current extents are actually Holocene features, wrought by a warmer and wetter climate.

John F. Hultquist
Reply to  James at 48
February 23, 2016 8:57 pm

With a large mass of water from oceans being converted to ice, it is not surprising to find some areas drier.
There are many regions of the world with much “loess” (wind blown silt) cover.
I’ve lived at the edge of one: (from Wikipedia): “The Palouse Hills of eastern Washington and northern Idaho is a fertile agricultural region based on loess deposits.
A search of ‘ images ‘ is advised.

Ian Wilson
February 23, 2016 6:43 pm

Forgive me if anyone else has said this already but isn’t the elephant in the room the fact that the warmer nights are restricted to the extra tropics in the winter months and the early months of spring. Surely, if CO2 was the cause of the increase in night time to day time temperature anomalies with time then it should be taking place at all latitudes through out the year.

February 23, 2016 7:26 pm

In the less populated areas, wood heated residences tend to cool off during the long winter nights as people go to bed early and burrow under covers rather than get up to feed the wood stove. Modern heating with propane or whatever keeps residences warm all night. So over time that is an extra heat source near the monitoring station that might amount to something. But more importantly, if you replaced the woodstove with oil or gas and aren’t chopping down trees in the immediate vicinity for wood heating, trees are now growing up and blocking IR paths to the night sky, making it warmer at night.

Paul Coppin
Reply to  Scott
February 24, 2016 5:42 am

That’s a difficult argument to make, in the context of subsistence heating. The amount of wood removed from the woodlot, relative to the replacement growth, isn’t going to change the net impact of the woodlot very much. Early users of wood for subsistence heating were usually quite well attuned to sustainability of the woods, much more so than urbanites. It’s not until you get into commercial clear-cut practices over a fairly large area that impacts are likely to be significant. Having said that, “butterfly hypothesis…” 🙂

john harmsworth
Reply to  Paul Coppin
February 24, 2016 9:20 am

Agreed, the area showing influence is sparsely populated and home to literally billion of trees. Human impact was and still is negligible.

February 23, 2016 8:00 pm

This is an excellent article. Very well researched and written and it makes that excellent point that the global warming of the past many decades hasn’t really been global.
I commented about the same phenomenon at your earlier article here at 6:50 pm.
“[R]ecent warming isn’t global at all. The same pattern can be seen in the UAH [satellite temperature] data. The data show no warming at the south pole, almost no warming in the southern extra-tropics, very slight warming in the tropics, slight warming in the northern extra-tropices, and several degrees of warming at the north pole.”
You wrote:
“I note in passing that while both the northern and southern hemisphere daytime temperatures dropped strongly from about 1945 to 1975, the corresponding drop in the nighttime temperatures is nowhere near as large. ”
It seems to me that increased cloud could be a cause of that. Cloud cools days but keep nights warmer.

February 23, 2016 10:12 pm

Unfortunately I have no link, but during the past few weeks I read an article in which Russian scientists said that the temperuture difference between Siberian cities and their surroundings has increased over time to 8 to 10 deg. C due to more and more leakage from the district heating systems. These scientists also said that probably the only place where global warming exists is in the IPCC offices and reports so could very well have been an article here at WUWT.

February 23, 2016 10:34 pm

Willis, interesting post.
When looking at your Figure 1, it seems that since 1970, nighttime temps have NOT increased more than daytime temps, not in the NH, but especially not in the SH. It appears it all happened between ~1920 and 1970. To me, this is your main find, because it really doesn’t make any physical sense at all …

February 23, 2016 11:39 pm

A positive trend of minimum temperatures in Arctic regions is a clear sign of UHI. Here in Sweden, the temperature outside the city of Uppsala can be up to 10C colder than within the city in cold and clear winter days with no wind. This effect can be present in relatively small cities and it is probably very difficult to eliminate this error from the temperature series.

February 23, 2016 11:39 pm

Kristian … That’s a good point.

brad ervin
February 24, 2016 2:24 am

The weatherman always attributed the much larger differences between day/night to cloud cover, as the clouds tended to “hold in” the heat much like a blanket would for bedtime. If CO2 acts as a kind of invisible (transparent) blanket then it would seem that if someone were to prove that day/night temps were less different then it may follow that CO2 is a possible culprit. This could be run on individual stations in many locations. The averages, in my opinion, are less valuable than many individual locations.
For example, the day/night temps of Venus don’t differ much (percentage wise) due to the makeup of the atmosphere.
WARNING: I am only an interested observer to these fascinating discussions. I am only an expert in….ah…well, I can’t think of anything just now…I’ll get back.

Reply to  Willis Eschenbach
February 24, 2016 8:11 pm

You wrote, “Increased CO2 would increase nighttime rates more than daytime … but I’m not sure why that would hit the extratropics hardest. Could be, though.?
CO2 could have more effect in extra-tropical winters because there would be less water vapor masking CO2’s greenhouse effect. This might also explain why a lot of the warming seems to occur in the middle of continents, away from humid coastal regions.

Reply to  Willis Eschenbach
February 25, 2016 5:54 pm
February 24, 2016 3:50 am

Good work, Willis.
This is something I wanted to look into but have not had time.
It the reason that Karl et al 2015 is bunk. The night time temperature record is not representative of the full 24h record, so using NMAT to “correct” SST is just adding bias to the data , not correcting it.
To prove the point, a similar exercise needs to be done using marine air temperatures MAT and NMAT to see a similar comparison.
ICOADS MAT, and hadNMAT are available from KNMI.

February 24, 2016 5:01 am

As always an interesting essay by Willis.
How does this look against the OCO-2 published here bu Erik Swenson?

Gary Young
February 24, 2016 8:26 am

During the Soviet era, it was common practice throughout Russia to report lower than actual temperatures in order to “game the system” and obtain a greater quota of heating coal. Some one else mentioned that many airports were added in northern areas. The significance was that they were the primary source of temperature data and with time subject to ever greater urban warming effects.

February 24, 2016 8:41 am

Your maps are great, but for many of us could probably be even better. We Europeans seem to be a bit in the shade, as it were! Would it not be possible to arrange for the edge of the plots to run roughly through the mid Atlantic? Or possibly the Pacific?
The reasoning is that there is virtually no data for these regions, whereas Europe, currently almost invisible, and presumably a region of general interest, would then become somewhere that could be studied. It would also keep the Americas in full view, so there’s little to be lost.
Just a thought. Robin

Reply to  Willis Eschenbach
February 25, 2016 2:44 am

I’ve not looked yet, Willis, but have total confidence that you will have done a great job. Thanks!

Joseph Murphy
February 24, 2016 8:56 am

In my layman (have no idea what I am talking about) opinion, it looks like heat is being transported from the tropics to the poles. We are doing a better job of observing that heat when it is over land and causing a significant variance (Canada, Siberia). I suspect the air temp over the northern oceans would have a similar pattern. The SH doesn’t have much for land stations to observe this movement and the graphs show this lack of stations rather than a lack of heat (potentially). I don’t think stations on Antarctica tell us too much about anything besides Antarctica. It seems to have it’s own climate cut-off from the rest of the planet. But, I would guess that warming in the SH would be concentrated over the southern oceans.
So the variance between the SH and NH could just be lack of data availability in key areas. Trying to measure such small changes over such a large area with such shabby data (not a jab at BEST) seems quit the daunting task.

john harmsworth
Reply to  Joseph Murphy
February 24, 2016 9:31 am

Oceans tend to convert heat to water vapour pretty effectively so if this heating actually exists- big if in my opinion, it may not show up as a temperature change. It would perhaps show up as greater snowfall in Antarctica, which whaaaat? There’s seems to be strong evidence of!

john harmsworth
February 24, 2016 9:33 am

Now I wonder if there is any indication of increased snowfall in the Arctic. If northern ocean temps are higher and water is more open, shouldn’t there be more snow?

john harmsworth
February 24, 2016 9:51 am

This is a very interesting finding, Willis. Do current climate models explain, predict or attempt to pretend that they foresee this specific development? I personally feel that these findings are very suspect, however, they do somewhat jive with what we see taking place in the Arctic.

February 24, 2016 10:28 am

@ Kristian February 23, 2016 at 10:34 pm
Actually, Willis’ Figure 1 seems to show …
1900 to 1940: Diurnal minimum temperature anomalies increased slightly faster than diurnal maximums.
1940 to about 1980: Diurnal maximum anomalies fell but minimums held steady.
After about 1980: Min and max anomalies rose at about the same rate.
Clouds tend to cool the days and warm the nights so increased cloudiness could be a cause of the 1940 to 1980 period.

February 24, 2016 12:45 pm

Thomas: I think Willis, Bob and you agree.
Personally, I think there are huge regional discrepancies but I am not capable of analyzing the data like they do so I will defer to my own biases.
I don’t know if Bob Tisdale will object to quoting him here from his book, if so, the mods can remove this:
(With apologies to Bob if you wouldn’t like this referenced)

Tisdale – On Global Warming and the Illusion of Control – Part 1 – Pages 285 – 286
For the period of 1988 to the present, climate models estimated that global daily minimum (Tmin) land surface air temperatures warmed faster than daily maximum temperatures (Tmax). This modeled decrease in the DTR (Diurnal Temperature Range) was trumpeted as being a “fingerprint” of human-induced global warming. The recently released Berkeley Earth Surface Temperature dataset show that the exact opposite happened. BEST global land surface air temperature data show Tmax warming faster than Tmin — that is, that the global diurnal temperature range since 1988 is increasing, not decreasing.
I also showed that climate models cannot simulate the observed rates of warming and cooling of global Tmin, Tmax and the DTR on latitudinal bases, for the period of 1988 to present, and for the period of 1950 to 1987.
Climate models were thus shown to be incapable of simulating what has been heralded as a “fingerprint” of human-induced global warming.

February 24, 2016 2:16 pm

@BC, February 23, 2016 at 4:17 pm:

Honestly, I think it’s from all the persistent contrails acting as a heat blanket.
Remember how temperatures at night went down after the 9/11 no fly time?

I don’t know what ‘persistent’ contrails are, but I often thought that contrails may have some impact.
Say, 5% of the sky are covered with contrails. At day, they reflect some light back to space and thus cool the
surface somewhat down. At night, the opposite happens, they keep some warmth from escaping to space.
Plus the jets propably warm up the air a bit, plus they leave a host of exhausts, say CO, CO2, NOx, SO2 and some particles in this layer of the atmosphere
Of course this all has some impact. But is it measurable? Is the effect bigger than the Hongkong butterfly flapping it’s wings?
But I think the contrail ‘density’ does not correlate to regions in Willis’ animations that show warming or cooling.
Regards, Lorenz

February 24, 2016 4:27 pm

If nothing else, this highlights the complex nature of the climate.

Or some of the (hidden) properties of the Berkeley Earth dataset used?

Bair Polaire
Reply to  TomRude
February 24, 2016 11:19 pm

If nothing else, this highlights the complex nature of the climate.

Or some of the (hidden) properties of the Berkeley Earth dataset used?

What would we expect to see if the CO2 theory were right? Uniform warming in all regions??
What would we expect to see if Willis Eschenbach’s theory were right? No warming in the tropics??

Mike M. (period)
February 24, 2016 5:20 pm

John Christy has long emphasized the point that daytime maximum temperatures are much more meaningful than nighttime minimum temperatures, at least over land. The reason is that a temperature inversion often forms at night, so the surface T is only representative of the lowest 50 to 100 meters. The daytime T is usually representative of the entire boundary layer (allowing, of course, for the lapse rate), with a thickness of several hundred meters up to 2 or 3 km. I think that you have provided more evidence in support of using just daytime max T.
Do you happen to know how much difference that would make in the temperature trend?

Reply to  Mike M. (period)
February 24, 2016 8:02 pm

Mike M.
I think the surface temperatures reported by most groups are the daily average. So, considering Figure 1. it looks like using only daily maximum temperature would cool the trend by a significant 0.3°C, which is about one third of the warming shown in, for example, the GISS temperature series since 1940.
Nightly minimums are also much more susceptible to localized, artificial, heating because man-made structures can slow nighttime surface winds, which reduces mixing, which decreases temperature.

February 25, 2016 9:38 am

I studied your first images again and there’s something I don’t understand:
The first image shows a temperature anomaly from -0.1 (1900) to around 1.0 (2015)
But the following animations only show temperature anomalies from -0.1 to 0.4. How does this sum up?
Regards, Lorenz

February 25, 2016 5:50 pm

With the data set starting around a cold AMO and ending on a warm AMO, there would be faster warming trends for the northern high latitudes.

Robert B
February 27, 2016 9:03 pm

Not a chance in hell that NH and SH are so in synch with each other. To see a 60 year period in the data but not the SH and NH out of sync like the Arctic and Antarctic sea-ice extent is a bit unbelievable,

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