A must read for anyone interested in Marine Cloud Brightening A ---------- Forwarded message ---------- From: "nathan currier" <[email protected]> Date: 30 Jul 2014 23:17 Subject: Response to my questions re marine cloud brightening - and a thought or two on potential micro-scale real-world testing..... To: "Stephen Salter" <[email protected]> Cc: "[email protected]" <[email protected]>, "David Willson" <[email protected]>, "Andrew Lockley" < [email protected]>, "Ken Caldeira" <[email protected]>, "Scott Elliott" <[email protected]>, "Susannah Burrows" < [email protected]>, "Cameron-smith, Philip" <[email protected]>, "Reagan, Matt" <[email protected]>, "P. Wadhams" <[email protected]>, "Sam Carana" <[email protected]>
Hi, Stephen - I hope you've been very well. If you remember, back in May I posted some questions at the Google geoengineering group that I had originally posed to you a year or so earlier about the potential for any problematic interactions with CLAW in doing MCB. While I didn't get much response there, I had also written at the same time, posing the same questions, to Scott Elliot at Los Alamos National Lab. He runs a biogeochemistry model there (COSIM), and I had once before tried to get John Nissen interested in reaching out to Scott for help and advice along the same vein, although I think he never followed up. Anyhow, as you'll see copied below, Scott just got back addressing my questions, has considerable interest in MCB, and passed my questions on to some others, one of whom, Susannah Borrows, at PNNL, also has an active interest in MCB, and posed a specific question for me to pass on for you. As you'll also see, they both have some concerns that aren't too far off from the kinds of questions I was raising, but they both have relevant expertise, work with relevant modeling that could be hugely helpful for MCB, I feel, and I hope that you'll be as excited to hear about it as I was. Susannah's specific question, as you'll see, concerns the filtering of the water in MCB - in particular, she mentions concerns that this might impact the formation of ice nuclei, which apparently are a potentially significant factor in marine clouds' radiative properties, so this might be an important conversation for you to have..... Indeed, one of Susannah's last comments struck me as particularly intriguing, where she suggests that, if the filtering *were* an adjustable feature of your instrument design, that it could possibly become the basis for some interesting experiments to generally explore sea spray/cloud formation relationships. This gave me the sudden idea that - perhaps a little like Russ George and his salmon, but without any of the PR or controversy!! - micro-tests of your design, or certain aspects of it at least, might be able to be begun under the guise of generalized marine cloud formation research, perhaps at one of these national labs..... All best, Nathan from: Elliott, Scott M <[email protected]> to: nathan currier < [email protected]> cc: "[email protected]" <[email protected]>, "Reagan, Matt" <[email protected]>, "Cameron-smith, Philip" <[email protected]>, "Elliott, Scott M" <[email protected]> date: Wed, Jul 23, 2014 at 8:52 PM subject: RE: a few questions on COSIM, methane paper, etc. Hello at last Nathan: Sorry your message has taken so long to answer. Things have been crazy... as they always are for everyone of course. But naturally I have to deal with my bosses first. They can be very demanding, and there are a huge number of them. I must have done something wrong somewhere down the line. Everybody in the world is my boss and I work for all of them simultaneously. How come I'm not one of them? But on to more important matters... Your email is extremely refreshing and much more interesting than most. I'll react to your points mainly/roughly in the order presented. My understanding is that Latham is a very smart guy. And of course Salter is a legend in his own time. I know Caldeira personally and can attest that he is a world class thinker. I hope you'll share his reaction if you manage to contact him. But nobody can know everything, and the surface of the ocean is a vast, remote and mysterious realm. As you seem to be aware, I've worked on CLAW pretty hard myself. The connection you make strikes me as quite valuable. Here are some thoughts from an old hand. The phytoplankton that produce DMS and the levels at which they do so tend to be nutrient determined, so the most simple and direct links with cloud brightening via reduction in photosynthetically available radiation are likely to be secondary. But if one alters the planetary albedo significantly, there will definitely be feedbacks onto ocean circulation patterns. A zeroth order guess is that in general, cooling leads to more vertical mixing leads to more nutrients. The effects on DMS are likely to be large, but they are sufficiently complex that one would almost immediately turn to a marine ecodynamics/biogeochemistry model to sort things out. Incidentally, I happen to be the proud developer of just such a model. In fact by some measures, mine is the best in the world. We dominated the first and only international intercomparison of ocean organ sulfur codes. The basic principle in all such simulations is that more nutrients favor more sophisticated primary producing organisms (phytoplankton). In the tropics the fancy bugs tend to yield more DMS than their simpler cousins. At higher latitudes the opposite is true... so quickly you can see that you have a messy three dimensional modeling problem on your hands. But the issue strikes me as very important. I know plenty of scientists who would not hesitate to plunge in and write peer reviewed papers just to patent the concept that you present to me. Such a publication would ramble on for a few thousand words, but basically it would just advise the community that there are connections to be researched. This gets done all the time. I would be tempted to try it myself if I weren't so damn busy working on the big, detailed codes that may ultimately be called upon to iron all this kind of thing out at a high level. But now let's get beyond DMS for a minute. I want to turn you on to my own favorite angle on the artificial sea spray. I have recently been involved in a couple of publications which attempt to use simple physical chemical principles to compute the surface activity of marine macromolecules. We then estimate their tendency to be flung up into the atmosphere by wave-generated bubbles that break as they reach the atmosphere. Turns out you can explain a lot of the organic content of natural sea spray world wide in this simple fashion. And the organics have several complex but fairly strong effects on cloud brightness. They much function in a manner analogous to DMS. The idea I'd like to pursue is this: If a Salter vessel is out there generating artificial sea spray, it will likely have to deal with the same organic material since it is present in copious quantities in all seawater. Will the surfactant and organic effects on the manufactured salt particles be similar to their role in nature? Will they reduce the efficiency of the cloud manipulation scheme? Will the reduction in efficiency depend on region of the ocean? My guess is that the answer is yes in all cases. This should translate to big money in a future of global carbon trading. And as always such questions imply that much more research is needed. This familiar cycle never ends when it comes to the geoengineering, and hence there are a lot of people like me making a good living thinking about such issues. I was originally an atmospheric chemistry person but for a decade or so now I have been focussed almost exclusively on ocean biology and chemistry modeling. I have some close colleagues I can put you in touch with, though, who are true experts on the issues you raise. They were my collaborators on the surfactant chemistry project and they mainly work at Pacific Northwest National Laboratory. PNNL is an analog of Los Alamos but they happen to be much better than we are at the atmospheric sciences. I recommend that you begin by interchanging a little bit with Susannah Burrows, because she is young and perhaps has a little bit more time than some of the others to think freely. She is copied here. Indeed the clathrates remain a great problem. We had a couple of papers in 2010 and 2011 in which we showed that the community is completely missing the single most important point. Everyone gets hung up on the fact that methane emitted from the sea floor will likely be consumed biologically before it gets to the atmosphere. So the greenhouse effect will not be outrageous. Fine and several dozen groups have by now made this point in various ways. But here's what everyone overlooked -the marine bacteria that will perform the consumption function for us will require certain metabolic resources to get the job done. In fact they will need huge quantities of several things that other microbes need. Nutrients and trace metals and the like. Plus when they are finished with the carbon they spit out CO2 as an oxidized product and in seawater it's an acid. So our conclusion was that much of the subsurface Arctic Ocean could become a dead zone in a few decades. The are affected could be the size of the state of Alaska. Cool huh? I certainly thought so. No one has argued with us and the result appears to be holding up pretty well. The press picked up on it and we got quite a bit of attention. But most of the bosses I told you about above are more interested in the greenhouse effect in the atmosphere, which we argued will be weak. So the project lost its funding and has gone dormant. I am however actively looking for ways to revive it. And here I will copy/recommend that you talk to a couple of other young collaborators, Matthew Reagan at Lawrence Berkeley Lab who is probably the world's leading expert on how much methane the Arctic continental shelf is likely to deliver, and Philip Cameron-Smith of Lawrence Livermore National Lab who did some very careful computations of the likely atmospheric effects of the small amount that gets there. Finally about the piano. It was the first love of my life. I went from classical to garage bands to some pretty serious modern jazz... then had to go off to college, become a science guy, raise a family. I haven't touched a keyboard in many years. In a way I'm afraid to. I could easily get sucked back into music, and that would be dangerous. Anyway thanks for a thoughtful interchange. I can assure you that your thinking is precisely on target. Find a way to pursue it. Scott from: Burrows, Susannah <[email protected]> to: "Elliott, Scott M" <[email protected]>, nathan currier <[email protected]> cc: "Reagan, Matt" <[email protected]>, "Cameron-smith, Philip" <[email protected]> date: Wed, Jul 23, 2014 at 9:45 PM subject: Re: a few questions on COSIM, methane paper, etc. Hello Nathan, This is an interesting question. As you may know, my postdoctoral advisor, Phil Rasch, and other colleagues here at PNNL such as Hailong Wang have done some interesting work on marine cloud brightening, so I am well aware of this idea. Right now I don't think I have time to devote to it or the necessary tools -- we are in the middle of some model development work that should make it easier for us to address such questions in the future, but that is eating up a lot of attention and time at the moment. The question you raised requires having a model set up with dynamic ocean biogeochemistry, coupled to an atmosphere model, and if all goes well we should have that completed and validated sometime in the next couple of years (*knocks on wood*). About the Salter vessels, and since you are working with Stephen Salter in 1250now.org, I also have a question I would like to offer you, which I have wondered about for a while. What I have wondered about is the filtering of the water used to produce the spray. I believe that the original design involves filtering the pumped water to remove larger particles, in order not to clog up the engines. Whether this is done and how it done will affect the organic content of the spray that is produced, which may affect its cloud-forming properties, including its efficiency at nucleating cloud ice (http://www.tinyurl.com/burrows2013a). So, I wonder whether this is something that has been considered in designing vessels for MCB, and whether it is possible to adapt the design to remove less organic matter or different fractions of the organic material if desired. If so, it could potentially also enable some interesting field experiments on the effects of sea spray chemistry on cloud properties. Best, Susannah -- --------------------------------------------------------------------------------- Susannah Burrows [email protected] +1 (509) 372-6183 Pacific Northwest National Laboratory Atmospheric Sciences and Global Change Division P.O. Box 999 MS K-24, Richland, WA 99352, USA --------------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. 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