Elevation Changes Inferred From TanDEM-X Data Over the Mont-Blanc Area: Impact of the X-Band Interferometric Bias

Dehecq, Amaury; Millan, Romain; Berthier, Étienne; Gourmelen, Noël; Trouvé, Emmanuël; Vionnet, Vincent

doi:10.1109/jstars.2016.2581482

Cited by 84 publications

(93 citation statements)

References 47 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mass changes reported by Gardelle et al (2013) are most likely too positive as SRTM C-Band penetration depth into snow Berthier et al, 2016) might have been underestimated for the cold and dry snow of accumulation areas (Dehecq et al, 2016 For Golubin Glacier, the inferred mass balance is in close agreement with the geodetic mass change reported by Bolch (2015) (Fig. 12b).…”

supporting

confidence: 82%

Multi-decadal mass balance series of three Kyrgyz glaciers inferred from transient snowline observations

Barandun

Huss

Kääb

et al. 2017

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract.Glacier mass balance observations in the Tien Shan and Pamir mountains are sparse and often discontinuous. Nevertheless, glaciers are one of the most important components of the high-mountain cryosphere in the region; they strongly influence water availability in the arid, continental and intensely populated downstream areas. This study provides reliable and continuous mass balance series for selected glaciers located in the Tien Shan and Pamir-Alay. A combination of three independent methods was 5 used to reconstruct for the past two decades the mass balance of the three benchmark glaciers, Abramov, Golubin and No.354. By applying different approaches, it was possible to compensate for the limitations and shortcomings of each individual method. This study proposes the use of transient snowline observations throughout the melting season obtained from satellite imagery and terrestrial automatic cameras. By combining modelling with remotely acquired information on summer snow depletion, it was possible to infer glacier mass changes for unmeasured years. Multi-annual mass changes based on high-10 accuracy digital elevation models and in situ glaciological surveys were used to validate the results for the investigated glaciers. balance modelling significantly narrows the uncertainty ranges of the estimates, and hence highlights the potential of the methodology for application to inaccessible glaciers at larger scales for which no direct measurements are available.

show abstract

supporting

confidence: 82%

Multi-decadal mass balance series of three Kyrgyz glaciers inferred from transient snowline observations

Barandun

Huss

Kääb

et al. 2017

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…As noted in the Introduction, Melkonian et al ( , 2016 accounted for this by subtracting the C-band and Xband SRTM DEM, assuming no penetration of the X-band DEM (Gardelle et al, 2012). However, X-band penetration can reach several meters into cold snow and firn (e.g., Dehecq et al, 2016;Round et al, 2017). In the case of the SIF, Melkonian et al (2016) assumed no penetration below 1000 m a.s.l.…”

Section: Discussionmentioning

confidence: 99%

“…Melkonian et al ( , 2016 accounted for this penetration by subtracting the simultaneous C-band and X-band SRTM DEMs, assuming no penetration of the X-band DEM (Gardelle et al, 2012), the best available correction at the time of their study. However, this strategy may not be appropriate given that the X-band penetration depth has recently been recognized to reach several meters in cold and dry snow/firn (e.g., Dehecq et al, 2016;Round et al, 2017). In this context, the goal of this brief communication is to recalculate the early-21st-century geodetic mass balances of the Juneau and Stikine icefields using multi-temporal ASTER DEMs, carefully excluding the SRTM DEM to avoid a likely penetration bias.…”

Section: Introductionmentioning

confidence: 99%

Brief communication: Unabated wastage of the Juneau and Stikine icefields (southeast Alaska) in the early 21st century

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. The large Juneau and Stikine icefields (Alaska) lost mass rapidly in the second part of the 20th century. Laser altimetry, gravimetry and field measurements suggest continuing mass loss in the early 21st century. However, two recent studies based on time series of Shuttle Radar Topographic Mission (SRTM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation models (DEMs) indicate a slowdown in mass loss after 2000. Here, the ASTER-based geodetic mass balances are recalculated carefully avoiding the use of the SRTM DEM because of the unknown penetration depth of the C-band radar signal. We find strongly negative mass balances from 2000 to 2016 (−0.68 ± 0.15 m w.e. a −1 for the Juneau Icefield and −0.83 ± 0.12 m w.e. a −1 for the Stikine Icefield), in agreement with laser altimetry, confirming that mass losses are continuing at unabated rates for both icefields. The SRTM DEM should be avoided or used very cautiously to estimate glacier volume change, especially in the North Hemisphere and over timescales of less than ∼ 20 years.

show abstract

“…Therefore, we measured median and NMAD over off-glacier We also found that NMAD strongly depends on slope in both time periods. Hence, we have not restricted our error analysis up to an arbitrary slope threshold (e.g., 40 • in [15]) given that most of the glaciated area covers slopes below this threshold. Using this approach the error is underestimated for areas steeper than this arbitrary slope threshold and overestimated for gentler areas.…”

Section: Uncertainty Estimatementioning

confidence: 99%

Elevation Change Rates of Glaciers in the Lahaul-Spiti (Western Himalaya, India) during 2000–2012 and 2012–2013

2016

View full text Add to dashboard Cite

Abstract:Previous studies have shown contrasting glacier elevation and mass changes in the sub-regions of high-mountain Asia. However, the elevation changes on an individual catchment scale can be potentially influenced by supraglacial debris, ponds, lakes and ice cliffs besides regionally driven factors. Here, we present a detailed study on elevation changes of glaciers in the Lahaul-Spiti region derived from TanDEM-X and SRTM C-/X-band DEMs during 2000-2012 and 2012-2013. We observe three elevation change patterns during 2000-2012 among glaciers with different extent of supraglacial debris. The first pattern (<10% debris cover, type-1) indicates maximum thinning rates at the glacier terminus and is observed for glaciers with no or very low debris cover. In the second pattern (>10% debris cover, type-2), maximum thinning is observed up-glacier instead of glacier terminus. This is interpreted as the insulating effect of a thick debris cover. A third pattern, high elevation change rates near the terminus despite high debris cover (>10% debris cover, type-3) is most likely associated with either thinner debris thickness or enhanced melting at supraglacial ponds and lakes as well as ice cliffs. We empirically determined the SRTM C-and X-band penetration differences for debris-covered ice, clean ice/firn/snow and correct for this bias in our elevation change measurements. We show that this penetration bias, if uncorrected, underestimates the region-wide elevation change and geodetic mass balance by 20%. After correction, the region-wide elevation change (1712 km 2 ) was estimated to be −0.65 ± 0.43 m yr −1 during 2000-2012. Due to the short observation period, elevation change measurements from TanDEM-X for selected glaciers in the period 2012-2013 are subject to large uncertainties. However, similar spatial patterns were observed during 2000-2012 and 2012-2013, but at different magnitudes. This study reveals that the thinning patterns of debris-covered glaciers cannot be generalized and spatially detailed mapping of glacier elevation change is required to better understand the impact of different surface types under changing climatic conditions.

show abstract

Elevation Changes Inferred From TanDEM-X Data Over the Mont-Blanc Area: Impact of the X-Band Interferometric Bias

Cited by 84 publications

References 47 publications

Multi-decadal mass balance series of three Kyrgyz glaciers inferred from transient snowline observations

Multi-decadal mass balance series of three Kyrgyz glaciers inferred from transient snowline observations

Brief communication: Unabated wastage of the Juneau and Stikine icefields (southeast Alaska) in the early 21st century

Elevation Change Rates of Glaciers in the Lahaul-Spiti (Western Himalaya, India) during 2000–2012 and 2012–2013

Contact Info

Product

Resources

About