spatial and temporal variability in snow accumulation on...
TRANSCRIPT
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)
620,000 640,000 660,000 680,000 700,000 720,000 740,000UTM zone 32 (m)
8,82
0,00
08,
840,
000
8,86
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880,
000
8,90
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920,
000
UTM
zon
e 32
(m)
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
W E
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)