Cryosphere: regions on earth that are affected by water in the frozen state, whether seasonally or permanently. Includes regions with ice sheets, glacier ice, permafrost, river ice, lake ice, sea ice and/or snow. Cold regions are extremely sensitive to environmental change, including global warming and pollution. *Relatively few measurents of cryosphere exist due to geographical remoteness, large scale, extreme conditions, and the long time-scale of some cryospheric processes.
Evidence for Recent Climate Change (10)
-T and P records -Unusual weather patterns -Glaciers -Coral reefs dying -migrating species -pests and diseases -arctic sea ice decline -treeline migration -longer growing season -permafrost melting
Glacier Du Trent (Hester’s first glacier) retreated 700m in 19 years (37m/yr);-In 1985, 48 glaciers advancing, 42 retreating, 14 stationary (Switzerland)-In 2006, 1 advancing, 84 retreating;-B/W 1850-2005, 50% area loss for all Swiss glaciers (15%/decade since 1985)
Why do Glaciers Matter?
-contain 90% world’s fresh water-one small glacier (1km2) contains water for 70 000 for 1 year (for Canadian water use of 300L/day) -In dry years, glaciers contribute 55% of the Bow River summer flow at Banff (up to 80% in late summer months)-Due to retreat flow reduction could be up to 70% by 2050 -Over a billion people rely on cryospheric water from the Himalayan snow and glaciers___________ Other Glacier Retreat Effects: Natural Hazards-Hazards pose a threat to human life and livelihoods and can cause damage to infrastructure and industry.
-floods-avalanches-mudflows-icebergs Kolka Glacier Disaster… (Russia)-sept 2002, glacier broke off and slid down valley-caused avalance and mudflos-overran Karmadon village 18km downstream->120 ppl killed Regions where glacier hazards are currently problematic:-BC-Iceland-Alps-Andes-Caucasus mountains
“The greatest climate change threat for humans lies in the potential destabilization of the Greenland and Antarctic Ice Sheets” (NASA) Sea Rise Contributions (possible)-Antarctic: 60m-Greenland: 7m-Other Glaciers: 0.5m-This century, prob 1m rise (50% glacier)-possible 4-6m -Greenland influences the THERMOHALINE ocean circulation (cold water and salt water both sink)
Permafrost affects infrastructure, ecosystems, leaks water to the oceans, and frees methane
Pollution and Disturbance in th Arctic
On 25 Dec 2008, 100 000 gallons of oil-ater mix escaped a corroded water-injection popeline at Kuparuk The Arctic tundra ecosystem is extremely sensitive to pollution and disturbance*-poor soils and harsh climate leave little margin for tundra systems to restore themselves-damage from erosion persists for centuries, and the extinction of any species affects many others. Petroleum infrastructure in the North is fairly extensive, and severly afectts caribou habitat disturbance(caribou density inversely correlated with road density)
Nanook of the North
Write down all the ways in which traditional knowledge depicted in this movie is threatened by environmental change.
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Fragment 1: Intro part 2: http://www.youtube.com/watch?v=9wmHvkrhmIIFragment 2: First episode: www.youtube.com/watch?v=cLERFRQl5EY
Environmental Change in Northern Ungava
-mining, tourism, trade, industrial activity-climate change-sea level change-ecological change-pollution, alcohol-politics (Ungava now a part of QC) POSSIBLE Effects due to changes:-materials-TK-landscape-population health-people’s self-esteem and dignity;socio-economic cultural, and psychological effects
-Globalization-changing economics and food sources-mixed cultures-technological and educational adjustments-obsolescence of annual calendars of innuit/other groups-tourism and consumer tourism and ecotourism
Sources of socio-economic resilience and vulnerability that characterize arctic systems
SOCIAL AND INSTITUTIONAL PROPERTIESsource of resilience-sharing of resources and risks across kinship networks-multiple jobs and job skills held by an individualsource of vulnerability–inadequate educational infrastructure to plan for future change-relatively unskilled labour forceopportunities for adaptation–learning and innovation fostered by high cultural diversity;ECONOMIC PROPERTIESsource of resiliance-flexibility to adjust to change in mixed wage-subsistence economysource of vulnerability-decoupling of incentives driving climatic change from economic consequences-non-diverse extractive economy: boom-bust cycles-infrastructure and political barriers to relocation in response to climate changeopportunity for adaptation-substitution of local resources for expensive imports (food, fuel)-national wealth sufficient to invest in adaptation
Chapter 1 Main Themes (7)
1. Global envionmental changes can be systematic and cumulative;2.
Linear vs Non-Linear Response;3.Feedback Mechanisms (pos + neg);4.System response: storage – lagged response – catastrophic events-this is why landscapes are always in “inclomplete transition” and “readjustment”;5.Scales of systems: spatial and temporal;6.Temporal and spatial variability: worldwide trend does not equal local trend.;7. Instabilities in systems and “tipping points”
Earth is the “blue planet”-Satellite imagery changed the view of scale of processes and interconnectivity;Typical Conditions on earth:Pressure: 1atm (101kPa)Temperature: -89 to 58C;Whether water is liquid, solid, or ice depends on Pressure and Temperature.
The “triple point” is where they meet.;RETENTION TIMES (Hydro Cycle)-Biospheric/atmospheric/river water = 1-2 week-ice caps/glaceris = ~1000 years-oceans and seas = ~ 4000 years-Groundwater = ~2weeks – 18000 years
Cryosphere response and archaeology
Changes in the components of the cryosphere occur at different time scales, depending on their dynamic and thermodynamic characteristics-frozen ground = biggest temporal range-ice sheets longest time scale-snow/river/lake/sea ice = shortest time scale-glaciers and ice caps in between;Human response times= seeing is believing… though many systems are so complex that it is hard to measure the systemic changes, let alone see them.;Otzi = the prehistoric iceman, found 1991, 5200 years old;10400 year old hunting weapon found in Melting Ice Patch in 2007..
organic material is preserved in snow and ice!!
Back to the future…
youtube.com/watch?v=0lgzz-L7GFgExcerpt from the educational documentary “Unchained Goddess” produced by Frank Capra for Bell Labs for their television program “The Bell Telephone Hour.”________1989http://archives.cbc.ca/environment/climate_change/clips/14650/The Arctic: ‘first and worst’ for global warming.
CBC News 12 Oct 1989______2009 http://www.ted.com/talks/james_balog_time_lapse_proof_of_extreme_ice_loss.htmlGlacier talk and time- lapse photography footage by James Balog, professional photographer, July 2009.
Many complex systems have critical thresholds (tipping points) at which the system shifts abruptly from one state to another.;ie. asthma, market crashes, climate, etc;”13th tipping point” – the shift in human perception from personal denial to personal responsibility?;** look up some common cryospheric tipping points
Radiative forcing factors (7)
1. orbital cariations (tilt, eccentricity, etc)2.solar energy variations3.land-ocean distribution (plate tectonics)4.
Natural and human influences influence direct and indirect changes in climate drivers, which impacts radiative forcing and non-initial-radiative effects, which result in climate perturbation and response, which can result in biogeochemical feedback processes.;The Keeling Curve-Mauna Loa observatory in Hawaii-CO2 concentrations in atmosphere have increase linearly since 1960 from ~310ppm to almost 400ppm (low variation… seasonal fluctuations very evident).-Natural range in the last 10kyrs has been 260-280ppm.;RELATIONS OF DIF TIME SCALES OF CLIMATIC CHANGE TO CRYOSPHERIC COMPONENTS10k-100kyrs = ice sheets1k-10kyrs = ice caps, ice fields, large valley glaciers100-1000yrs = small valley glaciers10-100yrs = cirque glaciers1-10yrs =; neves, snow fields
Ice sheet, permafrost, and sea ice changes in response to climate change
Greenland is meting at an alarming rate.
In some places, this increased meltwater results in a dramatic increase in ice flow, and related iceberg discharge.Rates of surface elevation change derived from laster altimeter measruements at over 16000 locations on the Greenland Ice Sheet indicate rapid thinning in many regions. Mass balance is estimated to be decreasing quickly.;Antarctic shows mixed trends, with thickening in some regions and thinning in others.;Permafrost – Permafrost zones occupy up to 24% of the exposed land area of the NH.;Trends in permafrost temperatures in N Alaska over last ~25 years are increasing. There has been a general increase in permafrost temperatures in N Hem over last several decades;Sea Ice extent is decreasing rapidly;Freeze-Up and Breakup dates from norther lakes and rivers are also changing in response to climate change
Antarctic Tourism Changes
Tourism activities are epanding tremendously with the number of shipborne tourists increasing by 430% in 14 years and land-based tourists by 757% in 10 years.
;Antarctic annual sea-ice extent is projected to decrease by 25% by 2100. This means easier access to the Antarctic continent by ship.This is likely to affect not only research, which is a main activity in a continent designated as a “natural reserve devoted to peace and science”, but also commercial activities, such as tourism.
Antarctica and measuring
-98% of antarctica is ice covered-70% of Earth’s freshwater is in teh Antarctic Ice-91% of earth’s ice is in Antarctica-average thickness=2.3km/ max=4.8km;*It is the highest, driest, windiest, and coldest continent-it hasn’t rained at Canada glacier for at least 2million years-can be down to -88C MEASURING ANTARCTICA-www.
youtube.com/watch?v=w4x5-QVRb7M In mid 2000, Pine Island Glacier formed a large crack in its ice shelf, which expanded 15m/day.In 2001, 7yrs of glacier outflow releaesed to the sea in a single event
Measuring and Data
Measurements-the process of measuring-the quantities coming directly from these measurement processes Observations-receiving knowledge of the outisde world through the senses, or through the recording of data using scientific instruments (=measuring) In Situ measurements/obervations-usually obtained through direct contact with the respective subject-may be precise, accurate and representative of site-specific location, but not necessarily of a larger region Data-quantification to represent geophysical state variables and with that the state or change of processes or systems CRYSOPHEREThere are currently efforts to both standardize/collect/distribute data (UN Global Observation Systems, World Meteorological Organization) as well as to centralise, catalogue, and distribute past/present data (World Data Centres, World Glacier Inventory, etc)
1. count and identify 200 pollen grains/sample 2. Divide census into three parts-arboreal pollen (AP)-non-arboreal pollen (NAP)-spores 3.express results as % of total AP at that particular depth 4.
Plant assemblage at a particular horizon — pollen spectrum 5. Curves from a series of stratigraphic positions — pollen diagram 6.age dates are determined by 14C dating and cross-dating 7.
History of vegetation change linked to climate, environment, and anthropological influences
MAIN: snow Extent, Thickness, and Density Additionally: Snowpit analysis for:-avalanche forecasting-recording of snow accumulation in glacier mass balance studies-assessment of snow variability-assessment of spring runoff SNOW PIT1.dig pit2.record layer stratigraphy3.measure resistance4.measure hardness5.record size and shape/form of snow crystals6.
record snow density7.record snow temperature8. record snow stability (shovel compression test) equipment…-shovel, tape, ruler, fieldbook, pencil, knife, thermometer, magnifying loupe, snow crystal card, density kit SNOW PILLOW & SNOWTEL STATIONSwww.youtube.com/watch?v=tlE8SDqW2Ow-lots of snowpillows in BC and Rockies
River freeze-up and break-up in the arctic
youtube.com/watch?v=0PMGDJULjwg&feature=related Torne River, Kiruna, Sweden, 2004
Sea Ice Depth and Extent
Can measure:-extent-concentration-ice type-thickness In Situ Ground measurementswww.youtube.com/watch?v=L3Ku5Oi188s In situ submarine measurements Satellite measurementsAMSR-E = concentration or driftICESat = thickness -with multiple sensors, can get sea-ice area flux and thickness, which can together give you sea-ice volume flux Ice thickness with satellites can be calculated from freeboard height, assuming hydrostatic balance and using in-situ and satellite snow depth data
Lichen as a proxy for ice retreat observations
Lichen = algae + fungus Algae = photosynthesis = good for lichenFungus = shelters algae in greenhouseCemetary grave stones have exact dates, from which you can get lichen growth curves Rhizocarpon geographicum-Most commonly used-growth 1-4mm/yr Compare calibrated lichen size with lichen size in geological terrain **Lichen growth rates vary with elevation, proximity to sea, aspect, and rock type-max is 5000 yrs before present R. geographicum does now like carbonate rocks, but needs silicate rocks
Scientific Revolution in the last 30 years
Geophysical methods (GPS, RES, Seismic, Gravity) RS Ice coring and analysis Computer modellingAWS Dating methods
Impurities in Polar Ice and their Sources
Sea Salt (Na+, Cl-, Mg++, SO4-, K+) – oceans Terrestrial Salt (Mg++, Ca++, CO3-, SO4-) – continents and continental shelves Tephra and gasses (H+, sulphate, nitrate, shards – ash layers) – volcanic eruptions Biological Gases (H+, NH4+, NO3-, SO4-, CH2, SO3-, F-, HCOO-, organic compounds) – biological/anthopogenic gas emissions Cosmogenic radionucleides (10Be, 36Cl, 14C) – interaction cosmic rays and atoms (solar activity and geomagnetic field)
Nitrate and Sulphate in Ice Cores
-both gradually increasing since 1900s due to coal combustion industrial revolution-both now well above 2000 year averages -some sulphate peaks related to volcanic eruptions US Clean AIr Act 1972 resulted in huge decrease in sulphates Problem with gas dating in ice is that there is mixing between layers!!
EPICA DOME C
longest continuous climate record Preliminary results: -Over the last 740kyr, earth experienced 8 glacial periods and 8 interglacial -In the last 400k yrs, warm periods had temperatures similar to todays, before that, warm periods were cooler, but lasted longer Cooling is gradual, warming can be abrupt Concentrations of sodium, sulphate, and dust are way higher during glacial periods Concentrations of methane, carbon dioxide, are way higher during interglacial CH4 residence time = 10yrs CO2 res is over 100yrs…
globally well mixed
Younger Dryas and Little Ice Age
The Younger Dryas stadial, also referred to as the Big Freeze, was a geologically brief (1,300 ± 70 years) cold climate period between approximately 12,800 and 11,500 years ago (between 10,800 and 9,500 BC). The Little Ice Age (LIA) was a period of cooling that occurred after the Medieval Warm Period. While not a true ice age, the term was introduced into scientific literature by François E. Matthes in 1939. It is conventionally defined as a period extending from the 16th to the 19th centuries
stadials and interstadials
periods of warm and cold within an interglacial Younger Dryas was a stadial
CO2 and ice cores
Relationship b/w CO2 and Temperature is not linear!!! CO2 max 290ppm in the last 650000 years until the most recent increase , which is unequivocally due to human activities CO2 accounts for only ~1/3 of the total temperature increase in teh past CO2 is amplifier of climate (dtrigger is most often orbital or ocean oscillations)
Dust and and Na Ice cores
-We get more dust during cold periods due to more wind, less vegetation, more fines available through erosion and lower sea levels. ~1400, got really cold, and sodium levels increased due to colder seas. Wiped out Vikings.
PSAs (potential source areas) for Antarctica during glacial periods are NZ, Dry Valleys, and South America Corroborating evidence:-size of source area-volcanic eruptions (tephra)-other chemicals and isotopes-LGM atmospheric circulation models
10Be concentration (relative to the mean value) at South Pole is a measure of solar insolation Thames Frost Fairs (1608-1814).. longest and coldest in 1683 (3 months)- London THE MILANKOVITCH CYCLEInsolation co-trigger of clmiate change at longer timescales Precession + Obliquity + Eccentricity + Solar Forcing combine to form “Stages of Glaciation” The cycles match gvery well to temperature in Antarctic ice cores, apart from recently the cycle has gone down, but the temperature has not.
Major findings from ice cores drilled in the Greenland and Antarctic Ice Sheets (9)
Close correlation b/w climate and GHG conc. 2.Ice ages are dustier, and storm tracks change 3.
Some atmospheric chemistry is regional (methane) 4. Anthropogenic influences on atmosphere are global (nuke tests, emissions) 5.Some climate oscillations are global, other confined to N Hem 6.
Coupling of timing and magnitude of global climate changes between the 2 hemispheres 7.Rapid and large oscillations during the last glacial period and the end of the last transition (start Holocene) 8. Climatic stability of the last 10k years contrasts with extreme climate variability through most of the rest of the last glacial 9. Last interglacial (125kyBP) was 2-5C warmer than present (orbital forcing)
Stefan-Boltzmann Law and Wien’s Displacement Law
Stefan-Boltzmann LawAs the temperature of an object increases, more radiation is emitted each second.;Wien’s Displacement LawAs the temperature of a body increases, so does the proportion of shorter wavelengts From these two laws it follows that: Sun’s radiated emission very high and mostly in the form of shortwave (SW) radiation.;Earth’s emission low and mostly longwave (LW) radiation Net heat transport is from the tropics to the poles. Greater outgoing radiation at the poles relative to incomming.
Contribution of RF associated with anthropogenic GHG emissions: ~2.
6W/m2 since 1750.-mostly CO2 and CH4 Combined anthropogenic RF: ~2.6W/m2 since 1750-inclued atmospheric aerosols (direct effect and cloud albedo effect)
Surface energy balance at a point
Q= Fsol(1-alpha)+FIR+FSE+FLE+Fcond Fsol = incoming solar shortwave radiation FIR = upwards and downward radiation flux at surface (Stefan Boltzman law) FSE & FLE = sensible and latent heat fluxes Fcond = conduction flux for ground/ice/snow/ocean surfaces (Fourier’s law);Fgeo = geothermal heat flux;ENERGY BALANCE OVER POLAR TERRAINClosed Forest and Coastal Tundra and Thick Sea Ice: large net income in summer, small net outgoing in winterGlacial Ablation Zone: net incoming in summer, no data for winterAntarctic Coast: Small incoming in summer, small (about the same) outgoing in winterThin sea ice (winter only) net is outgoing, most incoming comes from ocean.;;
Properties of the Cryosphere influencing surface energy balance
SNOW AND ICE-large albedo: reflect large part of incoming energy-store and release latent heat: affect the sasonal cycle of the surface temperature-Good insulators – reduce the heat loss from underlying surface (land or ocean) (largest effect in winter);SEA ICESea ice restricts heat and gas exchange between ocean and atmosphere-When sea ice forms, only a fraction of the salt present in the ocean is trapped in the ice, the remainder is ejected towards the ocean (brine rejection);PERMAFROST-patterned ground – albedo and surface roughness-melt – sea level
SNOW AND ICE-snow-ice-albedo feedback;SEA ICE-sea ice-albedo-polynia feedback;PERMAFROST-Melt-GHG release feedback
Heat Properties of Ice and Snow
Latent Heat of Fusion of Ice-amount of energy required to transform ice to water at the melting point=3.35*10^5 J/kg;Specific Heat-heat energy required to increase the temperature of a unit quantity of a material one degree (C or K);Water Vapour (100C) = 2.08 J/gKWater liquid (25C) = 4.18 J/gKIce (-10C) = 2.
05 J/gK;Bedrock specific heat capacity is only ~0.2 J/gK;So what is the effect of snow/ice cover on the earth’s energy budget given the above properties?
Effect of temporal variability of Snow Cover
SNOW COVER VARIES SPATIALLY AND TEMPORALLY! Bowen ratio:The ratio of sensible heat and latent heat energy fluxes from one medium to anotherB=Qh/Qe..
. and is related to the evaporative fraction
SNOW MEASUREMENTSMain:-snow extent-thickness-density Also, snow pit analysis for:-avalanche forecasting-recording of snow accumulation in glacier mass balance studies-assessment of snow variability-assessment of spring runoff (SWE)
SNOW COVER CHARACTERISTICS
Thickness and Stratification=F (snowfall, wind redistribution, T, forest cover, terrain) Densification and settling Metamorphosis-snopack T gradient->dry snow metamorphosis-Rounding and enlarging of crystals -> wet snow metamorphosisCrystal Type/Size-Before and after metamorphosisT Gradient-Critical instability when >1C/10cm
Inside the snowpack…
-Temperature at the base is 0C-Cold air wave penetrates into top of snowpack-Surface is usually relatively warm, it gets colder, and then gradually warmer again with depth Average temperature gradients in a snowpack over 10cm are approximately -0.1 to -0.6 degrees. However, these fluctuate more at higher elevations Thinning of layers due to settlement and metamorphosis occurs mainly in the first 3 weeks and after new snowfall SNOW STABILITY-can be tested using the shovel compression test-trying to find regions of fractures and weak layers-look at failure depth vs failure force graphs to determine danger Can also use the Rutschblock stability test-cut a block 2mx1.5m and jump on it with skis Conducinve to Avalanches:-Layer of platy or round crystals-large T gradient-Large density gradient-suddent air temp changes, considerable snowfall, wind-depth hoar is dangerous
Empirically-derived Function-local Degree Day Model-crude Multiple Regression-Need measurements and longitudinal time series
Microbial Life In Snow and Ice
‘Watermelon Snow’ – Chlamydomonas nivalis Lives in subglacial ecosystem-specific surface glacier ice conditions-results in blood falls-source area rich in iron, high chloride, salinity, and sulfate ____ Very recent research has found microbial life in subglacial lakes-Can use RADARSAT remote sensing to identify locations of underwater lakes LAKE VOSTEKDiscovered in 1996 from decades of seismic studies, radar surveys, and satellite imaging “one of the last unexplored frontiers of our planet” Lake Vostok is the biological equivalent of the Heisenberg uncertainty principle (how do you sample something without changing it?) Instead of drilling into the lake, they drilled into the accreted ice zone, which was recently frozen and contains preserved, contemporary speciments Names of new species: porpoise, thanksgiving leftovers, sphere
Remote Sensing of the Cryosphere
Sea ice, Glaciers, Ice-sheets, Snow cover-Remote, large, changing areas Monitoring of:-status-changes-process studies (understanding)-verification of models-early warnings-predictions MODIS true color image was used to identify Antarctica’s B-15A iceberg-also, other huge ice bergs which have broken off
RS of snow cover (what, why?)
WHAT-surface albedo-thickness-water content-melt onset;WHY?-surface energy balance-glacier mass balance-water availability (runoff, flooding, water management)-climate change
Which satellites are used for which studies?
Spectrum determines which spectral bands suitable for certain studies;Resolution determines smallest unit that you can capture;Revisit and size of image determines how often (days) you have coverage of target;Ground coverage determined how far N or S the images reach (usually poles not covered);Snow and ice have varying spectral reflectance curves-it is totally different for melting snow and fresh snow;Spectral reflectance is not static, but dynamic!!;Effects changes in the Snow/ice:-impurities visible spectrum-Grain size: near and middle IR-Liquid Water: increases effective grain size-Density: independent;ASTER has more spectral bands in the areas we would want to use (for snow), yet resolution is variable (at high wavelength, resolution is worse, in visible, it is better);Different Satellites have different Ranges/#bands,Resolution, and Return;Aster: 520-12400/14/15-90/;16Modis: 405-14385/36/250-1000/;3Landsat7: 450-12500/7+PAN/30-60/;16AHRR: 580-12400/6/1100-4000/0.5SPOT: 500-1750/4+PAN/10-20/;3GOES-8: 520-12500/5/1000-4000/15min;SMMRSSM/I (microwave)SAR (radar)
Procedure to convert satellite data to albedo
1) Take raw data numbers (DN-0-255) and convert to spectral refectance (L;)-For DN=0 and DN=255, the L; is known from the satellite characteristics (metadata)-linear interpolation to find L; values for the rest of the DN values;2)Atmospheric correction by ‘radiative transfer models’;3)Anisotropy corrections;4) Narrowband to broadband extrapolation (entire spectrum)
Moderate Resolution Imaging Spectroradiometer;Onboard Terra SatelliteRes: 500m and 0.
05deg (~5.6km)36 bandsReturn 1-2days;MEASURE:-global vegetation-land surface changes-albedo-temperature-snow and ice cover;Has automated snow-mapping algorithms!Use:-band 4/6 (normalised difference snow index: NDSI)-band 1/2 (normalised difference vegetation index: NDVI)-band 2;NDSI= (MODIS band 4- MODIS band 6)/(Modis band 4 + Modis band 6);;NDSI ;0.4 is snowReflectance in band 2 should be greater than 11$Band 6 stays high for clouds;If NDVI maps forest, then map snow for NDSI ;0.4 as well.Reflectance in Band 4 should then be ;10% in the forest;MODIS has determined that N America’s max snow cover occurs Jan17-24 on average PROBLEMS-Atmospheric corrections -> algorithms-Grid Size -> sub pixel snow-Darkness -> need passive microwave-Albedo -> narrowband to broadband reflectance-> anisotropy (need bidirectional reflectance correction) Clouds -> obscuring or ‘false’ snow (due to ice in high clouds: Summer)Errors of Omission -> snow free – snow – cloud – snow melted -need to use algorithm to remove cloud from snow Sometimes, snow cover can be >50% of N-Hemisphere land surface-Rivers help to determine whether snow or cloud Darkness is a problem for visual spectrum not a problem for radar)
Can determine snow depths and SWE-Volume scattering by snow reduces the microwave radiation from the underlying groundThere are active and passive microwave sensors Microwave satellite sensors are not susceptible to atmospheric scattering-active = imaging (strength backscatter signal, ie radar)-passive is non imaging (altimeters, scatterometers) Microwave wavelengths from ~75mm-0.1mSomewhere in the middle is used for microwave ovens RADAR-measures strength and round-trip time of microwave signals emitted by a radar antenna and reflected off a target (distance surface or object) -radar uses: microwave wavelengths (1cm-1m) and polarizations (waves polarized in a vert or horiz plane) -Earth’s surface scatters the energy in the radar pulse (some reflected back to antenna = backscatter);–Antenna receives backscatter as a weaker radar echo in a specific polarization (hor/vert, not necessarily the same as the transmitted pulse);-Echoes converted to digital data;-Radar pulse travels at the speed of light -; easy to calculate roundtrip time of a pulse to calculate the distance or ‘range’ to the reflecting point.
;****Backscatter is a function of electrical(absorption/transmittance) and gometrical (surface roughness) surface properties;***Ice roughness, water content, stratification, etc picked up by radar but not by optical photograph
GLACIER AND SNOW SURFACE DIELECTRIC PROPERTIES
;Liquid water -; absorbs microwave energy-low backscatter when liquid ;1%Liquid Water -; influences microwave penetration-wet snow/ice – backscatter from top cms -; surface scatter-dry snow pack – backscatter from tens of m -; volumetric scatter;Backscatter also f(stratigraphy causing dielectric contrast of different layers)-snow -; backscatter controlled by changing snow grain size due to ago-layers with a dielectric contrast (ie. dy snow/firn interface);COMPLICATED and sometimes CUMULATIVE EFFECTS-Melting areas = liquid water = low backscatter;-Dry homogeneous snow pack ;20m depth = low backscatter (little dielectric contrast);-Dry inhomogeneous snow pack (grain size changes) -; relatively high backscatter;-Firn overlain by dry snow -; rel high backscatter from interface of snow/firn layers;-Percolation or superimposed ice zone with ice lenses -; high backscatter if no active melting;-Active slush zone -; low backscatter: liquid water;-Dry ice -; low if not rough;***Sh= surface height variations-surface is considered smooth or rough (proportional to wavelength and incident angle);Radar can be used to detect snowline on a glacier!
Radar Error Estimates
Based on comparison with ground measurements and image comparison;Snow cover area:Modis, AVHRR, GOES-8, etc 5-10%Passive microwave ;1%;SWESAR and AMM/I large errors with point measurments, but ‘only’ 10-20mm w.e. when area averaged
Global Land Ice Measurements From Space;-GLIMS is an international consortium (26 nations)-Primary goal: to determine the extent of the world’s glaciers and the rate at which they are changing HOW?1)acquire a global set of multispectral, stereo satellite images of the world’s land ice near the peak or end of the melt season2)map the global extent of land ice3)analyze a representative selection of glaciers for length, area, ice flow, snowlines, and interannual changes in these4)Build and populate a publicly accessible digital database of te world’s glaciers Principal observing instrument: ASTER (aboard NASA’s Terra satellite)-supplemented by others (LANDSAT, Ikonos, etc);Consortium has 23 regional centers
-used mainly by GLIMS;APPLICATIONS-terrain classification-DEMs-Glacier motion-glacier monitoring-geomorphological and terrain changes-lakes-glacier hazards-GLIMSView;ASTER Global DEM (GDEM)-released June 2009-Free of charge for everyone-30 m resolution world-wide coverage;Was used at James Ross and Vega Islands-Antarctic Peninsula-monitored a retreat of 42.4km2-loss of ~4 glacier cover-mostly floating ice melted-retreat rate doubled from 75-88 to 88-01Can calculate ice velocities, lake growth;Hester did a GLIMS study “Glacier rereat and sensitivity related project”-Clemenceau Ice Field Group (CIG) and Chaba Icefield (CH)-In the area, 12 of 21 glaciers have significantly accelerated retreat rate for 1985-2001;
Changing landscape terminology
Slope Movement:-Gelifluction-Rockfall vs rockslies-Landslides and mudslides;Glacial Lake Outburst Floods (GLOFs);Permafrost:-patterned ground-pingos-thermokarst
READ ABOUT ALL OF THESE FEATURES!!;Cryoturbation (cryosols or gelisols);Ice/Frost wedge polygons-faulting;Hummocks;(non)sorted stone circles, polygons and stripes-polygons can be low-centred or high-centred;Alases (large thermokarst depressions);Palsas (frost heave of peaty ground /w ice lenses);Pingos (hydrolaccolith: a hill of earth-covered ice)-can be open or closed system, or collapsed (dead pingo);**much of the paleo-process information is from studying sediments (and stratigraphy of sedimentary units), rather than from landforms;High-latitude areas on Mars and Earth both exhibit patterned ground where shallow fracturing has drawn polygons on the surface
Continuous vs Discontinuous coveragecont: over 90% region covereddis: 10-90%;Permafrost is frozen groundPeriglacial environment;***Continuous permafrost zone coincides approximately with the 10C isotherm~74N;Present landcover ;20%-at LGM ~40%
Blockfields are a periglacial landformBlockfields = felsenmeer = blockmeer= stone fields;Large, sheet-like expanses of weathered blocks (over .25m in size)-Usually cover bedrock, though not necessarily same type of rock-low surface gradients-found in former arctic or alpine regions;No rock debris source (such as cliff) is seen, but the slope may rise to a ridge crest.
;The block in blockfields are usually angular and are often thought to be the result of ‘mechanical’ weathering processes;www.youtube.com/watch?v=jyWejbOV7coBlockfields sometimes survive subglacially-can survive under cold-based ice sheets
Arctic Ecozone Classification
Arctic ecozones based on the mean temperature of the warmest month;Arctic/Polar;2C = Polar desert2-6C = Northern Tundra;Subarctic/Subpolar6-10C = Southern Tundra;10C = Forest tundra to Boreal forest zone;Boreal Forest = Taiga = Swamp Forest-Norther Boreal forest in Canada vegetation:-Black Spruce (P. Mariana)-White Spruce (P.
glauca)-very low biodiversity-Black spruce adapted to slightly colder than White spruce, but not by much
Species are monitored in N America and EuroSiberia;Position of summer and winter arctic front in relation to the polar treeline/the southern boundary of the boreal forest in North America (they correlate strongly)-polar fron in summer and winter boundaries basically outline the boreal zone;Arctic Front=1)semipermanent, semi-continuous front b/w the deep, cold arctic air and the shallower, ess cold olar air of northern latitudes2) Southern boundary of the Arctic air mass;TREELINE MIGRATIONDifficult to measure:1)highest tree (or farthest North) often not found2) Present treeline inaccurate3) Present treeline not in equilibrium with present climate;Asymmetric response to climate forcing:-Northward (or up-mountain) migration of treeline much more rapid than southward (down-slope) migration;Established trees might survive for a while in deteriorated climate, but new trees will not establish in such a climate;Alpine treelines were ;200m higher than at present during Hypsithermal (6-3.5kyBP)
Degradation of cryospheric landforms
Permafrost is melting-affects infrastructure and ecosystems-leaks water to the oceans and frees methane-www.youtube.com/watch?v=vSLHvZnbYwc*top 3m of arctic permafrost may be gone by 2100;Dried mudflows occur along slopes especially in spring, when the uppermost layer of permafrost melts;Mudflows consist of sediment saturated with water and can have speeds ;100km/h;Bodies melting out of permafrost may contain smallpox virus (Science) as it is resilient to freezing;www.youtube.com/watch?v=31aOYcGo-sg;PINGO DEGRREDATION-is happening (look up)
Cryospheric Natural Hazards
Hazards pose a threat to human life and livelihoods and can cause damage to infrastructure and industry-Floods-Avalanches-Mudflows-Icebergs;*Look at hazard glacier regions map on review lecture*;GLOFS-In the Himalayas, the frequency of GLOFs has increased in the 2nd half of the 20th century-At present ; 200 lakes pose a flood hazard in Hindu Kush-Himalayan region aloneThe Dig Tsho GLOF (1985) killed 5 people, destroyed the Namche small hydropower project (~US 1.5million), 30 houses, 14 bridges, and cultivated land.
The BEAT THE GLOF ACTION RUN runners gather at Imja Lake (5010m), the fastest growing glacial lake in the Himalayas-It is growing at 74m in length annually as the glacier behind it melts away;KOLKA GLACIER DISASTER, RUSSIAN CAUCASUSSept2002-glacial broke off and slid down valley-caused avalanche and mudflows-overran Karmadon village 18km downstream-over 120 ppl killed;__Some research suggests that landslides are on the increase due to climate change.But is this also the case for rockfall and large rockslides? (See Hester’s Study)
Large Rockslides: Case Study- Tsar Mountain
STUDY OBJECTIVES-Is this rockslide typical for long-runout rockslides on glaciers?-What are possible triggers?-What are the effects of the rockslide on the glacier regime?-Can climate and seismic data constrain the timing of rockslides in this region?-What is the contribution of events like these to the overall sediment budget and denudation rates in alpine regions? METHODOLOGYImagery-Landsat7, ASTER, SPOT quicklooks, Astronaut photography, Airborne photography from helicopter Seismic Data-4 seismic stations (Earthquake Canada) Weather Data-2 automatic snow pillow stations (BC Ministry of Environment)-1 climate station (Environment Canada) Glacier Data-imagery-field measurements on Shackleton Glacier (8km NE)______ Study of Cirque glacier rockslide (2.2km long)-fall of 311m-length of rockslide runout depends on substrate RHETORICAL CONTROVERSY?Rockslides on glaciers have longer runout because-lower friction with bed?-confined flow by valley walls and moraines?-entrainment of snow/ice in the fockslide base: fluidization? POSSIBLE EFFECTS OF THE ROCKSLIDE ON THE GLACIER1)albedo effect2)increase/decrease of sensible heat flux3)increase in basal shear stress by increase apparent ice thickness4)hydrological effect by sudden impact5)alteration of the supraglacial drainage6)snow/ice incorporation during fluidization TIMING ROCKSLIDE-sat images bracken b/w 26 Aug and 23 Sept-weather data suggest 10-15 sept (huge precip and temperature variation)-seismic data pinpoints it to 14 sept 2000-for seismic data, had to differentiate b/w earthquakes and surface events-can do this with shape of seismograph CONCLUSIONSThe Rockslide-is similar to other rockslides on glaciers-stress fatigue in combination with intense rain (~30mm/day) and snowmelt around freezing T co-triggered the rockslide-caused a 0.2-0.4 m w.e.
/a reduction of ablation (7-12%) and had some hdrological effects on glacier SEISMIC EVENTS-since 1985: 26 significant seismic events <40km of the cirque: none large enough to trigger rockslides-Seismic waveforms and frequency spectra -> no unequivolcal evidence for seismic tremors caused by rockslides
Landscapes in transitionPalimpsest ProglacialPeriglacialParaglacial environmentParaglacial period Reinterpretation of landforms, sediments and stratigraphySediment exhaustion curves ___ The ‘paraglacial period’ is the period of readjustment from a glacial to a nonglacial condition, as fluvial, slope and aeolian systems relax towards a nonglacial state At the scale of the Pleistocene land ice, this paraglacial period occurred between 12-6kyBP At the smaller, alpine glacier retreat scale, we are still in the middle of it.
Geomorphological and System theories
Hutton (1880s): geological cycle Church (1970s): paraglacial Hewitt (1990s): landscapes of transition Brunsden (1990): system stability Holling: relisience (1973) & Panarchy (2002) Diamond’s (2005) collapse of societies
Landscape System stability and sensitivity
Hutton’s rock cycle (decay of continents to the sea and then to uplift again) = Uniformitarianism BUT:-landscape changes are through punctuated equilibrium… Is equilibrium a state of stability or conservation??? stability: the temporal behaviour of a landscape over timesensitivity: is the susceptibility of landforms to change Phillips (2009) framework for the assessment of geomorphic changes and responses based on 4Rs-Response (reaction and relaxation times)-Resistance (relative to the drivers of change)-Resilience (this is how well you maintain a self-organizing capacity? -> recovery ability, based on dynamical stability)-Recursion (positive and/or negative feedbacks resilience = capacity to dal with change and contiue to develop. Ecosystem resilience, social resilience, etc.
Holling’s panarchy cycle incorporates collapse and creative reorganisation as two of the NORMAL stages of an adaptive cycle;2-Phase Adaptive CyclePhase 1: expansion and prosperity with growth and accumulation of capital and wealth. Though changes may be slow, the effects can become substantial as they gradually accumulate.
;Phase 2: “back-loop” characterized by creative destruction and reorganization, potentially suddenly. Period of low predictability (potential for surprises). Suddenevents (eg. forest fire), can unexpectedly and sometimes irreversibly “flip” an ecosystem or economy into a qualitatively different state by triggering the release of biomass, capital and wealth.;1-growth phase2-phase wehre resources are less widely available3- release or creative destruction phase4-reorganization and restructuringAdaption = reaction to drivers and constraints;***Panarchy works at different scales and over dif time frames***Watch video on Buzz Holling, father of resilience theory (http://stockholmresilience.org
Panarchy and Sustainability
*Panarchy makes ‘sustainability not a static condition that need to be preserved for future generations Tradition ‘sustainability’ ignores transcience, transitional states and collapse as normal environmental characteristics Pattern of punctuated change is the norm.
PANARCHY/ADAPTIVE CYCLE PROPERTIES-wealth-connectedness-resilience-transformability(sustainability can be seen as the collective strength of the above)
Diamond’s Societal Collapse Model
Identifies 5 factors that can contribute to the decline and collapse of civilization:;1)environmental damage and population growth2)climate change3) hostile neighbors4)widespread trade partners5)failure to solve societal problems;Must increase resilience to avoid collapse.How do we promote the adaptive capacity of resource users? (increase resilience of local people?)www.youtube.com/watch?v=WOQUGtWOsVU;Prof Terry Chapin (UAF): plant physiology and Arctic ecosystem ecology, and resilience of social-ecological systems
Tipping points in a system are the critical threshold of a level of change in a (sub) system after which changes will proceed under their own momentum: like a run-away system.;Sometimes the changes after the tipping point are accelerated or step-wise.;Many of earth’s potential anthropogenic tipping points are related to the cryosphere Potential Global Warming Triggers:-Arctic Summer Sa Ice (1-2C)-Greenland Ice Sheet (1-2C)-Boreal Forest (2-3C)-West Antarctic Ice Sheet (3-4C)-Amazon Rainforest (3-4C) Biodiversity has already hit a tipping point.Another one has too (read on review)-Climate change is over halfway there-ocean acidification and P-cycle are getting there too. AMPLIFICATION-see Terry Chapin (1:41) videoWhat are consequences of climate change in the Arctic?-Rapidity of changes-Large scale environmental effects
Ice and Biome Distribution/ Peopling of the New World
5C colder than today-ice sheets-sea level-permafrost-loess-deserts Holocene Climate Optimum (~6000yr BP) “Hypsithermal”-2C warmer than today-sea level-wetter conditions-lakes-great lakes formed-tundra taiga/rain forest How did people come to the new world?
Present climate state is a “no analogue” stateTerm coined by Paul Crutzen to indicate anthropogenic change of natural climate system state -> most clearly defined as starting in 1990s. Ruddimen (2003) argues it started with early agriculture (~8000 years ago)-deforestation (increased CO2- 8kyrsBP)-rice cultivation (increased CH4 – 5kyrs) Radiative Forcing…280ppm pre-industrial CO2-700ppb pre-industrial CH4-these values high compared to expected (from solar radiation and natural CO2 trend) Anthopocene saw HUGE population growth-now 6.9 billion-impacts include waste, food, industry, agriculture, transport
Some main effects of Anthropocene (6)
1) New climate forcings (natural resilience insufficient?)2)connectivity (globalization3)monocultures (reducing resiliance)4)geomorphic agent5)introduction of foreign substances (pollutants, nuclear material, etc)6) Cascading effects through positive feedback.
Anthropocene, River Basins, and Vegetation
What are the consequences of River and Lake ice, sea ice, permafrost, glacier, and snow decline? River basins have huge hydrological significance, and many waterways are glacier-fed.
Present runoff trends in Russian Arctic Rivers variable, but predicted to increase. Present runoff rivers 2x annual P-E over Arctic Ocean -freshening due to estuarine influx changes ocean salinity-pollution-sediments Tundra treeline migrating to higher altitudes (1-4m/decade) and latitudes. Mosses colonise ice free rocks in Antarctica. Shrub vegetation expanding in Arctic-positive feedback due to snow-shrub interactions
Dynamic nature of cryosphere contradicts the classical notion of sustainability View systems over different time periods to understan the processes and ‘cycles’ Planners need to include change and uncertainty about the change (as well as possible surprises) into their plans Implement adaptive management techniques
~4million people live in the Arctic~10% indigenous people Canadian Arctic ~50% indigenousGreenland ~90% indigenous Arctic Council – high-level intergovernmental forum which addresses issues faced by the arctic governments (8 countries) and its indigenous people Inuit Circumpolar Council (ICC) – represents internationally the interests of Inuit in Russia, Alaska, Canada, and Greenland Watt-Cloutia is a Canadian Inuit activist, who made the world aware that climate change is a human rights issue.-Elected President of ICC – CanadaSpokesperson for Arctic indigenous people in the negotiation of the Stockholm Convention banning the manufacture and use of Persistent Organic Pollutants (POPs) Nominated for the 2007 Nobel Peace Prize (won by IPCC Al Gore) www.youtube.com/watch?v=GISh4XeoLBA
Himalayas2006: South Korean mountaineer Han Wang Yong and his international Clean Everest Expedition 2006 team conduct a month long cleaning campaign and collected over 1300kg garbage at basecamp.
AntarcticaAlien mammals in Antarctic and subantarctic regions include sheep, rabbits, dogs, cats, rats, mice, and humans Effects on local ecosystems include:-pollution of station areas by human wastes, and of waters by ships and accidents-intrusion of flotsam and floating debris in the antarctic waters-erosion from overgrazing by sheep-PCBs in lichen-decimation of bird populations by dogs and cats and of whale and fur-seal stocks by humans Antarctica remains by far the least contaminated land on earthUnder the Antarctic Treaty, it is now a special conservation area. At the Antarctic US base McMurdo Station the levels of PentaBDEs (used in flame retardants) were as high as in urbanized areas of North America and decreased with distance from the sewage outfall.
Pathways of Pollution
AirPrecipitationOceansRiversSoilIce (sea and glaciers) Local vs Global-often long-range transport Visitor invasionIndustrial activity **Chaning pathways due to climate change***-open water-air flow patterns-melting permafrost
Important Pollutants/Toxic Chemicals
POPs (persistant organic pollutants)legacy POPs: industrial byproducts (PCBs, PCDDs (dioxins), and organochlorine pesticides (DDT, chlordane, diendrin, toxaphene))Emergent POPs = brominated flame retardants (BFRs), endosulfan and lindane, fluorinated compounds (in non-stick coatings and stain repellents) ORGANOPHOSPHATE PESTICIDES-insecticides, herbicides, nerve gas, solvents, plsticizers, and extreme pressure additives (for lubricants)-degrade rapidly by hydrolysis on exposure to light, air, soil-small amounts can be detected in food and drinking water MERCURY-slowly phased out in scientific equipment-asia currently 50% of emissions Pb/Zn/Cu-pipes, fillings, paint RADIOACTIVITY-many contaiminants accumulate in fatty tissue __________ Some good news!US clean air act (1972 and 1996) and world-wide ban phasing out of leaded gasoline/petroleum.-decrease in nitrate, and later in Pb concentrations LOTS OF BAD-game sea birds, particularly eider, contain high concentrations of lead (but this is because the use of ‘lead shot’ in hunting the birds-human blood lead concentration is higher with the more sea birds consumed.
Radioactive ice cores found and can accurately date nuclear testing, chernobyl, and the testing ban. Russian underground nuclear explosions (71-88) occurred in the norht quite often. There were 43 underground explosions in Novaya Zemlyabefore 1991.
There is a great amount of radioactive material in the world. The potential exists for climate change to mobilize it. EFFECTS-acute radiation Syndrome (death due to high doses)-birth defects-cancer-damaged DNA (less resilience)-reproductive system-etc. etc. etc. input-atmosphere-earth’s surface=diet=tissue=dose-can skip steps;;PROJECT CHARIOT (58-62)US Atmoic Energy Commission proposal to detonate a string of underground nuclear devices at Cape Thompson on the N Slope of Alska;Inupiat vilage of Point Hope -; hunting grounds in the area…
Prediction of Pollution Effects
Heat and salt content are important factors affecting1)the functioning of polar ecosystems2)the rates of substance flows3)the stratification of the water, internal waves, circulation patterns, sea ice distribution;In order to predict and make timely decisions after teh appearance of undesirable trends or extreme environmental situations, it is necessary to understand enviornmental processes, and construct models of abiotic and biotic relationships.
Ecosystem Pollution and Arctic Foodwebs
Ecosystems have 4 basic components:1)the abiotic environment2) producers (autotrophs)3) consumers (heterotrophs)4) decomposers;Energy cycles through them;trophic level the position that an organism occupies in a food chain-what an organism eats and what eats the organism;*Marine food webs have more tropihc levels than terrestrial food webs;The Tundra Biome-Productivty very low-Recovery from any distrubance is very slow as tundra is a very delicate and fragile biome;Timescale of ecological processes in relation to natural disturbances in the Arctic….
NO FAST RESPONSES;
How do Contaminants get concentrated in Cold Environments?
Solvent Switching-ie. all of the contaminant moves from air to water: increased concentration in water;Solvent depletion-removal of solvent by a variety of processes-can lead to “fugacity amplification” (fugacity reflects the tendency of a substance to prefer one phase (liquid, solid, or gas)-Read about this, and look at diagram (lec9p5);Bioaccumulation-organism absorbs toxic substance at a greater rate than that at which the substance is lost-within a trophic level;Biomagnification-increase in concentration of a toxic substance in a food chain resulting from a)persistence (slow degradation), b)food chain energetics, or c) low rate of internal degradation/excretion (often due to water-inslubility)-ie DDT;Combined effects
Arctic pollution and glacier melt
DDT levels in the Adelie penguin have been unchanged since the 1970s, despite an 80% reduction in global DDT use (has been banned in N hemisphere);1-4kg of DDT are released into coastal waters annually along the W Antarctic Ice sheet from glacial meltwater;Glacier melt a probable source for DDT pollution of Antarctic marine systems____;MELTING ALPINE GLACIERS: POPs Releasedwww.youtube.com/watch?v=vxqf4GmHDNA-post-1990s peak-relevant release of POPs from melting Alpine glaciers-input fluxes from the high-alpine lake Oberaar into the lake sediment______;EFFECTS of both biomagnification and solvent depletion in glacial stream in the Italian Alps-peak in July possibly from solvent depletion (rain and melting of snow)-Glaciers and snow are temporary sinks for atmospherically transported pollutants
Bioaccumulation ; Biomagnification;
Causal link b/w POPs and adverse health in top predators-hormone, immune and reproductive systems;Many indigenous populations in the Arctic have poorer health than the national averages = combination of western food, lifestyle choices and polluted food.-cardiovascular, reproductive, hormone, neurological, metabolic and immune systemsTraditional food remains important for social, cultural, nutritional, economic and spiritual reasons.
SMOKE FROM FIRES;ARCTIC HAZE-reddish-brown smog (mostly N of 60N)-Sulfuric acid, nitrogen and organic aerosols formed in the air from the combination of naturally occurring chemicals and pollutant sulfur dioxide or hydrocarbon gases.;Aerosols smal enough to float in the air, but large enough to reflect sunlight, and cause haze.;Arctic haze also carries a mes of airborne toxic contaminants, heavy metals, and industrial organic compounts;It is seasonal.
Peaks in late winter and spring and is most severe when stable, high pressure systems produce clear, calm weather. Removed by wind or rain. This rain is often acid rain.;WHY does it form over the arctic region???;Arctic haze is the result of the ‘trapping’ of air masses in Arctic Dome (or cold air) that sits over the N Pole region. The Arctic Dome is confined by the Arctic front, which is the boundary between polar and arctic air masses and lies to the north of the Polar Front (boundary of polar and warmer air masses).
;The Arctic Front is discontinuous and wavy and depends on the temperature contrast between two air masses. It is particularly prominent during summer in N Eurasia.;Arctic haze can appear in distinct ‘bands’ or ‘layers’ at different heights because warm dirty air is forced upward. These bands can be 10-1000m thick and can extend over 20-200km. Within the bands, visibility can sometimes be just a few km.;Source Regions-smelter complexes in Siberia (largest source of sulfur dioxide emissions within Arctic region is at Norilsk);NAmerica contributes most ozone, Europe contributes most sulfate, black carbon. CO is mostly equal for all sources.
;SOURCE REGION SENSITIVITYSensitivities show strong seasonality…1) surface sensitivities typically maximize during boreal winter for European and during spring for E Asian and N American emissions2)Mid-tropospheric sensitivities nearly always maximize during spring or summer for all regions3)Deposition of black carbon (BC) onto Grenland is most sensitive to N American emissions.
Exxon Valdez (1989)ww.youtube.com/watch?v=MbjC9SMKClE;Exxon Valdez ran aground on a well-known reef and spilled 11million gallons of crude oil-one of the largest spills in US history and one of the largest ecological disasters-one of very few oil disasters in Arctic regions;Timeline for recovery depends on substrate:-bedrock shorelines in wave zone :weeks-exposed sandy beaches: months-marshes and salt flats: years to decades;Oil in sediments (sand/silt/clay) will remain there fore years/decades.;Prince William Sound has made a remarkable recovery from a severe injury, but it remains an ecosystem in transition, 20yrs later:-26000 gallons Valdez oil still in Alaska’s sand/soil-Deeply penetrated oil still leaches from a few beaches-in some areas, intertidal animals (mussels) are still contaminated by oil-some rocky sites that were stripped of heavy plant cover by high-pressure, hot-water cleaning remain mostly bare rock.
-Rich clam beds that suffered high mortalities from oil and extensive beach cleaning have not repopulated to previous levels
Pollution in Chernobyl, Rockies, and Tibet
RECENT CLIMATE EXTREMES ALTER ALPINE LAKE ECOSYSTEMS-Alpine lake ecosystems responsive to interannual variation in climate, based on long-term limnological and meteorological data from the Canadian Rockies In 2000s, rel to 1990s, in years with colder winters, higher snowfall, later snowmelt, shorter ice-free seasons, and drier summers, alpine lakes:1)became clearer, warmer, and mixed to deeper depths2)became more dilute and nutrient poor (leading to declines in total phytoplankton biomass)3)had increased concentrations of dissolved organic carbon (stimulating the appearance of small mixotrophic algal species, partially offsetting the decline in autotrophic phytoplankton biomass) CHERNOBYL-1 of 15 worst places to live-1986, home to over 14k residents, now is uninhabited due to contamination-worldwide spinach, mushrooms, lichen, caribou LA OROYA-one of 15 as well-in Peru-a soot-covered mining town in the Peruvian Andes-99% of the children who live here have blood levels over acceptable limits for lead poisoning, which can be directly attributed to an American-owned smelter that has been polluting the city since 1922.www.youtube.com/watch?v=Dc205KfQ7aAwww.youtube.
com/watch?v=VguzDVY7NAM&feature=related MINING TIBETMining operations in Tibet have been booming since the arrival of the Qinghai-Tibet rail line in 2006, bringing wealth to local governments and mine owners. Little benefit to local Tibetan farmers and nomads who say the mines scar mountains they consider sacred and kill the yaks and sheep they need in order to make a living Protests against China’s billion-dollar mining industry are rising.
Precautionary Principle, Future threats, and Arctic Charter
In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.
;Future Threats…-NW and NE passages-pop increase-climate change-new pollutants;ARCTIC CHARTER?www.youtube.
com/watch?v=D4CXCGWEbgQ;feature=related;Conclusions of the ALDE Conference on Arctic Governance (2008)-Borders and jurisdiction are not seen as the main obstacles for Arctic governance-environmenta changes and risks from human activity are the most important challenges-inerconnectedness of the arctic ecysystems should have implications for its governance-the regime in the Antarctic cannot be transferred to the Arctic; the two polar regions are totally different from each other in so many perspectives-existing treaties must be ratified, implemented and strengthened-at the moment it is not politically and legally feasible for a broad, binding legal regime at a regional Arctic scale (yet there is need for strategic coordination)-there are limitations in teh functionality of the Arctic council (scientific agenda), limiting the possibilities of acting as a strategic coordinating body-International collaboration, including nations outside the arctic, where most pollution is originating from, through partnership and stewardship.
How Animals Survive in Cold Regions
David Attenborough: The Frozen SeasNarwhals: www.youtube.com/watch?v=44sjE_x1X4k;PHYSIOLOGYReduce area:volume ratioFat or Blubber-distribution-amount-typeFur/Feathers – not such good insulators in water unless coated, not great in windCardiovascular System-antifreeze in blood (frogs)-vascular counter-current heat exchanger (fish);;BEHAVIOURHudddling-penguins, beesHeliothermic Behaviour-butterflies-lizardsMuscle Contractions-snakesHibernation-mammalsMigration-birds, butterflies, caribou, lemmings, narwhals and whalesMovement to keep ice open (warmer and can breathe)-ducks, whales, seals;Fattening up for winter!
Rain on Snow Events
In October 2003, a severe ROS event killed ~20 000 musk-oxen on Banks Island, westermost island in the Canadian Arctic;The event reduced the isolated herd by 25% and significantly affected the people dependent on the herd’s well-being ROS induced water and ice layers facilitate a) the growth of toxic fungi 2) significantly warm the soil surface under thick snowpack and 3) the hard snow crust deters large grazing mamals (musk oxen and caribou) ROS events are defined as a minimum of 3mm of rain falling on a minimum of 5mm of snow w.e. (~5cm snow) Increased frequency of ROS events in much of northwestern NA: habitat for several types of caribou.
How Plants Survive in Cold Climates
..video.google.com/videoplay?docid=303372183419001614# Migration-light, wind-dispersable seeds-dispersal by water-Use animals as vehicle to carry the seeds (berried cruits attractive to birds, burrs sticking onto fur, seedpod that are grazed)-seedlings dispersed when snowpack is covering land (smooth terrain, more wind, less chance of getting stuxk at close distance) PHYLOGENYFor diverse species (but not all) climate and extreme weather events are mechanistically linked to:-body size-individual fitness-population dynamics PhenolyStudy of periodic biological events as influenced by the environmentBio0indicator for global change and a determinant in climate change impact studies Last 100-150 years:-butterfly species showed diagnostic patterns of N expansion (new colonizations) and S contraction (population extinctions) Sign switching should occur as a response to opposing short term trends in climate (Warming vs cooling):-typical pattern: N range shifts during teh two 20th century warming periods (1930-45 and 1975-99) and S shifts during the interveneing cooling period (50-70).
Alpine Tree Lines
Both N-S and E-W gradient-will be lower on N slopes Alpine tree lines are climatically-determined ecotones (particularly sensitive to T change)-ecotone is a transition area between two adjacent but different plant communitiesEuropean Alps 20th Century: +2C and 1C since 1980-Average Alpine T lapse rate = 0.55C/100m (potential tree line shift of 200m) Get different tree communities and different tree lines depending on climate (ie, for alps Mediterranean, Continental, or Maritime) Treeline species (Switzerland) show:1)increased growth rates2)changing plant communities3)increased young tree establishmentBUT..
two anthro disturbances…1)rapid climate change2) land use change *abandoned agricultural land at higher elevations Average upward shift in 12 years: 38m-1/4 started without pre-established woody vegetation (shrub) Treelines elsewhere..
..NW CAN/GNP/Urals-minor changes in upper limit last 150 yrs-increase in density FRENCH MOUTAINS-more than 2/3 of 171 forest species moved over 18.5m per decade during 20th century Sedish Scandes-max 200m and means of 70-90m in last 100yrs-rapid upward advance since 1950s-spread of broadleaved thermophilic tree species into subalpine forest belt
Consevative Behaviour of treeline changes
Be careful in interpretation of tree line shifts over periods <50years!!!!-No complete forest establishment: hard to find exact treeline in first place-Permafrost and soil patchy: delayed establishment-Frequent stochastic processes (avalances, snow creep)-lagged response due to seed dispersal and tree recruitment peak processes (regeneration pulses >10-20yr period)-subalpine meadows resistant to tree invasion-in man yalpine regions during Holocene upper treeline in alpine shifted <100m N and S shifting is more sensitive than up and down? Trees are long life species and have low dispersal rate!-ability to adapt genetically or to seek refuge is limited if climate change is too abrupt-at present, their phenology has been less modified by T increase than other functional groups However, climate change can supersede the adaptive capacity of trees, esp if they can not seek refuge (migration is often the only way)
Parmesan and Yohe (Nature, 2003)
META-ANALYSIS Study of Phenology, Range and Distribution-quantitative meta-analyses of 334 species-qualitative global analyses of 1570 species (functional/biogeographic groups) Highly significant, nonrandom patterns of change in accord with observed climate warming in the 20th century, indicating a very high confidence (95%) in a global climate change fingerprint.
Climate is an important driving force of natural systems and even though the driving force might be relatively small, the impact is consistent:1)systematicaly affects century-scale biological trajectories2) ultimately affects the persistence of species A) PHENOLOGICAL (TIMING) SHIFTS-quantitative analysis of plants/animals: mean shift towards earlier spring of 2.3 days per decade-qualitative analysis of 677spp 62% showed trends towards spring advancement B)RANGE BOUNDARY SHIFTS99 spp of birds, butterflies and alpine herbs-Range limits of spp have moved on average 6.1 km/decade N-significantly in direction predicted by climate change C)COMMUNITY SPP DIST/ABUNDANCEQual.
anal. ~900spp-neither support nor refute a climate change signal-will be important for predictive biological models to eventualy determine what proportion of these are truly stable systems Range Distribution Shifts-New spp have colonized previously ‘cool’ regions-Some arctic spp have contracted in range size-over past 40 yrs, max range shifts vary from 200km (butterflies) to 1000km (marine copepods) REGIONAL SUMMARY-Difference b/w polar and temperate sppPolar: stable or declineTemperate: increased in abundance and/or epanded distributions.
www.youtube.com/watch?v=R34zshFRgbwA changing landscape: investigating a warming climate Also find and watch movie on Svalbard Global Seed Vault
Periglacial processes characerise regions with cold climates-periglacial used to describe proceses and features in areas adjacent to modern ice sheets A periglacial environment is difficult to define..-precise temp/precip
WHAT?-stones shaped and polished by wind abrasion-aeolian transported sand is dominant factorCreated by sand moving in the saltation zone FACETSCan be 3- or 4-siders-3=dreikanter4=vierkanter Produced on surfaces nearly perpendicular to wind direction PITS-small depressions eroded into surface-best developed on steep surfaces facing prevailing wind-begin and grow from points of weakness-what are some possible points of weakness? GROOVES-U-shaped depressions-grow from pitsFLUTES-extend across the rock surface linearly on surface facing wind-aligned parallel to strongest wind direction-most reliable type for determining wind direction YARDANG-Larger scale ventifactWind eroded ridge that is elongated parallel to prevailing wind (typically 2-3 times longer than they are wide)-usually less than 10m highCan extend for kilometresStoss side is blunt and steepCommon in regions underlain by relatively soft rocks HOW are ventifacts important?-provide useful information about periglacial wind conditions both past and present-former wind conditions are useful for reconstructing periglacial environments
Surface is only one or two stone layers thickFine sediment under stones Removal of finer sediments from the surfaceThis causes deflationOnce finer sediment is removed and only rocks are exposed, wind threshold cannot continue to erode WHERE?Common in aluvial fans and unsorted depositsOccurs under very windy conditions How is it periglacial?-alluvial fans from glacial outwash-katabatic winds next to a glacier Importance?-rocks in the pavement can be ventifacts-ventifacts help determine wind regime of past-wind regime can help reconstruct past climates
Wind deposited sedimentLoess deposits blanket the landscape over 50% silt, 5-30% clay, and 5-10% fine sand STRUCTURE-particles angular-porosity less than 50%-highly cohesive-sudden collapsibility when saturated-forms nearly vertical exposures SouRCE?-cold climate periglacial sediment deposits-originates from flood plains, (ie outwash from glacial streams)-silt and clay is transported by the wind as dust, it is called loess when it is deposited-thus, loess does not necessarily indicate a periglacial enviornment due to aeolian trasportation Thick loess sheets of central Europe, Russia, and China were deposited in glacial periods.Warmer climatic conditions allow organic layers (Paleosols) to form on the loess deposits-paleosols can be carbon dated-can reconstruct past climatic conditions-Thus, loess deposits are archives of past climatic conditions and environmental changes
Assymetrical mounds of sand that migrate by aeolian erosionContains: backslope, crest, slipface What are requirements for periglacial sand dunes?-sediment supply-wind-lack of veg-climate (arid, semi-arid) How are they periglacial?Sediment supply originates from glacio-fluvial and glacio-lacustrine sediment from glacial outwash and melt water-katabatic winds drive the formation of the dunes Barchan dunes vs Parabolic dunes-unidirectional wind Transverse dunes-unidirectional wind-ridges of sand with steep stoss face-barchan dunes transform into transverse dunes if the sediment supply increases Linear Dunes-form parallel to prevailing wind irections-wider and steeper at upwind end-tapering downwind-form in areas with limited sand supply
Commonalites (ventifacts, loess, desert pavement, and sand dunes)
All rely on :-sediment supply-aeolian activity-vegetation-climate Each landform occurs in a transitioning landscape relative to periglacial environments-ventifacts occur in areas with unsorted deposits and katabatic winds from glacier loess originates from outwash of glacial streams.
Deposits indicate glacial and interglacial periods. Desert pavement is common in alluvial fans and unsorted deposits. Kat winds from the adj glacier.
Dunes are supplied by glacial outwash sediment … again katabatic winds.
Measuring the Cryosphere
The cryosphere is the most sensitive to changes in climate of all environmental systems at the earth surface… BUT .
.relatively few measurements because of geographical remoteness, large scale, extreme conditions, extreme variability, and the long time-scale of some cryospheric processes.
Review- Cryosphere components and trends
Sea ice, ince 1978, has decreased in extent by about 2.1% per decade (slope of -9) Northern lakes are experiences earlier freeze and later breakup dates.
Mean lengths in global glacier tongues are all decreasing (small variability). RESPONSE TIMESVery slow!!Snow, river/lake/sea ice: day to monthGlaciers/Ice caps: months to centuriesFrozen ground: days to millenniaIce sheet margins: monthsice shelves: yearsice sheets: millennia
Relevance of Tayler’s presentation
Landscapes in transition!
Regions where glacier hazards are currently problematic
BC: moraine dammed lake outbursts following recesion;N Andes/Cascades: outburst floods from glacier topped volcanoes;Peruvian Andes: Moraine dammed lake outbursts following glacier recession-ice avalanches-debris flows;Iceland: outburst floods from subglacier volcanic eruptions;European Alps: ice avalanches-GLOFs from recession-debris flows;Caucasus mtns: Rock/ice avalanches-debris fowsTien Shan Mountains: Glacier dammed lake outburst following glacier advances;Karakoram/Himalaya:-GLOFs (recession)-GLOFs (surges)
Large fluctuations in energy/size of sediment;Angular, large boulders;Gully incisions;PARAGLACIAL SEDIMENT REWORKING-The paraglacial period of enhanced sediment yield commences at deglaciation and terminates when sediment yield is indistinguishable from the ‘gological norm’ resulting from primary denudation of the land surface by subaerial processes.;**review this graph (in review);At commencement of deglaciation, sediment yield increases a little bit then gradually goes down and levels off;That which is attributed to glaciation is the entrainment of paraglacial rock-slope debris.;Geological norm consists of debris input from valley walls and subglacial abrasion and quarrying;Also study paraglacial exhaustion curves (next slide);
Some tipping points…
Boreal Forest DIe Back.
.;Melt of Greenland Ice Sheet;Arctic Sea Ice Loss;Instability of West Antarctic Ice Sheet;Atlantic Deep water Formation;Changes in ENSO Amplitude/Frequency;West African Monsoon Shift;Indian Monsoon chaotic multistability;Permafrost/Tundra loss;Climate change induced ozone hole;Sahara greening;Tipping points of chemical polution and atmospheric aerosol loading have not yet been quantified…;Already past tipping points for biodiversity loss and Nitrogen cycle (biogeochemical flow boundary)
Do all the tasks!!!
Data exploration task (google earth) prob testable..;Taught us to:1)understand presented phenomena2)think about the wider implications3)think critically
Hocky stick graph
Temperature change!Comparison of NH temperature proxies with model simulations over the past 1000 years, and T record extension to 2000 years using long proxy temp data series;;
Climate denial with Peter Sinclain (crock of the week)
Mostly USA, lots of USSR/Russion, some France, UK, China, India, Pakistan, DPRK
Review: Solvent Depletion Process..
Meta-Analysis (Parmesan and Yohe) summary;
Highly significant, nonrandom patterns of change in accord with observed climate warming in the 20th century, indicating a very high confidence (95%) in a global climate change fingerprint.;A. Phenological shiftsB.
Range boundaries shiftC. community and/or species distribution and abundance;Climate is an important driving force of natural systems and even though the driving force might be relatively small, the impact is consistent:1)systematically affects century-scale biological trajectories2)ultimately affects the persistence of species
Review: Environmental Change and Culture
Environmental Change in Northern Ungava-mining, tourism, trade, industrial activity-climate change-sea level change-ecological changes-pollution, alcohol-politics (now part of Quebec);Effects-materials-traditional knowledge-ecology-landscape-population health-people’s self-esteem and dignity Socio-economic, cultural and psychological effects Review….
Annual calendars of cold region cultures..-when to bring sheep into mountains, and when to bring them down again-stages of fires, etc.-Shepherd life at Nuria, Spanish Pyrenees-see pg 28 of textbook -mixed cultures in these regions KANANGINAK POOTOOGOOK 1935-2010Cape Dorset print maker and artist.The “Audubon’ of the North-arctic evening-alcohol-watching the simpsons-stranded on the ice floes;**review “Sources of Social and Economic Resilience and Vulnerability that Characterize Arctic Systems”