Busy Hurricane Season is predicted for 2024

[ding]

But that does NOT say that changes in thermohaline properties drive the glacial-interglacial cycle. It says that the salinity difference between the Atlantic and Pacific may be increasing, it says that such a process (with rather ill defined end points) might be taking place at the same time scale as the glacial cycle and suggests that this process might be bringing freshwater from the Pacific to the Atlantic. It says NOTHING about the cycle cause. Nothing.

Look, I can see that you're trying. But you need to give some real consideration as to why you're having such a hard time finding anything to support your ideas.

Maybe try reading the other papers. Then get back to me.

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/PA005i004p00469

Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes - Nature​

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010PA002032

 

[Crick]

Maybe try reading the other papers. Then get back to me.

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/PA005i004p00469

Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes - Nature​

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010PA002032

For the third time, give us some quotes from these papers that show the authors believe as you believe. It's a common practice here with linked articles and studies. If these studies actually DO support you, it should not be difficult to find such things.

 

[ding]

For the third time, give us some quotes from these papers that show the authors believe as you believe. It's a common practice here with linked articles and studies. If these studies actually DO support you, it should not be difficult to find such things.

What part of the papers that mentions glaciation and deglaciation didn't you understand?

But please do feel free to post some papers that argue ocean currents aren't responsible for abrupt climate changes. Good luck with that as there are none.

 

[Crick]

What part of the papers that mentions glaciation and deglaciation didn't you understand?

That you dodge and weave a simple request that could make your case and show me the fool does not bode well for your position.

But please do feel free to post some papers that argue ocean currents aren't responsible for abrupt climate changes. Good luck with that as there are none.

I have already posted links to seven different peer-reviewed articles that state, unequivocally, that Milankovitch orbital cycle forcing triggers the glacial-interglacial cycle. I would not have to go back far to find you stating that no such papers exist. You were wrong then and you are wrong now. THIS is what Mr Stretched was talking about when he asked why you so begged to be mocked.

 

[ding]

That you dodge and weave a simple request that could make your case and show me the fool does not bode well for your position.

I have already posted links to seven different peer-reviewed articles that state, unequivocally, that Milankovitch orbital cycle forcing triggers the glacial-interglacial cycle. I would not have to go back far to find you stating that no such papers exist. You were wrong then and you are wrong now. THIS is what Mr Stretched was talking about when he asked why you so begged to be mocked.

No dodge. Just facts.

The role of the ocean in storing, distributing and establishing climate is well known and well understood. Change the currents and you change the climate. Some regions are more sensitive to change than others and have more of a global impact than others. The Arctic is that region. The Little Ice age was triggered by a disruption of the ocean's heat circulation to the Arctic and that when that heat circulation was restored, the planet returned to it's natural interglacial warming trend. The contribution of the Industrial Revolution isn't nothing but all warming is not due to it. 0.22C top 0.5C is the contribution of 120 ppm of CO2.

1. The ocean stores the majority of heat the earth receives from the sun
2. The ocean holds 1000 times more heat than the atmosphere
3. The ocean distributes that heat to the rest of the globe using currents
4. Without ocean currents the polar regions would be colder and the equator would be hotter such that much of the planet would be inhospitable for life
5. Ocean currents are affected by density (salinity and thermal expansion) and wind.
6. Wind patterns are affected by the sun
7. If heat circulation from the Atlantic to the Arctic were disrupted it would lead to catastrophic cooling

The following are excerpts from papers explaining the science behind the climate changes of the past 3 million years.

It is found that the global salinity variations associated with the thermohaline circulation may have a tendency to make the circulation increasingly asymmetric with respect to the equator. As a consequence the salinity difference between the Pacific and the Atlantic Ocean may be slowly increasing. Such a process could have a time scale long enough to be comparable with the time span between major glaciations. A speculative glaciation cycle is proposed which involves the above mentioned property of the thermohaline circulation. In this cycle the role of a Northern Hemisphere glaciation is to bring excess freshwater from the Pacific to the Atlantic.

https://www.sciencedirect.com/science/article/abs/pii/S0031018285800201

Atlantic Ocean Circulation During the Last Ice Age​

There is strong evidence that the circulation of the deep Atlantic during the peak of the last Ice Age, or the Last Glacial Maximum (LGM; ~22,000 to 19,000 years ago) was different from the modern circulation (Boyle & Keigwin 1987, Duplessy et al. 1988, Marchal & Curry 2008). Compilations of deepwater δ13C and CdW for the LGM (Figure 5) show several features that contrast with their modern distributions. Whereas much of the modern deep western Atlantic has similar δ13C values because it is filled with NADW, during the LGM, the range of δ13C values was larger than today, with higher values in NADW and lower values in AABW. The main core of high-δ13C, low-CdW NADW was at least 1000 meters shallower than today, probably because the density difference between surface waters and deep water was reduced — surface salinity may have decreased as a result of less evaporation due to colder glacial temperatures, and as a result of input of freshwater from glaciers surrounding the North Atlantic (Boyle & Keigwin 1987). In the western Atlantic, depths below ~2 km were filled with AABW. Radiocarbon data suggest that deepwater was older (Keigwin & Schlegel 2002), consistent with less NADW and more AABW as indicated by the δ13C and CdW of benthic foraminifera. Glacial δ13C data from the eastern Atlantic suggest that the boundary between glacial AABW and glacial NADW may have been shallower than in the western Atlantic (Sarnthein et al. 1994), although the difference may be the result of local effects caused by increased glacial productivity and higher rates of remineralization of low-δ13C organic carbon in the eastern basin. Inferences using other kinds of proxy data of deep Atlantic circulation are consistent with the changes inferred from δ13C, Cd/Ca and 14C of benthic foraminifera (Lynch-Steiglitz et al. 2007).

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

As shown by the work of Dansgaard and his colleagues, climate oscillations of one or so millennia duration punctuate much of glacial section of the Greenland ice cores. These oscillations are characterized by 5°C air temperature changes, severalfold dust content changes and 50 ppm CO2 changes. Both the temperature and CO2 change are best explained by changes in the mode of operation of the ocean. In this paper we provide evidence which suggests that oscillations in surface water conditions of similar duration are present in the record from a deep sea core at 50°N. Based on this finding, we suggest that the Greenland climate changes are driven by oscillations in the salinity of the Atlantic Ocean which modulate the strength of the Atlantic's conveyor circulation.

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/PA005i004p00469

Water Masses in the Deep Atlantic Ocean​

The Atlantic Ocean is the only ocean basin that features the transformation of surface-to-deepwater near both poles. Warm salty tropical surface waters flowing northward in the western Atlantic cool in transit to and within the high-latitude North Atlantic, releasing heat to the overlying atmosphere and increasing seawater density. Once dense enough, these waters sink and flow southward between ~ 1000 and 4000m. This North Atlantic Deep Water (NADW), as it is called, flows from the Atlantic to the Southern Ocean where much of it upwells — or rises to the surface — around Antarctica, and some of it circulates Antarctica before entering the rest of the world's deep oceans. Antarctic Bottom Water (AABW), which is formed close to Antarctica, is denser than NADW, and flows northward in the Atlantic below NADW. AABW is confined to water depths below 4000 meters in the tropical and North Atlantic. Antarctic Intermediate Water (AAIW) flows northward above NADW. The presence of these three water masses in the Atlantic Ocean is evident in cross-sections of many water properties, including salinity, phosphate concentration and carbon isotope ratios (Figure 2). The residence time of deepwater in the western Atlantic is approximately 100 years (Broecker 1979), meaning that the average water parcel spends about a century in the deep Atlantic.

Why is Deep Water Formed in the Atlantic and not the Pacific?​

Warren (1983) first noted that the difference in salinity between the North Pacific and the North Atlantic (Figure 1) was the principal reason deep water formation occurs today only in the North Atlantic. Salty water, when cooled, achieves a higher density and is thus able to sink to greater depth in the water column. Wintertime cooling occurs in both the North Atlantic and North Pacific, but since the surface waters of the North Atlantic are much closer in salinity to the mean of the ocean's deep water, they achieve a density high enough to sink to great water depths. Warren (1983) noted that the salinity of the North Pacific was low because of relatively low evaporation, little exchange with salty tropical waters, and an influx of fresh water from precipitation and river runoff. Emile-Geay et al.(2003) reevaluated the Warren (1983) results and fundamentally confirmed his thesis, noting that atmospheric moisture transport from the Asian monsoon was also an important source of fresh water to the North Pacific not originally considered by Warren. Interestingly, Warren also noted that the North Atlantic had much greater river runoff than the North Pacific, so its higher surface salinities must be the result of greater evaporation in the Atlantic basin.

Broecker et al. (1990a) noted that higher Atlantic salinities are the result of a net transfer of water vapor from the Atlantic to the Pacific over the Isthmus of Panama, equivalent to approximately 0.35 Sverdrup (106 m3 per second). In the absence of other processes, this would raise the salinity of the Atlantic by about 1 salinity unit each 1000 years. If the Atlantic salinity is in balance, then it must be exporting the excess salt (enough to compensate for the lost fresh water) through ocean circulation processes. Today this is occurring through the production and export of North Atlantic Deep Water.
At times in the past, rapid melting of ice sheets surrounding the North Atlantic was great enough to alter surface salinities, likely reducing the density of deep water formed, and slowing the export of deep water from the North Atlantic. Broecker et al. (1990b) hypothesized that natural oscillations in the rate of water vapor exchange between the Atlantic and the Pacific during the last glacial period were responsible for the rapid, short term fluctuation ocean circulation linked to the abrupt millennial-scale Dansgaard-Oeschger Events seen in the Greenland ice cores (Figure 9).

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

What Replaces the Deep Water that Leaves the Atlantic?​

There are three main pathways for water to return to the North Atlantic and renew NADW, a warm-water route and two cold water routes (Figure 3). The "warm-water route" begins with the flow of surface and thermocline water from the Pacific to the Indian Ocean through the Indonesian Seas. Both colder return flows involve Antarctic Intermediate Water (AAIW), described above. AAIW enters the southern South Atlantic through the Drake Passage between Antarctica and South America, with some flowing into the Atlantic and some flowing into the Indian Ocean. AAIW also enters the Indian Ocean from south of Tasmania and flows westward towards Africa, where it joins the warm-water flow and the other branch of AAIW before rounding southern Africa, entering the South Atlantic, and flowing northward (Gordon 1985, Speich et al. 2002). Along its transit to the North Atlantic, AAIW from the Drake Passage, flowing above Tasman AAIW, mixes with overlying water and contributes to the "warm-water route" (Gordon 1986). These return flows provide a significant source of heat to high northern latitudes. Together, southward flow of water in the deep Atlantic and its shallower return flows are a large component of what is known as the global Meridional Overturning Circulation (MOC).

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

 

[Crick]

No dodge. Just facts.

The role of the ocean in storing, distributing and establishing climate is well known and well understood. Change the currents and you change the climate. Some regions are more sensitive to change than others and have more of a global impact than others. The Arctic is that region. The Little Ice age was triggered by a disruption of the ocean's heat circulation to the Arctic and that when that heat circulation was restored, the planet returned to it's natural interglacial warming trend. The contribution of the Industrial Revolution isn't nothing but all warming is not due to it. 0.22C top 0.5C is the contribution of 120 ppm of CO2.

1. The ocean stores the majority of heat the earth receives from the sun
2. The ocean holds 1000 times more heat than the atmosphere
3. The ocean distributes that heat to the rest of the globe using currents
4. Without ocean currents the polar regions would be colder and the equator would be hotter such that much of the planet would be inhospitable for life
5. Ocean currents are affected by density (salinity and thermal expansion) and wind.
6. Wind patterns are affected by the sun
7. If heat circulation from the Atlantic to the Arctic were disrupted it would lead to catastrophic cooling

The following are excerpts from papers explaining the science behind the climate changes of the past 3 million years.

It is found that the global salinity variations associated with the thermohaline circulation may have a tendency to make the circulation increasingly asymmetric with respect to the equator. As a consequence the salinity difference between the Pacific and the Atlantic Ocean may be slowly increasing. Such a process could have a time scale long enough to be comparable with the time span between major glaciations. A speculative glaciation cycle is proposed which involves the above mentioned property of the thermohaline circulation. In this cycle the role of a Northern Hemisphere glaciation is to bring excess freshwater from the Pacific to the Atlantic.

https://www.sciencedirect.com/science/article/abs/pii/S0031018285800201

Atlantic Ocean Circulation During the Last Ice Age​

There is strong evidence that the circulation of the deep Atlantic during the peak of the last Ice Age, or the Last Glacial Maximum (LGM; ~22,000 to 19,000 years ago) was different from the modern circulation (Boyle & Keigwin 1987, Duplessy et al. 1988, Marchal & Curry 2008). Compilations of deepwater δ13C and CdW for the LGM (Figure 5) show several features that contrast with their modern distributions. Whereas much of the modern deep western Atlantic has similar δ13C values because it is filled with NADW, during the LGM, the range of δ13C values was larger than today, with higher values in NADW and lower values in AABW. The main core of high-δ13C, low-CdW NADW was at least 1000 meters shallower than today, probably because the density difference between surface waters and deep water was reduced — surface salinity may have decreased as a result of less evaporation due to colder glacial temperatures, and as a result of input of freshwater from glaciers surrounding the North Atlantic (Boyle & Keigwin 1987). In the western Atlantic, depths below ~2 km were filled with AABW. Radiocarbon data suggest that deepwater was older (Keigwin & Schlegel 2002), consistent with less NADW and more AABW as indicated by the δ13C and CdW of benthic foraminifera. Glacial δ13C data from the eastern Atlantic suggest that the boundary between glacial AABW and glacial NADW may have been shallower than in the western Atlantic (Sarnthein et al. 1994), although the difference may be the result of local effects caused by increased glacial productivity and higher rates of remineralization of low-δ13C organic carbon in the eastern basin. Inferences using other kinds of proxy data of deep Atlantic circulation are consistent with the changes inferred from δ13C, Cd/Ca and 14C of benthic foraminifera (Lynch-Steiglitz et al. 2007).

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

As shown by the work of Dansgaard and his colleagues, climate oscillations of one or so millennia duration punctuate much of glacial section of the Greenland ice cores. These oscillations are characterized by 5°C air temperature changes, severalfold dust content changes and 50 ppm CO2 changes. Both the temperature and CO2 change are best explained by changes in the mode of operation of the ocean. In this paper we provide evidence which suggests that oscillations in surface water conditions of similar duration are present in the record from a deep sea core at 50°N. Based on this finding, we suggest that the Greenland climate changes are driven by oscillations in the salinity of the Atlantic Ocean which modulate the strength of the Atlantic's conveyor circulation.

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/PA005i004p00469

Water Masses in the Deep Atlantic Ocean​

The Atlantic Ocean is the only ocean basin that features the transformation of surface-to-deepwater near both poles. Warm salty tropical surface waters flowing northward in the western Atlantic cool in transit to and within the high-latitude North Atlantic, releasing heat to the overlying atmosphere and increasing seawater density. Once dense enough, these waters sink and flow southward between ~ 1000 and 4000m. This North Atlantic Deep Water (NADW), as it is called, flows from the Atlantic to the Southern Ocean where much of it upwells — or rises to the surface — around Antarctica, and some of it circulates Antarctica before entering the rest of the world's deep oceans. Antarctic Bottom Water (AABW), which is formed close to Antarctica, is denser than NADW, and flows northward in the Atlantic below NADW. AABW is confined to water depths below 4000 meters in the tropical and North Atlantic. Antarctic Intermediate Water (AAIW) flows northward above NADW. The presence of these three water masses in the Atlantic Ocean is evident in cross-sections of many water properties, including salinity, phosphate concentration and carbon isotope ratios (Figure 2). The residence time of deepwater in the western Atlantic is approximately 100 years (Broecker 1979), meaning that the average water parcel spends about a century in the deep Atlantic.

Why is Deep Water Formed in the Atlantic and not the Pacific?​

Warren (1983) first noted that the difference in salinity between the North Pacific and the North Atlantic (Figure 1) was the principal reason deep water formation occurs today only in the North Atlantic. Salty water, when cooled, achieves a higher density and is thus able to sink to greater depth in the water column. Wintertime cooling occurs in both the North Atlantic and North Pacific, but since the surface waters of the North Atlantic are much closer in salinity to the mean of the ocean's deep water, they achieve a density high enough to sink to great water depths. Warren (1983) noted that the salinity of the North Pacific was low because of relatively low evaporation, little exchange with salty tropical waters, and an influx of fresh water from precipitation and river runoff. Emile-Geay et al.(2003) reevaluated the Warren (1983) results and fundamentally confirmed his thesis, noting that atmospheric moisture transport from the Asian monsoon was also an important source of fresh water to the North Pacific not originally considered by Warren. Interestingly, Warren also noted that the North Atlantic had much greater river runoff than the North Pacific, so its higher surface salinities must be the result of greater evaporation in the Atlantic basin.

Broecker et al. (1990a) noted that higher Atlantic salinities are the result of a net transfer of water vapor from the Atlantic to the Pacific over the Isthmus of Panama, equivalent to approximately 0.35 Sverdrup (106 m3 per second). In the absence of other processes, this would raise the salinity of the Atlantic by about 1 salinity unit each 1000 years. If the Atlantic salinity is in balance, then it must be exporting the excess salt (enough to compensate for the lost fresh water) through ocean circulation processes. Today this is occurring through the production and export of North Atlantic Deep Water.
At times in the past, rapid melting of ice sheets surrounding the North Atlantic was great enough to alter surface salinities, likely reducing the density of deep water formed, and slowing the export of deep water from the North Atlantic. Broecker et al. (1990b) hypothesized that natural oscillations in the rate of water vapor exchange between the Atlantic and the Pacific during the last glacial period were responsible for the rapid, short term fluctuation ocean circulation linked to the abrupt millennial-scale Dansgaard-Oeschger Events seen in the Greenland ice cores (Figure 9).

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

What Replaces the Deep Water that Leaves the Atlantic?​

There are three main pathways for water to return to the North Atlantic and renew NADW, a warm-water route and two cold water routes (Figure 3). The "warm-water route" begins with the flow of surface and thermocline water from the Pacific to the Indian Ocean through the Indonesian Seas. Both colder return flows involve Antarctic Intermediate Water (AAIW), described above. AAIW enters the southern South Atlantic through the Drake Passage between Antarctica and South America, with some flowing into the Atlantic and some flowing into the Indian Ocean. AAIW also enters the Indian Ocean from south of Tasmania and flows westward towards Africa, where it joins the warm-water flow and the other branch of AAIW before rounding southern Africa, entering the South Atlantic, and flowing northward (Gordon 1985, Speich et al. 2002). Along its transit to the North Atlantic, AAIW from the Drake Passage, flowing above Tasman AAIW, mixes with overlying water and contributes to the "warm-water route" (Gordon 1986). These return flows provide a significant source of heat to high northern latitudes. Together, southward flow of water in the deep Atlantic and its shallower return flows are a large component of what is known as the global Meridional Overturning Circulation (MOC).

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation​

You've posted this before and as I told you then, I have read all this and find nothing here that supports your claim. I ask, again, to identify specific statements that you believe do support your contentions, from these texts or others.

 

[ding]

You've posted this before and as I told you then, I have read all this and find nothing here that supports your claim. I ask, again, to identify specific statements that you believe do support your contentions, from these texts or others.

Then you are an idiot and a liar. You're own posts convict you.

Here is one paper investigating the possibility that they are due to the collapse of thermohaline circulation (THC) known in the Atlantic Ocean as the Atlantic Meridional Overturning Circulation (AMOC). High salinity water in North Atlantic cools and as it approaches maximum density (4C) it sinks several kilometers. A slow bottom flow then proceeds south and at the equator runs into a mirror image current coming from the southern pole. The two rise, bringing large amounts of dissolved nutrients to the surface at the equator. Warmed water slowly flows north (and south) to close the two loops. There is very little of such flow in the Pacific due to the low salinity of the water in the North Pacific. Even cooled to maximum density, it is not driven to sink. The difference between the behavior of the two basins has been recreated in a wide range of models. But there are strong indications that the current situation in the Atlantic is unstable and that it could be stopped altogether by a large input of fresh water, from melting ice in the Arctic and Greenland. Since this flow is responsible for the moderate temperature in Europe, the result would be catastrophic cooling there. That info is from the paper's abstract. Visit the link if you want more.
https://www.pnas.org/doi/10.1073/pnas.97.4.1347 [PNAS = Proceedings of the National Academy of Sciences]

Here is another paper that reports on an spontaneous abrupt cooling that took place in a high resolution model with sensitive sea-ice modelling. The cooling lasted approximately one century and stopped as abruptly as it had started. I'll let them explain: "The event was simulated in the preindustrial control run of a high-resolution climate model, without imposing external perturbations. Initial cooling started with a period of enhanced atmospheric blocking over the eastern subpolar gyre. In response, a southward progression of the sea-ice margin occurred, and the sea-level pressure anomaly was locked to the sea-ice margin through thermal forcing. The cold-core high steered more cold air to the area, reinforcing the sea-ice concentration anomaly east of Greenland. The sea-ice surplus was carried southward by ocean currents around the tip of Greenland. South of 70°N, sea ice already started melting and the associated freshwater anomaly was carried to the Labrador Sea, shutting off deep convection. There, surface waters were exposed longer to atmospheric cooling and sea surface temperature dropped, causing an even larger thermally forced high above the Labrador Sea. In consequence, east of Greenland, anomalous winds changed from north to south, terminating the event with similar abruptness to its onset" https://www.pnas.org/doi/10.1073/pnas.1304912110
Here is a third paper that points out that "complex environmental systems are never in equilibrium" being constantly driven by oscillating inputs such as seasonal cycles, Milankovitch forcing and internal climate oscillations (ENSO, PDO, etc). This is a broader discussion than just the interglacial cycle but it does point out that under non-equilibrium conditions it is possible to have multiple alternative pseudo-stable states under identical forcing conditions between which a system can be "tipped" by small changes in external forcing. Abrupt Climate Change in an Oscillating World - Scientific Reports [Nature magazine]

 

[Crick]

Then you are an idiot and a liar. You're own posts convict you.

Nothing in my text there or the articles to which I refer support your claims.

 

[ding]

Nothing in my text there or the articles to which I refer support your claims.

Except that part where you said the collapse of the AMOC would lead to CATASTROPHIC COOLING.

 

[Captain Caveman]

All climate predictions are based on the gambler's fallacy

 

[Crick]

Except that part where you said the collapse of the AMOC would lead to CATASTROPHIC COOLING.

In Europe, asshole.

 

[ding]

In Europe, asshole.

So the AMOC only warms Europe?

 

[Crick]

So the AMOC only warms Europe?

Look at the goddamned map. And think about the impact. A lot more of the Gulf Stream hits the North Atlantic and Europe than hits the Arctic Ocean. Something about Greenland and Iceland sitting in the way. And how many PEOPLE are going to be impacted by the Arctic dropping ten degrees? How many people are going to be impacted by Europe dropping ten degrees?

 

[ding]

Look at the goddamned map. And think about the impact. A lot more of the Gulf Stream hits the North Atlantic and Europe than hits the Arctic Ocean. Something about Greenland and Iceland sitting in the way. And how many PEOPLE are going to be impacted by the Arctic dropping ten degrees? How many people are going to be impacted by Europe dropping ten degrees?

Maybe read the papers.

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation

How has deep ocean circulation changed in the past, and how have the changes affected Earth's climate? Reconstructing ocean circulation and climate history using geological records.

www.nature.com

Destabilisation of the Subpolar North Atlantic prior to the Little Ice Age - Nature Communications

Bivalves reveal that the subpolar North Atlantic destabilised and shows signs of having crossed a tipping point during the transition into the Little Ice Age.

www.nature.com

Do you have any papers that support what you are saying?

 

[Crick]

Maybe read the papers.

Deep Atlantic Circulation During the Last Glacial Maximum and Deglaciation

How has deep ocean circulation changed in the past, and how have the changes affected Earth's climate? Reconstructing ocean circulation and climate history using geological records.

www.nature.com

Destabilisation of the Subpolar North Atlantic prior to the Little Ice Age - Nature Communications

Bivalves reveal that the subpolar North Atlantic destabilised and shows signs of having crossed a tipping point during the transition into the Little Ice Age.

www.nature.com

Do you have any papers that support what you are saying?

Straw man lies.

 

[ding]

Straw man lies.

Do you have any papers that show the ocean isn't responsible for abrupt climate changes?

 

[ding]

Straw man lies.

Do you have evidence that the following is in error?

Using statistical indicators of resilience in three annually-resolved bivalve proxy records from the North Icelandic shelf, we show that the subpolar North Atlantic climate system destabilised during two episodes prior to the Little Ice Age. This loss of resilience indicates reduced attraction to one stable state, and a system vulnerable to an abrupt transition. The two episodes preceded wider subpolar North Atlantic change, consistent with subpolar gyre destabilisation and the approach of a tipping point, potentially heralding the transition to Little Ice Age conditions.​

 

[ding]

Straw man lies.

Do you have any studies which disputes the following?

Studies agree that an initial export of Arctic sea-ice into key convective regions of the North Atlantic weakened ocean convection. Reduced convection may have weakened the Atlantic Meridional Overturning Circulation (AMOC)4,5,6,7 and/or the subpolar gyre (SPG) circulation strength4,7,8, leading to a reduction in poleward heat transport, ultimately reinforcing sea-ice expansion through a positive feedback3,4,5,6,7,8. Both elements, the AMOC and SPG, have been shown to exhibit bistability in numerical9,10,11,12 and theoretical models13,14, with transitions stimulated by changes in convection.​

 

[ding]

Straw man lies.

Do you have any studies which disputes the evidence of ocean circulation during the last glacial period or that it was very different from today?

​

Reconstructions of past ocean circulation have relied heavily on the chemistry of foraminifera, single-celled organisms that secrete a shell made of calcium carbonate (CaCO3). The shells of foraminifera that live on the sea floor, or "benthic" foraminifera, record many chemical properties of the overlying seawater. Critical for paleoceanographic reconstructions, benthic foraminifera incorporate carbon to make their shells in approximately the same carbon-13 to carbon-12 isotope ratio as the overlying seawater (Curry et al. 1988). Similarly, benthic foraminifera incorporate cadmium (Cd) into their shells in a known proportion to seawater Cd, and so cadmium/calcium (Cd/Ca) measured in benthic foraminifera enable estimates of seawater Cd (CdW) (Boyle 1988).​

​

CdW and the ratio of carbon-13 to carbon-12 (13C/12C, reported as δ13C) in deep water covary with nutrient content. In the deep Atlantic, phosphate content is correlated to salinity, which helps define the different water masses (Figure 2), and so measuring δ13C or Cd/Ca in fossil foraminifera with known ages can tell us whether the properties and boundaries of the important deep water masses — NADW, AABW, and AAIW — have changed in the past.​

​

Foraminifera also record the abundance of carbon-14 in seawater. Carbon-14 is a radioactive carbon isotope produced in the atmosphere, and enters the surface ocean through air-sea gas exchange. The difference between its abundance in deep water and in surface water provides a measure for how much time has passed since the deep water was last at the surface and in contact with the atmosphere. This "ventilation age" can be estimated in the past by measuring the difference in the abundance of 14C between coexisting benthic foraminifera and foraminifera that lived at the ocean surface, or "planktic" foraminifera (Benthic-Planktic radiocarbon age). Radiocarbon measurements therefore provide a way to evaluate whether the renewal rate of deepwater by surface water was slower or faster in the past (Broecker & Peng 1982). Ventilation age estimates are complicated by variations through time in the production of radiocarbon in the atmosphere (Adkins & Boyle 1997) and by variations in surface ocean radiocarbon due to changes in oceanography (e.g., mixing with deeper, older water) (Bard et al. 1994). These complications can be circumvented to some extent if there is an independent timescale for a sediment record that does not rely on the radiocarbon chronology (e.g., Thornalley et al. 2011).​

​

To reconstruct deep ocean circulation using the geochemistry of foraminifera, scientists use sediment cores, taken from a range of water depths along the continental margins, mid-ocean ridges, and other bathymetric highs in the ocean basins. This strategy allows them to sample sediments that intersect the main water masses: AAIW, NADW, and AABW (Figure 4). Once they have acquired the sediment cores, they use a variety of methods, including radiocarbon dating of foraminifera, to identify sediments that were deposited at times in the past, like the last Ice Age, when climate was very different from today.​

​

 

[Crick]

Do you have any studies which disputes the evidence of ocean circulation during the last glacial period or that it was very different from today?

​

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Reconstructions of past ocean circulation have relied heavily on the chemistry of foraminifera, single-celled organisms that secrete a shell made of calcium carbonate (CaCO3). The shells of foraminifera that live on the sea floor, or "benthic" foraminifera, record many chemical properties of the overlying seawater. Critical for paleoceanographic reconstructions, benthic foraminifera incorporate carbon to make their shells in approximately the same carbon-13 to carbon-12 isotope ratio as the overlying seawater (Curry et al. 1988). Similarly, benthic foraminifera incorporate cadmium (Cd) into their shells in a known proportion to seawater Cd, and so cadmium/calcium (Cd/Ca) measured in benthic foraminifera enable estimates of seawater Cd (CdW) (Boyle 1988).​

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CdW and the ratio of carbon-13 to carbon-12 (13C/12C, reported as δ13C) in deep water covary with nutrient content. In the deep Atlantic, phosphate content is correlated to salinity, which helps define the different water masses (Figure 2), and so measuring δ13C or Cd/Ca in fossil foraminifera with known ages can tell us whether the properties and boundaries of the important deep water masses — NADW, AABW, and AAIW — have changed in the past.​

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Foraminifera also record the abundance of carbon-14 in seawater. Carbon-14 is a radioactive carbon isotope produced in the atmosphere, and enters the surface ocean through air-sea gas exchange. The difference between its abundance in deep water and in surface water provides a measure for how much time has passed since the deep water was last at the surface and in contact with the atmosphere. This "ventilation age" can be estimated in the past by measuring the difference in the abundance of 14C between coexisting benthic foraminifera and foraminifera that lived at the ocean surface, or "planktic" foraminifera (Benthic-Planktic radiocarbon age). Radiocarbon measurements therefore provide a way to evaluate whether the renewal rate of deepwater by surface water was slower or faster in the past (Broecker & Peng 1982). Ventilation age estimates are complicated by variations through time in the production of radiocarbon in the atmosphere (Adkins & Boyle 1997) and by variations in surface ocean radiocarbon due to changes in oceanography (e.g., mixing with deeper, older water) (Bard et al. 1994). These complications can be circumvented to some extent if there is an independent timescale for a sediment record that does not rely on the radiocarbon chronology (e.g., Thornalley et al. 2011).​

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To reconstruct deep ocean circulation using the geochemistry of foraminifera, scientists use sediment cores, taken from a range of water depths along the continental margins, mid-ocean ridges, and other bathymetric highs in the ocean basins. This strategy allows them to sample sediments that intersect the main water masses: AAIW, NADW, and AABW (Figure 4). Once they have acquired the sediment cores, they use a variety of methods, including radiocarbon dating of foraminifera, to identify sediments that were deposited at times in the past, like the last Ice Age, when climate was very different from today.​

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Have you ever noticed that when Trump doubles down on one of his idiotic moves, it is taken as evidence that he's even stupider than thought? I have never said that ocean circulation doesn't change over time. I have never said that changes in ocean circulation couldn't affect climate, particularly regionally. I'm saying that changes in ocean circulation are NOT responsible for the glacial-interglacial cycle nor are they responsible for the warming observed over the past 150 years. That no one has dedicated a study to refuting your contention is simply prima facie evidence that your contention has never been considered a hypothesis worthy of the least pursuit.