Intermittent thinning of Jakobshavn Isbræ, West Greenland, since the Little Ice Age

Csathó, B. M.; Schenk, Toni; Veen, C. J. van der; Krabill, William B.

doi:10.3189/002214308784409035

Cited by 115 publications

(137 citation statements)

References 37 publications

Supporting

Mentioning

127

Contrasting

Order By: Relevance

“…From 1850 to 1964, the calving front shrunk back at a mean speed of 0.3 km/yr but then stagnated from 1964 to 2000. After 2000, it began retreating again at a rate of 3 km/yr (Csatho et al, 2008).…”

Section: First Glaciological Results Using Spirit Dtms and Ortho-mentioning

confidence: 99%

SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year (2007–2009)

Korona

Berthier

Bernard

et al. 2009

ISPRS Journal of Photogrammetry and Remote Sensing

222

257

View full text Add to dashboard Cite

Section: First Glaciological Results Using Spirit Dtms and Ortho-mentioning

confidence: 99%

SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year (2007–2009)

Korona

Berthier

Bernard

et al. 2009

ISPRS Journal of Photogrammetry and Remote Sensing

222

257

View full text Add to dashboard Cite

“…On the other hand, it also means slowly flowing upstream areas will continue to respond and contribute to mass loss at a reduced rate for the longer-term future as also demonstrated by Price et al (2011) and further, that changes, currently observed upstream, may still be affected by terminus perturbations that happened several decades ago. This is important regarding interpretation of the present observations of thickness change in context of the longer-term terminus retreat of JIB since the Little Ice Age, when the terminus position was 35 km further advanced then at present (Csatho et al 2008;Young et al 2011).…”

Section: Dynamic Adjustmentmentioning

confidence: 99%

Understanding and Modelling Rapid Dynamic Changes of Tidewater Outlet Glaciers: Issues and Implications

Vieli¹,

Nick²

2011

The Earth's Cryosphere and Sea Level Change

View full text Add to dashboard Cite

Recent dramatic acceleration, thinning and retreat of tidewater outlet glaciers in Greenland raises concern regarding their contribution to future sea-level rise. These dynamic changes seem to be parallel to oceanic and climatic warming but the linking mechanisms and forcings are poorly understood and, furthermore, large-scale ice sheet models are currently unable to realistically simulate such changes which provides a major limitation in our ability to predict dynamic mass losses. In this paper we apply a specifically designed numerical flowband model to Jakobshavn Isbrae (JIB), a major marine outlet glacier of the Greenland ice sheet, and we explore and discuss the basic concepts and emerging issues in our understanding and modelling ability of the dynamics of tidewater outlet glaciers. The modelling demonstrates that enhanced ocean melt is able to trigger the observed dynamic changes of JIB but it heavily relies on the feedback between calving and terminus retreat and therefore the loss of buttressing. Through the same feedback, other forcings such as reduced winter sea-ice duration can produce similar rapid retreat. This highlights the need for a robust representation of the calving process and for improvements in the understanding and implementation of forcings at the marine boundary in predictive ice sheet models. Furthermore, the modelling uncovers high sensitivity and rapid adjustment of marine outlet glaciers to perturbations at their marine boundary implying that care should be taken in interpreting or extrapolating such rapid dynamic changes as recently observed in Greenland.

show abstract

“…Khan et al, 2010;Schrama et al, 2011). Whereas the retreat and thinning of numerous marine-terminating glaciers has not been limited to recent years (Csatho et al, 2008), the acceleration of many major outlets and consequent increase in iceberg discharge is, and has become a significant component of the overall net mass loss in the last decade (Rignot and Kanagaratnam, 2006;Howat et al, 2011). However, mass loss is not confined to regions with marine-terminating glaciers.…”

Section: Introductionmentioning

confidence: 99%

Large surface meltwater discharge from the Kangerlussuaq sector of the Greenland ice sheet during the record-warm year 2010 explained by detailed energy balance observations

et al. 2012

View full text Add to dashboard Cite

Abstract. This study uses data from six on-ice weather stations, calibrated MODIS-derived albedo and proglacial river gauging measurements to drive and validate an energy balance model. We aim to quantify the record-setting positive temperature anomaly in 2010 and its effect on mass balance and runoff from the Kangerlussuaq sector of the Greenland ice sheet. In 2010, the average temperature was 4.9 • C (2.7 standard deviations) above the 1974-2010 average in Kangerlussuaq. High temperatures were also observed over the ice sheet, with the magnitude of the positive anomaly increasing with altitude, particularly in August. Simultaneously, surface albedo was anomalously low in 2010, predominantly in the upper ablation zone. The low albedo was caused by high ablation, which in turn profited from high temperatures and low winter snowfall. Surface energy balance calculations show that the largest melt excess (∼170 %) occurred in the upper ablation zone (above 1000 m), where higher temperatures and lower albedo contributed equally to the melt anomaly. At lower elevations the melt excess can be attributed to high atmospheric temperatures alone. In total, we calculate that 6.6 ± 1.0 km 3 of surface meltwater ran off the ice sheet in the Kangerlussuaq catchment in 2010, exceeding the reference year 2009 (based on atmospheric temperature measurements) by ∼150 %. During future warm episodes we can expect a melt response of at least the same magnitude, unless a larger wintertime snow accumulation delays and moderates the melt-albedo feedback. Due to the hypsometry of the ice sheet, yielding an increasing surface area with elevation, meltwater runoff will be further amplified by increases in melt forcings such as atmospheric heat.

show abstract

Intermittent thinning of Jakobshavn Isbræ, West Greenland, since the Little Ice Age

Cited by 115 publications

References 37 publications

SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year (2007–2009)

SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year (2007–2009)

Understanding and Modelling Rapid Dynamic Changes of Tidewater Outlet Glaciers: Issues and Implications

Large surface meltwater discharge from the Kangerlussuaq sector of the Greenland ice sheet during the record-warm year 2010 explained by detailed energy balance observations

Contact Info

Product

Resources

About