I'm not a climate modeler and my understanding of what goes in to conventional physics process-based atmospheric models is very limited, so correct me if I am wrong mike, but I was under the impression that it was the horizontal not the vertical pressure gradients that M & G think is inadequately treated in conventional models. Isn't it those horizontal pressure forces that power their biotic pump.
At least in the context of the Amazon, I would like to see a back of the envelope comparison of the pressure forces driven by condensation and the larger-scale forces that power the trade winds. John Harte Professor of Ecosystem Sciences ERG/ESPM 310 Barrows Hall University of California Berkeley, CA 94720 USA jha...@berkeley.edu On Jun 1, 2015, at 4:56 PM, Mike MacCracken <mmacc...@comcast.net> wrote: > Hi Ronal, Brian, John, et al.—As a modeler, I would imagine the question is > just what is it that one would want added to the models. Quite a number of > skeptics want the models to add in long cycles evident in the > observations—that would be fine in empirical models, but the whole idea of > physical models (i.e., models based on the physics, chemistry, etc.--but > process based on physical principles, etc.) is not to put in arbitrary items > for which there is not a physical process. > > So, for this forest case, what might this be? Well, having finer resolution > would likely help and as one goes down to relatively fine resolution the > hydrostatic assumption enforced by the formulation of the equations in these > models needs to be adjusted so that non-hydrostatic influences can be > included (i.e., so that the models can treat the vertical acceleration of the > winds). Whether that would help in the simulations I have no real idea or > experience. > > Another reason for going to finer resolution is to better represent > orographic features, and this might be a contributing factor. There is also > an aspect of doing this that I have been suggesting needs to be included. For > those who remember flying into Los Angeles and seeing thin, elevated levels > of pollution during the descent, it took a while to understand what was > causing these (it was not formation and reformation of the inversion, for > example). What a UCLA meteorology professor named James Eddinger, as I > recall, found was that in the afternoon when the Sun was shining on hillsides > facing to the southwest thin layers of air could rise along the heated slope, > and the heating of the air would compensate the adiabatic cooling, so the air > parcel would keep rising into the inversion. This continued until the air > reached the top of the mountain and so ran out of the surface heating. At > this point, the polluted air, having started in the marine boundary layer, > could neither rise further through the inversion nor sink due to its warmth, > so it spread out at its density in the inversion, forming widely spread thin > layer at the altitude of the mountain. > > I have been suggesting there are at least two other examples of this > happening (i.e., of low level air being carried up the sun-heated slopes of > mountain sides that faced the afternoon sun position). One likely place would > seem to be India and the Himalayas—in the region, the polluted air is of > order 9K meters high or so—how could moist polluted air get to that altitude; > I‘d suggest only by hot mountainsides in the Himalayas carrying such air > upward, keeping it warm so that it does not cool and precipitate out the > particulate matter. The second is the late afternoon mountain top > precipitation that occurs along Mexico’s Pacific coast mountain ridge; the > whole area is under an intense anticyclone, so very dry air and a strong > inversion, and yet there is precipitation at the top of the mountains in the > late afternoon—so, I’d suggest that most marine air is rises along the > heated, southwestward facing mountain slopes in the afternoon until it > reaches the mountaintop, where it can cool and so condensation occurs, > leading to the misty precipitation in what would otherwise be a very dry air > mass. > > The global models really don’t represent this—their resolution is too coarse > and their vertical layering is generally more box-shaped than sloped (use of > the sigma vertical coordinate system could technically handle this if > resolution fine enough). I had encouraged a modeler experienced with finite > element models to do some schematic tests of the idea, but, being retired, no > way to really push for that to get done on someone’s extra time (if you know > someone who could do it, student or prof, I’d be happy to go into a bit more > detail). Whether this might have anything to do with the Amazon situation I > don’t know. > > Another general problem with the climate models has been not having fine > enough resolution to really do the boundary layer very well—having to retain > strong vertical layering an be pretty difficult to do. So, again, resolution > may be an issue. > > And then there is the issue of the CCN loadings and sources and types, etc. > > So, indeed, there could be model problems, but to fix them in such models one > needs to focus on getting the physics right, not introduce arbitrary > empirical observations—those are what we need to evaluate the representations > of the physics. > > Best, Mike > > > On 6/1/15, 7:05 PM, "Ronal W. Larson" <rongretlar...@comcast.net> wrote: > >> List, especially Mike and John, cc Brian (who started this) >> >> 1. This is to explore further how this biotic pump topic would influence >> any part of geoengineering. I have concluded, like Brian, that this paper >> is important in promoting regrowth of forests. John certainly agrees and >> probably (?) Mike. Anyone disagree? >> >> 2. Inadvertently (I thought this was a 2015 paper for a while), I read not >> only the final paper, but the many difficulties in getting it published (> >> 1000 days). From the 24 subsequent papers found through Google Scholar, I >> conclude that it is not now a continuing controversy - but I have found no >> evidence that the paper has changed any existing models (as I’m sure the >> authors intended and hoped). Anyone know? >> >> 3. Others may find it interesting to see how the controversy was handled. >> Although it took a long time, I think the Journal basically did a good job >> and made a correct (but controversial) decision to publish. I was surprised >> how all (?) the editorial review correspondence is still available (nothing >> anonymous) - at a site given by the main editor in the paper’s last >> paragraph. >> The main author, Dr. Makarieva, was indefatigable - many dozens of pages >> defending everything in the paper. Here is the summary (with >> forest-oriented emphases added) from her invited post-publication comment >> at: >> >> http://judithcurry.com/2013/01/31/condensation-driven-winds-an-update-new-version/#comment-291429 >> Summary and outlook >> The Editor’s comment on our paper ends with a call to further evaluate our >> proposals. We second this call. The reason we wrote this paper was to ensure >> it entered the main-stream and gained recognition. For us the key >> implication of our theory is the major importance of vegetation cover in >> sustaining regional climates. If condensation drives atmospheric circulation >> as we claim, then forests determine much of the Earth’s hydrological cycle >> (see here <http://www.bioticregulation.ru/pump> for details). Forest cover >> is crucial for the terrestrial biosphere and the well-being of many millions >> of people. If you acknowledge, as the editors of ACP have, any chance – >> however large or small – that our proposals are correct, then we hope you >> concede that there is some urgency that these ideas gain clear objective >> assessment from those best placed to assess them. >> >> 4. A slightly later paper entitled “Revisiting forest impact on >> atmospheric water vapor transport and precipitation”, by many of the same >> authors is also NOT behind a paywall - and carries this forest theme >> further: http://www.bioticregulation.ru/common/pdf/taac-en.pdf. There are >> numerous other climate related papers from this Russian group - that almost >> certainly have relevance also on the SRM side of “Geo”. >> >> Ron >> >> >> On May 31, 2015, at 11:02 AM, Mike MacCracken <mmacc...@comcast.net> wrote: >> >>> Re: [geo] Re: Smart reforestation must go beyond carbon: expert | CIFOR >>> Forests News Blog >>> How are they not both important—the condensation releases the heat that >>> carries the air upward, creating a pressure gradient that pulls the air >>> ashore? >>> >>> Mike >>> >>> >>> On 5/31/15, 10:09 AM, "John Harte" <jha...@berkeley.edu >>> <x-msg://153/jha...@berkeley.edu> > wrote: >>> >>>> The work of Makarieva and Gorshkov (note: not Gorshkov and Makarieva; she >>>> is first author on their papers on this topic) is challenging atmospheric >>>> scientists not because it points to the huge role of forests in the >>>> hydrocycle (I have been teaching that for decades) but rather the specific >>>> mechanism they propose. Their argument is that it is the pressure >>>> difference created by condensation, not the heat released by condensation, >>>> that is the more important driver. Certainly both play a big role; my >>>> understanding is that the pressure effect was largely ignored in the past. >>>> >>>> >>>> John Harte >>>> Professor of Ecosystem Sciences >>>> ERG/ESPM >>>> 310 Barrows Hall >>>> University of California >>>> Berkeley, CA 94720 USA >>>> jha...@berkeley.edu <x-msg://153/jha...@berkeley.edu> >>>> >>>> >>>> >>>> On May 30, 2015, at 2:49 PM, Brian Cartwright <briancartwrig...@gmail.com >>>> <x-msg://153/briancartwrig...@gmail.com> > wrote: >>>> >>>>> To the geoengineering group, >>>>> >>>>> I'm curious whether group members are familiar with the "biotic pump" >>>>> model of Gorshkov and Makarieva; this article gives a quick introduction: >>>>> >>>>> http://news.mongabay.com/2013/0130-hance-physics-biotic-pump.html >>>>> >>>>> A big climate benefit of inland forests is that phase change from >>>>> evapotranspiration -> condensation creates low-pressure areas that pull >>>>> in moisture and create healthy weather circulation. Seems to me that >>>>> widespread deforestation is aggravating stalled hot-weather trends by >>>>> blocking this kind of circulation. The leaf area of a mature forest >>>>> offers considerably more surface area for evaporation than the same area >>>>> of open water on ocean or inland lake. >>>>> >>>>> Brian Cartwright -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
