This is the beginning of what I hope is a new feature sharing contributions by our commenters in areas of their expertise. Late last September, Boussinesque reached out to me because his comments were disappearing into the aether. We solved that problem, and in doing so, solved similar issues for others. You can’t ask for a more satisfying resolution!
In chatting with him, I found out about his field of study, and after we talked a bit more in-depth, I asked if he’d like to do a guest post and answer questions. He said yes, and we planned to do it right after the election, while the world was celebrating and returning to normal. And then……
So, months later, not so much recovered as resigned, here we are: I present to you, Boussinesque’s Introduction to Oceanography, Part One.
You can ask him questions in the comments, or submit them to me anytime using the Contact a Frontpager form and I’ll forward them to him.
[av_dropcap1]H[/av_dropcap1]ello, jackals! Long time (8-10 years) lurker, first time poster. Alain helped solve an issue that was causing my comments to always go straight into the trash bin (the algorithms, how did they KNOW?!?) back in October/November, and during our conversation, suggested that I might do a guest post related to my areas of expertise–namely, Ocean Science and climate science in general. Then the election happened, and, well, it just never seemed like the right time to get back to it. But now it feels like we could use the occasional break from the all-Trump-all-the-time season of reality TV that America is living through.
My specific subfield is physical oceanography (think large-scale current modeling), but I’ve been to sea several times to support research in ocean chemistry and biology. Depending on interest, this could either be a one-off, or the first in a series of posts about ocean/earth/climate science in general, so let us know what you think! This one will be kind of an overview of the ocean system in general, just to sort of establish a floor for any future discussions/posts, so forgive me if some of this touches on things some of you already know.
The ocean covers ~70% of the earth’s surface to an average depth of ~4000m, buffers our climate, and serves as home to the organisms responsible for half of the total oxygen production on the planet—if the rain forests are one of Earth’s “lungs”, the oceans are the other. In order to properly understand the ocean, you need to study it in a holistic fashion. The physics affects the chemistry, which affects the biology, which in turn feeds back on the chemistry…
So first, I’ll touch a bit on ocean physics—the large scale circulation is primarily driven by heat fluxes and salt content (in the ocean, almost everything dissolved in the water gets referred to as “salt”, so we’re talking about more than sodium chloride (NaCl) here). The more salt a given volume of water contains, the denser it is. Similarly, the colder a volume of water is, the denser it is. When considered in tandem with latitudinal and seasonal effects on received sunlight, wind stress, and surface precipitation, we wind up with a picture of global thermohaline (thermo—temperature, hal—salt) circulation frequently referred to as the “Global Conveyor Belt”
An important point to consider when looking at this diagram is to remember that the total volume of water in the ocean is mostly stable (glacial melt, seasonal evaporation/precipitation, and our current catastrophic warming notwithstanding), so water that moves laterally, sinks, or rises results in the displacement of whatever water was there, which is what leads to the bulk transport shown here.
The two primary sources of sinking water flux are the North Atlantic (where low surface temperatures cool the surface layer, causing it to become denser than the water below it, leading to the water sinking) and the Southern Ocean around Antarctica (because hey, it’s cold in the Antarctic—go figure). Everywhere else in the ocean, surface current divergence (due to interactions with the wind, bathymetric features, etc.) leads to “upwelling”, where deep water gets brought up to the surface. This is important because the surface is where almost all the action happens, biologically speaking.
When I said that the oceans were one of Earth’s lungs, the specific organisms that fulfill the role trees play on land are the phytoplankton—microscopic photosynthetic autotrophs. They use CO2 dissolved in the sea water, plus nutrients in the ambient environment (nitrate, phosphate, and sulfate, primarily) to photosynthesize and grow. They serve as the base of the oceanic food web for pretty much every other organism (the exceptions are exotic and interesting, but not salient here), from similarly-sized animals called zooplankton, to larval-stage/young fish/molluscs/etc., and through those up to fish, sharks, whales and the rest. Because dead organic matter is made up of the stuff living organisms need to grow, and because said matter sinks below the surface where photosynthesis is possible over time, the deep ocean serves as a kind of repository for delicious nutrients—that material dissolves as it sinks, returning to a form readily useable by phytoplankton.
This is why upwelling is important—it brings cold, nutrient-rich water back to the surface where it can be utilized by phytoplankton. As an example, the California Current System (CCS) is unusually productive because it is an upwelling regime during the majority of the year. Other notable regions include the Gulf of Alaska, the coast of Peru/Chile, and portions of the west coast of Africa.
Aside from the biology, the physical properties of the ocean have a strong impact on our climate, through the ocean’s capacity to buffer heat and CO2. The specific heat of water is much much higher than air, which means that the same amount of heat flux (sunlight) will warm the air a lot more than the ocean. This is why coastal regions can have somewhat more stable climate—during the day, the ocean remains colder than the air, and thus is able to absorb more heat through direct interaction with the atmosphere (as distinct from what it absorbs via direct radiation from the sun), moderating the temperature change experienced by the air. Once the sun goes down, the land cools off much faster, and if the air temperature drops below the water temperature, you start having the atmosphere getting warmed by the ocean. You can think of it like the ocean serving as a kind of “heat battery”.
As with heat, the chemical components of our atmosphere will interact with the ocean; depending on the concentration of a gas in the atmosphere (“partial pressure”, for you chemists), some will diffuse across the air/sea interface to dissolve in the surface layer of the ocean. The exact rate and equilibrium conditions depend on the temperature and a number of other factors, but the overall relationship is pretty straightforward: increase concentration of CO2 in the atmosphere, and more CO2 will be pushed into the oceans. Because the oceans are so huge, they can absorb a LOT of CO2 before the concentration in surface waters changes significantly.
The converse here is where things become troubling—we frequently hear about changes in atmospheric CO2 concentration, and elevation of global temperatures. The nightmare fuel lying behind that for those of us who study climate professionally is how that is reflected in the ocean. If the amount of energy needed to raise the average temperature of the atmosphere by 1 degree is X, then the amount of energy needed to raise the average temperature of the ocean (even if we’re just looking at the surface layers) by 1 degree is many times X (for reference, the specific heat of ocean water per kg is about 4 times that of a kg of air, and a kg of air occupies a lot more volume than a kg of ocean water). So when we look at temperature changes and think about the amount of energy they represent, we also mentally add in the amount of energy that the ocean absorbed…which is a lot. Same with CO2—for concentrations in the atmosphere to increase substantially, you also need to dissolve enough “extra” CO2 into the surface ocean to bring the system to chemical equilibrium with the new atmospheric value…which again, is a lot. This also has a direct effect on oceanic pH, but I’ll save the discussion of ocean acidification for another post, assuming people are interested.
I am, of course, happy to answer as many questions as my time and internet access permit, so fire away if you have any (or requests for clarifications, etc.).
– Boussinesque
Alain the site fixer
Welcome all – Boussinesque, hope you’re here to answer questions. I appreciate you taking the time to write this and being here in the thread.
Boussinesque
@Alain the site fixer: Thanks for the vote of confidence!
I’ll be here for a couple hours, and will be monitoring the comments sporadically after that.
Elizabelle
@Boussinesque: Oh cool. Cuz I got a kitchen to straighten up. But I’ll be right back.
Alain the site fixer
Cool. I had to remove the Jackals picture because it threw a security warning and so Google ads weren’t showing. That’s why you may think you saw something there but it isn’t now. Good luck – and have a great weekend and holiday everybody. I’m signing off and unplugging for the next few hours as I redo my home office.
gene108
What’s an autotroph?
scav
Oceanographers and global scale processes! Oddly enough, this is the second time today that upwelling has crossed my reading today. It’s importance to whales is becoming apparent. BBC: Whales reached huge size only recently and this one (that I just started reading) Science: Why whales grew to such monster sizes.
Boussinesque: Is your personal area of research more grounded in the climate change aspect of things or the physical processes / modelling and biology interaction arena?
ruemara
There’s a giant picture of screaming white male Trump fans in the middle of this post. I feared Mssr Boussinesque was going to talk about hunting Moby Dick.
Jokes aside, welcome.
A few years ago I did an article with a marine biologist regarding sustainable fishing. He felt lower trophic scale eating and sensible conservation of resources was going to preserve our tuna sashimi habits. I know your discipline is different, but would you have any thoughts on whether the increased rate of warming of the oceans is affecting fish populations?
Boussinesque
@gene108: An organism that makes its own food. Kinda redundant, given “photosynthetic”, but that’s the official designation.
schrodingers_cat
Will climate change affect ocean currents? What do models predict?
Elizabelle
@Alain the site fixer: Remove the jackals. Keep the jackasses. Story of our lives. Le sigh.
Humdog
What generates the motion of the “global conveyor belt”?
schrodingers_cat
@Humdog: I am guessing the earth’s magnetic field.
MomSense
Hi Boussinesque!
I live in Maine where we are dealing with many changes as a result of the rapid warming of the Gulf of Maine. It’s already causing economic problems (some violence,too) for people who lobster as the lobsters are moving north to colder waters. I also worry about acidification and phyto plankton. I don’t think enough people realize how dependent we are on phyto plankton for the air that we breathe!
Do you ever work with Bigelow Laboratory for Ocean Sciences out of Boothbay? In addition to the great research they do, they are also a wonderful educational resource for our schools here in Maine.
Cowgirl in the Sandi
This is an example of one of the reasons I love Balloon Juice (although I almost never comment). Such an eclectic group of posters and posts.
I love this topic and hope to see more about our oceans in the future! Well done!
SiubhanDuinne
Thanks, Boussinesque. Quickly read through your opening statement — it strikes me as an excellent introduction to oceanography writ large, and I’ll be going back to it often for refreshers. I have absolutely no background in this or indeed in any of the sciences, so forgive any of my questions that may seem naïve, if not downright stupid.
I was interested in your statement that biologically, just about all the activity is at the ocean’s surface. How do you define “surface” in this context — what would be the depth (generally speaking — I know there are variations) within which that bio activity occurs? We’ve all seen film of deep sea divers coming across all kinds of life (plant and animal) at depths that I would guess are considerably sub-surface.
Thanks if you can unravel this awkwardly phrased question. And thanks to Alain for setting up the discussion.
Boussinesque
@scav: I mostly dealt with physical processes, but my particular area of study touches on chemistry and biology. My thesis work was on mesoscale eddies in the Gulf of Alaska
Kitfoxer
Hey there Boussinesque,
I work for IODP. Have you ever sailed on the JR? We did a cruise recently on the Agulhas current and climate-related studies.
West of the Rockies (been a while)
Informative and engaging! Thanks. I love when Science Friday has on Sylvia Earle.
Tim F.
Awesome! Email me (portusjacksonii at yahoo). We might have bumped into each other.
The Moar You Know
@Humdog: Heat. And landmass interference. Currents would be circular without the land in the way. And those belts and landmasses affect a lot; Antarctica was not icebound until the connection between South America and Antarctica broke a few millions of years ago, after which Antarctica was surrounded by nothing but cold ocean moving in a circle around it forever. The ice started piling up then.
@schrodingers_cat: Barely enough energy to move a compass needle. And yet, just enough – acting on the particles streaming towards us – to keep all life of this planet from dying in a hellfire of solar radiation.
The magnetic field keeps us all alive. But it does not move the ocean at all. Heat does that.
Sourmash
Always interesting to hear about those points of contact between two systems, “where the rubber meets the road” in the vernacular, so your discussion of the sea surface and interaction with the atmosphere is fascinating. My question: What are the mechanisms for dissolving oxygen into water? Is it primarily from phytoplankton generating oxygen, larger plants (ex. seaweed), wave/wind action absorbing oxygen from the atmosphere? And how does the absorption and diffusion of oxygen, and CO2 for that matter, affect ocean chemistry? Thanks!
SiubhanDuinne
@The Moar You Know:
I find that absolutely fascinating. Glad to have you and other knowledgeable commenters weighing in. What a great new BJ feature this is!
Elmo
Fascinating, fascinating, fascinating. Just wanted to say PLEASE PLEASE PLEASE continue, even if you don’t get a lot of comments on these posts. I think many people might be like me – reading with intense interest, very much looking forward to the next installment on acidification (or whatever you choose), but not even having enough of a grounding in the material to ask intelligent questions or make worthwhile comments. But reading and going WOW NEAT. WOW NEAT doesn’t really make much of a good post, so I might not do it often even if I’m avidly thinking it.
schrodingers_cat
@The Moar You Know: Earth’s magnetic field is the reason that the compass points north.
Boussinesque
@ruemara: that’s a really good question, and while I’m not an expert, I can weigh in on how the physics of a warming ocean impacts that.
Many ocean species have passive larval stages–they release thousands to millions of eggs and the current takes them where they will. It’s a statistical approach to species survival–even if the success rate is low, with that many attempts, it works out. The physics impacts this a few ways–some of these larvae have very narrow viable temperature bands, so warmer may just outright kill them. The other way is through stratification–when the surface of the ocean is warmer, the gradient between it and deeper water is larger. This serves as an effective barrier to transport, reducing the strength of upwelling and preventing diurnal migration.
The short of it is that a warming ocean is pretty much bad for everything. There may be some local winners from place to place, but it’s going to be bad for far more organisms than it’s good for.
Emma
I vote for more. I really feel ignorant of something so important and any enlightening is welcome.
Ceci n est pas mon nym
Spent several years of my life studying surface waves for purpose of simulating them (various Navy contracts). It’s a fascinating and difficult problem.
When Nemo pops up on the ocean’s surface in Finding Nemo I was blown away. They got it perfect!!! I could just stare at those few seconds of film for hours.
The classic book on the subject is Blair Kinsman, “Wind Waves”. I love the intro. He makes the point that anyone purporting to study waves should go out every once in a while and actually look at some. Also he says something along the lines of “anyone who ever spouts a rule like every seventh wave is the big one, is sooner or later knocked on their ass by wave number six.”
Boussinesque
@schrodingers_cat: @Humdog: The motion of the “conveyer belt” is basically a combined push-pull from the sinking of dense water. The water becomes denser either through the addition of salt (or from evaporation increasing the relative salt concentration) or through cooling. If surface water is denser than the water below it, it starts sinking, displacing the water below. It creates a sort of chain reaction, but the net effect is to pull water sideways to make up for what is sinking. If you were to take a string and make a loop, you can think of it that way–the sinking “pulls” the marked segment downward, but the rest of the string follows.
I don’t know if that’s the best way to describe it, so I’ll see if I can’t think of another way while I answer some other questions.
As far as warming changing currents, absolutely. The “stratification” I mention before depends on the change in water density with depth. With warmer surface waters, the stratification is stronger, which creates a larger gradient to overcome for things to sink. Some scenarios have warming sufficient to halt the “conveyer belt” completely, which would be a disaster (would impede upwelling, sequestering nutrients in the deep ocean, and preventing dissolved CO2 in the surface ocean from moving to the deep ocean for sequestration).
scav
@Boussinesque: Ah, thanks! As a geographer with GIS connections, my oceanographic colleges tended to work more on the modelling end of things (various scales, although at least one of them was seriously into eddies) so it will be most interesting to read about the biology creeping into the system analysis.
Boussinesque
@MomSense: I wish I could say I had–the region sounds interesting! I worked primarily through UC Santa Cruz, with a bit of collaboration with the University of Washington and Wood’s Hole.
Aleta
Why is the Gulf Stream located where it is?
stinger
I read with enjoyment, and am hoping for additional installments.
“Organism that makes its own food” — coprophiliac, top chef, gardener…?
Aleta
(For next time perhaps?)
What’s going to happen when the ocean gets too acidic?
Boussinesque
@SiubhanDuinne: Thanks for the warm welcome, Siubhan! There are no stupid questions, and the one that you’ve posed is actually a very good one. When oceanographers talk about the “surface ocean”, we’re usually referring to the “surface mixed layer”–the depth to which physical turbulence and wind cause the water column to mix to a reasonable approximation of homogeneity. Depending on the location and time of year, this can be up 500m. The other standard reference is the “euphotic zone”, generally considered to be the depth to which light penetrates at intensities sufficient for photosynthesis to occur.
When it comes to deeper depths than that, it really depends on the location–continental shelves, due to the complex bathymetry and currents, can frequently have substantial activity deeper than the surface mixed layer. As a general matter, anything between ~1000m and the area just above the bottom layer tends to be fairly barren.
Boussinesque
@The Moar You Know: Thanks for supplementing my answer, Moar–you’re quite right about that!
Do you have a background in the earth sciences as well, or are you just an enthusiast?
Aleta
Do biologists know what is the deepest ocean creature?
nightranger
Why would you post such an annoying picture?
A lot of contributors seem to be into masochism.
At least you could have hide it under the readme link with a NSFS (Not Safe For Sanity) label
Boussinesque
@Sourmash: I’ll be touching on ocean acidification more in a subsequent post (since there seems to be sufficient interest for at least one more article =3), but the short answer is “all of the above”. There’s straightforward pressure-gradient diffusion (think kind of like how you force CO2 into a drink to carbonate it, just…much slower), mixing caused by surface turbulence (when a wave crashes over, it is covering some atmosphere–the percolation of that back to the surface is part of what causes the foaming), and in-situ alteration from the biology. The phytoplankton use CO2 and create O2 in solution, but other organisms in the ocean then use that O2 to respire, turning it back into CO2.
Boussinesque
@Elmo: Thanks for the kind words, Elmo–I’ll certainly keep that in mind (and my own commenting usually follows similar constraints–I don’t like responding if I don’t have much to say beyond “right on!”)
scav
@Boussinesque: Would the basic dynamics of those large ocean currents be essentially the same as similar scale atmospheric convection-driven belts / cells? I’ve seen the idealized versions of those and how they get more complex and realistic as one adds in the spin of the earth, its tilt and rotation vis-a-vis the sun, etc. Are there similar mental experiments for showing how the oceanic currents work from a simplified sphere to one with all the continents etc (meaning ones we can go study on the interwebs) to help firm it up in our brains?
Aleta
This memory or the facts might be wrong….Jacques Cousteau once showed lobsters marching out to deep waters (part of their life cycle). I think he said their destination was not known. When they move out to the deep, is it known how far they go, what kind of environment they are headed for?
Not sure if this is the one, but here’s
Spiny lobster migration – La migration des langoustes
John Weiss
Good post! Keep it up!
hovercraft
@Aleta:
The Orange Pustule, though it roams the earth during the day?
I’d like to echo @Elmo: , fascinating read. @Boussinesque: this is important stuff, if you could just tighten up your next post and include Twitler’s name, then maybe we can get him to understand the importance of the oceans to life on this planet and the the importance of the scientists who study them. Seriously thanks for this.
Boussinesque
@Aleta: The Gulf Stream is an example of what we call a “Western Boundary Current”. They form on the west side of ocean basins (so eastern continental coasts) due to ocean gyre dynamics. The Coriolis effect, combined with atmospheric wind patterns, causes the formation of “gyres”, which are basin-scale…vortexes, I guess? The short of it is that a combination of factors cause equatorward motion of surface water across most of the ocean basin, but that has to be balanced by a poleward motion somewhere, in order to balance mass transit and vorticity (angular momentum) concerns. It’s actually a really deep topic, and the wikipedia article on Boundary Currents is quite good, if you feel like investigating further =3
Boussinesque
@Aleta: Ocean acidification is a huge issue, so I’ll leave the longer answer for next time, but the short answer is “we start killing the base of the food chain”.
Omnes Omnibus
@Boussinesque: Right on!
Betty Cracker
I don’t have any questions, Boussinesque, but I wanted to thank you for that informative write-up. I learned a lot.
Mary G
I have always wanted to see the Great Barrier Reef and was pretty horrified to see this week that half of it is dead due to bleaching. How does that work?
They had to close the beaches where I live this week because there were 15-25 great white sharks right off the shore. We moved here in 1960 and as far as I know that’s never happened before.
Boussinesque
@scav: There are definitely some analogues–Hadley Cell circulation captures the “up/down” motion in combination with the latitudinal motion, but lacks the interaction with bathymetry that influences the meridional transport. Although I suppose you could say atmospheric currents smashing into mountain ranges would be similar. They’re both fluids, after all–the atmosphere is just much less dense =p
And to answer your actual question, I’ll see if I can dig up some good references–my introduction to it was through lectures and textbooks, which was also how we presented it to students in the undergraduate classes while I was TAing.
Scamp Dog
@Boussinesque: I figured you were a fluid dynamics person, since I remember hearing about the Boussinesque approximation when I was in grad school way back when (can’t remember what it is, though). Welcome!
amygdala
Boussinesque, welcome, and many thanks for a fascinating piece.
Alain, thank you for arranging all of this. I think it’s a great idea.
The name of my next band will be passive larval stages.
Aleta
@Ceci n est pas mon nym: The idea that the water molecules in a wave don’t travel along with it is pretty cool, kind of buddhist. After the wave has passed through, a molecule ends up in about the same place as it was before the wave. At least in the motion physics.
clay
Sorry to interrupt:
Sources: Comey acted on Russian intelligence he knew was fake
sharl
The idea you and Alain cooked up for posts like this is a great idea; I hope to see more along these lines.
Do you have any favorite “reputable” websites, twitter accounts, etc. that are oriented toward science laypeople?
I sometimes get concerned (and sometimes downright irked) that I’m being suckered into reading online pieces that are inappropriately alarmist or that exaggerate the importance of stories. I understand the strong temptation for university media relations staff and cash-hungry environmental organizations to chuck clickbait into the social media waters, but that sort of thing can really depress the signal-to-noise ratio of what’s worth reading out there.
Gen
Very interested. This is just a plea for you to keep writing
Boussinesque
@Betty Cracker: Thanks, Betty. I don’t comment super-frequently, but I always enjoy your posts and cartoons, so your vote of confidence means a lot to me.
Bill Arnold
Is there a consensus prediction of what will happen to the base levels of the food chain as the ocean surface waters warm, combined with acidification? And are there any decent models for this?
Boussinesque
@Mary G: I’m not an expert on the topic, but my understanding is that bleaching is a stress response to warmer temperatures on the part of coral–they eject the things that contain the pigmentation to try to conserve resources in the short-term, but when the temperature doesn’t return to their “normal” band, they just die.
Boussinesque
@Scamp Dog: A good catch–Boussinesq was an oceanographer, and the “Boussinesq approximation” is a simplification for the equations dealing with surface waves whose wavelength is long relative to the depth of the fluid they’re occurring in. Since I only have a Master’s degree, not a PhD, I figured “-esque” would capture the “approximation to an oceanographer” aspect of my background.
Aleta
@Boussinesque: Thanks for this, and for the great post.
stinger
@Elmo: Yes, I suspect there are a lot of us out here like that.
SiubhanDuinne
@Boussinesque:
Perfect and understandable answer! Merci bien!
Major Major Major Major
Cool piece, thanks. Can’t wait to read more!
I have an odd question. I’m writing a novel where all of the fish in the world disappear, poof, gone. Would this have much of an immediate effect on the ocean, physically?
Boussinesque
@sharl: a very good question–while I still attend the occasional conference or seminar, I don’t actually read much by way of online climate discussion (something that I may wish to change, going forward). Realclimate.org is sort of the go-to for “reliable” climate science, but Think Progress has a good list that includes some that are more geared towards the layperson, which should be more accessible:
schrodingers_cat
@Aleta: That’s actually true for any wave, in any medium, including waves on a string or in an air column. Electromagnetic waves (visible light, for example) need no medium at all.
sharl
@Boussinesque: Thanks! I’m looking forward to your future posts.
Ceci n est pas mon nym
@Aleta: What surprised me was that they don’t ride the wave up and down as it goes past, the way a person treading water does. Particles in ocean waves move in big vertical circles.
Boussinesque
@Bill Arnold: I’ve not surveyed the literature recently, but the last time I did, things were a bit up in the air. As a general matter, we expect coccolithophores (a type of phytoplankton) and other marine calcifiers to have a bad time of it, since ocean acidification directly affects the chemical processes they use to build…well…themselves? Diatoms (another class of phytoplankton) use silicate instead of calcium carbonate, and so are less directly impacted by the pH changes, but my recollection is that they’re also fans of colder climes.
Part of the problem with modeling ocean biology response to warming and acidification is that lab experiments on phytoplankton are invariably somewhat limited–there’s only so much of the diverse processes of the actual ocean that can be accurately reproduced. What we do know is that there will likely be some species that do better while the majority do worse, and that the chances for successful adaptation drop as the timescale of change shortens–evolutionary timescales are much, much longer than the timescale for the changes we’re inducing =/
Boussinesque
@sharl: Gah, FYWP appears to have eaten the link. Here’s the raw one, I guess? https://thinkprogress.org/top-ten-climate-change-blogs-7a3dc53ceb80
Jim Parene
Please, Bouissinesque! More of these very informative articles!
As a lifelong water rat, I appreciate any insight into the working of the Oceans.
hovercraft
Could a front pager give us an open thread, this is very interesting, and not the place for normal jackal behavior,so could you please give us a place to play, please.
hovercraft
@Boussinesque:
FYI the link is in the reply button on # 64
Sourmash
Thanks for the oxygenation answer! So what happens to the currents if the Greenland ice sheets melt precipitately, say over the course of months they flow into the ocean, and dilute the cooling, highly saline waters of the northern gulf stream? Would the water dilute at all, given the difficulty of mixing water with such different content, or would the supercool water just take the place of the gulf stream and make the hypersaline water pile up at Norway?
Boussinesque
@Major Major Major Major: Short-term, I don’t think that it would have much of an immediate impact. The cascading effects would be fairly interesting, though–with less respiration occurring, dissolved oxygen concentrations would rise, and the absence of predation would cause a zooplankton bloom (microscopic animals that feed on phytoplankton), which would help bring down the phytoplankton bloom (we call this “top-down” control, where grazing by predators is the limiting factor in biomass accumulation, rather than the lack of nutrients (“bottom-up” control)). Longer term, the lack of larger organisms would impact transport of carbon and nutrients into the deep ocean–you get food scraps and fecal matter aggregating into larger pellets to sink out of the surface layer more quickly, so no larger organisms impacts the degree to which that occurs. And I say “larger” pellets, but we’re still talking microscopic. Look up “Marine Snow” for a more thorough treatment.
The Moar You Know
@Boussinesque: I don’t know what you’d call me :) I have some class work, and field work done through Scripps here in San Diego when I was a kid/teen, but most of it is just practical stuff from working with radio comms for a long time (magnetic fields, space weather, that sort of thing). We share an alma mater, kind of hard to go to UCSC and not get exposed to ocean sciences, and growing up next to the ocean, well…if that doesn’t make you want to know how it works nothing could.
I guess “enthusiastic enthusiast!”
My three main fields of expertise are network security, electromagnetic communications of all types, and acoustic musical instrument construction.
Bill Arnold
@Boussinesque:
Many thanks. Follow-up question: is there any literature that exhaustively examines the effects of regional climate fluctuations (“natural experiments”) on ocean productivity? (Don’t know enough to know good search keywords.)
Major Major Major Major
@Boussinesque: Thanks!
Boussinesque
@Sourmash: Hmm, absent a model to rely on, this will be speculation on my part, but I’ll take a stab at it. Ice sheet melt will be, by definition, quite cold, which brings the temperature characteristic much closer to the existing water masses off the coast of Greenland. The North Atlantic already has fairly fresh sinking water (due to precipitation), so I don’t know how much of a difference in density the salt content of the existing water masses would account for. On top of that, the North Atlantic is reasonably stormy, so we have strong mechanical mixing that could help homogenize the incoming glacial melt reasonably quickly. That being said, I’m unsure how it would interact with the Gulf Stream output.
When we think of glacial melt/ice sheet loss screwing up global circulation, I think the Antarctic is what is usually focused on–there isn’t quite as much precipitation down there, so the sinking water is cold and saline–put some *colder* but *much less saline* water on top of that, and you may shut off the sinking completely, if enough of it is injected at once.
realbtl
Boussinesque- Thanks for this and I look forward to many in the future. I spent my 1st 18 years within 2 mile of the coast in San Diego area and have always been fascinated by oceanography, having roamed through the Scripps Institute many times many years ago.
Bill Arnold
Are oceanographers up-in-arms about the proposed cancellation of the NASA PACE (Plankton, Aerosol, Cloud, ocean Ecosystem> satellite mission?
( White House budget proposal targets ARM, Earth science missions, education )
The Dangerman
MORE, please.
I don’t have the time to read thoroughly right now, but I think I’ve seen the effects of some of these ocean properties with the effect on the Sea Lion population in Central CA; I’ve witnessed cycles of Domoic Acid poisoning on the SL’s (it’s been a while; as memory serves, it’s only the female SL’s that are affected, which might be a body weight thing). Some seasons are really bad, others, well, not so much.
It’s been a while since I last volunteered with the local Marine Mammal Rescue Center (I was a “Pinniped Paramedic” for a while) so some of the Domoic Acid facts escape me right now (it’s Friday and I don’t have nearly enough coffee right now) but I’ve bookmarked and will come back after proper caffeination and/or sleep levels have been attained.
rikyrah
I don’t have a question.
But, welcome to BJ!
This has been one of the most interesting threads that I have read in a long time.?
catclub
@schrodingers_cat: Actually, gerbils.
No, actually it is heating and cooling from the sun. Or the fact that water is nearly incompressible, so if you make slightly denser water, it pushes less dense water away.
germy
Origuy
I have been reading a book called How to Read Water: Clues and Patterns from Puddles to the Sea by Tristan Gooley. I’m not too far in it; he has discussed how Polynesian navigators learn how to use ocean currents to navigate in the open ocean.
Boussinesque
@Bill Arnold: Very good questions. I think you could probably classify a lot of the oceanic work that goes on as “Natural Experiments”, since the ocean is large enough that trying to experimentally induce a change over a big enough area is somewhat problematic. I think the closest we’ve come to that kind of change are some of the Iron Fertilization experiments (SOIREE, IronEx, SERIES, SEEDS, SOFeX).
When it comes to estimating impacts on ocean productivity, we usually have to combine lab experiments with modeling–we get a general sense of the response of an organism or organisms to a particular type of change (temperature, chemical concentrations, etc.) in the lab, then use that to create a parameterization that responds to that type of change appropriately in the model. We then run the model (or an assemblage of models) to get a feel for how larger-scale processes might be impacted.
Aside from that, comparisons of productivity in different years from observational data allows us to do correlations, regressions, ANOVA-type investigations to try to “unpack” how much of the variability in year-to-year productivity can be attributed to variations in the various physical parameters (this is usually pretty involved, since linear relations aren’t usually expected–there are a number of interacting factors or “turn-on” step factors that can complicate the analysis).
My own thesis work was looking into how cross-shelf transport from mesoscale eddies in the Gulf of Alaska impacted biological activity, with the aim towards linking eddy variability to climate variability, to try to infer the impact of climate change on productivity due to eddies.
As far as keyword searches go, I’d say you have a pretty decent start–Regional Climate Change effects on Oceanic Productivity turned up the following Nature article: http://www.nature.com/nature/journal/v444/n7120/abs/nature05317.html
(Has a paywall, so I can only really comment on the abstract)
Another good search might be “Variability in Oceanic Productivity” or “Net Primary Production” (that’s what we refer to phytoplankton growth as).
scav
@Boussinesque: Thanks. I always found that working through the basic dynamics and adding things (both for the atmospheric models and the hypothetical continent for biomes and climate) really helped cement things in my mind.
catclub
@Boussinesque:
I have always been puzzled by this, combined with your schematic of the global conveyor belt showing no production of deep water in the Antarctic.
In the old days they said that deep water should form in the Antarctic, then they decided not much was formed there. I could never adjust to that change.
Boussinesque
@Bill Arnold: Yes, the potential disruption of many of our earth-observing satellite missions is a HUGE issue for ocean scientists and earth scientists alike. A lot of the value in these data sets comes from them being continuous. If there’s a gap in the time series, you open the door for all kinds of denialism linked to “well, we can’t say for *sure* since anything could’ve happened during that gap…”. It’s really scary, quite frankly. There’s undeniable value in these scientific data products, and we can only collect them contemporaneously–once time moves on, that information is lost. That they’re proposing “money-saving” cuts to missions like these that cost a pittance compared to anything in our military budget is so transparent a fig-leaf as to be outright insulting.
So yes, scientists are very cognizant of what Twitler and his cronies are doing to us, and we don’t like it one bit.
catclub
@Sourmash:
This was the basic observation of the silly movie about superfast climate change. You turn off the North Atlantic circulation and climate (weather) changes very fast. London is no longer warmed by the Gulf Stream, etc.
Boussinesque
@catclub: Hrm, I realize now that the image I selected months back when I first wrote this may be a bit deficient–there IS deep water formation in Antarctica, and the figure I used doesn’t explicitly call it out. Antarctic Bottom Water (AABW) and North Atlantic Deep Water (NADW) are the two main sources of sinking fluxes for the ocean. Where did you hear that not much was formed around Antarctica? If I’ve missed out on a more recent discovery, I’ll have to bone up on my material @[email protected]
Boussinesque
@The Dangerman: Thank you for your efforts to help the Sea Lions. I had colleagues on the biology side that studied Harmful Algal Blooms (HABs) and looked at how climate change impacted their frequency of occurrence and severity. My recollection is that the general conclusion was warmer ocean -> more HABs -> more domoic acid issues, among other things.
Boussinesque
@Kitfoxer: Sorry I missed this post in my rush to respond to questions! I haven’t had any direct dealings with the IODP (although I know we all appreciate the work being done—MOAR CORES). The two cruises I’ve been on were on the R/V Thomas J. Thompson, out of the University of Washington, and the R/V Point Sur, out of Moss Landing. I’m currently trying to transition into industry doing data-analytics related work, but I do keep an eye out for chances to rejoin the community–was in final-round consideration for a Research Technician position at MBARI last November (didn’t wind up getting it, but felt good to get that close).
Boussinesque
@Tim F.: Sent you an e-mail. Would be pretty wild if we had bumped into each other–I’ve not been to any of the CA meetups for BJ yet.
David Anderson
First, thank you for your time and your willingness to share your expertise, Boussinesque!
Secondly as a warning —- I thought I was only going to be here for a couple of months and maybe 30,000 words — OOPS :)
Aleta
@Boussinesque: I watched a discussion from the streamed sessions of the LPI science conference in which there was some effort to reassure the earth scientists, by saying the planetary research budget could encompass some part of the earth research that becomes unfunded. Earth being a planet and all. (Don’t know if there was political motivation in saying that.) Perhaps by combining projects, more sharing of satellite resources? Sounds inadequate of course, and assumes generous cooperation would outweigh usual resource competition…
Boussinesque
@David Anderson: Thank you, David! Funny coincidence–the point where “inability to comment” finally pushed me to take the step of contacting Alain had to do with trying to respond to one of your insurance posts. Being unemployed (although in California) means that knowing about potential changes to the health insurance situation is of great interest to me.
And I’m glad you’re still posting–health insurance and policy is so complicated, it’s super helpful to have an expert guide. I may not comment on your threads all that often, but I always make sure to read them.
Oh, and apologies if I missed the explanation, but why the shift from “Richard Mayhew” to “David Anderson” (always makes me think of The Matrix…”Mister Anderson~~”)
David Anderson
@Boussinesque:
Dave is my real name. Richard was a pen name. I’m now working at Duke University as a researcher/policy geek/professional nerd (my sister’s description) so I can use my real name. “Richard” was useful when I was working in the industry and I wanted to comment on controversial topics or state things plainly. I liked the HR folks at UPMC but I tried to minimize the number of conversations I had with them to the mandatory once a year session for patient privacy compliance and off-site continuity of operations planning.
More detail here:
https://balloon-juice.com/2017/01/06/i-must-now-cheer-for-the-patriots-of-college-basketball/
Aleta
@Boussinesque: Thanks for doing this and for such clear and interesting explanations.
MomSense
@Origuy:
That looks like a great book. Thanks for the tip.
Matt
Maybe you could finish the calculation you alluded to, about the heat capacity of the atmosphere vs that of the ocean? Specifically, by what factor does the specific heat of the ocean exceed that of the atmosphere (for a given small solid angle, at an average ocean depth and temperature)?
Elizabelle
Alain, could we have a picture of sharks or anemones or something? None of those MAGA white boys, please.
I cannot figure out what they’re doing there.
Where’s Nemo?
trollhattan
Many thanks for the informative post and thread! My (very valuable) vote is to make it a series.
My workplace directs much attention to things like the Pacific and Arctic oscillations; the El and La Ninas (and “La Nadas”); the jetstream, etc. and I’d love to be able to parse the information such that I can grasp it at least a bit.
J R in WV
@The Moar You Know: Interesting, my next door neighbor is a musician also getting involved with repair and restoration of old instruments. He’s getting work from out of state now, so getting recognized some.
Lots of variety here!
Bill Arnold
@Boussinesque:
Thanks, “Net Primary Production” gives a scary number of results. (in scholar.google.com for others )
I’m supposing that intermediate between iron fertilization experiments and purely natural variations are the studies on air pollution deposition of nutrients especially Fe, and also air pollution effects on cloud cover (and rainfall for land-dwellers). Are these a big deal in your opinion? Air pollution levels/composition can change fairly rapidly at national/international geographic levels for political reasons.
Boussinesque
@Matt: The ocean has a specific heat that’s between 3 and 4x as great as the atmosphere. If we want to talk total heat capacity, the ocean weighs in at almost 1000x the total energy storage per degree C of change. This is a fairly good discussion of the topic: https://scholarsandrogues.com/2013/05/09/csfe-heat-capacity-air-ocean/
Boussinesque
@Bill Arnold: with the usual caveat of “not my specific area of expertise”, I think that there’ve been a decent number of studies on the impact of pollutants, and while there may be the odd case where some beneficial process is enhanced or some harmful process is hindered, it’s mostly negative impacts.
Basically, whenever we’re able to detect a persistent difference in forcings (whether it’s pollutants or other factors), that opens an avenue to take measurements to do comparative analysis on present/absent, although some of the connections aren’t immediately evident unless you go out and look directly (soot and other particulates deposited on ice/snow enhancing melt rate, for instance).
The relatively rapid changeability of air pollution levels/composition that you point out is also why environmentalists focus on pollution as a lever for effecting change–it’s one of the more accessible classes of solutions we have available (geo-engineering has problems all its own).
Alain the site fixer
Sorry the joyful trump voters offend so many; it was an illustrative picture, useful in adding some humor and vivid emphasis. It is my idea, he had nothing to do with it.
joel hanes
@Major Major Major Major:
all the fish disappear
We’re pretty much conducting that experiment now.
IIRC, almost 50% of the original fishes biomass has been removed from the oceans by human fishing,
and that number is rising as the trawlers have to abandon large and valuable fish that have become too scarce
and to concentrate on smaller and less valuable species.
The first-order answer might be “jellyfish”
Without predation from bony fishes, jellies proliferate.
Bill Arnold
@Boussinesque:
Thanks for the nuanced answer. Looking forward to future posts.
(You’ve been notably non-alarmist in your post and replies here; is that primarily professionalism? No need to answer, just curious. )
Boussinesque
@Bill Arnold: I actually hadn’t noticed that until you pointed it out. I’m not sure what the root reason actually is, but I’ve got a few ideas I’ll brainstorm here.
1: Professionalism definitely plays a role–I had an elective graduate seminar on “Doing Policy-Relevant Science and Engineering” where we read a book called “The Honest Broker”, and I sort of subconsciously slip into that voice when talking to the public about science stuff, which leads me to…
2: The primary intent of this post was to educate, not serve as a a call to arms for activism, so I probably eschewed forceful normative statements as a consequence, without necessarily thinking much about why I was doing so.
3: I don’t think that being hyperbolic or alarmist actually helps much. My professional opinion is that we should be very, very concerned, and my personal opinion falls somewhere along the “WASF” axis, but I also refuse to take counsel of despair–I’m in the Al Gore camp to the extent that I think “we’re in big trouble, but if we work together, it’s possible to get through this.” I also think that whether or not that’s actually true, it’s something that we have to believe in order to galvanize any action at all, because inaction won’t solve anything.
4: I think that the facts speak for themselves, so helping people to understand the underlying processes and concepts will get them to think through the ramifications on their own, likely leading to similar conclusions to my own. Basically, I don’t think I need to convince you–I think that you’ll be able to convince yourself.
Thanks for giving me an opportunity/prompt to actually kind of unpack that in public–I think that it’s an important conversation to have.
Prometheus Shrugged
@Kitfoxer: It’s amazing that you mention that specific cruise, because I was a member of the science party for the Agulhas current expedition and just finished my work today by looking at the latest data from those exact sediment sequences. Unbelievably random coincidence on Balloon Juice…
Prometheus Shrugged
@Boussinesque: Carl Wunsch’s favorite figure! He hates it, in part because of his prickly relationship with Wally Broecker (who popularized it), but also in part because it misrepresents some key aspects of the ocean’s overturning circulation. The lack of upwelling and deep water formation around Antarctica is one of these misrepresentations.
J R in WV
Boussinesque,
Thanks so much for taking time to talk about these issues with the Ravening Jackals here at B-J. Bill Arnold, thank you for your questions and conversation with Boussinesque – you helped the conversation a great deal.
When I was a child in the 1950s, I was pretty well behaved out in public, so my Dad took me to meetings in Charleston WV, aka Chemical Valley. We were driving from home in Beckley, nearly 2000 feet higher and about 55 miles SE, and there was no comparable industrial pollution around home. Some burning gob piles, which put some sulfur compounds into the air, bot nothing like the dozen giant chemical plants.
We drove north, downhill, until we came to the old tunnel between the Paint Creek watershed and the Cabin Creek watershed. On the other side of that tunnel the air was yellow, and thick, and smelled scary to a 5 or 6 year old. In the 50 years since then, a few of those plants are closed, and all the remaining plants have scrubbers and devices to accumulate those poisons, instead of spewing them into the air for everyone to absorb into their lungs and bodily systems.
I thought for years that we had won the air pollution battle. Then I got hired to work in IT for the Department of Environmental Protection. In the beginning we worked on coal data issues, as they had money. Before I retired I learned that most of what the Air Quality program did was keep track of emissions. How many pounds of ethyl death did the companies admit to discharging, on the honor system? Because it’s hard to weigh gaseous discharges, isn’t it!
Then I learned that the odorless, colorless pollutants weren’t even being counted, really. Like CO2.
Then I learned about the chemistry of global warming. And Methane, and Fluorocarbons for refrrigeration, that are much worse than CO2.
And they – big business and their bought and paid for politicians – are still lying about pollution. Because they’ll kill a million people to make a buck. They will, ask Don Blankenship. Or that bigger coal magnate, Robert E. Murray. Who lied about his mine pulling pillars out in Utah. The permit documents were all online when the mine collapsed… but the next day, they were GONE.
Thanks for coming in guys, i hope you’re right about the facts speaking for themselves. I’m glad Mar-a-Lago is about 4 feet above mean sea level, if you know what I mean! The old mean sea level… no telling about the new one, is there?
Bill Arnold
@Boussinesque:
Agreed; respect your stance/style; was just curious.
The only thought I’ll add is that it is key to our future that a significantly large number of the people who believe in climate change denial (and related) primarily for tribal/political affiliation reasons flip, ASAP [1]. Don’t much care if the flipping is actively or passively encouraged, or from what seeds it emerges, e.g. small-c-conservatism should have a lot to say about the crazy gambles we’re taking (“betting it all on red”), and have seen a few such voices recently.
[1] I’ve seen several papers on the subject in the last 6 months, if you’re interested. Another related approach is helping people to develop the mental tools needed to reliably identify FF-industry-generated propaganda. (And that generalizes to any propaganda.)
Bill Arnold
@Bill Arnold:
Re this, search (e.g. scholar.google.com) on “Inoculation theory”.
Kitfoxer
@Prometheus Shrugged: Hello, fellow sailor! Which lab were you in? I did description support on X361. One of the techs.
Prometheus Shrugged
@Kitfoxer: I was one of the stratigraphic correlators. Not the smelly one with the big beard. The internet world couldn’t be smaller–what a random encounter!
Sara L. Price
Thank you for your time writing this very important oceanography article. I hope you continue doing so. As a lifelong learner and marine science enthusiast, articles like yours are very difficult to come by. Too much sensationalism and click-bait dominate media nowadays. First time here, it won’t be my last.