This is a “speculative” posting.
It’s largely just so that I can collect some bits of ideas together in one place. I’ve not reached a conclusion. I’ve not even fully worked out the connections. But my progress is not as fast as I’d like, so it’s going here as speculation. Where it can remind me of the “unfinished bits” and where others can chime in if they see something interesting.
has a nice write up of the geologic scale events that lead to a frozen Antarctic, including the impact of the closing of the Isthmus of Panama and the opening of Drakes Passage.
The development of ice sheets in the Southern Hemisphere around 34 million years ago seems fairly straightforward. The supercontinent of Gondwana broke apart, separating into subsections that became Africa, India, Australia, South America, and Antarctica. Passageways opened between these new continents, allowing oceans to flow between them.
When Antarctica was finally severed from the southern tip of South America to create the Drake Passage, Antarctica became completely surrounded by the Southern Ocean. The powerful Antarctic Circumpolar Current began to sweep all the way around the continent, effectively isolating Antarctica from most of the warmth from the global oceans and provoking large-scale cooling.
My thesis here is basically that the Drakes Passage event was not an atomic event. It is a ‘gradation spectrum’ and further, that the degree of impact is still variable. Both with changes of water level AND with changes of wind speed of the Antarctic Cirumpolar Winds as they drive the Antarctic Circumpolar Current (ACC).
Weather and the Arctic Oscillation
This all started with the weather this year. The Arctic Oscillation, or AO, changed and Europe got frozen along with Canada and the USA Midwest. One chain of things lead to another and I was looking at the ANTarctic Oscillation too. (Called the AAO). I was wondering if there was some way that these might account for the cold we’re getting now. Maybe they were both weakening and letting all the cold out of the Polar Lockers?
These folks have a very nice and very readable description of how the AO effects things (with very nice pictures):
And include this picture that shows how the AO seems to match rather nicely with our hot / cold cycles over the last 60 years. It cuts off before our present, cold blue, shows up:
But when I looked, the AO and AAO seemed to be moving in opposition more than in unity. What could be the deal? I’d seen hints of an alternation between polar regions in some of the temperature data. One place warming when the other cools. The idea of both working together to cool things off was not looking so hot. But… the cooling in the south Pacific looked like it had to be WATER driven, while that in the north was clearly AIR driven. Was there something in that difference that mattered?
The Antarctic Circumpolar Current
And Drakes Passage
So I looked more closely at the AAO. The south pole circumpolar wind drives the Southern Ocean current. Called the Antarctic Circumpolar Current. So if we had MORE wind down south when we had LESS up north, that would speed up the ACC… which would move more water faster around the Southern Ocean… untill… it bangs into Drakes Passage.
That bottleneck in the Antarctic Circumpolar Current between South America and Antarctica.
At that point, we’d have an interesting problem. There is an interface between the Antarctic side and the rest of the oceans called the Polar Front.
So as I looked at it, the thought occurred to me that attempting to make this spin faster ought to cause some of the water to “puddle up” on the ‘up current’ side, to the West of Drakes Passage. That would then send more water into the Humboldt Current up the side of South America and out into the central Pacific. That “cold dagger” we see here:
And, as the polar side is fully land constrained, ought to move the polar front somewhat more north. Perhaps even putting more deep cold polar water into the mix.
Hmmm…. Now I’m thinking: So, let me get this straight. If we have a natural OFFSETTING and balanced oscillator that swaps circumpolar wind speeds between the North and South poles, such that when one speeds up the other slows down, that will cause warming and cooling cycles globally?
When the Arctic wind speeds up, it traps cold air, warming the N.H., but the S.H. winds slow down, slowing the water currents that lets the oceans warm up. Warming in both cases.
And like now, when the Arctic wind slows down and lets the freezer door open to the Northern Hemisphere, the Antarctic wind picks up speed and sends more cold water into the Pacific and we get pressure toward cold everywhere on the planet. Cooling in both cases. What ought to be a “wind changes offset and do, net, nothing globally” is instead a “hot / cold oscillator”.
All because one end has a lot of land and the other has a lot of water around the pole. The Arctic is almost land locked, so air changes dominate while the Antarctic is a nice wide open circumpolar run for the water, but the air has no land forms pushing it around. Until that water hits Drakes Passage.
I’m also wondering if the difference in magnetic poles and / or solar driven charged particles might account for the differential speeds of the polar vortex between north and south… but I’ll leave that for the particle and magnetic fields guys to work out. Perhaps it’s related to this:
Geomagnetic field in both North and the South hemisphere has an effect on the polar vortex, eventually reflecting its influence on the global atmospheric movements, polar and global temperatures.
From a very interesting article by Vukcevic found here:
Then there are these folks:
Try to spin it as all AGW induced catastrophic warming of the Antarctic Peninsula. To me, it looks like they’ve got the right data, but the wrong “spin”. They can’t see the reality in front of their face. A warm Antarctic Peninsula may just be the barometer that gives an early reading of a cooling Pacific ocean. They’ve got all the data, even a nice map showing the water move. Just can’t get their Political Officer Blinders taken off long enough to see it. Oh, and they have the wind going in the wrong direction. Like all things AGW, they’ve got things “exactly backwards”. (If they catch and fix the error, I’ve saved a copy…. tee hee ;-) Someone needs to tell them that “westerly winds” means the wind comes FROM the west…
Stronger winds warming Antarctica?
Stronger westerly winds around Antarctica are increasing eddy activity in the Southern Ocean and consequently may be driving more heat southward across the formidable Antarctic Circumpolar Current – the world’s largest current (see map below).
Winds over the Southern Ocean are strengthening due, at least in part, to human-induced change such as ozone depletion and greenhouse gas emissions. Scientists, examining satellite measurements of the ocean surface and using high-resolution computer models, have found that the Antarctic Circumpolar Current only shows a slight acceleration when these winds blow stronger, but that there is a large increase in ocean eddy activity. Eddies are the ocean equivalent of atmospheric weather systems, and in the Southern Ocean they play a key role in moving heat southward toward the Antarctic continent.
Researchers already know that the Southern Ocean is warming rapidly. The findings from the British Antarctic Survey suggest that ocean eddies could be responsible
So they have ALMOST got it. Faster currents. More eddy action. Cold water headed out (being replaced by water a bit warmer). They just get the understanding all backwards. It takes TIME for the impacts to work through. We’ve now got that cold water making it to the central Pacific and that “warmer Antarctic water” has had it’s heat dumped to space (judging by the SST map above).
Heck, even the wiki has it right on which way the wind blows:
The Antarctic Circumpolar Current (ACC) is an ocean current that flows from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feature of the Southern Ocean and, at approximately 125 Sverdrups, the largest ocean current. It keeps warm ocean waters away from Antarctica, enabling that continent to maintain its huge ice sheet.
The ACC has been known to sailors for centuries; it greatly speeds up any voyages from west to east, but makes sailing extremely difficult from east to west; though this is mostly due to the prevailing westerly winds. The circumstances preceding the Mutiny on the Bounty and Jack London’s story “Make Westing” poignantly illustrated the difficulty it caused for mariners seeking to round Cape Horn on the clipper ship route between New York and California. The clipper route, which is the fastest sailing route around the world, follows the ACC around three continental capes – Cape of Good Hope (Africa), Southeast Cape (Australia) and Cape Horn (South America).
Though their picture isn’t as nice at showing how the water builds up in ‘eddys’ around South America:
Though you can see how the edge of it runs into the land form at the tip of South America.
Meanwhile, NOAA too joins the “exactly wrong” brigade by claiming that the Arctic Ice drives the wind. They need to understand that it’s the wind and water that drive the ice. They do make nice pictures, though:
Sometimes I think you could have a gold mine of easy discovery just by taking any assertion of causality the Warmers put forth and turning it exactly around, as they are so often “exactly wrong”.
Start with a cold decending near stratospheric air mass changing the air currents at the Arctic, from our now thinner air column as the sun cooled the UV output, then see what happens to the ice… Like here:
We know the air is decending. We know the UV levels have tanked. We know it’s colder. Now, just ask “what happens next”…
Nice Theory, Got any DATA?
It fits. Nice theory. But….
Got any evidence for the AO and AAO moving in opposition? And just what IS the relationship between those pressure oscillators and the actual wind speeds?
Well, one of the biggest problems I ran into was that I just could not find a source of historical data for the circumpolar winds at either pole. Maybe I just don’t know what Google terms to use to make them show up…
(There are at least THREE names for the AO and AAO each depending on when in historical time you are looking and exactly what aspect of it is being recorded. For example, the AO can be called the Arctic Oscillation, Northern Annular Mode, or the North Atlantic Oscillation (though per the wiki the NAO is only a PART of the AO “It is highly correlated with the Arctic oscillation, as it is a part of it“) and is related to the Arctic Dipole Anomaly, which seems to be simply an alternate state of the pressure distribution that alternates with the AO sometimes). For some reason climate guys can’t just keep things constant and consistent for very long… Given that, who know what would be a good search term to find a long term record of Arctic Vortex speeds.)
But I did find data for the AO and AAO so I’m hoping they are a decent proxy for wind speeds. They do show something of a complementary behaviour, but with a fairly fast cycle. To do this properly would require a “low pass filter” to make longer duration trends out of this stuff. For now, just kind of ‘visually integrate’ and notice how much blue or red is above / below the line for each time series.
I have this nice chart of the Monthly Running Mean AO Index:
I have this nice chart of the Monthly Running Mean AAO Index (watch that extra “A” in the name:-):
Now comes the hard bit (that could undoubtedly be done much more correctly with decent raw data and a clean mathematical comparison… but I’ve not had time. So we get to use the error prone “eyeball” technique). Take a look at the overall time periods. When one is red, and the other tends to blue.
Easiest “pick” is the tail end. Right now the AO is blue (as Europe and North America feeze) and the AAO is blue. From about 1999 to date, the AO has been mostly red while the AAO has been more blue. 1979 has a very blue AO and a very very red AAO. But in 1980 they both go quite blue, then there’s a decade of nothing much happening. No strong bias to either side. The details, like ’83-’84 being opposites, then do tend to confirm the opposite sign tendencies, though. Yet in ’89 the AO goes VERY red and it isn’t until ’92 that the AAO goes VERY blue. So there are likely some timing issues that the “Mark One Eyeball” just can’t get. (And I’d really rather be doing this with simple circumpolar wind speeds in any case).
All in all, I think there’s “enough here, here” to be a decent “Dig Here”.
I know it’s an unfinished symphony. It hints at interesting things, and teases about brilliant insights, that it then says are hidden just at the end of that rainbow over there. But that’s how an investigation is, mid stream.
To me, it looks like there is some grand “Bi-Polar Oscillator” at work. One with about a 60 year period. It stirs the air (that then stirs the waters) and we get long bits of hotter and colder as things that ought to offset end up amplifying. As some minor “wind shift” gets turned into “30 years of cold or hot”.
And that leaves me wondering what the world would be like if Drakes Passage were just a little bit wider?
And how much does it enhance ice ages when the water becomes 400 feet more shallow and Drakes Passage that much harder to cross, sending that much more cold water north?
In this article:
The find that 20,000 years ago as we exited the last Ice Age Glacial, the circulation in the Atlantic Ocean changed direction. Related to the depth of Drakes Passage perhaps? Of course, the article has to have the “Conspicuous Random AGW Suckup” CRAS for short, stuck in. I’ve bolded the CRAS below along with some interesting bits:
Earth’s climate change 20,000 years ago reversed the circulation of the Atlantic Ocean
November 3, 2010
An international team of investigators under the leadership of two researchers from the UAB demonstrates the response of the Atlantic Ocean circulation to climate change in the past. Global warming today could have similar effects on ocean currents and could accelerate climate change.
The Atlantic Ocean circulation (termed meridional overturning circulation, MOC) is an important component of the climate system. Warm currents, such as the Gulf Stream, transport energy from the tropics to the subpolar North Atlantic and influence regional weather and climate patterns. Once they arrive in the North the currents cool, their waters sink and with them they transfer carbon from the atmosphere to the abyss. These processes are important for climate but the way the Atlantic MOC responds to climate change is not well known yet.
Someone needs to tell them that the “Science IS SETTLED“; as we're constantly being reminded by the AGW Policy Police.
An international team of investigators under the leadership of two researchers from the UAB now demonstrates the response of the Atlantic MOC to climate change in the past. The new research results will be published on 4 November 2010 in the international front-line journal NATURE. The research project was led by Rainer Zahn (ICREA researcher) and Pere Masque, both of the UAB at the Institut de Ciència i Tecnologia Ambientals (ICTA) and Department of Physics. With collaborators at the universities of Seville, Oxford and Cardiff (UK) they investigated the distribution of isotopes in the Atlantic Ocean that are generated from the natural decay of uranium in seawater and are distributed with the flow of deep waters across the Atlantic basin.
The study shows that the ocean circulation was very different in the past and that there was a period when the flow of deep waters in the Atlantic was reversed. This happened when the climate of the North Atlantic region was substantially colder and deep convection was weakened. At that time the balance of seawater density between the North and South Atlantic was shifted in such a way that deep water convection was stronger in the South Polar Ocean. Recent computer models simulate
Groaannn …. more simulated model science. Sometimes I wonder why we ever let them play with the new shiny computer toys in the first place. And notice, not a peep about the potential impact of Drakes Passage and, oh, I don’t know, maybe a whole lot lower ocean and a huge load of ice in it?
a reversal of the deep Atlantic circulation under such conditions while it is only now with the new data generated by UAB scientists and their colleagues from Seville and the UK that the details of the circulation reversal become apparent. This situation occurred during the ice age 20,000 years ago. Although this was far back in time the results are relevant for our climate today and in the near future. The new study shows that the Atlantic MOC in the past was very sensitive to changes in the salt balance of Atlantic Ocean currents. Similar changes in seawater salt concentration are expected to occur in the North Atlantic in the course of climate warming over the next 100 years. Therefore the data to be published in Nature offer the climate modelling community the opportunity to calibrate their models and improve their capacity to predict reliably future ocean and climate changes.
Remember back when data was collected instead of “generated”? I miss those days… and, of course, the purpose of all this is to let the toy model community polish the new lacquer on their latest Christmas toys…
Perhaps they could start by looking at what happens to ocean currents in Drakes Passage during an ice age?
As a final note, this bit of a news tease. We still don’t know how all the currents work. And they are, IMHO, the keys to the city. So, as of April of this year, we’ve just discovered a “massive” unknown current… Wonder how that one works? So much for “settled science” ;-) I’ve bolded some bits.
Massive Southern Ocean current discovered
April 26, 2010
The Indian Ocean sector of the Southern Ocean where the ocean current has been identified. Image credit – CSIRO
(PhysOrg.com) — A deep ocean current with a volume equivalent to 40 Amazon Rivers has been discovered by Japanese and Australian scientists near the Kerguelen plateau, in the Indian Ocean sector of the Southern Ocean, 4,200 kilometres south-west of Perth.
In a paper published today in Nature Geoscience, the researchers described the current -more than three kilometres below the Ocean’s surface – as an important pathway in a global network of ocean currents that influence climate patterns.
“The current carries dense, oxygen-rich water that sinks near Antarctica to the deep ocean basins further north,” says co-author Dr Steve Rintoul from the Antarctic Climate and Ecosystems CRC and CSIRO’s Wealth from Oceans Flagship.
While earlier expeditions had detected evidence of the current system, they were not able to determine how much water the current carried. The joint Japanese-Australian experiment deployed current-meter moorings anchored to the sea floor at depths of up to 4500m. Each mooring reached from the sea floor to a depth of 1000m and measured current speed, temperature and salinity for a two-year period.
“The continuous measurements provided by the moorings allow us, for the first time, to determine how much water the deep current carries to the north,” Dr Rintoul said. The current was found to carry more than 12 million cubic metres per second of Antarctic water colder than 0 °C (because of the salt dissolved in sea water, the ocean does not freeze until the temperature gets close to -2 °C).
“It was a real surprise to see how strong the flow was at this location. With two-year average speeds of more than 20cm per second, these are the strongest mean currents ever measured at depths three kilometres below the sea surface.
“Mapping the deep current systems is an important step in understanding the global network of ocean currents that influence climate, now and in the future. Our results show that the deep currents near the Kerguelen Plateau make a large contribution to this global ocean circulation,” Dr Rintoul said.
Antarctic waters carried northward by the deep currents eventually fill the deep layers of eastern Indian and Pacific Oceans.
So, like, maybe now we’ll start to get a handle on the Indian Ocean Dipole too?
This looks like an eddy from the venturi made by Drakes Passage. Perhaps as things “back up” at South America you get more of that ‘deep return current’ behind the traffic jam? That would imply that at times of greater volume flow it would pick up in speed too (faster ‘jet’ spinning it faster). As the size of Drakes Passage is pretty much fixed, backing up the current ought to make more turn ‘down and out’. After the venturi, the flow ought to be up higher, too, so a bottom return current would be expected. It ought to be a quick and easy thing to falsify or confirm. Circumpolar current speed vs Antarctic Vortex speed vs Indian Ocean Dipole state (with time lags).
So much to do… so much to think about…