Spatial and temporal variability in snow accumulation on...
Transcript of Spatial and temporal variability in snow accumulation on...
Spatial and temporal variability in snowaccumulation on Austfonna, Svalbard.
Andrea Taurisano, Jack Kohler, Jon-Ove Hagen, Trond Eiken, Even Loe and Kjetil Melvold
Austfonna
• Area ~8200 km2
• Simple-dome shape topography with a number of drainage basins
• Maximum elevation c.a 800 m a.s.l., max. ice thickness 560 m
• Polythermal - highest part is below the percolation-zone for most years
Period: 15 April – 1 May 2004
Team: Andrea Taurisano and Jørgen Haagensli (NPI) Jon Ove Hagen, Trond Eiken and Even Loe (UiO)
Airborne measurements: AWI team on Dornier Do228-100
Depot on Oxfordhalvøya Camp on Austfonna summit
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
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Austfonna
Norddomen
SørdomenIsdomen
Brsvellbreen
Etonbreen
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
Approx. 20 stakes were drilled along transects and measured with GPS
Mass balance and ice surface velocities
Ablation stakes7
5 reflectors along Cryosat orbit tracks
Airborne radar altimetry measur. (image calibration)
Corner reflectors8
2 complete stations + 5 temperature miniloggers at different altitude
Air temperature, wind speed and direction, solar radiation, snow depth. Temp. lapse rate.
Automatic weather station (AWS)
6
8 shallow snow/firn cores along transects + a 17m ice core at summit
Visual stratigraphy, density profiles. Used to study theoretical response of firn to GPR and radar altimeter
Bulk density and electromagnetic measurements (DEP) on firn cores
5
At corner reflectors, at summit and along transects
Density variationSnow density profiles, grain size and shape, stratigraphy measurements in snow pits
4
At corner reflectors + relevant features along transects
Characterize small scale surface roughness
Digital photography and profiling of the snow surface
3
Continuous along transects (c.a 800 km tot)
Density layer variation, also calibrates dielectric modelling
Ground Penetrating Radar profiling at 800 MHz
2
Continuous along transectsCharacterize surface topography (large scale rough.)
DGPS location/elevation1
Coverage / FrequencyProperties MeasuredMeasurement Technique
Cryosat Cal-Val field campaign Spring 2004: Austfonna (Svalbard)
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Austfonna: snow accumulation (1999)
Sand, K., Winther, J.-G., Marechal, D., Bruland, O., Melvold, K., 2003. Regional variations of snow accumulation on Spitsbergen, Svalbard, 1997-99. Nordic Hydrology, 34(1/2), 17-32
Austfonna: snow accumulation (2004)
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Austfonna: snow accumulation (1999 and 2004)
δ = 0.345 g/cm3
δ = 0.375 g/cm3
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Austfonna: snow accumulation,1999 vs. 2004 vs. distance along profile
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Austfonna: snow accumulation,1999 vs. 2004 vs. elevation
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Austfonna: snow accumulation (1999)
Austfonna: snow accumulation (2004)
Depth-Density data from Austfonna ice cores
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Austfonna: accumulation from ice cores
Data 1998 and 1999: Watanabe, O., Motoyama, H., Igarashi, M., Kamiyama, K., Matoba, S., Goto-Azuma, K., Narita, H., Kameda, T., 2001. Studies on climatic and environmental changes during the last few hundred years using ice cores from various sites in Nordaustlandet, Svalbard. Mem. Natl. Inst. Polar Res., Spec. Issue, 54, 227-242.
- a 16.4 m ice core was drilled in 2004 near summit
- δ18O seasonal cycles for counting annual layers (5cm res.)
- Cs analysis at 20 cm resolution
Austfonna: accumulation variability and elevation changes
Austfonna: elevation changes
Bamber, J., Krabill, W., Raper, V., and Dowdeswell, J., 2004. Anomalous recent growth of part of a large Arctic ice cap: Austfonna, Svalbard. Geophysical Research Letters, 31.
• Repeated airborne laser altimetry 1996-2002 (NASA)
• Thinning (<0.6m/yr) at low elevations and thickening (>0.6m/yr) above 500 m asl
• The central thickening is interpreted as possible result of increased precipitation (not shown by meteo data)