We are unable to create an online viewer for this document. Please download the document instead.
Dec. 14, 2009 JSK Satellite-era glacier changes in High Asiahttp://www.glims.orgJeffrey S. Kargel*, Richard Armstrong, Yves Arnaud, Etienne Berthier, Michael P. Bishop, Tobias Bolch, And Coy Bush mple, Graham x and shifting HiCogley, Koji Fujita, Alan Gillespie, malaUmesh Harit yan ashya, Georg Kaser, Siri Jodha Singh Khalsa, Greg Leonard, Adina Racoviteanu, Bruce Raup, and Cornelis Van derVeen. . * Lead aut glacier hor: University of Ariz changona (Email: jeffr es eyskarg email@example.com tom) o complex and shifting climate driving processesBackground support presentation for NASA “Black Carbon and Aerosols” press conference associated with Fall AGU, Dec. 14, 2009 For further information, please contact any author Dec. 14, 2009 JSKUpdated Jan. 14, 2010Why this presentation was produced.Dec. 14, 2009 JSKUpdated Jan. 14, 2010-- A series of media and science errors has produced confusion about the actual state of Himalayan glaciers (slides 40-42).-- Some errors exaggerate the rate of melting, and others go the other way and errantly claim climatic in Cosensi mpletivity x and shifting Hiof glaciers. malayan -- A planned NASA press conference (which occurred Dec. 14*) appeared likely to reproduce .and reinf glacier orce some changof those errors, es and this poinhad to be t t avo coided. omplex *www.nasa.gov/topics/earth/features/himalayan-warming.html-- The lead auth and or of this shifting climapresentation was asked to joitn e the drivpress c ing onference as a guest panelist (not part of the team whose work was to be featured).-- A nuanced perspective on Hiprmalayan ocessesglaciers, and the effects of glacier changes on water resources and other matters, is necessary; reality is complex. Oversimplification, exaggeration, or ignoring serious matters can be consequential. -- An expert team has been assembled to build the case and buttress statements by Kargel that the glaciers will not disappear by 2035, but that they are melting rapidly in some areas and responding differently to climate change in other areas of the Himalaya/Hindu Kush (including some glacier advances).-- This effort has expanded now to present a more complete view for the benefit of scientists as well as the media and public.Dec. 14, 2009 JSKUpdated Jan. 14, 2010Presentation Summary-- We will show examples of: - Wasting, disintegrating glacier tongues - Stagnating tongues that are thinning but have stably positioned termini- A surging glacierComplex and shifting Himalayan -- Total Himalayan mass balance is distinctly negative; some anomalies may exist.-- There is glacier complexity in changglacier parame es ters, poine.g., t tglacier ar o cea, ompletypes, and debris- x cover, and in and how they shifting climarelate to the integrated Etarth s e yste drivm.ing -- Glacier responses and response times depend on climate, topographic characteristics, and unique aspects of each glacier, e. prg., d ocessesebris cover and types and sizes of lakes.-- There may be a geographic pattern to aspects of the glacier dynamical complexity.-- Glaciologists and climatologists have partial explanations for what is happening (but much is still not known or understood): - Anthropogenic emissions (gases and aerosols) affect the global climate system and regional transport/precipitation of moisture. - Regional variation in Elevated Heat Pump (EHP), Monsoons, and Westerlies.-- We attempt to correct recent media and space agency errors and summarize and quantify some more realistic rates of glacier retreat and impacts on water resources.Generalized glacierGlaciers try to achieve a balance between snow accumulation and melting. When climate or any environmental condition shifts even a little, the balance is thrown off, so glaciers continually readjust.Annual average freezing temperatureCONTACT: Jeff KargelCONTACT: Jeff KargelGeneralized glacierThe Equilibrium Line Altitude is where snow accumulation (snowfall and any added snow avalanches) is balanced by melting and sublimation losses. It is not the same as the elevation where annual average temperature is at the melting point (but there is a relationship).Snow accumulates high in the mountains and gets buried by more snow.Melting can’t keep up with snowfall (or there is no melting at all).Snow compresses and recrystallizes to solid ice.Ice flows downhill under force of gravity.Equilibrium Line Altitude(where snow accumulation is balanced byloss of ice mainly from melting)Ice flows down to warmer climate zones.Melts faster than the snow season adds new snow.Downslope flow and melting maintain glacier length (if in mass balance).CONTACT: Jeff KargelThe melting influence of atmospheric aerosols and deposited soot and dust vary across the glacierAtmospheric aerosols and Elevated Heat Pump:Atmospheric thermal structure, H2Otransport, clouds and precipitationReduced sunlight reaching glacier surface (+)Snow and rain precipitation (+)Melt line evolution through the year (-)Surface temperature and melting (-)Deposited black carbon and dust:Albedo, melting above dry snow zone (0) Albedo, melting in snowmelt zones (-)Albedo, seasonal melt line evolution (-)Albedo, melting in exposed ice areas (-)Albedo, melting in debris covered zones (0)0 no significant influence+ influence tending toward positive balance- influence tending toward negative balanceCONTACT: Yves Arnaud and Jeff KargelMODIS summer and autumn composite base image.Contact: Jeff KargelBase image courtesy of GSFC/NASAPrecipitation seasonality and E-W/N-S gradients over the mountains of Central AsiaClimateAnnual Mean PrecipitationWinter precipitation focused over Summer monsoon precipitation focused the Karakoram and western Himalayaover the eastern and Central HimalayaPrecipitation 2-5X on the south side compared to north sideBöhner (2006), BoreasADDITIONAL CONTACT: Tobias BolchMore Westerly dominated precipitationLess monsoon-influenced precipitationGlaciers grow by winter accumulationLess intense melting, more intense sublimationLess glacier disintegration & lake growth More cold-based iceEHP net influence is more neutral?*Less debris coverSpatial variability of Elevated Heat-Pump effectLess soot-affected exposed ice surfaces 1But more exposed ice to be affected2More sensitive to precipitation changes and wind3More intense meltingMore warm-based iceMore debris cover4Strong Elevated Heat Pump effectMore soot effect on exposed ice surfacesLess Westerly dominated precipitationBut less exposed ice to be affectedMore monsoon dominated precipitationGlaciers are more sensitive to warmingGrow mainly by summer snow accumulationMore lake growth and glacier disintegrationElevated Heat Pump reduces glacier stabilityContact: Jeff Kargel*MODIS base image courtesy of GSFC/NASA•Glacier behavior varies across the region, with faster retreat in the east. Possibly glaciers in northwest pick up more snow precipitation due to Elevated Heat Pump (EHP) and other climate mechanisms thus partly offsetting heating/melting. Glaciers in the eastern Himalaya may be more sensitive to EHP heating and are melting more quickly.