From the “correlation may be causation, at least in this case” department comes a press release from the University of Delft about a student PhD thesis that seems unable to connect the dots about length of day and solar energy absorption on Earth. Reading his thesis though, especially the preface it seems that UD has churned out another potential SJW, because oddly, this old news clip is in the preface:
That aberration aside, the PhD thesis seems quite detailed, spanning over 170 pages.
Here is the Press Release from UD:
Increasingly accurate picture of accelerating rise in sea levels
Days become slightly longer as land ice melts
Rising sea levels are affected by all kinds of different factors, most of which we can now effectively unravel and explain almost everywhere in the world. This is according to TU Delft researcher Thomas Frederikse, who has also established that the average rise in sea levels worldwide is accelerating. Moreover, the days on earth are becoming slightly longer… Frederikse will be awarded his doctorate on Monday, 19 March.
Regional
The increase in sea levels is not the same across the world: there are significant regional differences. Thomas Frederikse has conducted a thorough study of the data from the last decades (1958-2014). ‘All kinds of factors play a role: for example, the melting of land ice, the expansion of seawater caused by increasing temperatures, but also the use of groundwater and the storage of large quantities of fresh water in inland reservoirs. Another factor is what is known as glacial isostatic adjustment (GIA). This is the ‘rebounding’ of the land after the ice ages.’
Average
‘Because of all these factors, there is no single place on earth where the sea level exactly matches the global average. In order to understand regional patterns and be able to develop regional future scenarios, a good understanding is needed of the relevant underlying processes and associated regional patterns’, says Frederikse. ‘It is now possible to estimate local and global changes in sea levels accurately with the help of satellites. Before satellites, we only had local sea-level measurements in a limited number of places at our disposal. In this dissertation, I have been able to confirm that the sea-level rises measured in the decades before satellites can be effectively explained by the sum of all relevant physical processes.’
Trend
‘The rise in sea levels was studied for two coastal regions and on a global scale. The physical processes that we took into account were the loss of mass in glaciers and ice caps, the depletion of groundwater reservoirs, the retention of water by dams, GIAs, changes in the specific volume of seawater, local wind effects and changes in air pressure. We were able to unravel and precisely model all of these different influences for the North Sea, for example. In the period 1958-2014, the rise in sea levels in the North Sea amounted to ‘just’ around 8 cm. This is comparable to the average worldwide increase over the same period, which is approximately 1.5 mm per year, but the underlying causes are different: the melting of glaciers and Greenland have hardly any effect here, but when it comes to Antarctica, we get the full blast. This is not good news for us, because the ice cap in Antarctica could lose a lot of mass in a future warmer world.’
Acceleration
‘We are now able to explain sea-level rises in almost all oceans’, explains Frederikse. ‘Although the issue of rising sea levels is complex, we now have a good understanding of most factors at play. As a result, the models and predictions are better, which is good news. The picture emerging is of rising sea levels and a significant acceleration in that process (with considerable regional differences). This is not only based on modelling; the measurements demonstrate that it is already happening. That is the bad news.’
Figure skater
Frederikse’s research also reveals something else: days on earth are becoming slightly longer (around 0.2 milliseconds in the last 25 years) as a result of the melting land ice. This is causing mass (in the form of ice) to disappear, primarily in Greenland and Antarctica, which moves in the direction of the equator as liquid water. This results in slight changes in the distribution of the earth’s mass. ‘Just like a figure skater who stretches out their arms during a pirouette, it makes the earth turn slightly more slowly, and the days therefore last slightly longer now.’
Here is the part I found interesting:
Global sea level can not be described by a linear or quadratic trend with white noise residuals. One of the reasons why simple functional models are not well-suited to describe the global sea-level curves is the presence of temporal autocorrelation, which manifests itself as large decadal and multi-decadal oscillations in the curve. This property of auto-correlated residuals is well-known, and results in substantial uncertainties when estimating long-term trends and accelerations from tide-gauge records and reconstructions (Dangendorf et al., 2014b; Haigh et al., 2014). All global reconstructions in Figure 1.2 show decadal variability, although the variability is far from consistent between the methods. Hence, it is difficult to assess whether this variability is a real phenomenon in global-mean sea level or an artefact of the sparse observations. Some work suggests the presence of long-term oscillations with a fixed period in global sea level (Chambers et al., 2012). The attribution of this variability on a wide range of scales to individual processes still forms a challenge.
- Which fraction of the observed sea-level rise has an anthropogenic cause?
Since sea-level change is not a recent phenomenon, as visible in Figure 1.1a, one key question is which part of the observed rise can be attributed to human causes, and which part is due to natural fluctuations. Using statistical values or earth system models, various studies find widely-varying fractions of observed 20th-century sealevel changes that can be attributed to anthropogenic activities (Slangen et al., 2016; 1.3. The open questions about global sea-level changes during the 20th century Dangendorf et al., 2015; Marcos et al., 2017; Kopp et al., 2016), although most are in the order of 30 to 60 percent.
One of the problems for estimating this fraction is the inability of earth system models to reproduce the observed sea-level changes over the 20th century: the observed sea-level rise substantially outpaces the rate predicted by the earth system models (Slangen et al., 2016, 2017a), and hence, attributing the changes to specific changes in the forcing of the earth system remains challenging.
- We have estimates of many individual processes that cause sea-level changes. Does the sum of these processes explain the curves shown here?
One of the main arguments that led to Munk’s enigma is the inability of the ocean volume and mass changes to explain the reconstructed sea-level rise. When ice sheets and glaciers lose mass, a net shift of water from high latitudes towards the equator affects the earth’s dynamic oblateness, and hence, its rate of rotation. The increase of the earths moment of inertia around its axis of rotation increases when ice sheets and glaciers lose mass, resulting in an increase of the earth’s length-of-day. Specific phenomena, such as solar eclipses, critically depend on the length-of-day, which allows for an accurate reconstruction of its changes back in time. The observed increase in the length-of-day over the 20th century cannot be reconciled with the amount of ice mass loss required to explain the reconstructed sea-level rise (Munk, 2002; Mitrovica et al., 2015). However, as already noted above, recent reconstructions suggest a substantially lower sea-level change over the twentieth century (Hay et al., 2015; Dangendorf et al., 2017).
Here are the figures:
The full paper is here: https://repository.tudelft.nl/islandora/object/uuid:0912fa9b-4442-4a6b-8831-db5ec2603cb8?collection=research
One graph that is missing from the paper is one showing changes in Length of Day and temperature. Since it was discussed in the paper, but wasn’t included, I’ll show one. This one is from NASA in 2011:
The article that uses the graph says:
The researchers found that the uncorrected temperature data correlated strongly with data on movements of Earth’s core and Earth’s length of day until about 1930. They then began to diverge substantially: that is, global surface air temperatures continued to increase, but without corresponding changes in Earth’s length of day or movements of Earth’s core. This divergence corresponds with a well-documented, robust global warming trend that has been widely attributed to increased levels of human-produced greenhouse gases.
But an examination of the corrected temperature record yielded a different result: the corrected temperature record remained strongly correlated with both Earth’s length of day and movements of Earth’s core throughout the entire temperature data series. The researchers performed robust tests to confirm the statistical significance of their results.
“Our research demonstrates that, for the past 160 years, decadal and longer-period changes in atmospheric temperature correspond to changes in Earth’s length of day if we remove the very significant effect of atmospheric warming attributed to the buildup of greenhouse gases due to mankind’s enterprise,” said Dickey. “Our study implies that human influences on climate during the past 80 years mask the natural balance that exists among Earth’s rotation, the core angular momentum and the temperature at Earth’s surface.”
Read the full article here, where they suggest internal Earth processes are responsible for LOD change, with a hat tip to Svensmark:
https://www.nasa.gov/topics/earth/features/earth20110309.html
It seems to me that Frederikse missed a big opportunity to link LOD to increased temperature, and to increased ice melt resulting in sea level rise.
Off topic but perhaps more on point with weird weather patterns across the planet.
https://youtu.be/CRKXlF2dqlg
I’ve always read that the longer term increase in LOD was due to tidal drag of the moon. Strange not to see any mention of it here.
So why is he looking at air temperature? 70% of the surface is water and marine air temperature is dominated by SST. In fact SST is often taken in preference as a proxy for MAT. And once again you can not meaningfully “average” or add temperatures of different media. If you are looking for physical causes, you have to stick to the laws of physics.
So he thinks that he “knows” how much of the warming of the air/water chimera temperature is due to AGW. Cool. He then “corrects” for this and finds the residual matches better to LOD. So the conclustion is that AGW does not melt ice and does not affect LOD.
.
This looks like a formal proof that AGW is a non physical myth. .
short term changes in LOD are strongly influenced by atmospheric angular momentum. In particular large scale shifts of water mass from the surface ( liquid state ) to upper troposphere : 6-8km. Usual ice-skater analogies apply for the physics-challenged reader. Beginnings of El Nino events in Nino 1.2 region bear a striking resemblance to dLOD.
d/dt(LOD) is inverted for visual comparison with SST in Nino 1.2 region: 10S-0S ; 90W-80W
Greg, of course they “know”.
http://www.ipcc.ch/publications_and_data/ar4/syr/en/fig/figurespm-4-l.png
How much is due to changes in the amount and location of groundwater storage?
“As a consequence, there is no single location on the earth that is subject to the global-mean sea-level change.” from the abstract.
Don’t get it!
Incidentally the newspaper clip is from an area close to where I grew up.
Knowing the standard of journalism here plus the date of the clip, I wouldn’t give too much significance to it.
Cheers
Roger
Another thing I wondered when I read this post is whether the slowing of the Earth’s rotation could result in less centrifugal force, which would allow the oceans to slump a bit compared to the faster rotation? Does that offset the additional water from the melt?
Just curious.
The change in the length of day is only 0.2 milliseconds. I suspect that the change in centrifugal force is too small to measure with anything we’ve got at present.
But it’s plus 0.2 milliseconds, not minus, isn’t it?
So you admit it. Human life expectancy has gone down as sea level has risen. Finally, the best evidence to date of the threat carbon poses to our, and all organic life on earth.
This is a champagne day for scientists, and a multiple whiskeys—neat—day with a sympathetic bartender for denihilists. As a supporter of the former, I wouldn’t like to trade places today.
0.2 milliseconds multiplied by the population of the Earth is over two weeks. It’s worse than we thought.
There is no such thing as centrifugal force, there is only centripetal force. The former is a “fictitious” force in the opposite direction of centripetal force.
JimG1,
“negative pressure” is also a fictitious construct but, as I learned while trying to master respiratory medicine, they’re part of the language. Fighting them on pedantic grounds is futile.
@ JimG1
centrifugal force is fictitious in the sense that it is an adjustment for another fiction which is viewing a rotating , non inertial system as though it was static. The force causing the oblateness of the Earth and the equatorial bulge is simply linear inertia.
Coriolis is another “fictional” force but it does make the ocean gyres go round, cyclones to form and weather patterns to loop around.
Unless you have the metal agility to see a 3D world spinning and intuitively anticipate the impact of linear inertia in all particles all going at different speeds in different directions, you’d do well accept the reality of these “fictional forces”.
hey, do the maths. 2ms in in 25y , what’s that as a percentage ?
“whether the slowing of the Earth’s rotation could result in less centrifugal force, which would allow the oceans to slump a bit compared to the faster rotation?”
Centrifugal force is the reaction to centripetal force. Newton’s 3rd law, centripetal is the action, centrifugal is the reaction. Slower rotation results to less centripetal force:
F = m r w^2
where: F is centripetal force, m is mass, r is radius, w is angular velocity
The effect of rotation on sphere is to bulge at the equator. Slower rotation, less bulge. The bulge is due to less compressive force:
G = F + C
C = G – F
where: C is compressive force, G is gravity
Assume G is constant. Less F means more C so the magma in Earth’s interior gets more compressed and less bulge at equator
Isn’t it due to the drag from all those windmills?
Brilliant Ian!
No, the atmosphere rotates geosynchronously. I would find it hard[er] to stand upright if the Earth’s gaseous envelope circumnavigated the globe, relative to me, on a daily basis. But then I live in Ecuador. Your knottage may vary.
“the atmosphere rotates geosynchronously. ”
Then why do the major weather systems persistently advance across the N. Alt. from Canada to Europe ? The atmosphere is not static relative tot he fixed stars but neither is it really geosynchronous.
“Then why do the major weather systems persistently advance across the N. Alt. from Canada to Europe ?”
In search of a
betterworse lifestyle for themselves and their kids“No, the atmosphere rotates geosynchronously.”
This is absolutely false. As the “solid Earth” changes its axial rotation rate, Atmospheric Angular Momentum changes, giving rise to a very strong correlation between the two over high frequency oscillations like ENSO. In part, this is explained by simple conservation of angular momentum. Over longer periods there is evidence of differential torque applied to atmosphere and “solid Earth”. It means in any event that the RELATIVE velocity of the atmosphere changes as LOD changes, and this can be most clearly seen in the changes of equatorial wind speeds – or in the correlation between AAM and LOD that I mentioned above. This is not even controversial.
Because of the enormous difference in moment of inertia between the “solid Earth” and the atmosphere, the small changes in axial rotation rate of the solid body have a disproportionately large effect on atmospheric momentum. The total energy exchanged between the two is of order 4*10^22 joules over the quasi 60 year period observed in climate indices – a non-trivial but generaly ignored oscillatory addition and subtraction of energy into the climate system.
Thanks kribaez. I stand corrected. But at least I stand—a miracle that kept me awake at night as a child, back when I assumed the atmosphere was a free-floating spherical layer surrounding, but entirely independent of, the daily-revolving geosphere upon which anyone who wishes to stand must perforce plant his his or her feet.
I think the original wind-farms joke (which we are at serious risk of analysing to death) only makes us laugh because our intuitive selves never really grow out of that childlike model of the atmosphere as something “stationary relative to the fixed stars,” as a previous commenter put it.
So although I think you’re taking my response to that joke more seriously than necessary, I still wanted to thank you for teaching me quite a few things.
Cute but it’s actually due the tidal drag of the moon on the liquid and solid earth. Mainly the friction of the tides encountering continental borders. Something that the authors do not seem to account for.
The hypothetical tidal “bulges” are pushed slightly ahead of the earth-moon line of centres by interaction with the continents. The lunar gravitational field then pulls back on the eccentric mass acting to slow the earth’s rotation.
This causes a long term trend in LOD.
The counter part of this is the acceleration of the moon’s orbit which further leads to an increase in the Earth-Moon distance. circa 4cm/y from memory. This is a transfer of angular momentum from the Earth rotation to the E-M couple’s angular momentum.
Maybe this is somewhere in the 720 pages but did not get covered here.
The continents have an impact, but the advanced tidal bulge would exist regardless, due to the viscosity of the waters. The bulge leads the Earth-Moon line because the rotation of the Earth is faster than the revolution of the Moon. If it were the reverse, the bulge would lag, and the Moon would spiral in, rather than out. This happens on Mars’ near moon, Phobos. It revolves every 7 and a half Earth hours, while a Mars day is a little longer than an Earth day. Phobos is spiraling in at a rate of about 2 cm/year.
Why should we expect a smooth, continuous correlation with melting and temperature when Ice melts at a specific temperature? That is, temperatures might increase for decades before it crosses the threshold of melting in very cold regions around the poles or at high elevations at mid-latitudes. One would then expect a pulse of meltwater when none existed previously. Methinks this is a little more complex than presented.
Excellent point Clyde as usual.
A “pulse” of meltwater? You patently ignore the latency inherent in the latent heat of H2O at the liquid-solid boundary. Is this blatant on your part, or merely fragrant?
Clyde, you inherently assume that all glaciers are at the same height and latitude and thus all at the same temperature. If that were the case your idea of the melting pulse could be logical.
However, since the conditions of hitting the melting point of ice will progress slowly up hill and further north, the melting will be progressive and average out, not occur as a pulse.
” I have been able to confirm that the sea-level rises measured in the decades before satellites can be effectively explained by the sum of all relevant physical processes.” This seems to be a “duh.” The challenge is in knowing what all the relevant processes are, and the precise value of each.
Looking at this quickly, the NASA dataset for temperature seems to be their adjusted one, not a raw dataset for temp – which might throw off the assumptions a bit. But an interesting conclusion.
I recognize the profile of the LOD trend line. It matches with my view that the shift points for warm/cool trends of around 30 years apiece are from 1885/86 cool to 1915/16, warm to 1946/47, cool to 1976/77, warm to 2006/07. Take a look at Hadcrut 3 for an example of close correlation across the entire profile shown on the graph. Also, the LOD is in synch with global temp changes in the oceans, imo. Amazing,
If you bring mass from the heights to sea level, you should speed up rotation! the little bit that adds to oblateness would ameliorate the speed up but not erase it (Aren’t the Himilayas, Alps, Andes, Rockies considered the most vulnerable). This also goes for removal of ground water. Dams would slow rotation.
I’m totally confused about the temperature/corrected temperature stuff. It looks to me that had we gone with uncorrected temps ? Los would fit the models!!
dang Samsung LOD not Los
It depends on how far those “heights” are from the equator.
Gary,
The Earth is only approximately spherical. There is 21 km difference between the Earth polar minimum radius of about 6,357 km and the equatorial maximum radius of about 6,378 km. This 21 km is much higher than the height of the mountains you mentioned. So the distance of the melt water originated from the mountains and the Earth center will be increased.
The number that matters is how far the mass in question is from the axis of rotation.
Compared to that 3000+ kms, the height of the mountain is pretty meaningless.
If a glacier melts some of the water will move towards the poles, and increase the rotation of the earth, and some of the water will move towards the equator and slow the rotation of the earth.
The further north a melting glacier is, more of it’s water will end up closer to the equator. A melting glacier on the equator (don’t laugh, there are a couple of small ones), will cause a increase in the rate of rotation.
The other factor is the shape of the ocean basins. That also determines how the new water will spread out.
Note: I have made no mention of, nor did I intend to get into, whether or not any glaciers are actually melting.
I’m sorry Gary, no offence was meant and I must admit that I was wrong. Oblateness of Earth has nothing to do with slowing down of rotation as a consequence of glaciers melting. It was a mistake, my mistake.
So, from the beginning. I have made some approximate calculations. The result is that the latitude of the melting glacier is important in this regard. If it is between (about) 15 degree N and (about) 15 degree S then the Earth rotation will speed up. On the other hand, if the melting glacier is located norder than (about) 15 degree N or southern than (about) 15 degree S then the Earth rotation will slow down. As far as I know, majority of the melting glaciers are located so, meaning the Earth rotation slows down a little because of the melting.
Once again, it was a mistake from me to think that the shape of the Earth plays a role in this process.
MarkW is right. Thank MarkW for paying attention.
Tari, if the earth was a perfect sphere, than water shifting towards the equator would have slightly less impact than it actually does.
However the difference between being 3,178.5 miles from the axis and being 3,189 from the axis is pretty small.
Km, not miles. Sorry all.
Guys
If you move a big mass (melted ice) from poles to equator, the effect is slowdown in Earth’s rotation. The cause is more mass at equator will move the center of hemispherical mass away from the axis of rotation, this distance is the radius of gyration. Mathematical description:
w = L/I
where: w is angular velocity, L is angular momentum, I is moment of inertia
I = m k^2
where: m is mass of sphere, k is radius of gyration
k will increase if you move mass from poles to equator and w will decrease because L is constant due to conservation of angular momentum and m is also constant (mass of Earth)
Gary P
The water flows from the melting mountain tops and goes to the oceans. The Earth is rotating so the added mass raises the oceans a little. That ‘little’ at the equator causes the surface to fling a little more towards space, increasing the girth of the Earth and reducing the polar radius. As the radius of the surface has been increased, and angular momentum must be conserved, the Earth slows down, hence the analogy of the spinning skater opening their arms.
All melted ice, no matter from where it originates, ends up pushing the surface at the equator a little outwards. At the same time, slowing down rotation increases the height of the Arctic Ocean which is ‘flattened’ by the rotation – about 22 km top and bottom. If the Earth stopped rotating, the Arctic Ocean would theoretically increase in depth by 22 km. However, there is a twist to that simplistic notion.
The surface of the Earth follows very closely, the oblate sphere’s outline, meaning that if the Earth really did stop rotating, the continents and plates would slosh upwards 22 km and sea level would not change much at all.
This effect, the realignment of the oceans to the oblate outline, can be observed to take place when the planet is struck by a high velocity meteor at high latitude. It makes the Earth wobble, causing a permanent change in the tilt by the time things settle down, based on the impact energy and mass re-distribution. The effect on sea level at the equator is nil, at the poles, nil, but sea level at 45 Deg N and S changes about 1000 ft overnight for an axial tilt of 0.5 degrees. There are indications on the E shore of Ireland and E Australia that large changes in sea level have occurred suddenly at least twice since since 3300 BC. The folklore about the destruction of the civilisation living on what is now the Irish Sea and the escape of the King to an island to the north survive as a description of what may have been one such event.
The tilt of the Earth can also change suddenly for others reasons. Don’t be too surprised if you wake up one morning and the North Pole is in Siberia.
Believe it or not some water on Earth is moved from the oceans and deposited at altitude. And last I looked there are sedimentary rocks high up in some of the mountain ranges. Aren’t we in a net sum game here? And the numbers are so frigg’n small isn’t this just playing with your navel?
And the two sea level graphs. The one on the left is in meters and the one on the right is in mm. I suggest if you change the scale on the right to meters, you basically have a flat line, and this sea level rise thing goes away.
A glacier in mid latitudes, when it melts, some of it’s water will go towards the poles and cause an increase in the rotation rate.
Some of it’s water will go towards the equator and cause a decrease in the rotation rate.
Which effect predominates is determined by the latitude of the glacier and the shape of the ocean basins.
(For example, if the equator was say, 90% land, then sea level increases would have much less impact on the rotation rate.)
Gary
The earth’s “oblate spheroid” is about 21 km larger in radius at the equator than at the poles (https://en.wikipedia.org/wiki/Equatorial_bulge). The “heights to sea level” argument depends on the latitude of the changes. Assuming most of the melt comes from polar latitudes (which are thousands of km closer to the axis of rotation), this single factor would tend to slow rotation (a la the figure skater).
Ice melt is insignificant compared to the transfer of angular momentum from the earth to the moon. The moon’s distance from the earth is increasing +38.247±0.004 mm/y due to tidal acceleration https://en.wikipedia.org/wiki/Tidal_friction#Earth%E2%80%93Moon_system
…
This increase in distance is much more pronounced that sea level rise.
I thought the authors had already factored that out when they did their calculations.
Well gee whiz. There I have always been told that the momentum lost to the earth’s rotation is going into the moon’s orbital momentum. Might be a correlation there somewhere who knows.
Something here doesn’t fit with other findings, especially archaeological ones. There are old towns found in off the coast in the Mediterranean in 20 foot of water that are maybe 1800 years old. There is a Native American burial “pond” found in 20 foot of water off the coast of Florida – they think its 7,000 years old.
On a graph above (Kopp et al., 2016), they show the maximum amount of sea level change over 3,000 years to be about 7 inches. Now some of these old sites likely “dropped” due to land subsidence, but you can’t explain away all of these sites that way. Obviously the sea has risen more than 16 inches over 7,000 years, and likely more than 7 inches in 3,000 years based on sites found under water.
I guess I’ll go find his paper and try to understand how they came up with these estimates.
Oh… They “modeled” the sea level rise based on temperature reconstructions. No wonder it makes no sense. Why use real data when its so much easier to just make some up?
Causes for variations in the terrestrial length of day (LOD) addressed more comprehensively, persuasively and criticallyl in the seventh part of the series of eight “Nature Unbound” posts on Dr. Curry’s site, Climate Etc., on January 21 of this year by a skeptical researcher whose nom de plume is “Javier.”
https://judithcurry.com/2018/01/21/nature-unbound-vii-climate-change-mechanisms/
In it he writes, “Our ability to measure very slight fluctuations in the Earth’s speed of rotation, that result in micro-second changes in the length-of-day (LOD), has produced some interesting evidence on how climate-related phenomena affect the rotation of the planet. The rotation of the Earth is being constantly slowed by the friction of the tides with the ocean bottom, but once this secular increase in LOD is accounted for, excessive variations of the order of 1 millisecond in LOD are taking place in a scale from hours to decades.”
He continues, ‘The evidence shows that atmospheric angular momentum (AAM) changes are responsible for LOD changes at certain time scales, but not others. Two mechanisms are proposed to explain the imposed torques that transfer the angular momentum between the atmosphere and the solid Earth. One is due to surface wind tangential stresses across the surface, causing friction torques. The other one is due to mountain torques caused by surface pressure variability near areas of high topography.”
Several pages covering recent (and somewhat more sensible )findings related to LOD follow. They are worth perusing if you haven’t already.
Thanks, Tom.
So they are saying when LOD increases (earth ‘s rotation slows ) the temperature trend is up and when LOD decreases (earth’s rotation speeds up) the temperature trend is down?
Correct?
That actually makes sense. With longer daytimes/nighttimes, AVERAGE insolation from the sun would stay the same, but with daytime temperatures higher with longer days and nighttime temperatures lower with longer days. Temperature EXTREMES would increase, but since temperature is proportional to the fourth ROOT of radiation, average temperatures would go down.
[The mods believe all the recent changes with Daylight Savings Time puts the excess energy into the banks, rivers, and deep seas. .mod]
“Temperature EXTREMES would increase, but since temperature is proportional to the fourth ROOT of radiation, average temperatures would go down.”
There’s no time in SB law. It’s a power flux (W/m^2). Increasing exposure time doesn’t increase the power flux. For time-dependent temperature, use specific heat formula:
Q = C m dT
dT = Q/(C m)
where: dT is change in temperature, Q is net heat flow, C is specific heat, m is mass
Q is time-dependent. Q = heat flow rate x time
Good point. 1 ms dark, 1 ms light. Energy evens out.
Not quite, as the temperature difference increases, radiation increases at the 4th power.
What’s with the scaling of the temp anomaly on the right side of the graph?
Why do LOD changes precede T changes? If ice melting is the cause, then it should be other way round… Also, this graph shows, that anthropogenic warming is pure fiction and the red line is the real world T.
Figure 1.1 says that sea level has varied only about 200 mm in 3000 years. Is that what he is saying? 8 inch variation in 3000 years?
The length of day change is just a couple milliseconds. How is that going to seriously affect temperature?
Iceberg Rafting?
‘Continental ice launched at high latitudes becomes water in equatorial seas, and the Globe’s radius of gyration increases as a result.
‘Angular momentum must be preserved; hence the Globe slows down, and length-of-day increases. But the oceans are not glued to the earth’s crust, and the linear momentum of the great ocean flows must also be preserved. The flow most vulnerable to even minor adjustments in trajectory relative to its basinal boundaries, for reasons of geometry, is that which carries tropical heat via the Atlantic into the Arctic.’
R j Foster
Another question:
This website regularly presents good articles seemingly showing SLR is not accelerating.
This article says that it is, and so do others.
It seems to me that this is a question that ought to be definitively demonstrable from the data, at least for each of the various data sets. So why is there argument about it? Either it has accelerated or it has not. If “climate science” can’t answer that basic question, then what kind of science is it?
“Reconstructions based upon tide gauges” are said to be accelerating. The key word is “Reconstructions,” – read: altered data!!!
If you look at the actual tide gauge data, they show no acceleration ANYWHERE in the world. Robert of Texas asks: “Why use real data when its so much easier to just make some up?” The answer is if they used “real” data that was measured, verified, and validated, they would NOT show the accelerating rise that they are claiming to find. CO2 has risen quadratically 38% since the 1880s. Sea-Level rise in verified tectonically inert locations that neither rise nor subside, rises straight-line linear between 1 and 1.4mm/yr.
what kind of science is it?
Some day, generations from now, volumes will be written trying to answer that question.
TDBraun
“what kind of science is it?”
Settled. Incorrectly settled, but settled.
The data are problematic. Some gauges are sited near places that are affected by runoff. The ocean changes height at different rates. It’s noisy data, so it’s hard to get a signal. Depends on the data set and the way it’s assessed.
tomwys1 disagrees. He ends, “Sea-Level rise in verified tectonically inert locations that neither rise nor subside, rises straight-line linear between 1 and 1.4mm/yr.” This is interesting, since NASA satellite readings say it’s now rising at 3.2 mm/yr.
If the length of day increases then there must be a corresponding increase in the length of night. Warming = cooling?
Yup. Same energy. LOD doesn’t make a difference, not on its own. Could make something up though in order to find the correlation this paper is missing. Something about bananas growing at a higher altitude in Costa Rica and, being unused to them, the local villagers slip on their skins and go flying off into the atmosphere, thereby transferring heat..
Wouldn’t the greenhouse effect itself tend to increase net energy absorption with the length of day? If the water vapor and CO2 in the air inhibit the loss of heat at night more than they enhance the retention of heat during the day, and we’re told that this is how it should theoretically work, then lengthening both the time of day and the time of night in equal increments should be more efficient at capturing heat in the day than releasing it at night,
Kurt – I would think that overall, since both day and night were extended, it wouldn’t make a difference. That’s just my intuitive guess, though. I wasn’t aware that the greenhouse effect is any greater at night. Why would this be? Its effect is certainly felt more at night, since otherwise the heat stored in the Earth would go radiating off into space. But the planet is still radiating during the day, no? Oh – I suppose if warm moist air is over the oceans during the day that could decrease evaporation.
I suppose if the length of day were increased enough there might be hotter days and colder nights, if the movement of heat away from the earth/oceans is dependent on a temperature gradient, which presumably it is.
Sorry, I’m sort of thinking aloud and shouldn’t even be saying anything – I’m sure there are people with more expertise around. It’s interesting to think about these things, though.
My recollection is that the wavelength bands at which heat is absorbed by CO2, and perhaps water, match up better with surfaces radiating at relatively cool temperatures. In other words, CO2 captures more energy from a surface radiating at 32F than at 80F. I do recall a great deal of talk some years ago that greater increases in the daily low temperatures relative to increases in daily high temperatures was supposed to be an alleged “fingerprint” of CO2 warming,
We rarely hear about the largest factor in sea level variation: tectonic activity. Slow though it may be, changes in the crust can result in major changes in water levels
The water level really doesn’t change, but the height of the tide gauge does!
I presume it’s more a function of the % of the earth’s surface that’s land and average depth of the ocean basins.
Also depends on how you define “water level”: (1) relative to land (ie: tide gauge) or (2) water level radial distance from center of earth.
Good to see my local newspaper getting an international airing. Threepence a copy seems a bit steep, though. Tradesmen were probably on one shilling and sixpence an hour in 1912, which means it took ten minutes to earn the price of a single issue. I’m guessing a skilled worker today would be on at least $30 an hour, so five bucks every ten minutes. Nobody’s paying that for a bi-weekly these days — although, with no radio, TV or internet the press had a monopoly in the information game back then and could charge what the market would bear. And publish whatever they liked . . . hang on, that hasn’t changed.
0.1C precision in global temperatures from the late 1800s from NASA.
What a crock.
I did some further reading. When the speed of the earth’s rotation slows(LOD increases)the temperature decreases and the atmospheric circulation is more meridional.
When the earth’s rotation speeds up the atmospheric circulation is more zonal and temperatures warm ‘
LOD decreases.
Does everyone see it that way? I think that is correct.
The iceberg fleets in the Southern Ocean during the 19th century should tell us something of the mechanisms involved.
http://www.warwickhughes.com/climate/Iceberg.htm
Earth receives the same solar energy regardless of rotational speed but average temperature could decrease when you have more extreme high and low temperatures because the specific heat of nitrogen and oxygen, which consist 99% of atmosphere, is not constant but increases slightly with temperature. Roughly speaking, it is harder to heat at higher temperature than to cool at lower temperature.
Until the LOD becomes 365 current days for one side of the planet and LON [length of night] becomes 365 days for the other side.
Presumably the “average” temperature will rermain the same
The UN FAO 2001 study of fisheries showed a correlation between detrended LOD and temperature and how it correlates with fishery cycles. See: http://appinsys.com/globalwarming/SixtyYearCycle.htm
Exacty. That is something that has intrigued me for may years now:
http://www.fao.org/docrep/005/y2787e/y2787e00.pdf
Page 10, 2.1 Summary
“A phenomenon of close correlation between the main climatic index dT and geophysical index (-LOD)
still remains an intricate puzzle of geophysics. Another challenging puzzle is the observable 6-year lag
between the detrended run of dT and -LOD. Taking into account this lag, the LOD observations can be
used as a predictor of the future climatic trends.
Even without a mechanism for a causal relationship between the detrended climatic (dT) and geophysical (LOD) indices, the phenomenon of their close similarity for the last 140 years makes LOD a convenient tool to predict the global temperature anomaly (dT) for at least 6 years ahead.”
So LOD predicts dT.
Wattsupwiththat?
Well, here we have more evidence that the warming is exaggerated – the green line is likely more accurate than the black line.
So not only are we all going to die from climate change, we’re going to not be able to sleep because of the longer days?
“The increase of the earths moment of inertia around its axis of rotation increases when ice sheets and glaciers lose mass, resulting in an increase of the earth’s length-of-day.”
So how much longer is today’s length of day compared to 13 K years ago when sea level was 120 m lower and the moon 520 m closer than today?
Could this be the reason the Woolly mammoth went extinct? Some sort of jet lag?
Of course the rotation of the Earth is slowing down. We keep sucking oil out, so the bearings are beginning to seize up.
I have wondered about the impact of pulling all that stuff, from miles below the surface, and putting it into the atmosphere.
“We were able to unravel and precisely model all of these different influences for the North Sea, for example. In the period 1958-2014, the rise in sea levels in the North Sea amounted to ‘just’ around 8 cm. This is comparable to the average worldwide increase over the same period, which is approximately 1.5 mm per year, but the underlying causes are different: the melting of glaciers and Greenland have hardly any effect here, but when it comes to Antarctica, we get the full blast. This is not good news for us, because the ice cap in Antarctica could lose a lot of mass in a future warmer world.’”
I am a bit puzzled as to how the North Sea is NOT influenced by the glaciers and Greenland but Antarctic does…?
Or is he trying to say ‘g & GL’ don’t influence WORLD levels but Antarctica does?
What could the reasoning be here?
We’ll just ignore the usual ‘priest of AGW’ prophetic BS about ‘COULD’ lose mass ‘IF’ warming.
Then we can assume that as the next ice age develops, days will become shorter. This must have happened beofre many times over. So what?
So the last 100 K years we had 90 K years of shorter days and 10 K longer ones. That means we still need 80 K longer ones..
Here’s raw LOD for the past 55 years–no change to speak of:
https://upload.wikimedia.org/wikipedia/commons/5/5b/Deviation_of_day_length_from_SI_day.svg
…and this is in terms of an 1830 standard, a millisecond gain in 180 years. So without invoking CAM we have a problem, and I’m not sure CAM solves it. Secular acceleration due to tides is about -2.2ms/century (LOD). Secular acceleration due to post glacial GIA is about 0.6mm/century, so we’re still spinning too fast. Even with the uncertainty polar ice melt is still highly constrained, but they claim to have measured J2 alteration–the only direct effect of LOD (in all other respects LOD is the effect rather than the cause). LIA GIA may have something to do with it.
–AGF
The most interesting part of the NASA article wasn’t included.
“So what mechanism is driving these correlations? Dickey said scientists aren’t sure yet, but she offered some hypotheses.
“Since scientists know air temperature can’t affect movements of Earth’s core or Earth’s length of day to the extent observed, one possibility is the movements of Earth’s core might disturb Earth’s magnetic shielding of charged-particle (i.e., cosmic ray) fluxes that have been hypothesized to affect the formation of clouds. This could affect how much of the sun’s energy is reflected back to space and how much is absorbed by our planet. Other possibilities are that some other core process could be having a more indirect effect on climate, or that an external (e.g. solar) process affects the core and climate simultaneously.”
Would not the change in speed of the rotation also cause “tide” like effect? Just like the water in a bucket when you stop/accelerate a car.
LOD is measured in tenths of milliseconds out of 86,400 seconds–parts per billion. So may the tides be affected in parts per billion. –AGF
But were tides a lot stronger when lungfish evolved? Yup.