North Atlantic warming and the retreat of Greenland's outlet glaciers

Straneo, Fiammetta; Heimbach, Patrick

doi:10.1038/nature12854

Cited by 403 publications

(410 citation statements)

References 99 publications

Supporting

Mentioning

384

Contrasting

Unclassified

Order By: Relevance

“…Although the incubation temperatures were higher than in situ, we argue that our experimental set-up nonetheless reflects a realistic scenario for the current, and certainly the future Arctic Ocean. The incubation temperatures at the final sampling (6.3°C) were within the range of naturally occurring temperatures in Arctic outflow shelf regions (Beszczynska-Möller et al 2012;Straneo and Heimbach 2013). Furthermore, such temperatures can be expected to become more common in the future (AMAP 2013;Pörtner et al 2014).…”

Section: Assemblages Did Not Respond To Ocean Acidificationmentioning

confidence: 94%

“…Regions of particularly rapid change are the outflow shelves of the Arctic Ocean, including Baffin Bay. Over the past two decades, rapid sea-ice loss as well as warming, freshening, and associated changes in productivity patterns have been documented in these near-shore Arctic regions (Straneo and Heimbach 2013;Bergeron and Tremblay 2014;Soltwedel et al 2015).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Resistance of Arctic phytoplankton to ocean acidification and enhanced irradiance

et al. 2017

View full text Add to dashboard Cite

The Arctic Ocean is a region particularly prone to ongoing ocean acidification (OA) and climate-driven changes. The influence of these changes on Arctic phytoplankton assemblages, however, remains poorly understood. In order to understand how OA and enhanced irradiances (e.g., resulting from sea-ice retreat) will alter the species composition, primary production, and ecophysiology of Arctic phytoplankton, we conducted an incubation experiment with an assemblage from Baffin Bay (71°N, 68°W) under different carbonate chemistry and irradiance regimes. Seawater was collected from just below the deep Chl a maximum, and the resident phytoplankton were exposed to 380 and 1000 latm pCO 2 at both 15 and 35% incident irradiance. On-deck incubations, in which temperatures were 6°C above in situ conditions, were monitored for phytoplankton growth, biomass stoichiometry, net primary production, photo-physiology, and taxonomic composition. During the 8-day experiment, taxonomic diversity decreased and the diatom Chaetoceros socialis became increasingly dominant irrespective of light or CO 2 levels. We found no statistically significant effects from either higher CO 2 or light on physiological properties of phytoplankton during the experiment. We did, however, observe an initial 2-day stress response in all treatments, and slight photo-physiological responses to higher CO 2 and light during the first five days of the incubation. Our results thus indicate high resistance of Arctic phytoplankton to OA and enhanced irradiance levels, challenging the commonly predicted stimulatory effects of enhanced CO 2 and light availability for primary production.

show abstract

Section: Assemblages Did Not Respond To Ocean Acidificationmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Resistance of Arctic phytoplankton to ocean acidification and enhanced irradiance

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Atlantic water (AW) , also known as subpolar mode water or intermediate Irminger water (Ribergaard, 2007), is the deepest and warmest water body present in the fjord. This water type is advected along the coast by the west Greenland Current (Mortensen et al, , 2013Ribergaard, 2007;Straneo and Heimbach, 2013;, entering the fjord via the Uummannaq Bay trough carved across the continental shelf. Throughout our surveys, AW was always present below 400 to 500 m depth and had highly consistent temperature and salinity characteristics (θ = 2.8 ± 0.2 • C and S = 34.8 ± 0.1 PSU) for both fjords over both years.…”

Section: Water Types Present At the Glacier Frontmentioning

confidence: 99%

Ice–ocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers

et al. 2014

View full text Add to dashboard Cite

Abstract. Warm, subtropical-originating Atlantic water (AW) has been identified as a primary driver of mass loss across the marine sectors of the Greenland Ice Sheet (GrIS), yet the specific processes by which this water mass interacts with and erodes the calving front of tidewater glaciers is frequently modelled and much speculated upon but remains largely unobserved. We present a suite of fjord salinity, temperature, turbidity versus depth casts along with glacial runoff estimation from Rink and Store glaciers, two major marine outlets draining the western sector of the GrIS during 2009 and 2010. We characterise the main water bodies present and interpret their interaction with their respective calving fronts. We identify two distinct processes of iceocean interaction which have distinct spatial and temporal footprints: (1) homogenous free convective melting which occurs across the calving front where AW is in direct contact with the ice mass, and (2) localised upwelling-driven melt by turbulent subglacial runoff mixing with fjord water which occurs at distinct injection points across the calving front. Throughout the study, AW at 2.8 ± 0.2 • C was consistently observed in contact with both glaciers below 450 m depth, yielding homogenous, free convective submarine melting up to ∼ 200 m depth. Above this bottom layer, multiple interactions are identified, primarily controlled by the rate of subglacial fresh-water discharge which results in localised and discrete upwelling plumes. In the record melt year of 2010, the Store Glacier calving face was dominated by these runoff-driven plumes which led to a highly crenulated frontal geometry characterised by large embayments at the subglacial portals separated by headlands which are dominated by calving. Rink Glacier, which is significantly deeper than Store has a larger proportion of its submerged calving face exposed to AW, which results in a uniform, relatively flat overall frontal geometry.

show abstract

“…High surface melting has been attributed to rising atmospheric Greenland temperatures (Box et al, 2009;Hall et al, 2008;Tedesco et al, 2016), which may also increase crevassing and calving at the ice front. Conversely, the recently enhanced discharge of ice into the ocean is thought to be directly connected to warmer Atlantic waters entering Greenland's fjords (Holland et al, 2008a;Rignot et al, 2010;Straneo et al, 2010;Straneo and Heimbach, 2013). Higher oceanic temperatures increase the submarine melting at the calving front of tidewater glaciers, contributing to their acceleration, ice mass discharge into the ocean and potentially grounding-line retreat.…”

Section: Introductionmentioning

confidence: 99%

The sensitivity of the Greenland Ice Sheet to glacial–interglacial oceanic forcing

et al. 2018

View full text Add to dashboard Cite

Abstract.Observations suggest that during the last decades the Greenland Ice Sheet (GrIS) has experienced a gradually accelerating mass loss, in part due to the observed speedup of several of Greenland's marine-terminating glaciers. Recent studies directly attribute this to warming North Atlantic temperatures, which have triggered melting of the outlet glaciers of the GrIS, grounding-line retreat and enhanced ice discharge into the ocean, contributing to an acceleration of sea-level rise. Reconstructions suggest that the influence of the ocean has been of primary importance in the past as well. This was the case not only in interglacial periods, when warmer climates led to a rapid retreat of the GrIS to land above sea level, but also in glacial periods, when the GrIS expanded as far as the continental shelf break and was thus more directly exposed to oceanic changes. However, the GrIS response to palaeo-oceanic variations has yet to be investigated in detail from a mechanistic modelling perspective. In this work, the evolution of the GrIS over the past two glacial cycles is studied using a three-dimensional hybrid ice-sheetshelf model. We assess the effect of the variation of oceanic temperatures on the GrIS evolution on glacial-interglacial timescales through changes in submarine melting. The results show a very high sensitivity of the GrIS to changing oceanic conditions. Oceanic forcing is found to be a primary driver of GrIS expansion in glacial times and of retreat in interglacial periods. If switched off, palaeo-atmospheric variations alone are not able to yield a reliable glacial configuration of the GrIS. This work therefore suggests that considering the ocean as an active forcing should become standard practice in palaeo-ice-sheet modelling.

show abstract

North Atlantic warming and the retreat of Greenland's outlet glaciers

Cited by 403 publications

References 99 publications

Resistance of Arctic phytoplankton to ocean acidification and enhanced irradiance

Resistance of Arctic phytoplankton to ocean acidification and enhanced irradiance

Ice–ocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers

The sensitivity of the Greenland Ice Sheet to glacial–interglacial oceanic forcing

Contact Info

Product

Resources

About