Abstract Rapid ice loss is occurring in the Amundsen Sea sector of West Antarctic Ice Sheet. This assumed to be a long‐term response oceanographic forcing, but ocean conditions are unknown prior 1994. Here we present modeling study from 1920 2013, using an ensemble ice‐ocean simulations forced by climate model experiments. We find that during early twentieth century, likely experienced more sustained cool periods than at present. Warm become dominant over (mean trend 0.33°C/century) causing...

Abstract The combination of the Pine Island Ice Shelf (PIIS) draft and a seabed ridge beneath it form topographic barrier, restricting access warm Circumpolar Deep Water to cavity inshore ridge, thus exerting an important control on PIIS basal ablation. In addition, has recently experienced several large calving events further could significantly alter geometry. Changes in ice front location, together with changes thickness, might relax barrier change melt rates. Here, we consider impact...

Abstract. The Amundsen Sea sector has some of the fastest-thinning ice shelves in Antarctica, caused by high, ocean-driven basal melt rates, which can lead to increased streamflow, causing sea level rise (SLR) contributions. In this study, we present results a new synchronously coupled ice-sheet–ocean model sector. We use Wavelet-based, Adaptive-grid, Vertically Integrated sheet (WAVI) solve for velocities and Massachusetts Institute Technology general circulation (MITgcm) thickness...

Abstract The Amundsen Sea has the highest thinning rates of ice shelves in Antarctica. This imbalance is caused by changes ocean melting induced warm Circumpolar Deep Water (CDW) intrusions. resulting changing freshwater balance could affect on‐shelf currents and mixing. However, a clear understanding sources sinks region lacking. Here we use model Sea, with passive tracers, to investigate relative magnitudes spatial distributions different components. In surface layer as depth average, all...

The West Antarctic Ice Sheet (WAIS) is losing ice and its annual contribution to sea level increasing. biggest changes are found in the Amundsen Sea sector of WAIS, which contains two most rapidly thinning streams, Pine Island Glacier (PIG) Thwaites (TG). future behaviour these glaciers will impact societies worldwide, yet deep uncertainty remains expected rate loss. One prominent question whether retreat this region has already passed a tipping point. In ice-sheet projections using WAVI...

The relative contributions of anthropogenic climate change and internal variability in sea level rise from the Antarctic Ice Sheet are yet to be determined. This is primarily because uncertainty arising poorly constrained model parameters chaotic forcing as well a relatively short observation period. Using an established quantification framework (known calibrate-emulate-sample), we have quantified, for first time, role on retreat major glacier. We find that trends forcing, beginning 1960s,...

Abstract The relative contributions of anthropogenic climate change and internal variability in sea level rise from the West Antarctic Ice Sheet are yet to be determined. Even way address this question is not clear, since these two linked through ice-ocean feedbacks probed using ice sheet models with substantial uncertainty. Here we demonstrate how their can assessed by simulating retreat a synthetic setup an model. Using Bayesian approach, construct distributions associated retreat. We that...

Abstract. The Amundsen Sea sector has some of the fastest-thinning ice shelves in Antarctica, caused by high, ocean-driven basal melt rates, which can lead to increased stream flow, causing sea level rise (SLR) contributions. In this study, we present results a new synchronously coupled ice-sheet/ocean model sector. We use WAVI sheet solve for velocities and MITgcm thickness three-dimensional ocean properties, allowing full mass conservation ice/ocean system. is initialised day run forward...

Abstract Sea level rise contributions from the Pine Island Glacier (PIG) are strongly modulated by backstress that its floating extension – Ice Shelf (PIIS) exerts on adjoining grounded ice. The front of PIIS has recently retreated significantly via calving, and satellite theoretical analyses have suggested further retreat is inevitable. As well as inducing an instantaneous increase in ice flow, may result increased ocean melting, relaxing topographic barrier to warm water currently provided...

Pine Island Glacier is a fast flowing ice stream in West Antarctica. At present, it rapidly thinning and retreating, has been since at least the 1970s, when satellite records began. Sediment indicate that this retreat was initiated 1940s, but influence of climate change on key forcing components only became significant 1960s, i.e. trigger for occurred naturally. However, current loss remains responsive to fluctuations forcing, indicating not undergoing purely unstable after trigger. This...

Ice sheet models are used to improve our understanding of the past, present, and future evolution ice sheets.To do so, they solve equations describing flow when forced by other climate elements, particularly atmosphere oceans.We present WAVI.jl, an model written in Julia.WAVI.jl is designed make modelling more accessible beginners low-level users, whilst including sufficient detail be for addressing cutting-edge research questions.

The West Antarctic Ice Sheet is thinning and losing mass at an accelerating rate. However these changes have yet to be formally attributed anthropogenic climate change, primarily because of the potential for positive feedbacks on ice sheet loss which may been triggered even within limits natural internal variability. This begs question: has thinning, loss, ultimately sea level rise from Antarctica resulted changes? Or, ongoing simply result a feedback playing out long timescales sheets...

The Amundsen Sea Sector has some of the highest thinning rates ice shelves in Antarctica, thought to be driven by high, but interannually variable, ocean melt rates. This can lead increased flow speeds, eventually leading sea level rise. To fully represent these processes and other feedbacks, a coupled ice/ocean model must used. Therefore, synchronous mass conservative ice-sheet/ocean been developed. new builds upon previous coupling developments involves WAVI ice-sheet 3D MITgcm, via...

The relative contributions of anthropogenic climate change and internal variability in sea level rise from the West Antarctic Ice Sheet are yet to be determined. Even way address this question is not clear, since these two linked through ice-ocean feedbacks probed using ice sheet models with substantial uncertainty. Here we demonstrate how their can assessed by simulating retreat a synthetic setup an model. Using Bayesian approach, construct distributions associated retreat. We that it...

Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Oceans. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]The Influence Pine Island Ice Shelf Calving on MeltingAuthorsAlexander ThomasBradleyiDDavid ThomasBettPierreDutrieuxJanDe RydtPaulHollandSee all authors Alexander...