On the formation of blue ice on Byrd Glacier, Antarctica

Ligtenberg, Stefan; Lenaerts, Jan T. M.; Broeke, M.R. van den; Scambos, T. A.

doi:10.3189/2014jog13j116

Cited by 19 publications

(21 citation statements)

References 41 publications

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“…We convert the presentday and historical DEMs to orthometric heights using Pavlis et al [72] EGM2008 model. This portion of Byrd Glacier is entirely blue ice [73], so a firn correction is not necessary in our calculations [74]. A glacier is in hydrostatic equilibrium where Equation 2is approximately zero.…”

Section: Grounding Zonementioning

confidence: 99%

Structure-From-Motion Photogrammetry of Antarctic Historical Aerial Photographs in Conjunction with Ground Control Derived from Satellite Data

et al. 2020

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A longer temporal scale of Antarctic observations is vital to better understanding glacier dynamics and improving ice sheet model projections. One underutilized data source that expands the temporal scale is aerial photography, specifically imagery collected prior to 1990. However, processing Antarctic historical aerial imagery using modern photogrammetry software is difficult, as it requires precise information about the data collection process and extensive in situ ground control is required. Often, the necessary orientation metadata for older aerial imagery is lost and in situ data collection in regions like Antarctica is extremely difficult to obtain, limiting the use of traditional photogrammetric methods. Here, we test an alternative methodology to generate elevations from historical Antarctic aerial imagery. Instead of relying on pre-existing ground control, we use structure-from-motion photogrammetry techniques to process the imagery with manually derived ground control from high-resolution satellite imagery. This case study is based on vertical aerial image sets collected over Byrd Glacier, East Antarctica in December 1978 and January 1979. Our results are the oldest, highest resolution digital elevation models (DEMs) ever generated for an Antarctic glacier. We use these DEMs to estimate glacier dynamics and show that surface elevation of Byrd Glacier has been constant for the past ∼40 years.

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Section: Grounding Zonementioning

confidence: 99%

Structure-From-Motion Photogrammetry of Antarctic Historical Aerial Photographs in Conjunction with Ground Control Derived from Satellite Data

et al. 2020

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“…In places, this contribution is a major one to the extent that no snow can accumulate even though snow fall occurs (Genthon et al, 2007). These are the wind-induced "blue ice" areas which affect ∼ 0.8 % of the surface of Antarctica (Ligtenberg et al, 2014). Over the bulk of Antarctica, although estimates have been suggested from remote sensing (Das et al, 2013), 5 only meteorological/climate models including parameterizations for blowing snow are likely to provide a fully consistent evaluation of the contribution of blowing snow processes to the SMB of the ice sheet (Déry and Yau, 2002;Lenaerts et al, 2012b).…”

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confidence: 99%

Blowing snow at D17, Adélie Land, Antarctica: atmospheric moisture issues

Barral¹,

Genthon²,

Trouvilliez³

et al. 2014

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Three years of blowing snow and meteorological observations have been collected along a 7 m mast at site D17 in coastal Adélie Land, Antarctica. This is a region particularly exposed to katabatic winds. The atmospheric surface layer is often close to saturation because of the sublimation of the airborne snow particles. A systematic dry 5 bias results in atmospheric models that ignore blowing snow and its moistening effects, and in meteorological analyses that use such model. The Crocus snow-pack model, including a parameterization for the erosion of surface snow by wind, reproduces the observed march of snow accumulation and ablation if the observed meteorology is used as input. Because of subsaturation, a 2.5 fold increase in surface sublimation 10 is obtained if analyzed surface air meteorology is used. The sublimation obtained in the Crocus model poorly agrees with the moisture fluxes evaluated using the profile method along the mast. Moisture gradients are very weak, particularly when blowing snow saturates the air, to a point where measurement accuracy is an issue. Using the profile method, the measurement uncertainties are strongly amplified in case of strong 15 wind. In such conditions, a single level bulk parameterization with surface energy balance closure as in the Crocus model is preferred. At D17, more than half of the total snow fall is removed by erosion and sublimation, both at the surface and, mainly, of airborne snow particles. 25 ing and blowing snow to the surface mass balance (SMB) of Antarctica is estimated 2760 TCD

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“…In places, the contribution of eroding and blowing snow to the surface mass balance (SMB) of Antarctica is a major one, to the extent that no snow can accumulate even though snowfall occurs (Genthon et al, 2007). These are the windinduced "blue-ice" areas that affect ∼ 0.8 % of the surface of Antarctica (Ligtenberg et al, 2014). Over the bulk of Antarctica, although estimates have been suggested from remote sensing (Das et al, 2013), only meteorological/climate models including parameterizations for blowing snow are likely to provide a fully consistent evaluation of the contribution of blowing-snow processes to the SMB of the ice sheet (Déry and Yau, 2002;Lenaerts et al, 2012b).…”

Section: Introductionmentioning

confidence: 99%

Blowing snow in coastal Adélie Land, Antarctica: three atmospheric-moisture issues

et al. 2014

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Abstract. A total of 3 years of blowing-snow observations and associated meteorology along a 7 m mast at site D17 in coastal Adélie Land are presented. The observations are used to address three atmospheric-moisture issues related to the occurrence of blowing snow, a feature which largely affects many regions of Antarctica: (1) blowing-snow sublimation raises the moisture content of the surface atmosphere close to saturation, and atmospheric models and meteorological analyses that do not carry blowing-snow parameterizations are affected by a systematic dry bias; (2) while snowpack modelling with a parameterization of surface-snow erosion by wind can reproduce the variability of snow accumulation and ablation, ignoring the high levels of atmospheric-moisture content associated with blowing snow results in overestimating surface sublimation, affecting the energy budget of the snowpack; (3) the well-known profile method of calculating turbulent moisture fluxes is not applicable when blowing snow occurs, because moisture gradients are weak due to blowing-snow sublimation, and the impact of measurement uncertainties are strongly amplified in the case of strong winds.

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On the formation of blue ice on Byrd Glacier, Antarctica

Cited by 19 publications

References 41 publications

Structure-From-Motion Photogrammetry of Antarctic Historical Aerial Photographs in Conjunction with Ground Control Derived from Satellite Data

Structure-From-Motion Photogrammetry of Antarctic Historical Aerial Photographs in Conjunction with Ground Control Derived from Satellite Data

Blowing snow at D17, Adélie Land, Antarctica: atmospheric moisture issues

Blowing snow in coastal Adélie Land, Antarctica: three atmospheric-moisture issues

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