The ‘Little Ice Age’ hundreds of years ago is STILL cooling the bottom of Pacific, researchers find

From The Daily Mail

  • The Little Ice Age brought colder-than-average temps around the 17th century
  • Researchers say temperatures in deep Pacific lag behind those at the surface
  • As a result, parts of the deep Pacific is now cooling from long ago Little Ice Age

By Cheyenne Macdonald For Dailymail.com

As much of the ocean responds to the rising temperatures of today’s world, the deep, dark waters at the bottom of the Pacific Ocean appear to be doing the exact opposite.

A Harvard study has found that parts of the deep Pacific may be getting cooler as the result of a climate phenomenon that occurred hundreds of years ago.

Around the 17th century, Earth experienced a prolonged cooling period dubbed the Little Ice Age that brought chillier-than-average temperatures to much of the Northern Hemisphere.

Though it’s been centuries since this all played out, researchers say the deep Pacific appears to lag behind the waters closer to the surface, and is still responding to the Little Ice Age.

A Harvard study has found that parts of the deep Pacific may be getting cooler as the result of a climate phenomenon that occurred hundreds of years ago. The models suggest In the deep temperatures are dropping at a depth of around 2 kilometers (1.2 miles)

A Harvard study has found that parts of the deep Pacific may be getting cooler as the result of a climate phenomenon that occurred hundreds of years ago. The models suggest In the deep temperatures are dropping at a depth of around 2 kilometers (1.2 miles)

‘Climate varies across all timescales,’ said Peter Huybers, a professor at the Harvard John A. Paulson School of Engineering and Applied Sciences.

‘Some regional warming and cooling patterns, like the Little Ice Age and Medieval Warm Period, are well known.

‘Our goal was to develop a model of how the interior properties of the ocean respond to changes in surface climate.’

The Medieval Warm Period was a period lasting between the 9th and 12th centuries during which Earth’s climate leaned on the warmer side.

It was followed not long after by the Little Ice Age, which lasted from the 16th through 19th century, though some argue it began even earlier.

According to researchers from the Woods Hole Oceanographic Institution and Harvard University, this long-ago cooling period could still be showing its face in the temperatures of the deep ocean.

‘If the surface ocean was generally cooling for the better part of the last millennium, those parts of the ocean most isolated from modern warming may still be cooling,’ said Jake Gebbie, a physical oceanographer at Woods Hole Oceanographic Institution.

To test this, the team compared measurements taken during the 1870s by scientists on the HMS Challenger to modern data.

During the study in the late 1800s, the researchers of the time dropped thermometers deep down into the ocean between 1872 and 1876, collecting more than 5,000 measurements in total.

Around the 17th century, Earth experienced a prolonged cooling period dubbed the Little Ice Age that brought chillier-than-average temperatures to much of the Northern Hemisphere

Around the 17th century, Earth experienced a prolonged cooling period dubbed the Little Ice Age that brought chillier-than-average temperatures to much of the Northern Hemisphere

‘We screened this historical data for outliers and considered a variety of corrections associated with pressure effects on the thermometer and stretching of the hemp rope used for lowering thermometers,’ Huybers said.

As expected, the comparisons showed most of the world’s ocean has been warming up over the last century.

In the deep Pacific Ocean, however, temperatures are dropping. This effect could be seen at a depth of around 2 kilometers (1.2 miles).

Read the full Daily Mail story here.

H/T David L Hagen and MarkW

And the  from Phys.org.

Researchers find bottom of Pacific getting colder, possibly due to Little Ice Age
January 4, 2019 by Bob Yirka, Phys.org report

“The model showed that the Pacific Ocean cooled over the course of the 20th century at depths of 1.8 to 2.6 kilometers. The amount is still not precise, but the researchers suggest it is most likely between 0.02 and 0.08° C. That cooling, the researchers suggest, is likely due to the Little Ice Age, which ran from approximately 1300 until approximately 1870. Prior to that, there was a time known as the Medieval Warm Period, which had caused the deep waters of the Pacific to warm just prior to the cooling it is now experiencing.”

More information: G. Gebbie et al. The Little Ice Age and 20th-century deep Pacific cooling, Science (2019). DOI: 10.1126/science.aar8413

Read more at: https://phys.org/news/2019-01-bottom-pacific-colder-possibly-due.html#jCp

HT/WimR

 

 

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110 thoughts on “The ‘Little Ice Age’ hundreds of years ago is STILL cooling the bottom of Pacific, researchers find

  1. “The Medieval Warm Period was a period lasting between the 9th and 12th centuries during which Earth’s climate leaned on the warmer side.

    It was followed not long after by the Little Ice Age, which lasted from the 16th through 19th century, though some argue it began even earlier.”

    More like MWP from 9th to 14th and LIA 14th to 19th centuries.

  2. “getting cooler as the result of a climate phenomenon that occurred hundreds of years ago.” I haven’t read the entire paper but could it be the result of recent climate phenomenon?

    • Hundreds of years ago is recent, just not for us humans. But imagine, this is a new multi-decadal or longer factor that can impact climate over longer than 30 years. It’s not settled and shouldn’t be. Science demands that we account for new information.

    • Nope. It takes well over a thousand years for the deep water of the Pacific Ocean, which is formed in the Arctic and Antarctic, to finally work itself to the surface in the tropics. Looking at the chart, I’m wondering if the difference between the Pacific and Atlantic is more because the Pacific has a much larger source region than the Atlantic and thus takes longer to circulate

  3. So the new researchers used the same technique as the Challenger expedition, so as not to introduce artifacts from new equipment?/sarc

      • The authors wrote:

        “we turn to the deep-ocean temperature measurements from the HMS Challenger expedition that were obtained near the beginning of the instrumental era, 1872–1876 CE. There were 5010 temperature observations along the cruise track, including 4081 observations below the mixed layer and 760 observations from deeper than 2000 m (Fig. 2). Previous analysis (18) showed a 0.4°C warming between the 1870s and 2000s in the upper 500 m of the ocean, tapering off to values indistinguishable from zero at 1800 m depth. Challenger temperature trends were not assessed at deeper levels, however, over concerns regarding depth-dependent biases.

        But then they wrote this further on in their Science manuscript:

        “The bulk of the Challenger observations that indicate 20th-century cooling are found in the Pacific between 2000 and 4000 m depth.

        Their Methods section in the Supplement has this on Challenger recordings;

        HMS Challenger observations.
        We correct for pressure-compression effects altering the mercury level in the max-min thermometers used in the Challenger expedition by applying a correction of -0.04◦C per kilometer
        of depth (19), as diagnosed in pressure-tank experiments. With this adjustment, the amount of
        Pacific cooling is diminished between the Challenger and WOCE eras.

        There are other issues related to the depth of the observation. In abyssal locations with temperature inversions, the max-min thermometer will lead to a cold bias that may obscure trends
        in temperature since the Challenger expedition. For this reason, 164 points are eliminated.
        Another bias involves the fact that depth was recorded on the basis of length of line let out, and depth will be overestimated insomuch as the line is not exactly vertical.
        Examination of reported bottom depths relative to modern estimates, however, suggests a systematic bias toward underestimating depth by about 4%. This bias is consistent with rope stretch. The Challenger expedition used one-inch diameter hemp rope that was loaded to as much as 35% of its breaking strength for deep soundings, and which is associated with a similar amount of stretch in modern hemp ropes (37). As our aim is to minimize the potential for spuriously detecting cooling, we do not adjust depths because doing so would involve comparing Challenger observations against deeper and generally colder recent observations. Also, Southern Ocean temperatures south of 45◦S are not examined because strong, pervasive currents are expected to cause greater departures from vertical in the line (18).

        My take on this. The Pacific Ocean at depth is cooling. The immense bulk of this abyssal water reservoir is that of a giant storage buffer that indicates what is happening to Earth’s climate on time scales of millennia, and a data point set from over 100 years ago tells us it got colder since then. And it is likely still getting colder. The ever so slow onset of the next glaciation probably has started, but it is noisy at scales of a hundred years or so — the interglacial we have enjoyed for 10,000 years is closing… exit stage left very slowly as the proxy records of the past 800,000 years shows happens as interglacials fade away.
        The current Climate Change alarmism is nothing but a scam on humanity in pursuit of a political power structure from a small group of elitists. A scam if followed that will leave modern society little prepared for the return to glaciation conditions of the NH.

        • Thanks! Borehole data are said to reveal surface temperatures hundreds of years ago, but rocks don’t move about on that timescale.

        • It’s obvious:
          The super wealthy elites are misanthropes who want population reduction (and there are copious quotes from their own mouths) in order to hoard readily available resources for themselves.
          They are pushing artificial intelligence, in conjunction with smart technology to monitor all the plebs, so once the next big cool hits, and the lifestyle of most is sedentary and filled with highly processed chemical food, void of immune boosting nutrition and verifiably destroyed through extreme vaccination schedules that place heavy metal toxins in the body…
          Oh and don’t neglect the sensory overload video game culture/androgenous agenda/#metoo unholy marriage, that is destroying young males interest in sexual relations with the opposite gender:

          It’s either “I’m not interested” or not worth the risk (affirmative consent is for cucks and real women despise permission every step of the way).

          They can control a significantly smaller population in a few major metropolitan hubs, and deploy drones to snuff out anyone caught in the no human zones. Agenda 21/2030. You think the constant mention of 2030 is just coincidence?

          It’s all happening and this CAGW hoax is the trojan horse the leftists refuse to unveil. The rest of what I’ve mentioned regarding proper immune health and how that plays a role is dismissed by trad-cons who are equally enthralled with pharma and other big corporations in the same fashion as the left and government.
          Silly, really, that supposed logical thinkers can pick apart all the horse hockey in CAGW but refuse to investigate human health with the same rigor.

          That’s the real plan folks.

          • Canadianliberty.com/?p=21969

            Go ahead and read through that document, if you haven’t already.

            You can download a copy of the document in PDF format.
            Control +F type vaccine, or also try economy and look at what they are pushing

          • Hey, write that up for a novel. You might be able to make it a best seller like Larry Niven and Jerry Purnell’s “Fallen Angels.” Oh, wait, that is the subject of their novel. Oh, well sometimes ones good ideas are so good someone else has ‘stolen’ them.

          • Way off topic. I would prefer a mini-epidemic to a major epidemic. Remember 80% of Amerindians died of smallpox without ever seeing a white man.

          • interestingly, you folks are quick to point out conflict of interest (and rightfully so) with the climate fear industry, yet refuse to employ the same logic and pattern recognition in other facets of society, because of your confirmation bias and misplaced trust in Big Corporation:

            Dr. Paul Offit remains the single biggest vaccine myth debunker and the person who is most often cited as the ‘vaccine safety guru, and ‘settled science’ prophet in the scientific and vaccine health policy communities. Interestingly, he a chief developer of the Rotovirus vaccine. Offit invented RotaTeq, a pentavalent rotavirus vaccine manufactured by Merck & Co. Since 2006, RotaTeq has been one of two vaccines currently used against rotavirus. Yet, he continues to be less than honest about the safety risks inherent in this globally administered vaccine and the profits he has made with patents he holds. His is a story of tremendous conflicts of interest, yet, he is the front face to ‘settled science, vaccines are safe’ movement. https://www.nvic.org/vaccines-and-diseases/Rotavirus.aspx

            all of this in interconnected, and it has all been openly discussed. All of it. What do you need? Does this need to happen to people you care about for you to pull your collective heads out of your tushies?

        • “The XBT fall rate minimum from 1975 to 1985 appears as a 10-yr “warm period” in the global ocean in thermosteric sea level and heat content estimates using uncorrected data. Upon correction, the thermosteric sea level curve has reduced decadal variability and a larger, steadier long-term trend.”
          https://journals.ametsoc.org/doi/10.1175/2008JCLI2290.1
          If not for corrections, there was no warming of the oceans in the past 40 years.

  4. “The model showed that the Pacific Ocean cooled over the course of the 20th century at depths of 1.8 to 2.6 kilometers. The amount is still not precise, but the researchers suggest it is most likely between 0.02 and 0.08° C”

    Wow these guys and their computers are amazing!

    • Too small of a database to provide meaningful trends, if the PDO is some 60 years, and the AMO is ?? years. But what you do show seems to indicate the cooling bottomed out in 2016 and is now coming back up.

  5. Another falsification of the hockey stick, and the propaganda spread throughout the world by the hockey team. If this was “fact based science” they would have been discredited long ago. But we have a OPM addiction that runs deep into the science-for-hire community.
    If natural causes resulted in the Medieval Warming period, and the Little Ice Age, how much of today’s climate is due to natural causes? Best estimate is most of the current warming is a continuation of the approximately 0.1*C / decade, that we have been getting since we started keeping temperature records in more than a few locations. But natural warming does not “feed the beast” and that is the reason it is shunned.
    And what will be the name of the current climate 200 years from now?
    The Political Science Age?
    The GIGO Age?
    The Anthropophobia Period?

  6. So, what I see here is “we don’t have a $#@$#ing clue what is going on, but since we’re funded to study it here goes…Did I miss anything?

  7. Oh, I thought upwelling of warm water was going to melt the Antarctic ice from below and other Jerry Brown scare tactics for funding schemes.

  8. Cooling is more ‘conservative’ than warming in the deep ocean. I guess this will last a long time still.
    But does it matter for the IPCC, as it is not in their mandate to consider natural climate change, only manmade!

  9. This paper serves as an example of why the meme of “well if it isn’t human CO2 then what IS causing modern warming?” is a sophist question that shows a lack of understanding for something as complex as global climate.

    Climate is a very complex hysteretic non-linear chaotic system that exhibits stochastic resonance. Trying to explain the current state of this type of system with just one noise variable (CO2) is beyond pseudoscience and approaching science fiction.

    After realizing the importance of this paper, some climate scientist might even dare to suggest the blasphemous idea that modern warming is being influenced by events that happened before the LIA – relatively warm bottom waters from the MWP recirculating to the surface.

    • …AND allowing more CO2 to be released into the atmosphere. Go back 800 years from today, and you’re in the MWP. Remember how the ice core reconstructions show CO2 level changes FOLLOWING temperature changes with a time lag of about 800 years?

  10. “The amount is still not precise, but the researchers suggest it is most likely between 0.02 and 0.08° C. That cooling, the researchers suggest, is likely due to the Little Ice Age”

    Any time I see miniscule temperature variation in something as vast and variable as the ocean I’m skeptical

  11. I did not see anyone else who picked up the most telling quote in the article: “Some regional warming and cooling patterns, like the Little Ice Age and Medieval Warm Period, are well known”. So, the LIA and the MWP were regional phenomena, huh?…

    • But it also correctly says that “Earth” experienced cooling, albeit for too short an interval, while also limiting it to “much of the NH”:

      “Around the 17th century, Earth experienced a prolonged cooling period dubbed the Little Ice Age that brought chillier-than-average temperatures to much of the Northern Hemisphere.”

      But of course both the MWP and LIA were global climate signals, with somewhat varying effects and timing from place to place. Same as prior warm and cool cycles in the Holocene and previous interglacials. And glacials.

    • Wall to wall political correctness, see also MWP “on the warm side” and of course the need to explain any cooling as natural variability. I imagine they went looking for heating everywhere.

    • Joe,
      As soon as I saw the “regional” bit, I stopped reading. There is so much evidence now that shows the LIA and MWP were global events, that one would have to be a some sort of “denier” to believe otherwise.

  12. I’m struggling with Laws of Thermodynamics to figure out how cooling of seawater occurs without heat pumped out and without any big refrigerator in the deep (same thing). If heat is in fact being added due to surface interaction with a warming atmosphere, how do you get the deeper part of the ocean to cool? There’s something fundamentally wrong with this idea.

    • It’s more accurately described as not cooling, but a pulse of colder water going forward and cooling an area. The water is not cooling there.

      LoT is a four letter word, at least the 2nd one.

    • This is where thinking in anomalies is appropriate. Ocean currents are ongoing and some of them have a period of over 1,000 years. So relatively cooler surface waters (cooler atmosphere caused more heat released from the ocean) during the LIA are still being downwelled into the deep ocean today while the modern warm period is currently causing surface waters to warm.

    • That water went below many centuries ago and is slowly moving through the deep sea. It isn’t cooling, as a matter of fact it is very slowly warming through geothermal energy, but as slightly warmer waters from the MWP upwells it is replaced by somewhat colder LIA water in the deep North Pacific.

      Or at least that is the theory. However the: colder climate=colder deep water produced/warmer climate=warmer deep water produced is not a trivially true proposition since it also depends on the salinity of the water. More saline water will sink at a slightly higher temperature.

      And there is really no interaction between the deep water below the thermocline and the atmosphere. Except at the beginning and the end of the thermohaline conveyor belt about a thousand years apart.

      • tty January 9, 2019 at 11:09 am

        And there is really no interaction between the deep water below the thermocline and the atmosphere. Except at the beginning and the end of the thermohaline conveyor belt about a thousand years apart.

        Just one more step, namely the realization that the heat content of the water below the thermocline is completely caused by geothermal energy and we have the explanation for our very high surface temperatures. Deep oceans ~275K (already 20K above the infamous 255K) and the sun increasing the mixed surface layer temperature ~15K to ~290K and now the atmosphere only has to reduce the energy loss to space from ~390W/m^2 to ~240W/m^2.
        No GHE increasing the surface temperatures (and thus implicitly the deep oceans) anymore.

    • There is big ice cube that is stuck at the bottom of the Pacific, many cubic miles is size, that has not yet fully melted. It is either a new form of ice with density higher than cold water. Or perhaps this ice cube is stuck in a deep sea trench, where it scares away the hot vents of boiling water coming up from the cracks in the earth’s crust, and therefore refuses to melt as it cools all the vodka tonics for sharks.

  13. It takes about a thousand years for the thermohaline circulation to completely replace the deep ocean water, so the deep water upwelling now went below during the MWP and the water from the LIA won’t be coming up for a few more centuries.

    It is this fact that makes the ECS (“Equilibrum Climate Sensitivity”) concept completely meaningless. There is never equilibrum because long before it has been reached the CO2 the oceans were supposed to equilibrate with is gone.

    The ocean and the atmosphere are never in equilibrum.

  14. Well at least these climateers admit that the LIA and MWP were significant global temperature events, but even then they had to downplay the MWP wih this bit of sciency gibberish, “The Medieval Warm Period was a period lasting between the 9th and 12th centuries during which Earth’s climate leaned on the warmer side.”

    So today, the Earth’s climate apparently is “leaning” on the warmer side and it just happens to coincide with increasing atmospheric CO2. The end of this Climate Change charade is coming with accelerating human CO2 emissions and declining global temps.

  15. So if the cold water is displacing the warm water at the bottom, what happened to the warmer water?
    Have we just found yet another natural cause of warming to confound with the effect of CO2?

    • Exactly. Water has a much greater heat capacity than air. Warmer than average water coming to the surface creates warmer than average atmosphere. Cyclical climate change brought to you by ocean cycles. If the Climate Aristocracy could put a toll gate on it, they would consider it as a source of climate change. Since they can’t it must be scrutinized for any inconsistencies and then ignored, to promote more profitable scenarios.

    • Can’t be. I was told decades ago on UseNet but no less a personage as William Connolly that the LIA was short and local (i.e., Europe. Ok, and some parts of North American. Sure, maybe some parts of Asia, and really, not much of South America.) But LOCAL, for sure.

  16. At first glance, the idea that the deep oceans could still be cooling because of the LIA sounds like bunk.

    In a mechanical system, energy can be stored in a spring or as inertia. Thus, the system can continue to respond to an input after the input has stopped. A pendulum is an example. You can give it a push and it swings back and forth in spite of the fact that you quit pushing. (Gravity supplies the spring force.) link

    Systems such as described above are described by second order differential equations so they are called second order systems.

    In the previous sections, all the systems had only one energy storage element, and thus could be modeled by a first-order differential equation. In the case of the mechanical systems, energy was stored in a spring or an inertia. In the case of electrical systems, energy can be stored either in a capacitance or an inductance. In the basic linear models considered here, thermal systems store energy in thermal capacitance, but there is no thermal equivalent of a second means of storing energy. That is, there is no equivalent of a thermal inertia. link

    Actually I can imagine a system involving a heated compressed gas which would be described by a second order differential equation but water is basically not compressible.

    Thermodynamics is a bear and I am not a mechanical engineer however my first response is to be skeptical. If they are going to assert that the deep ocean is still cooling because of the LIA, they are going to have to describe the mechanism by which it does so. And no, merely waving their hands at a second order differential equation won’t do. It is dead common for people to try to apply equations to systems for which they are not appropriate.

    • Red for surface waters, blue for deep currents.

      https://upload.wikimedia.org/wikipedia/commons/4/4c/Thermohaline_Circulation_2.png

      As Tty notes, turnover is about a millennium, so water rising to surface now dove down around AD 1020.

      Water masses at the bottom of the cycle date from about AD 1520. They fell through waters colder than now after the end of the MWP c. 1300 to 1400, before reaching the coldest depths.

      Surface waters c. AD 1690 or shortly thereafter were the coldest of the latter Holocene.

      • Or, put another way, the deep ocean contains a form of temperature memory, a massive river of water of salinity, temperature and gas content that represents the state of the atmosphere and ocean surface where it began.

  17. Seriously, the only way anything cools is either: it’s heat transfers to outer space, or to objects on earth, or in the ocean, colder that it.

    Despite “Global Warming,” or more CO2 in the air, there could be parts of the ocean that are still loosing heat and even going colder than the same water (i.e. water now in the same region) as was in that area during the Little Ice Age (LIA). But I don’t see how they can blame that phenomenon on the LIA which was most likely caused by astronomical events leading up to it (i.e., less insolation).

    • @ OTI..
      Precisely. This is complete crap.
      Things do not *just* warm up or cool down – a forcing has to be applied from somewhere.

      If something is cooling, it is losing energy – so where is the energy? Gotta show up somewhere.
      Maybe it explains the current warming?

      Or maybe a big slab of cold water is sliding gracefully down into then abyss
      Okaaaay……
      It started its descent ‘hundreds of years ago’?
      If it set off from (west coast) North America or east coast Asia, what took it so long and how did nobody notice it in the meantime?
      Maybe it started from the North Atlantic (a failure of the Gulf Stream at the time?) – that might explain its tardy arrival in the Pacific – but *that* really rather trashes the notion that the LIA was ‘global’

      Was it a big slug of water from a melting Arctic ‘hundreds of years ago’ – *that* totally trashes the LIA Full Stop – but what melted the Arctic ice if the Gulf Stream had slowed/stopped?

      The science is junk and the first statement says it all – temperature of things is NOT like the inertia of a car coasting in neutral along a road – *something* has to be applying a force to effect the change.

      • and we hear about The Deep Pacific yet only mention 2,000 metres.
        The Pacific is over 4,000 metres deep (on average)

        Possibly it happened but, were those intrepid sailors of the1870’s REALLY throwing two and a half miles or rope overboard?

        If The Pacific at a paltry 2,000 metres is presently cooling, I for one would really start to get worried….
        Remember, all those little CO2 molecules are punching holes in the atmosphere, holes that are letting heat escape that would otherwise be keeping us warm.

        Maybe ‘something else’ is causing modern thermometers to do what they’re doing

      • You really need to read up on thermohaline circulation Peta.

        “Or maybe a big slab of cold water is sliding gracefully down into then abyss
        Okaaaay……
        It started its descent ‘hundreds of years ago’?”

        Exactly!

        “Maybe it started from the North Atlantic (a failure of the Gulf Stream at the time?) – that might explain its tardy arrival in the Pacific – but *that* really rather trashes the notion that the LIA was ‘global’”

        It set off either from the North Atlantic or from Antarctica. If the former it was not due to a failure of the Gulf Stream but rather as a result of the Gulf Stream, that carried very salty water up into the far north, where it was cooled down to a point that it was dense enough to sink to the deep ocean floor.

        Have you never reflected how odd it is that the deep ocean is so very cold? Even in the tropics? Despite having warm water above and hot rocks underneath? Or that it is well oxygenated despite being isolated from the atmosphere and having no photosynthesis?
        It is because the deep ocean holds the densest water, and in this icehouse world that water comes either from the North Atlantic or from the waters just off the Coast of Antarctica. And those are also stormy waters, so it is well oxygenated as well.

        It was very different in the Hothouse world before 35 million years ago. With no continent-wide ice in the Antarctic the densest water was warm and very salty and formed at low latitudes, and the deep ocean was warm and oxygen poor.

    • @ OTI: Don’t mistake the ‘cooling’ to mean a change in temperature of the water that was there previously. What it means is that the water that is there NOW is colder than the previous water.

      The deep currents have moved colder water to the location.

  18. I reported about the Challenger expedition and its findings in my April 2018 article:
    https://wattsupwiththat.com/2018/04/26/the-60-year-oscillation-revisited/
    Where more information can be found and a figure of a comparison between Challenger New York Saint Thomas temperature transect compared to recent Argo data, where it can be seen that some areas are cooler now, while most are warmer. It was data from a 2012 article by Roemmich et al.

    The ocean is temperature and salinity stratified and resists vertical mixing except at upwelling and downwelling areas. The wind does surface and subsurface vertical mixing, and tides are responsible for vertical mixing all the way to the bottom.

    The time that it takes the climate system to respond to obliquity-caused orbital forcing is around 6500 years, as that is the delay between obliquity changes and their climatic effect (see figure where temperature data was lagged by that time to orbital data). This delay is probably due to full ocean equilibration. A delay of a few centuries is like nothing for the planet.

    https://i.imgur.com/fI1uUqZ.png

    Peter Huybers is one of the biggest experts on the glacial-interglacial cycle, so he knows perfectly well about these delays.

  19. Have the laws of physics changed? Why does the warm water sink? I have been told that warm water rises, other than when at 4 oC (39oF) where has its highest density of 1000 kg/m3 or 1.940 sl/ft3. Is it changed by the salt content? Also doesn’t water get denser the deeper it is?

    • The simple picture is that warm water flowing into the north Atlantic (i.e. Gulf Stream) experiences a lot ow cold winds blowing from west to east. So there’s a lot of evaporation and the water vapour is carried away towards northern Europe by the wind (which is why my memories of living in Scotland include a lot more rain than sunshine). Evaporation cools the warm water somewhat but more importantly increases the salinity, and when its density gets greater than the native north Atlantic water, it starts to sink, and then it goes on its long, sinuous trip around the bottom of the world’s oceans.

  20. ‘Some regional warming and cooling patterns, like the Little Ice Age and Medieval Warm Period, are well known…

    Regional? This is what the hockey-stickers say, the deniers of past climate change. (Hey, turn-about is fair play.)

    Seems the authors elsewhere talk about the earth warming and cooling over these periods but then what is this “regional” business?

    Their own research would seem to support LII and MWP as periods of lower and higher global average temperature. Surely regional differences would have mingled into an average temperature by the time they affect the ocean bottom hundreds of years later.

  21. If anyone thought their temperature readings were gonna be used 150 years hence, to upset world economies, they might have demanded a better wage.

    • OR…..you could argue that they were earning what they deserved, as they were likely blissfully unaware of how accurate their data actually was. Two miles of any kind of rope is quite heavy, easily stretched, and easily moved around by currents. If its density were much above the water it was in, it would stretch, and break from its own weight. If its density were much below the water, it wouldn’t sink at all to the depth that was played out. In addition, as it soaked in the water, its displaced density would be slowly changing.

      At near neutral density, it would be quite sensitive to local currents, which would also make the perceived depth to be quite wrong. All this doesn’t even address the accuracy of “max-min” mercury thermometers. Assuming they were played out slowly enough to respond to the temperatures they were passing through, they would obviously reading the max-min temperatures of the water they passed through, not necessarily the water at depth. I’m sure there are many more issues that could be possible.

      All this being said, I do commend them for their measurements. As with any true experiment, The greatest gain in knowledge comes from the first data point taken. As the data points go from zero to the percentage gain is infinite. It’s just that this is hardly enough data to use to destroy the world’s economy.

  22. Regarding climatic events before 1880 I recall that the big conference in 1985 at Villack, Austria declared that as we did not have accurate thermometers prior to that date, all mention of major climatic events earlier than that date were to be disregarded.

    So as they did not apparently occur, we must not mention them.

    So says the wise ones in the UN IPCC.

    MJE

  23. Let me please rephrase what I read:

    They have gone to the same depths at almost the same locations of historical expedition of 1870+ to record deep ocean temperatures.

    They have found that at certain depths today’s temperature are lower than that of 1870s.

    Hence they conclude that the LIA cooling of deep seas is ongoing.

    Question:

    Was the temperatures at the end of MWP was warmer than 1870s?
    Is it possible that deep ocean has been cooling since Younger Drayas?

    They have only found that temperature is cooler that 1870s but they have not refuted at least these two possibilities.

  24. Does anyone have links to other temperature reconstructions that show the MWP and the LIA and, thus, show that Mann’s hockey stick temperature reconstruction is an outlier?

    Also, how did we come up with the temperature reconstructions that show the MWP and LIA? Did they come from other tree rings, ice cores, or another proxy?

    Thanks,
    Daniel

  25. Meh, my interpretation is that in current time cooling at the bottom of the ocean is happening today. As Antarctica loses it’s shelves it allows cooler waters to push down towards the bottom of the ocean and cool it off. Later causing the re-glaciation.

    • . As Antarctica loses it’s shelves it allows cooler waters to push down towards the bottom of the ocean and cool it off. Later causing the re-glaciation.

      Because more water is exposed to the cold air? Makes sense to me.

  26. been busy, so I reread stuff to keep it light. Been reading Ringo’s “The Last Centurion” published in 2008, and he had this statement in the book that currents are affected by temps for hundreds of years after the events due to some lag in the system. The Mail is a bit behind on this (oh, sorry, it’s the Daily Mail. . . it is always behind)

  27. It is not possible to cool the cold deep oceans with warmer surface water. The Daily Mail did not understand the story or tried to fool everyone: “As a result, parts of the deep Pacific is now cooling from long ago Little Ice Age”. WR: wrong, cooling from the Medieval Warm Period!

    Science tells: “The ongoing deep Pacific is cooling, which revises Earth’s overall heat budget since 1750 downward by 35%.” Source: http://science.sciencemag.org/content/363/6422/70.

    WR: as I read it: the previously estimated total heat content of the oceans in 1750 has been estimated too low, because there was warmer Medieval water down in the Pacific which has not been known at the moment of the previous estimation.

    Therefore the Oceans did not warm as much as previously estimated. Pacific deep oceans already were warmer than thought.

    And the hockey stick also was not correct: the Medieval has been warmer than last century. We can still find the Medieval fingerprint in the temperatures of Medieval water in the Deep Pacific: Medieval down welling water was warmer than the down welling water from last [‘warm’] century that was replacing that layer.

    The above is revealed in the very last sentence of the following excerpt from https://phys.org/news/2019-01-bottom-pacific-colder-possibly-due.html#jCp

    “The model showed that the Pacific Ocean cooled over the course of the 20th century at depths of 1.8 to 2.6 kilometers. The amount is still not precise, but the researchers suggest it is most likely between 0.02 and 0.08° C. That cooling, the researchers suggest, is likely due to the Little Ice Age, which ran from approximately 1300 until approximately 1870. Prior to that, there was a time known as the Medieval Warm Period, which had caused the deep waters of the Pacific to warm just prior to the cooling it is now experiencing.”

    WR: The Little Ice Age cooled the surface that much that the surface still is recovering and still not has reached the temperature the surface had during the Warm Medieval. Nothing new, present warming.

  28. Looking at Figure 3, “Difference between WOCE and Challenger temperature…”, which shows the difference between the 19th-21st century Pacific and Atlantic temperatures, the 95% confidence uncertainty bars between 2500 m and 1000 m are about ±0.05 C.

    However, the Miller-Casella thermometer used on the Challenger was accurate only to about ±0.15 C (±0.25 F). That means the minimal 95% uncertainty is ±0.3 C. And that is under ideal (laboratory) reading conditions.

    So, the published uncertainties are about 6 times smaller than the best resolution available using that thermometer.

    That lower limit of resolution makes the Figure 3 Pacific and Atlantic temperature differences indistinguishable from zero. There may be a real temperature difference, but it’s not resolvable in the Challenger data.

    Further, the WOCE ocean temperatures are from Argo float measurements.

    The few field-calibrations of Argo floats using high-accuracy ship-borne CTD instruments indicated ±0.6 C errors in the Argo temperatures. The usual approach in consensus climatology is to assume these errors all
    subtract away when taking differences (anomalies). Or that all the systematic errors are normally distributed and average away. However, neither assumption has never been tested, and I don’t buy it at all.

    Taking differences, i.e., Challenger minus WOCE, requires combining the uncertainties as the root-mean-square. The minimum uncertainty in any anomaly is no less than ±0.15 C — the Challenger lower limit, and
    likely much more given the field performance of the Argos.

    Regarding the ocean model simulations, Carl Wunsch has noted that ocean models don’t converge. That makes the simulations in the paper pretty much physically meaningless.

    Wunsch says that ocean modelers dismiss the ‘doesn’t converge’ criticism because the model results “look reasonable.”

    That’s OK for movie graphics, but not for science.

    It appears that all the measurement and model errors and uncertainties are neglected in order to be able to say something.

    So, all-in-all, Figure 3 (and the entire paper) looks like fantasy science to me.

  29. ‘Our goal was to develop a model of how the interior properties of the ocean respond to changes in surface climate.’

    None of their models ever foresaw the winter 2018 / 2019.

    Why should anyone trust their “models. “

  30. (Very late to this discussion. Life and computer issues.)
    Hmmm…. “The Missing Heat” is supposed to hiding in the oceans, or so said one the CAGWist.
    Hmmm…. The Hockey Stick puppeteer says there was no “Little Ice Age”.

    Gosh! What some claimed never happened might be the solution to the “missing heat”? It got iced by reality?

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