How long until the Climate Cult re-appears, now that there's hot weather?

[ding]

Is that a quote? You know, Ben Franklin? Voltaire? Nietsche? Quayle?

It's a fact.

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​

 

[otto105]

It's a fact.

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​

Another useless dinger fail

 

[ding]

Another useless dinger fail

1. The ocean stores the majority of heat 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
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

 

[otto105]

1. The ocean stores the majority of heat 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
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

Another useless talking point by denial dinger.

 

[ding]

#WINNING

 

[Crick]

1. The ocean stores the majority of heat 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
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

None of this supports your contentions. None of it.

 

[ding]

None of this supports your contentions. None of it.

Ocean currents establish climate.
The ocean is the largest collector of solar energy.
The ocean stores the majority of the planet's heat.
The ocean is the largest feature of the planet.
The mass of the ocean is 300 times the mass of the atmosphere.
The ocean contains 1000 times more heat than the ocean.
The ocean heats the atmosphere.
The atmosphere does not heat the ocean.
Physical evidence shows that when ocean currents change, the climate changes.
Physical evidence shows ocean currents are responsible for northern hemisphere glaciation.
Physical evidence shows ocean currents are responsible for the initiation of the Little Ice Age.
Physical evidence shows ocean currents are responsible for the end of the Little Ice Age.
The current warming trend began 250 years before the industrial revolution.
The geologic record is littered with examples of naturally caused warming and cooling trends.
Empirical climate evidence shows the planet cooled for millions of years with >600 ppm of CO2.
The last interglacial period was 2C warmer with 26ft higher seas and 120ppm less CO2 than today.

 

[Crick]

Ocean currents establish climate.
The ocean is the largest collector of solar energy.
The ocean stores the majority of the planet's heat.
The ocean is the largest feature of the planet.
The mass of the ocean is 300 times the mass of the atmosphere.
The ocean contains 1000 times more heat than the ocean.
The ocean heats the atmosphere.
The atmosphere does not heat the ocean.
Physical evidence shows that when ocean currents change, the climate changes.
Physical evidence shows ocean currents are responsible for northern hemisphere glaciation.
Physical evidence shows ocean currents are responsible for the initiation of the Little Ice Age.
Physical evidence shows ocean currents are responsible for the end of the Little Ice Age.
The current warming trend began 250 years before the industrial revolution.
The geologic record is littered with examples of naturally caused warming and cooling trends.
Empirical climate evidence shows the planet cooled for millions of years with >600 ppm of CO2.
The last interglacial period was 2C warmer with 26ft higher seas and 120ppm less CO2 than today.

None of this supports your contention. None of it.

 

[ding]

None of this supports your contention. None of it.

How so?

 

[Crick]

How so?

Show us a single, peer-reviewed statement that concludes, suggests or even hints that the glacial-integlacial cycle is caused by changes in ocean circulation. And, while you're at it, you might suggest an explanation as to why any query as to its cause is invariably answered with Milankovitch orbital forcing.

 

[ding]

Show us a single, peer-reviewed statement that concludes, suggests or even hints that the glacial-integlacial cycle is caused by changes in ocean circulation. And, while you're at it, you might suggest an explanation as to why any query as to its cause is invariably answered with Milankovitch orbital forcing.

https://www.science.org/content/article/crippled-atlantic-currents-triggered-ice-age-climate-change

 

[Crick]

https://www.science.org/content/article/crippled-atlantic-currents-triggered-ice-age-climate-change

This is not the glacial-integlacial cycle. And if it is cooling in the north while it is warming in the south, it is not affecting the planet as a whole. As I have said repeatedly, it is simply moving heat around on the Earth's surface. I do note that it says "Another question is whether the AMOC—currently known to be in decline—could drop off suddenly today, as depicted in the 2004 movie The Day After Tomorrow, causing temperatures to plummet across northwestern Europe."

 

[ding]

This is not the glacial-integlacial cycle. And if it is cooling in the north while it is warming in the south, it is not affecting the planet as a whole. As I have said repeatedly, it is simply moving heat around on the Earth's surface. I do note that it says "Another question is whether the AMOC—currently known to be in decline—could drop off suddenly today, as depicted in the 2004 movie The Day After Tomorrow, causing temperatures to plummet across northwestern Europe."

III.1. North Atlantic circulation as a trigger or an amplifier in rapid climate changes.

The circulation of the north Atlantic Ocean probably plays a major role in either triggering or amplifying rapid climate changes in the historical and recent geological record (Broecker 1995, Keigwin et al., 1994, Jones et al., 1996; Rahmstorf et al., 1996). The North Atlantic has a peculiar circulation pattern: the north-east trending Gulf Stream carries warm and relatively salty surface water from the Gulf of Mexico up to the seas between Greenland, Iceland and Norway. Upon reaching these regions, the surface waters cools off and (with the combination of being cooler and relatively salty because it mixes with mid-depth overflow water from the Mediterranean) becomes dense enough to sink into the deep ocean. The 'pull' exerted by this dense sinking water is thought to help maintain the strength of the warm Gulf Stream, ensuring a current of warm tropical water into the north Atlantic that sends mild air masses across to the European continent (e.g., Rahmstorf et al., 1996; Schmitz, 1995) (Fig. 3).

If the sinking process in the north Atlantic were to diminish or cease, the weakening of the warm Gulf Stream would mean that Europe had colder winters (e.g., Broecker, 1995). However, the Gulf Stream does not give markedly warmer summers in Europe - more the opposite in fact - so a shutting off of the mild Gulf Stream air masses does not in itself explain why summers also became colder during sudden cooling events (and why ice masses started to build up on land due to winter snows failing to melt during summer). In the North Atlantic itself, sea ice would form more readily in the cooler winter waters due to a shut-off of the Gulf Stream, and for a greater part of the year the ice would form a continuous lid over the north Atlantic. A lid of sea ice over the North Atlantic would last for a greater proportion of the year; this would reflect back solar heat, leading to cooler summers on the adjacent landmass as well as colder winters (e.g., Jones et al., 1996; Overpeck et al., 1997). With cooler summers, snow cover would last longer into the spring, further cooling the climate by reflecting back the sun's heat. The immediate result of all this would be a European and west Siberian climate that was substantially colder, and substantially drier because the air that reached Europe would carry less moisture, having come from a cold sea ice surface rather than the warm Gulf Stream waters.

After an initial rapid cooling event, the colder summers would also tend to allow the snow to build up year-on-year into a Scandinavian ice sheet, and as the ice built up it would reflect more of the Sun's heat, further cooling the land surface, and giving a massive high pressure zone that would be even more effective at diverting Gulf Stream air and moisture away from the mid-latititudes of Europe. This would reinforce a much colder regional climate.

The trigger for a sudden 'switching off' or a strong decrease in deep water formation in the North Atlantic must be found in a decrease in density of surface waters in the areas of sinking in the northern Atlantic Ocean. Such a decrease in density would result from changes in salinity (addition of fresh water from rivers, precipitation, or melt water), and/or increased temperatures (Dickson et al., 1988; Rahmstorf et al., 1996). For example, an exceptionally wet year on the landmasses which have rivers draining into the Arctic sea (Siberia, Canada, Alaska) would lead to such a decreased density. Ocean circulation modelling studies suggest that a relatively small increase in freshwater flux (called 'polar halocline catastrophe') to the Arctic Sea could cause deep water production in the north Atlantic to cease (e.g., Mikolajewicz and Maier-Reimer, 1994; Rahmstorf, 1994; Rahmstorf et al., 1996; 141).

During glacial phases, the trigger for a shut-off or a decrease in deep water formation could be the sudden emptying into the northern seas of a lake formed along the edge of a large ice sheet on land (for instance, the very large ice-dammed lake that existed in western Siberia), or a diversion of a meltwater stream from the North American Laurentide ice sheet through the Gulf of St. Lawrence , as seems to have occurred as part of the trigger for the Younger Dryas cold event (e.g., Kennett, 1990; Berger and Jansen, 1995). A pulse of fresh water would dilute the dense, salty GulfStream and float on top, forming a temporary lid that stopped the sinking of water that helps drive the Gulf Stream. The Gulf Stream could weaken and its northern end (the North Atlantic Drift) could switch off altogether, breaking the 'conveyer belt' and allowing an extensive sea ice cap to form across the North Atlantic, preventing the ocean current from starting up again at its previous strength. Theoretically, the whole process could occur very rapidly, in the space of just a few decades or even several years. The result could be a very sudden climate change to colder conditions, as has happened many times in the area around the North Atlantic during the last 100,000 years.

The sudden switch could also occur in the opposite direction, for example if warmer summers caused the sea ice to melt back to a critical point where the sea ice lid vanished and the Gulf Stream was able to start up again. Indeed, following an initial cooling event the evaporation of water vapour in the tropical Atlantic could result in an 'oscillator' whereby the salinity of Atlantic Ocean surface water (unable to sink into the north Atlantic because of the lid of sea ice) built up to a point where strong sinking began to occur anyway at the edges of the sea ice zone. The onset of sinking could result in a renewed northward flux of warm water and air to the north Atlantic, giving a sudden switch to warmer climates, as is observed many times within the record of the last 130,000 years or so.

The process of switching off or greatly dimishing the flow of the Gulfstream would not only affect Europe. Antarctica would be even colder than it is now, because much of the heat that it does receive now ultimately comes from Gulf Stream water that sinks in the north Atlantic, travels in a sort of river down the western side of the deep Atlantic Basin and then rat least partially esurfaces just off the bays of the Antarctic coastline (e.g., Schmitz, 1995). Even though this water is only a few degrees above freezing when it reaches the surface, this water is much warmer than the adjacent Antarctic continent, helping to melt back some of the sea ice that forms around Antarctica in the ice-free regions called polynyas. The effect of switching off the deepwater heat source would be cooler air and a greater sea ice extent around Antarctica, reflecting more sunlight and further cooling the region. However, the north Atlantic deep water takes several hundred years to travel from its place of origin to the Antarctic coast, so it could only produce an effect a few centuries after the change occurred in the North. It is not known what delay was present in the various climate changes that occurred between the north Atlantic region and Antarctica, but it is generally thought that other (relatively indirect) climate mechanisms, such as greenhouse gases in the atmosphere, linked these two far-flung regions and sometimes produced closely synchronised changes (i.e. within a few centuries of one another).

Although the end of the Last Glacial and various other sudden climate events such as Heinrich events do show up in the Antarctic ice record, not all large changes show such a closely linked occurrence and timing around the world. For example there is no clear trace of the Younger Dryas in the Vostok ice core from Antarctica (Chapellaz et al. 1993; Broecker, 1998), and the warming at the start of the Eemian also does not seem to particularly closely linked to the timing of the warming which took place in the northern latitudes (Sowers et al. 1993).

During the colder glacial phases, deep water formation in the present areas between Greenland, Iceland and Norway would have ceased or dimished due to a thick cap of sea ice (though there is evidence it occasionally opened up to let Gulf Stream water through to the sea between Iceland and Norway, this did not result in much deepwater formation and so the pull and the northward heat flux seems to have been small). Instead, during the most intense cold phases the deepwater formation area seems to have moved to the south of the British Isles, at the edge of the extended sea ice zone (e.g., , Imbrie et al. 1992, Duplessey et al. 1984; Maslin et al., 1997). Even here, deep water formation seems to have been weaker than at present, producing relatively small quantities which penetrated to mid-depths rather than to the deepest ocean basins. This was probably at least partly because the whole surface of the Atlantic Ocean (even the tropics) was cooler; with less evaporation from its surface, even the water that did reach northwards was less briney (and thus less dense), so less able to sink when it reached the cold edge of the sea ice zone. An initial slowdown of north Atlantic circulation may have been the initial trigger for a set of amplifying factors (see below) that rapidly led to a cooling of the tropical Atlantic, reinforcing the sluggish state of the glacial-age Gulf Stream.

The idea of Gulf Stream slowdowns as a mechanism in climate change is not merely theoretical. There is actually evidence from the study of ocean sediments that deepwater formation in the north Atlantic was diminished during the sudden cold Heinrich events and other colder phases of the last 130,000 years, including the Younger Dryas phase (e.g., Fairbanks, 1989; Kennett, 1990; Maslin, 199x). The same appears to have been true further back in time to 1.5 Myr ago (Raymo et al. 1998). The process also 'switched on' rapidly at times when climates suddenly warmed around the north Atlantic Basin, such as at the beginning of interstadials or the beginning of the present interglacial (Ramussen et al. 1997). Decreasing deep water formation occurred at times when the climate was cooling towards the end of an interstadial, and it diminished suddenly with the final cooling event that marked the end of the interstadial (Ramussen et al., 1997), and over a period of less than 300 years at the beginning of the Younger Dryas (e.g., Berger and Jansen, 1995).

Sudden climate changes in the recent geological record

 

[Crick]

I have highlighted portions of your text in bold red and than added my comments in [bracketed blue]

III.1. North Atlantic circulation as a trigger or an amplifier in rapid climate changes.

The circulation of the north Atlantic Ocean probably plays a major role in either triggering or amplifying rapid climate changes [NOT THE GLACIAL-INTERGLACIAL CYCLE] in the historical and recent geological record (Broecker 1995, Keigwin et al., 1994, Jones et al., 1996; Rahmstorf et al., 1996) [EVERY SINGLE ONE OF WHOM HAS STATED THAT THE GLACIAL-INTERGLACIAL CYCLE IS INITIATED BY ORBITAL FORCING]. The North Atlantic has a peculiar circulation pattern: the north-east trending Gulf Stream carries warm and relatively salty surface water from the Gulf of Mexico up to the seas between Greenland, Iceland and Norway. Upon reaching these regions, the surface waters cools off and (with the combination of being cooler and relatively salty because it mixes with mid-depth overflow water from the Mediterranean) becomes dense enough to sink into the deep ocean. The 'pull' exerted by this dense sinking water is thought to help maintain the strength of the warm Gulf Stream, ensuring a current of warm tropical water into the north Atlantic that sends mild air masses across to the European continent (e.g., Rahmstorf et al., 1996; Schmitz, 1995) (Fig. 3).

If the sinking process in the north Atlantic were to diminish or cease, the weakening of the warm Gulf Stream would mean that Europe had colder winters (e.g., Broecker, 1995). However, the Gulf Stream does not give markedly warmer summers in Europe - more the opposite in fact - so a shutting off of the mild Gulf Stream air masses does not in itself explain why summers also became colder during sudden cooling events (and why ice masses started to build up on land due to winter snows failing to melt during summer). In the North Atlantic itself, sea ice would form more readily in the cooler winter waters due to a shut-off of the Gulf Stream, and for a greater part of the year the ice would form a continuous lid over the north Atlantic. A lid of sea ice over the North Atlantic would last for a greater proportion of the year; this would reflect back solar heat, leading to cooler summers on the adjacent landmass as well as colder winters (e.g., Jones et al., 1996; Overpeck et al., 1997). With cooler summers, snow cover would last longer into the spring, further cooling the climate by reflecting back the sun's heat. The immediate result of all this would be a European and west Siberian climate that was substantially colder, and substantially drier because the air that reached Europe would carry less moisture, having come from a cold sea ice surface rather than the warm Gulf Stream waters.

After an initial rapid cooling event, the colder summers would also tend to allow the snow to build up year-on-year into a Scandinavian ice sheet, and as the ice built up it would reflect more of the Sun's heat, further cooling the land surface, and giving a massive high pressure zone that would be even more effective at diverting Gulf Stream air and moisture away from the mid-latititudes of Europe. This would reinforce a much colder regional climate.

The trigger for a sudden 'switching off' or a strong decrease in deep water formation in the North Atlantic must be found in a decrease in density of surface waters in the areas of sinking in the northern Atlantic Ocean. Such a decrease in density would result from changes in salinity (addition of fresh water from rivers, precipitation, or melt water), and/or increased temperatures (Dickson et al., 1988; Rahmstorf et al., 1996). For example, an exceptionally wet year on the landmasses which have rivers draining into the Arctic sea (Siberia, Canada, Alaska) would lead to such a decreased density. Ocean circulation modelling studies suggest that a relatively small increase in freshwater flux (called 'polar halocline catastrophe') to the Arctic Sea could cause deep water production in the north Atlantic to cease (e.g., Mikolajewicz and Maier-Reimer, 1994; Rahmstorf, 1994; Rahmstorf et al., 1996; 141).

During glacial phases, the trigger for a shut-off or a decrease in deep water formation could be the sudden emptying into the northern seas of a lake [Which currently does not exist] formed along the edge of a large ice sheet on land (for instance, the very large ice-dammed lake that existed in western Siberia), or a diversion of a meltwater stream from the North American Laurentide ice sheet through the Gulf of St. Lawrence , as seems to have occurred as part of the trigger for the Younger Dryas cold event (e.g., Kennett, 1990; Berger and Jansen, 1995). A pulse of fresh water would dilute the dense, salty GulfStream and float on top, forming a temporary lid that stopped the sinking of water that helps drive the Gulf Stream. The Gulf Stream could weaken and its northern end (the North Atlantic Drift) could switch off altogether, breaking the 'conveyer belt' and allowing an extensive sea ice cap to form across the North Atlantic, preventing the ocean current from starting up again at its previous strength. Theoretically, the whole process could occur very rapidly, in the space of just a few decades or even several years. The result could be a very sudden climate change to colder conditions, as has happened many times in the area around the North Atlantic during the last 100,000 years.

The sudden switch could also occur in the opposite direction, for example if warmer summers caused the sea ice to melt back to a critical point where the sea ice lid vanished and the Gulf Stream was able to start up again. Indeed, following an initial cooling event the evaporation of water vapour in the tropical Atlantic could result in an 'oscillator' whereby the salinity of Atlantic Ocean surface water (unable to sink into the north Atlantic because of the lid of sea ice) built up to a point where strong sinking began to occur anyway at the edges of the sea ice zone. The onset of sinking could result in a renewed northward flux of warm water and air to the north Atlantic, giving a sudden switch to warmer climates, as is observed many times within the record of the last 130,000 years or so. [Within one glacial-interglacial period, not outside it]

The process of switching off or greatly dimishing the flow of the Gulfstream would not only affect Europe. Antarctica would be even colder than it is now, because much of the heat that it does receive now ultimately comes from Gulf Stream water that sinks in the north Atlantic, travels in a sort of river down the western side of the deep Atlantic Basin and then at least partially resurfaces just off the bays of the Antarctic coastline (e.g., Schmitz, 1995). Even though this water is only a few degrees above freezing when it reaches the surface, this water is much warmer than the adjacent Antarctic continent, helping to melt back some of the sea ice that forms around Antarctica in the ice-free regions called polynyas. The effect of switching off the deepwater heat source would be cooler air and a greater sea ice extent around Antarctica, reflecting more sunlight and further cooling the region. However, the north Atlantic deep water takes several hundred years to travel from its place of origin to the Antarctic coast, so it could only produce an effect a few centuries after the change occurred in the North. It is not known what delay was present in the various climate changes that occurred between the north Atlantic region and Antarctica, but it is generally thought that other (relatively indirect) climate mechanisms, such as greenhouse gases in the atmosphere, linked these two far-flung regions and sometimes produced closely synchronised changes (i.e. within a few centuries of one another). [An example of the atmosphere - via greenhouse gases - driving ocean behavior]

Although the end of the Last Glacial and various other sudden climate events such as Heinrich events do show up in the Antarctic ice record, not all large changes show such a closely linked occurrence and timing around the world. For example there is no clear trace of the Younger Dryas in the Vostok ice core from Antarctica (Chapellaz et al. 1993; Broecker, 1998) [And so was not fully global in extent], and the warming at the start of the Eemian also does not seem to particularly closely linked to the timing of the warming which took place in the northern latitudes (Sowers et al. 1993).

During the colder glacial phases, deep water formation in the present areas between Greenland, Iceland and Norway would have ceased or dimished due to a thick cap of sea ice (though there is evidence it occasionally opened up to let Gulf Stream water through to the sea between Iceland and Norway, this did not result in much deepwater formation and so the pull and the northward heat flux seems to have been small). Instead, during the most intense cold phases the deepwater formation area seems to have moved to the south of the British Isles, at the edge of the extended sea ice zone (e.g., , Imbrie et al. 1992, Duplessey et al. 1984; Maslin et al., 1997). Even here, deep water formation seems to have been weaker than at present, producing relatively small quantities which penetrated to mid-depths rather than to the deepest ocean basins. This was probably at least partly because the whole surface of the Atlantic Ocean (even the tropics) was cooler; with less evaporation from its surface, even the water that did reach northwards was less briney (and thus less dense), so less able to sink when it reached the cold edge of the sea ice zone. An initial slowdown of north Atlantic circulation may have been the initial trigger for a set of amplifying factors (see below) that rapidly led to a cooling of the tropical Atlantic, reinforcing the sluggish state of the glacial-age Gulf Stream.

The idea of Gulf Stream slowdowns as a mechanism in climate change is not merely theoretical. There is actually evidence from the study of ocean sediments that deepwater formation in the north Atlantic was diminished during the sudden cold Heinrich events and other colder phases of the last 130,000 years, including the Younger Dryas phase (e.g., Fairbanks, 1989; Kennett, 1990; Maslin, 199x). [Again, not driving the glacial-interglacial cycle but shorter events: Heinrich and D-O, within glacial periods] The same appears to have been true further back in time to 1.5 Myr ago (Raymo et al. 1998). The process also 'switched on' rapidly at times when climates suddenly warmed around the north Atlantic Basin, such as at the beginning of interstadials or the beginning of the present interglacial (Ramussen et al. 1997). Decreasing deep water formation occurred at times when the climate was cooling towards the end of an interstadial, and it diminished suddenly with the final cooling event that marked the end of the interstadial (Ramussen et al., 1997), and over a period of less than 300 years at the beginning of the Younger Dryas (e.g., Berger and Jansen, 1995).

Sudden climate changes in the recent geological record

So, again, nowhere does this text state, suggest or even hint that changing ocean currents are responsible for the glacial-interglacial cycle.

 

[ding]

I have highlighted portions of your text in bold red and than added my comments in [bracketed blue]

So, again, nowhere does this text state, suggest or even hint that changing ocean currents are responsible for the glacial-interglacial cycle.

Read the paper, ya political hack.

 

[Crick]

Read the paper, ya political hack.

I quite obviously read it more closely than did you. In how many of your linked articles have I now pulled comments that refute your own contentions?

 

[ding]

I quite obviously read it more closely than did you. In how many of your linked articles have I now pulled comments that refute your own contentions?

https://www.science.org/doi/10.1126/science.aaf5529?adobe_mc=MCMID%3D24445298415631476812898182430771639861%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1723213472

https://www.science.org/doi/10.1126/science.aaf5529?adobe_mc=MCMID%3D24445298415631476812898182430771639861%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1723213472

https://www.science.org/content/article/crippled-atlantic-currents-triggered-ice-age-climate-change

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]

https://www.science.org/doi/10.1126/science.aaf5529?adobe_mc=MCMID%3D24445298415631476812898182430771639861%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1723213472

https://www.science.org/doi/10.1126/science.aaf5529?adobe_mc=MCMID%3D24445298415631476812898182430771639861%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1723213472

https://www.science.org/content/article/crippled-atlantic-currents-triggered-ice-age-climate-change

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​

How about pointing out ANYWHERE in the text you just posted in which it states, suggests or even hints that changes in ocean circulation are responsible for the glacial-interglacial cycle.

 

[ding]

How about pointing out ANYWHERE in the text you just posted in which it states, suggests or even hints that changes in ocean circulation are responsible for the glacial-interglacial cycle.

Changes in ocean currents are responsible for glaciation and deglaciation. That's what the papers say. There is physical evidence that shows ocean currents are responsible for the northern hemisphere glaciating and deglaciating.

 

[Crick]

Changes in ocean currents are responsible for glaciation and deglaciation. That's what the papers say. There is physical evidence that shows ocean currents are responsible for the northern hemisphere glaciating and deglaciating.

Quotes. I'd like to see quotes. And if you can't find them and you're a grown up with any ethics whatsoever, an admission that you can't locate any if that's the case.