An ear to the ocean

By Phil Plait | February 11, 2012 7:06 am

The Terra satellite is designed to study our planet from space, examining the environment over large scales and in high resolution. While passing over south Africa it took this seemingly normal — if still very beautiful — image:

I rotated it, so north is to the left. You can see land to the left, the southernmost tip of Africa, called Cape Agulhas. To the top is the Indian ocean, with the Atlantic to the right. A weather system is forming there, and all looks as it should… until your gaze settles all the way to the right (south). Wait… what’s the blue swirly thing?

Holy otology! Is that a giant ear?

Nope. It’s an eddy, a vortex, in the ocean, probably spun off the ocean current that flows around the southern cape of Africa. These eddies can dredge up material from deeper waters, including nutrients. Phytoplankton in the water feeds of those nutrients, and bang! Plankton bloom.

The plankton flows along with the water, coloring it blue, making it stand out eerily against the water. As I pointed out in an earlier post about these blooms, we can learn a lot about the environment from them. Plankton are sensitive to climate change, for example, and can act as indicators of the water’s physical characteristics.

When I see an image like this I think of all the funding cutbacks NASA is facing right now — and yeah, I’ll be writing about that soon. Our planet is on a cusp right now, and I can’t help but fret about the opportunities we might miss if we step back from space. Exploring space, even just being in space, has given us a perspective on our home world we couldn’t possibly have achieved otherwise. Some things, once begun, shouldn’t be stopped. Try as they might, some politicians can’t make us unsee what we’ve seen, and unlearn what we’ve learned.

Unless we let them, of course. I won’t, and I hope you won’t either. Let the picture above serve as a reminder: when it comes to keeping track of the Earth, we have to keep our eyes and ears open.


Related posts:

Stunning view of a bloom from space
Phytoplankton bloom
Planktondolia
Titanic’s revenge

Comments (32)

  1. Pffft! Trans-dimensional vortex from the lost civilization of Mu if I ever saw one.

  2. I see. ‘Ear, ear! ;-)

    Joking aside – well said BA, I couldn’t agree more.

    Freaky image. Wonder if the astronauts and cosmonauts aboard the International Space Station can see this and how many more such eddies / phytoplankton blooms there are staining our oceans blue still bluer.

  3. Melusine

    That eddy/vortex in the top photo is very cool the way it stands out, and it’s not touched up in any way to bring out its blueness? It looks like some blue galaxy swirling in the ocean. Yeah, these satellites are an ongoing classroom as changes are constantly happening. Volcanoes, light pullution, hurricanes, etc. Such great inventions.

  4. Ganzy

    That’s no plankton vortex. If you look really carefully at the centre, you can just see the bow of the USS Cygnus emerging! But…but.. I saw it’s destruction with my own eyes back in 1979!! This is going to trawl up all those old nightmares of being shredded by Maximilian’s blender thing. Ohh V.I.N.C.E.N.T where are you now?? o_O

  5. Chris

    I wonder if Phil really thought it looked like a wormhole but then went “Nah, I better not put that up, all the nutjobs will start calling me and referencing that in their conspiracy theories.”

  6. Tony Mach

    All forms of earth-imaging are very necessary – but we don’t need to put people in space for that, and sure as hell don’t need to put them on a moon base. Spreading fears about “stepping back from space” and declaring everything to be “space exploration” muddies the waters, and I fear that things like a moon base, next generation space telescopes or even a permanent maned space station are hurting divisions that we need much more like said earth-imaging. Don’t get me wrong, all these things like JWST are scientific and cultural contributions by and for the entire human race – but it won’t hurt us if we spend a little less there and a bit more here. Neither our galaxy nor the space beyond are going anywhere in the near future, but as you are never tired to say, the planet might – so let’s put the money where it is needed and don’t waste it in areas that can wait a little bit more.

    And by the way, if there is one species that will be the least impacted by climate change and will handle it the best of all species (unless the oceans boil away or freeze completely), then it is plankton. And please note the rate of warming of the ocean is just so abysmally small to be very very hard to measure and the ocean acidification is a theoretical risk rather than a firmly established fact – if you want to disagree, please, show me studies that show the measured effects of climate change on plankton, that accounts for other influences on plankton, whether man-made like overfishing (not man-made).

    There are differences between “space exploration” and “space exploration” and not everything is caused by CO2.

  7. Rick

    Does the swirling motion actually reach the surface? The vortex seems to take on a 3 dimensional shape. Are we seeing any great depth here or is most of what we can see at a very shallow depth?

    I assume this is miles wide?

  8. Great picture.

    I don’t think that is called The Horn or the Southern Horn. It is The Cape. The Horn is the part up by Ethiopa, Somalia, etc.

    The current that goes around the cape is accounted for by the fact that the Indian Ocean is transected by the equator, yet has no northern outlet, so extra heat builds up and makes its way around the cape in big giant blobby sometimes vortexy things like shown here. Eventually the blobs of warm water combine into a more coherent current, and when they reach the N. Atlantic they evaporate to become more saline, sink, and this heavy colder highly saline water goes all the way back down the Atlantic, around the cape again, and into the Indian Ocean.

    Rick, it is mainly a surface feature, but this is a large thing so “surface” may be relative.
    Thus, the famous “Atlantic Conveyor” which is the main source of ocean-current born heat for norther Europe and the thing that is usually shut off during glacial periods and is running during non-glacial periods.

    Before the rise of the seabad of the Tethys Sea (now a hand full of puddles along the African-Euraisian boundary) this current probably did not exist, thus a totally different climate system prevailed.

  9. I’m very worried about the health of the oceans. Between increasing pH and warming surface temperatures, I fear that we’re headed for large scale anoxic dead zones.

    Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation (and this summary article)

    Global phytoplankton decline over the past century (and this summary article)

  10. Greg (8): Ah, you’re right. I fixed the text, thanks.

  11. So, what’s the scale here? How large is that vortex?

  12. Mr. Dave

    This is the first image I’ve seen of an eddy from space. It appears to be a cold core eddy, as they rotate counter-clockwise. Fronts and eddys can be, under the right oceanographic conditions, a strategic place to hide a hunted submarine. Very cool.

  13. Mike

    An ear to the ocean? What do you think, you’ll hear a seashell?

    lol

  14. Ross Marsden

    Ken B (11): The visible vortex is about 150 km (93 miles), end to end.

  15. Mike G

    Does the swirling motion actually reach the surface? The vortex seems to take on a 3 dimensional shape. Are we seeing any great depth here or is most of what we can see at a very shallow depth?

    The eddies extend from the surface to about 1500 meters down, but the color you’re seeing is from the phytoplankton, which are all living in the first 100-200m from the surface. Deeper than that there isn’t enough light for them to live.

    I assume this is miles wide?

    These mesoscale eddies tend to be on the order of 100 or so miles wide.

  16. Mike G

    And by the way, if there is one species that will be the least impacted by climate change and will handle it the best of all species (unless the oceans boil away or freeze completely), then it is plankton.

    You realize that there isn’t one species of plankton, right? Plankton is hundreds of thousands of species across at least 4 kingdoms. The term “plankton” is a description of a mode of living that covers everything from jellyfish, larval fish, crustaceans and echinoderms, algae, small crustaceans and mollusks, worms, bacteria, etc. It has no taxonomic meaning. The statement that plankton are sure to be the least impacted is about as vague as saying that terrestrial animals are sure to handle climate change the best.

    And please note the rate of warming of the ocean is just so abysmally small to be very very hard to measure and the ocean acidification is a theoretical risk rather than a firmly established fact – if you want to disagree, please, show me studies that show the measured effects of climate change on plankton, that accounts for other influences on plankton, whether man-made like overfishing (not man-made).

    One example of a paper showing a worldwide decrease in primary production of plankton correlated with temperature. http://www.gfdl.noaa.gov/bibliography/related_files/wwg0301.pdf

    One showing a decrease in calcification in Antarctic pteropods (planktonic snails):
    http://ecite.utas.edu.au/70806/

    Your request is a bit disingenuous though since this question (can we already measure the effects of climate change on marine plankton?) has only really been studied in earnest for about a decade. As a result, there’s little baseline data to compare against (which is true for a lot of marine ecology) and only short time series of relevant data. As the author of the pteropod article points out, that makes it very hard for us to spot the signal, even if it is already there.

  17. Randy A.

    Great picture! I just added it to my “Currents” powerpoint that I’ll show my class in a few weeks. Thanks Phil!

  18. Daniel J. Andrews

    And please note the rate of warming of the ocean is just so abysmally small to be very very hard to measure and the ocean acidification is a theoretical risk rather than a firmly established fact – if you want to disagree, please, show me studies that show the measured effects of climate change on plankton, that accounts for other influences on plankton, whether man-made like overfishing (not man-made).

    First, “abysmally small to be very hard to measure” does not mean it can’t be measured. Second, are talking about the upper 700 m or the deeper ocean? It is harder to know what is going on below 700m but the heating is not negligible although is it poorly characterized.

    realclimate.org/index.php/archives/2011/10/global-warming-and-ocean-heat-content/

    Next why is ocean acidification a theoretical risk only? The pH has decreased 30% (8.25 to 8.14). To assume that the decrease won’t produce risk, or that further decreases will not occur seems like poor risk assessment even if there weren’t any studies done yet, which there are. There are also paleo studies showing how various species (formaniferans for e.g.) changed as ocean pH changed in relationship to atmospheric CO2 changes.

    And as already pointed out “plankton” is a catch-all phrase and is essentially meaningless in your statement. You either didn’t know that (in which case why should we listen to you) or you did know that and are just being disingenuous.

  19. @13. Mike : “An ear to the ocean? What do you think, you’ll hear a seashell?”

    And what does a seashell sound like again? ;-)

  20. @16. Mike G :

    You realize that there isn’t one species of plankton, right? Plankton is hundreds of thousands of species across at least 4 kingdoms. The term “plankton” is a description of a mode of living that covers everything from jellyfish, larval fish, crustaceans and echinoderms, algae, small crustaceans and mollusks, worms, bacteria, etc. It has no taxonomic meaning. The statement that plankton are sure to be the least impacted is about as vague as saying that terrestrial animals are sure to handle climate change the best.

    Thanks for that. :-)

    I knew there were many species of “plankton” – first thing I think of is zoo(o?)plankton and the plant variety (botanoplankton? Make that phytoplankton) but I must admit I thought they were a class (genus?) or two of their own not quite such an eclectic varied mixture of things.

    Wikipedia confirms that and has more here :

    http://en.wikipedia.org/wiki/Plankton

    Including adding that the singular form of plankton is plankter! ;-)

    Something new I’ve learnt for today cheers again! :-)

    @6. Tony Mach :

    And please note the rate of warming of the ocean is just so abysmally small to be very very hard to measure ..

    You may want to check this link out :

    http://www.skepticalscience.com/cooling-oceans-intermediate.htm

    before embarrassing yourself any further Tony.

    ..the ocean acidification is a theoretical risk rather than a firmly established fact – if you want to disagree, please, show me studies that show the measured effects of climate change on plankton, that accounts for other influences on plankton, whether man-made like overfishing (not man-made).

    Plus this link too :

    http://www.skepticalscience.com/ocean-acidification-global-warming-intermediate.htm

    In fact I’d recomend checking that Skeptical Science site before making *any* climate contrarian claims at all. Because chances are whatever you’re going to argue has already been well & truly debunked there, ‘k?

  21. One area where humans in space – in colonies whether lunar or O’Neill / Babylon-5 / Deep Space Nine type space stations – may really be able to learn is ecologies and how to set them up and get them to work well.

    Trying to construct and develop ecologies so they are able to sustain themselves in space and provide resources such food, good air and pyschological benefits may be one of the key activities and key steps in Humanity truly growing and developing and understanding our cosmos and ourselves as we – hopefully – become a space faring – and terraforming species.

    If we ever terraform Mars as I hope we one day will, we can and surely must learn a great deal in lunar “biospheres” III, IV V and so on first.

    *****

    “Curiousity and a drive to understand the cosmos have characterised humanity for as long as we can tell. Our telescopes and space probes are simply the most recent steps in a journey that began many thousands of years before Stonehenge.”
    – Robert Burnham, page 43, “Glorious Universe” in ‘Astronomy’ magazine, October 1991.

    “Earth will benefit in the end, {from Space Exploration / terraforming Venus} and not just because there’s a new world to go to, but because of what we’ll learn.”
    – Page 237, ‘Venus of Dreams’, Pamela Sargent, Bantam, 1986.

    “Earth is the cradle of humanity, but one cannot live in a cradle forever.”
    – Konstantin Tsiolkovsky

  22. James

    “Try as they might, some politicians can’t make us unsee what we’ve seen, and unlearn what we’ve learned.”

    Yes they can; that’s what Dark Ages are for.

  23. Sili

    That’s no vortex.

    That’s a gyre.

  24. james

    Some folk’s understanding of geography comes across as being limited, so if you don’t mind, living as I do in South Africa…

    The cold Benguella and warm Agulhas currents collide off Cape Point, near Cape Town, which is further east than Cape Agulhas itself, which is correctly indicated as the Southernmost tip of Africa.

    There may be spirals of cold Benguella dragged off up along with the warmer Agulhas current along the East coast of SA but these soon dissipate. As far as I know, there is no warm water dragged up the West coast.

    The picture as shown has the Atlantic to the bottom, not to the right. Technically, because of the two currents split off Cape Point, the Atlantic and Indian Oceans meet at Cape Point, which is hidden by cloud in the picture.

  25. @6. Tony Mach :

    See also :

    http://blogs.discovermagazine.com/80beats/2009/03/10/no-more-speculation-scientists-prove-ocean-acidification-is-already-underway/

    &

    http://www.oceanclimatechange.org.au/content/index.php/site/report_card_extended/category/phytoplankton

    &

    http://www.neaq.org/conservation_and_research/climate_change/effects_on_ocean_animals.php

    From which we find – if you scroll down to the bit about right whales :

    Between 1997 and 1999, zooplankton numbers plummeted. Over 50 years of observation, scientists have learned that zooplankton are abundant when the North Atlantic Oscillation (NAO) Index — which charts variations in atmospheric pressure centers over the North Atlantic — is predominantly positive. When it becomes negative, the numbers decline. Right whales illustrate the dramatic “downstream” significance of NAO conditions. … (snip) .. The big drop occurred in 1998; it took two years before the 1996 drop in the NAO Index had its effects on the zooplankton population downstream in the Gulf of Maine, where it dropped tenfold. By 1999 the zooplankton numbers were climbing back up again. However, because of the right whales’ long reproductive cycle, the consequences of this climatic event were not over yet for the whales. In 1999, only one right whale calf was born, the lowest on record (there were 21 born in 1996). But in 2001, two years after the abundance of the zooplankton increased, 30 right whale calves were born, the most recorded since 1982.

    Where does all this fit into global warming? Some scientists suggest that increased climate variability or a prolonged period of negative NAO index, which are both expected under a global warming scenario, would undermine the already tenuous recovery of the North Atlantic right whale.

    To find a lot more do a google search : “studies that show the measured effects of climate change on plankton”.

    That’s what I found in about two minutes.

  26. So.. that shape. That nearly perfect ear shape? that was formed by nature and not by god? that can’t be possible.
    Sorry, every time I notice an ear, the only thing I can think of is how stupid Kurt Cameron is and that damn video.

    BLARRGH!

  27. I wonder if warmer surface temperatures will cause more frequent or larger eddies?

    This paper just published yesterday is highly relevant: Changes in marine dinoflagellate and diatom abundance under climate change (summarized here and here).

    Climate change includes wind that is also altering how nutrients mix in the warming surface waters of the North Atlantic. These conditions seem to favor diatoms, a more toxic form of plankton to marine life, over dinoflagellates.

    I’ve been tracking die-off news on the Facebook page, Anthropocene Mass Extinction. I’ve seen evidence there are ongoing unexplained marine die-off events happening in numerous other species that may be related…. butI’m probably over my link quota for this post. The history of news posted on that FB page tells the grim story.

    Save the dinoflagellates!

  28. Mike G

    These conditions seem to favor diatoms, a more toxic form of plankton to marine life, over dinoflagellates…. Save the dinoflagellates!

    Eeek, no! Long live the diatoms! I realize the first summary gives the impression that diatoms are more toxic than dinoflagellates, but I think we’re missing some important context from the quotes (unfortunately, there’s an embargo on the full article so I can’t access it yet).

    There are about 2 dozen or so different dinoflagellates that cause harmful algae blooms, and they tend to be the most common and most severe blooms. In contrast there’s only 1 (AFAIK) species of diatom that’s a common cause of HABs. Diatoms also tend to be a much more important part of marine food webs than dinoflagellates.

  29. Brian Too

    Looks like a freeform interpretation of the opening scene from the movie Blue Velvet!

  30. Thanks Mike G. I did a little more reading and found this which provides a nice overview. I’m browsing the abstract link for this conference last fall on harmful algae blooms which tells a similar story.

  31. Holms

    If north is to the left, and this is the southerly extent of Africa, I think you have misplaced the Atlantic ocean. Surely the Indian is at the top of the photo, the Southern ocean at right and the Atlantic along the bottom?

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