Hi John‹I am not sure one can separate then. For example, where one has a thin boundary layer and then the free atmosphere above, it is like having two different fluids that don¹t mix all that well, so if far inland one gets convection pulling the lower layer in with a horizontal gradient, so resolution can matter in the vertical to maintain the distinction of the two layers, allow wave, etc. AS I said before I am not sure one can really separate the two aspects.
Best, Mike On 6/1/15, 8:16 PM, "John Harte" <[email protected]> wrote: > 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 > [email protected] > > > > On Jun 1, 2015, at 4:56 PM, Mike MacCracken <[email protected]> wrote: > >> Re: [geo] Smart reforestation must go beyond carbon: expert | CIFOR Forests >> News Blog >> 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; >> IŒd 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 Mexico¹s 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, I¹d 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 don¹t 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 someone¹s extra time (if you know >> someone who could do it, student or prof, I¹d be happy to go into a bit more >> detail). Whether this might have anything to do with the Amazon situation I >> don¹t 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" <[email protected] >> <x-msg://1239/[email protected]> > 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 I¹m 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 paper¹s 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-ve >>> rsion/#comment-291429 >>> Summary and outlook >>> The Editor¹s 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 Earth¹s 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 ³Revisiting forest impact on >>> atmospheric water vapor transport and precipitation², 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 ³Geo². >>> >>> Ron >>> >>> >>> On May 31, 2015, at 11:02 AM, Mike MacCracken <[email protected] >>> <x-msg://1239/[email protected]> > 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" <[email protected] >>>> <x-msg://1239/[email protected]> <x-msg://153/[email protected] >>>> <x-msg://153/[email protected]> > > 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 >>>>> [email protected] <x-msg://1239/[email protected]> >>>>> <x-msg://153/[email protected] <x-msg://153/[email protected]> > >>>>> >>>>> >>>>> >>>>> On May 30, 2015, at 2:49 PM, Brian Cartwright <[email protected] >>>>> <x-msg://1239/[email protected]> >>>>> <x-msg://153/[email protected] >>>>> <x-msg://153/[email protected]> > > 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
