Sorry about the numbering being repeated before. I am suffering from lack of food, fresh air and human companionship, except for what I get here and will rectify the first two shortly. So don't interpret a pause in the abstract postings as meaning the Red Team has found my safe house and eliminated me. Although I bet they're looking...
http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=tilmes&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c446%7c3544%7cImpact%20Of%20Geo-engineered%20Aerosols%20On%20Stratospheric%20Chemistry%20And%20Dynamics%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54598379%2054601923%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt : U43A-0047 TI: Impact Of Geo-engineered Aerosols On Stratospheric Chemistry And Dynamics AU: Tilmes, S EM: [EMAIL PROTECTED] AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000, United States AU: * Garcia, R R EM: [EMAIL PROTECTED] AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000, United States AU: Kinnison, D E EM: [EMAIL PROTECTED] AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000, United States AU: Gettelman, A EM: [EMAIL PROTECTED] AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000, United States AU: Rasch, P J EM: [EMAIL PROTECTED] AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000, United States AB: Geo-engineering schemes have been proposed to alleviate the consequences of global warming; one proposed scheme is to inject sulfur into the stratosphere so as to mimic the effects of large volcanic eruptions. Past volcanic eruptions have shown that strongly enhanced sulfate aerosols in the stratosphere result in a higher planetary albedo, leading to surface cooling. However, the increase of sulfate aerosol surface area enhances heterogeneous reactions in the stratosphere that lead to ozone loss. The potential for high Arctic ozone depletion in the context of geo-engineering is known. On the other hand, halogen compounds are now decreasing in the atmosphere as a result of the enforcement of the Montreal Protocol and its amendments, and this is expected to bring about the recovery of the ozone layer and to lessen the potential impact of aerosols. In this study we present results of calculations made with NCAR's Whole Atmosphere Community Climate Model (WACCM), focusing on the impact of Geo-engineering on stratospheric chemistry and dynamics. Aside from changes in heterogeneous reactions, changes in stratospheric dynamics have a significant impact on ozone. On average, changes of both chemistry and dynamics result in a slowdown of the recovery of ozone for mid- and high latitudes. An increase of ozone depletion as a result of geo-engineering was found in both polar regions for the period between 2040-2050. DE: 0305 Aerosols and particles (0345, 4801, 4906) DE: 0340 Middle atmosphere: composition and chemistry DE: 0341 Middle atmosphere: constituent transport and chemistry (3334) DE: 0360 Radiation: transmission and scattering DE: 0370 Volcanic effects (8409) SC: Union [U] MN: 2008 Fall Meeting [Comments. I can't tell if this is a repeat of the Royal Society/Science Paper work that got the media into a frenzy earlier this year. In that work, the ozone depletion estimates were based on a doubling of CO2 by 2016 or thereabouts. I would hope that error is not repeated in this analysis. The reporters won't be able to take it. AG] http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=avallone&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c669%7c3611%7cMeasurements%20of%20Unexpected%20Ozone%20Loss%20in%20a%20Nighttime%20Space%20Shuttle%20Exhaust%20Plume:%20Implications%20for%20Geo-Engineering%20Projects%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54574174%2054577785%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt U43A-0040 TI: Measurements of Unexpected Ozone Loss in a Nighttime Space Shuttle Exhaust Plume: Implications for Geo-Engineering Projects AU: * Avallone, L M EM: [EMAIL PROTECTED] AF: Laboratory for Atmospheric and Space Physics, University of Colorado 590 UCB, Boulder, CO 80309-0590, United States AU: Kalnajs, L E EM: [EMAIL PROTECTED] AF: Laboratory for Atmospheric and Space Physics, University of Colorado 590 UCB, Boulder, CO 80309-0590, United States AU: Toohey, D W EM: [EMAIL PROTECTED] AF: Department of Atmospheric and Oceanic Sciences, University of Colorado 311 UCB, Boulder, CO 80309-0311, United States AU: Ross, M N EM: [EMAIL PROTECTED] AF: The Aerospace Corporation, Environmental Systems Directorate 2350 E. El Segundo Blvd., El Segundo, CA 90245, United States AB: Measurements of ozone, carbon dioxide and particulate water were made in the nighttime exhaust plume of the Space Shuttle (STS-116) on 9 December 2006 as part of the PUMA/WAVE campaign (Plume Ultrafast Measurements Acquisition/WB-57F Ascent Video Experiment). The launch took place from Kennedy Space Center at 8:47 pm (local time) on a moonless night and the WB-57F aircraft penetrated the shuttle plume approximately 25 minutes after launch in the lowermost stratosphere. Ozone loss is not predicted to occur in a nighttime Space Shuttle plume since it has long been assumed that the main ozone loss mechanism associated with rocket emissions requires solar photolysis to drive several chlorine-based catalytic cycles. However, the nighttime in situ observations show an unexpected loss of ozone of approximately 250 ppb in the evolving exhaust plume, inconsistent with model predictions. We will present the observations of the shuttle exhaust plume composition and the results of photochemical models of the Space Shuttle plume. We will show that models constrained by known rocket emission kinetics, including afterburning, and reasonable plume dispersion rates, based on the CO2 observations, cannot explain the observed ozone loss. We will propose potential explanations for the lack of agreement between models and the observations, and will discuss the implications of these explanations for our understanding of the composition of rocket emissions. We will describe the potential consequences of the observed ozone loss for long-term damage to the stratospheric ozone layer should geo-engineering projects based on rocket launches be employed. DE: 0340 Middle atmosphere: composition and chemistry DE: 0394 Instruments and techniques DE: 7853 Spacecraft/atmosphere interactions SC: Union [U] MN: 2008 Fall Meeting [Comments. Back to beating up on the rocket launchers again, this time with a new previously unknown mechanism for ozone destruction sans sunlight. I wonder if the conclusions from their other abstract were based on this or just on the solar photolysis-based destruction? AG] http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=murphy%20d.m.&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c478%7c1702%7cThe%20effect%20of%20deliberate%20stratospheric%20aerosols%20on%20direct%20sunlight%20and%20implications%20for%20concentrating%20solar%20power%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54596677%2054598379%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt U43A-0046 TI: The effect of deliberate stratospheric aerosols on direct sunlight and implications for concentrating solar power AU: * Murphy, D M EM: [EMAIL PROTECTED] AF: NOAA Earth System Research Lab /CSD, 325 Broadway, Boulder, CO 80305, AB: Both calculations and data show that stratospheric aerosols reduce direct sunlight by about four watts for every watt reflected to outer space. The balance becomes diffuse sunlight. Calculations show how the amount of diffuse sunlight depends on the size of the stratospheric aerosol particles. One consequence of deliberate enhancement of the stratospheric aerosol layer would be a significant reduction in the power output of solar generation systems using parabolic or other concentrating optics to collect direct sunlight. This is evident in the output of solar electricity generating plans [plants AG] after the eruption of Mt. Pinatubo. DE: 0305 Aerosols and particles (0345, 4801, 4906) DE: 0340 Middle atmosphere: composition and chemistry DE: 0370 Volcanic effects (8409) SC: Union [U] MN: 2008 Fall Meeting [Comments. There are no conclusions, so I don't know what new information is being revealed. Pinatubo reduced output by about 20% and we spent some time discussing the implications here earlier this year or late last year. One has to be careful tossing around terms like "significant" as Pinatubo levels wouldn't have to be reached for many decades if that was the only way AGW was to be combatted. AG] http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=toon&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c388%7c3494%7cTerraforming%20the%20Planets%20and%20Climate%20Change%20Mitigation%20on%20Earth%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54446594%2054450088%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt U41E-01 INVITED TI: Terraforming the Planets and Climate Change Mitigation on Earth AU: * Toon, O B EM: [EMAIL PROTECTED] AF: University of Colorado, Campus Box392, Boulder, CO 803090392, United States AB: Hopefully, purposeful geo-engineering of the Earth will remain a theoretical concept. Of course, we have already inadvertently changed the Earth, and over geologic history life has left an indelible imprint on our planet. We can learn about geo-engineering schemes by reference to Earth history, for example climate changes after volcanic eruptions provide important clues to using sulfates to modify the climate. The terrestrial planets and Titan offer additional insights. For instance, Mars and Venus both have carbon dioxide dominated greenhouses. Both have more than 10 times as much carbon dioxide in their atmospheres as Earth, and both absorb less sunlight than Earth, yet one is much colder than Earth and one is much hotter. These facts provide important insights into carbon dioxide greenhouses that I will review. Mars cools dramatically following planet wide dust storms, and Titan has what is referred to as an anti- greenhouse climate driven by aerosols. These data can be used to reassure us that we can model aerosol caused changes to the climate of a planet, and also provide examples of aerosols offsetting a gas-driven greenhouse effect. People have long considered whether we might make the other planets habitable. While most of the schemes considered belong in the realm of science fiction, it is possible that some schemes might be practical. Terraforming brings to mind a number of issues that are thought provoking, but not so politically charged as geo-engineering. For example: What criteria define habitability, is it enough for people to live in isolated glass enclosures, or do we need to walk freely on the planet? Different creatures have different needs. Is a planet habitable if plants can thrive in the open, or do animals also need to be free? Are the raw materials present on any planet to make it habitable? If not, can we make the materials, or do we have to import them? Is it ethical to change a planetary climate? What if there are already primitive creatures hidden somewhere, does that change the ethics? Or perhaps, if left alone, the planet would later evolve to have life, is it ethical to alter that path? Many of these questions have parallels to things we need to consider when we talk about geo-engineering Earth. I will touch upon some of these subjects in this talk. DE: 0305 Aerosols and particles (0345, 4801, 4906) DE: 0315 Biosphere/atmosphere interactions (0426, 1610) DE: 0343 Planetary atmospheres (5210, 5405, 5704) DE: 1630 Impacts of global change (1225) DE: 5405 Atmospheres (0343, 1060) SC: Union [U] MN: 2008 Fall Meeting [Comments. And remember, the Prime Directive must not be violated. So no more space missions. AG] http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=daniel&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c518%7c2022%7cCooling%20Earth%27s%20temperature%20by%20seeding%20marine%20stratocumulus%20clouds%20for%20increasing%20cloud%20cover%20by%20closing%20open%20cells%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54584012%2054586034%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt U43A-0043 TI: Cooling Earth's temperature by seeding marine stratocumulus clouds for increasing cloud cover by closing open cells AU: * Daniel, R EM: [EMAIL PROTECTED] AB: The transition from open to closed cellular convection in marine stratocumulus is very sensitive to small concentrations of cloud condensation nuclei (CCN) aerosols. Addition of small amounts of CCN (about 100 cm-3) to the marine boundary layer (MBL) can close the open cells and by that increase the cloud cover from about 40% to nearly 100%, with negative radiative forcing exceeding 100 wm-2. We show satellite measurements that demonstrate this sensitivity by inadvertent experiments of old and diluted ship tracks. With the methodology suggested by Salter and Latham for spraying sub-micron sea water drops that serve as CCN, it is possible to close sufficiently large area of open cells for achieving the negative radiative forcing that is necessary to balance the greenhouse gases positive forcing. We show calculations of the feasibility of such an undertaking, and suggest that this is an economically feasible method with the least potential risks, when compared to seeding marine stratocumulus for enhancing their albedo or with seeding the stratosphere with bright or dark aerosols. Global Circulation models coupled with the ocean and the ice are necessary to calculate the impact and the possible side effects. DE: 1600 GLOBAL CHANGE SC: Union [U] MN: 2008 Fall Meeting [Comments. How can this method be less risky than the Salter/Latham method? The reflected sunlight will still be non uniform relative to the rest of the Earth's surface and one would think that the effects on El Nino's and monsoonal flows would still apply. AG] --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
