Investigating controls on flow variability in Greenland's tidewater glaciers: the impact of runoff on fjord circulation and termini melt rates

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Geosciences

Abstract

The greatest store of fresh water in the northern hemisphere - equivalent to ~7m of sea level rise - is held within the Greenland Ice Sheet (GrIS). In the last decade, it has become clear that the ice sheet is losing mass and has become a significant contributor to global sea-level rise. The rate of mass loss has accelerated in the last decade and the ice sheet is now contributing about 1 mm/yr to sea level rise. This behaviour is a result of: 1) dramatic increases in the speed of many large outlet ('tidewater') glaciers, thereby increasing ice flux to the sea; and 2) substantial increases in both melt rates and the area of the ice sheet experiencing summer melting thereby increasing runoff from the ice-sheet surface to the ocean. These increases in ice motion and surface melt rate have been linked with warmer air and ocean temperatures over and around Greenland. A major concern for policymakers, society and scientists is how the GrIS will continue to react to the temperature rises that are predicted during the coming centuries. However, to better understand ice sheet sensitivity to projected global warming, the processes which affect how ocean terminating glaciers flow and discharge into the sea must be better understood.

This project will improve our understanding of why tidewater glaciers are losing mass at an accelerating rate. Recent observations suggest warmer ocean temperatures have resulted in tidewater glacier acceleration through a process known as 'dynamic thinning'; here warm ocean waters access the front of tidewater glaciers causing them to thin by enhanced melting and to retreat through increased rates of iceberg calving. However, while ocean waters off the coast of Greenland have warmed in the last decade, it is unclear how these warm waters actually access the front of glaciers which are often located at the head of long narrow fjords tens of kilometres from the warm ocean shelf waters. An increasingly popular theory contends that summer meltwater runoff from the glaciers establishes fjord circulation whereby strong ouflow of meltwater down the fjord sets up an opposing flow drawing in the warm water from the coastal shelf. As the runoff increases, the fjord circulation strength and thus volume of warm offshore water drawn into the fjord also increases. This theory is supported by some observations of water flow and temperature in fjords but the sensitivity of the process has not been tested.

This proposal aims to address this limitation by investigating how variations in glacial runoff perturb fjord circulation and thus the submarine melt rate and dynamic behaviour of tidewater glaciers. More specifically, the project will use a previously tested model (the Bergen Ocean Model (BOM)) to determine how variations in fjord geometry and meltwater runoff affect the seasonal delivery of 'warm' shelf waters to the marine termini of tidewater glaciers. The project will achieve this by:

1) Running a suite of fjord modeling experiments using a range of synthetic model parameters and boundary conditions (e.g. fjord geometry (length, width, depth); runoff volume; coastal ocean temperature) which will be varied systematically to establish the sensitivity of along-fjord heat transportation (and thus tidewater terminus melt-rates) to the different parameters.

2) Investigating the extent to which decadal (2000-2009) changes in glacier runoff and offshore ocean temperatures can explain observed changes in glacier margin position at ten tidewater glaciers along Greenland's east coast

3) Investigating how projected ocean and atmospheric warming by 2100 will affect the along-fjord heat transportation and thus terminus melt-rates at our ten 'test-case' glaciers.

Through the delivery of these objectives, the project will make a fundamental contribution to our understanding of how the GrIS will likely respond dynamically to future climate change and specifically, changes in atmospheric and ocean temperatures.

Planned Impact

1. Potential users

a) Environmental agencies with statutory duties to monitor and plan for flooding risk (e.g. Environment Agency, Scottish Environmental Protection Agency (SEPA)). The outcomes from the proposed research (advancing our understanding of future Greenland Ice Sheet (GrIS) ice loss and sea level contributions) could be used to predict UK coastal flooding.

b) Environmental Protection (UK) to ensure that their lobbying role is well informed in terms of current activities and research outcomes in the area of climate change and sea level rise. Information sources for government, politicians and policy-makers (e.g. SPICE - Scottish parliamentary information resource to provide briefing notes to MSPs).

c) The Scottish Government's Coordinated Agenda for Marine, Environment and Rural Affairs Science (CAMERAS).

d) Scotland and Northern Ireland Forum For Environmental Research (SNIFFER) and the Scottish Climate Change Impacts Partnership (SCCIP) which aims to increase the resilience of organisations and infrastructure in Scotland to meet the challenges and opportunities presented by the impacts of climate change.

e) General public: sea level rise will affect everyone. Nienow has given numerous public talks and interviews with the media on ice sheet stability and sea level rise including presenting at the British Science Festival in Aberdeen in 2012.

f) Learned societies who are involved in reviewing the state of the scientific evidence base and providing advice to policy-makers, including The Royal Society, the Royal Society of Edinburgh, the Royal Geographical Society (with Institute of British Geographers), the Royal Scottish Geographical Society and the Scottish Hydrological Society (who Nienow has already given an invited talk to on Greenland Ice Sheet hydrology and dynamics).

2. Specific/existing links
a) The proposed meeting between with the Scottish Government's environmental policy makers and their science advisors will build on the relationship between Alliance for Geoscience, Environment and Society (SAGES) and the Scottish Government.

b) The Dynamic Earth Exhibition follows a successful exhibition organized by Sole and Cowton in 2011, and will build on the existing good working relationship between Dynamic Earth and the School of Geosciences at the University of Edinburgh (see LoS from Dynamic Earth).

c) The proposed Climate Change Workshop at the RGS will build on an existing relationship since Sole ran a similar workshop for secondary school children at the RGS as part of Science Week in 2007 focusing on the role of the cryosphere in the climate system.

3. Economic impacts
a) Furthering our understanding of future GrIS ice loss will reduce uncertainties associated with predictions of sea level rise allowing more effective planning and protection against coastal flooding in low-lying areas such as South East Asia, small islands in the Pacific, and coastal cities, such as Mumbai and London.

b) Improving our understanding of how the GrIS will respond to climate change will enable more robust predictions of potential changes to the North Atlantic thermo-haline circulation which ultimately provides the UK with warmer temperatures than other regions at comparable latitudes. This will inform planning for significant shifts in the UK's climate.

4. Public policy or legislatory impacts
a) Evidence-based policy making: The proposed meeting between with the Scottish Government's environmental policy makers and their science advisors will provide a forum for the research findings to be presented directly to policy makers.

5. Quality of life and public good impacts
a) Increasing public engagement with research and related societal issues. The Dynamic Earth exhibition and Cafe Scientifique session will present the research findings in an engaging and understandable manner. It is hoped that this will help to engage the general public and lead to changes in their daily routines.

Publications

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publication icon
Cowton TR (2018) Linear response of east Greenland's tidewater glaciers to ocean/atmosphere warming. in Proceedings of the National Academy of Sciences of the United States of America

 
Title Science advisor for the documentary film 'Aquarela' 
Description A film by Aconite Productions and iconic Russian director Victor Kossakovsky about the power, beauty and potentially destructive nature of water in all its forms - with the inevitable links to climate change and environmental warnings. I acted as a scientific (and location) advisor for the glacier and iceberg content of the documentary filmed in Greenland, I am in the credits as a Science Advisor and was invited to the film premier (attending the UK premiere in Glasgow). 
Type Of Art Film/Video/Animation 
Year Produced 2018 
Impact The film premiered at the Venice International film festival. In the UK, it premiered at the Glasgow film festival in Feb 2019. 
URL https://www.scottishfield.co.uk/culture/whatson/enjoy-the-wonders-of-nature-in-the-winter/
 
Description Greenland's marine-terminating glaciers may be sensitive to variation in the availability of oceanic heat, but the fjord processes controlling the delivery of this heat to the glacier termini remain poorly constrained. We have used MITgcm and IcePlume (Cowton et al., 2015) to model Kangerdlugssuaq Fjord, east Greenland, to examine controls on the exchange of water between the fjord and shelf. We have found that intermediary circulation resulting from fluctuations in the depth of isopycnals on the shelf (as generated by coastal winds) can replace up to ~ 25 % of the fjord volume with water from the shelf in < 10 days. This exchange is however limited to the outer reaches of the fjord, and does not transport water from the shelf to the fjord head on seasonal timescales. We have found that buoyancy-driven circulation, forced by the input of subglacial runoff from marine-terminating glaciers, results in an exchange rate between fjord and shelf ~ 10-100x greater than the runoff input. Although the intermediary circulation can generate higher peak exchange rates between the fjord and shelf, the buoyancy-driven circulation is more consistent over time and so more effective at drawing water from the shelf to the fjord head, which occurs on sub-seasonal timescales. This suggests that an increase in shelf water temperatures and more vigorous buoyancy-driven circulation (due to higher ice sheet surface melt rates) caused the mean rate of heat delivery to Kangerdlugssuaq Glacier to increase by ~ 50 % between 1993-2001 and 2002-2011, broadly coincident with the onset of rapid terminus retreat at this glacier.
Previous work as part of NE/K014609/1 (Slater et al., 2015) has shown that the spatial pattern and magnitude of submarine ice melt depends on the distribution of ice sheet runoff at marine-terminating glacier grounding lines. However, we know very little about the near-terminus subglacial hydrology that controls this. Theoretical plume models can be used to determine the discharge rate required for a single plume to reach the fjord surface given a certain water depth and fjord stratification. If we know the water depth, stratification and total glacier runoff, we can use time-lapse imagery of plume visibility to constrain the number of channels out of which the ice sheet runoff is emerging. For example, if the runoff from a single channel required for a plume to reach the surface is 30 m3s-1, and the total glacier runoff is 100 m3s-1, but we see no plume at the fjord surface, we can infer there must be more than three channels. Using this idea, and time-lapse imagery from Kangiata Nunata Sermia (a large marine-terminating glacier in south west Greenland) we have shown that the near-terminus subglacial drainage system is only channelized for a limited time around the peak melt period. For the rest of the time, the lack of visible plumes suggests that the distribution of runoff at the grounding line is more distributed. This has implications both for the magnitude and spatial pattern of submarine melt rate (Slater et al. 2015) as well as the relationship between ice surface melt and ice motion. This work is currently being prepared as a paper (Slater et al., in prep).
We have used IcePlume (Cowton et al., 2015) and MITgcm to simulate the effect on nutrients and primary productivity (PP) of changes in subglacial injection of freshwater into an idealised Greenlandic fjord. We have found that increased subglacial runoff substantially enhances fjord and coastal PP because the resulting buoyant plumes entrain deep nutrient-rich waters and bring them into the photic zone (rather like classic wind-driven coastal upwelling). This leads to a late summer/early autumn spike in productivity (in addition to the typical spring 'bloom' related to light availability) that has been observed at the mouth of Godthabsfjord in south west Greenland and is evident in remotely sensed (MODIS AQUA) ocean colour data. This work was presented at the American Geophysical Union Fall Meeting and is currently being prepared as a paper (Sole et al., in prep).

UPDATE March 2017
The research for this grant uses the widely used Massachusetts Institute of Technology General Circulation Model (MITgcm) to model ice ocean interactions in glacial fjords.


1. MITgcm is used to simulate the upwelling driven by the injection into a fjord of meltwater draining from beneath a marine-terminating (tidewater) glacier. While it is known that this upwelling can stimulate enhanced melting of the submerged glacier front, there has as yet been little consideration of how this process might be influenced by the spatial distribution of meltwater emerging at the glacier grounding line. We find that the distribution of meltwater input from the glacier exerts an important control on submarine melting; under certain conditions a spatially distributed subglacial drainage system can induce an order of magnitude more melt than a system in which meltwater is concentrated into discrete subglacial channels. Furthermore, plumes emerging from a single channel are unable, in isolation, to drive large melt volumes even at high discharges, while even small discharges from a distributed system can induce substantial melt. Our results highlight the need to constrain near-terminus subglacial hydrology at tidewater glaciers if we are to represent ocean forcing accurately. This work has been published: Slater, D. A., P. W. Nienow, T. R. Cowton, D. N. Goldberg, and A. J. Sole (2015), Effect of near-terminus subglacial hydrology on tidewater glacier submarine melt rates, Geophysical Research Letters, 42, doi:10.1002/2014GL062494
2. We have developed IcePlume: a sub grid-scale buoyant plume parameterisation for the MITgcm. This development enables three-dimensional simulation of large (>500 km2) glacial fjords on annual to decadal timescales. Previously this was computationally impractical because it was necessary to incorporate both the fine scale, highly non-hydrostatic dynamics of the turbulent glacial outflow plume as well as the wider circulation of fjords that may be hundreds of square kilometres in area. IcePlume is detailed in a manuscript which has now been published: T. Cowton, D. A. Slater, A. J. Sole, D. N. Goldberg, and P. W. Nienow (2015) Modeling the impact of glacial runoff on fjord circulation and submarine melt rate using a new subgrid-scale parameterization for glacial plumes. Journal of Geophysical Research Oceans, 120, doi:10.1002/2014JC010324.

Initial results from this work show that for an idealised fjord of typical Greenlandic dimensions (without shelf-driven circulation), subglacial runoff produces a thin, strong and warm down-fjord current in the upper part of the water column, balanced by a thick and slow up-fjord current at greater depth. Submarine melt rates increase with runoff due to higher melt rates where the plume is in contact with the ice front. Annual submarine melt rate across the whole ice front is however relatively insensitive to variability in annual runoff, indicating that atmospheric warming may be of secondary importance to oceanic warming with respect to the stability of Greenland's marine-terminating glaciers.

3. We have also obtained 17 years of 1/4o ocean reanalysed ocean data from Mercator Ocean http://www.mercator-ocean.fr/eng for the ocean surrounding Greenland. This product will be used to characterise forcing for longer duration simulations of actual Greenlandic fjords using MITgcm with IcePlume.

4. Greenland's marine-terminating glaciers may be sensitive to variation in the availability of oceanic heat, but the fjord processes controlling the delivery of this heat to the glacier termini remain poorly constrained. We have used MITgcm and IcePlume (Cowton et al., 2015) to model Kangerdlugssuaq Fjord, east Greenland, to examine controls on the exchange of water between the fjord and shelf. We have found that intermediary circulation resulting from fluctuations in the depth of isopycnals on the shelf (as generated by coastal winds) can replace up to ~ 25 % of the fjord volume with water from the shelf in < 10 days. This exchange is however limited to the outer reaches of the fjord, and does not transport water from the shelf to the fjord head on seasonal timescales. We have found that buoyancy-driven circulation, forced by the input of subglacial runoff from marine-terminating glaciers, results in an exchange rate between fjord and shelf ~ 10-100 times greater than the runoff input. Although the intermediary circulation can generate higher peak exchange rates between the fjord and shelf, the buoyancy-driven circulation is more consistent over time and so more effective at drawing water from the shelf to the fjord head, which occurs on sub-seasonal timescales. This suggests that an increase in shelf water temperatures and more vigorous buoyancy-driven circulation (due to higher ice sheet surface melt rates) caused the mean rate of heat delivery to Kangerdlugssuaq Glacier to increase by ~ 50 % between 1993-2001 and 2002-2011, broadly coincident with the onset of terminus retreat at this glacier. This work has now been published: Cowton, T., Sole, A., Nienow, P., Slater, D., Wilton, D. & Hanna, E. (2016) Controls on the transport of oceanic heat to Kangerdlugssuaq Glacier, East Greenland, J. Glaciology, 62, 1167-1180.

5. Previous work as part of NE/K014609/1 (Slater et al., 2015) has shown that the spatial pattern and magnitude of submarine ice melt depends on the distribution of ice sheet runoff at marine-terminating glacier grounding lines. However, we know very little about the near-terminus subglacial hydrology that controls this. Theoretical plume models can be used to determine the discharge rate required for a single plume to reach the fjord surface given a certain water depth and fjord stratification. If we know the water depth, stratification and total glacier runoff, we can use time-lapse imagery of plume visibility to constrain the number of channels out of which the ice sheet runoff is emerging. For example, if the runoff from a single channel required for a plume to reach the surface is 30 m3s-1, and the total glacier runoff is 100 m3s-1, but we see no plume at the fjord surface, we can infer there must be more than three channels. Using this idea, and time-lapse imagery from Kangiata Nunata Sermia (a large marine-terminating glacier in south west Greenland) we have shown that the near-terminus subglacial drainage system is only channelized for a limited time around the peak melt period. For the rest of the time, the lack of visible plumes suggests that the distribution of runoff at the grounding line is more distributed. This has implications both for the magnitude and spatial pattern of submarine melt rate (Slater et al. 2015) as well as the relationship between ice surface melt and ice motion. This work has now been published: Slater, D., Nienow, P., Sole, A., Cowton, T., Mottram, R., Langen, P., & Mair, D. (2017). Spatially distributed runoff at the grounding line of a large Greenlandic tidewater glacier inferred from plume modelling. Journal of Glaciology, 1-15. doi:10.1017/jog.2016.139

6. We have used IcePlume (Cowton et al., 2015) and MITgcm to simulate the effect on nutrients and primary productivity (PP) of changes in subglacial injection of freshwater into an idealised Greenlandic fjord. We have found that increased subglacial runoff substantially enhances fjord and coastal PP because the resulting buoyant plumes entrain deep nutrient-rich waters and bring them into the photic zone (rather like classic wind-driven coastal upwelling). This leads to a late summer/early autumn spike in productivity (in addition to the typical spring 'bloom' related to light availability) that has been observed at the mouth of Godthabsfjord in south west Greenland and is evident in remotely sensed (MODIS AQUA) ocean colour data. This work was presented at the American Geophysical Union Fall Meeting and is currently being prepared as a paper (Sole et al., in prep).

7. Submarine ice melt induced by buoyant glacial plumes is often assumed to scale with subglacial runoff discharge into the plume to the power of 1/3. Using buoyant plume theory, we have shown that for buoyant plumes of either line of point source geometry, this relationship holds as long as the discharge remains below a critical value. Above this value, the relationship changes, but melt rates can nevertheless be estimated as a function of discharge, fjord temperature, and calving front height. In linearly stratified fjords, a good approximation of many fjords in Greenland, the exponent increases to ¾ for a point source plume, and 2/3 for a line source plume. This work is published in: Slater, D., D. Goldberg, P. Nienow and T. Cowton (2016), Scalings for submarine melting at tidewater glaciers from buoyant plume theory, J. Phys. Oceanography, doi: 10.1175/JPO-D-15-0132.1

8. We have used plume theory to derive a relationship between glacier runoff, calving front depth and up-fjord volume flux which results from the buoyancy-driven circulation set up by plumes at the glacier calving front. Combined with knowledge of shelf ocean temperatures, this volume flux can be converted into an ocean heat flux. We have shown that over a 20 year period at 10 tidewater glacier-fjord systems along Greenland's east coast, variations in the magnitude of this heat flux can explain 70 % of the variability in tidewater glacier front positions. Our findings indicate that despite the complexity of tidewater glacier behaviour, over multi-year time scales a significant proportion of terminus position change can be explained as a simple function of key environmental variables. This work will be submitted shortly to Nature Communications T.R. Cowton, A.J. Sole, P.W. Nienow and D.A. Slater (in prep). Linear response of east Greenland's tidewater glaciers to climate forcing. Nature Communications.

Our IcePlume model has been used in several grant applications:

? ERC Starting Grant, 1.7 M Euro. PI Andrew Sole. Submitted October 2016. 'Productivity and air-sea CO2 exchange in southwest Greenland waters: the influence of ice sheet runoff (PROGRES)'
NERC Standard Grant, $439k, PI Peter Nienow. Submitted Jan 2017. Investigating tidewater glacier and iceberg submarine melt rates in Greenland's fjords?
NERC Large Grant, £3.5 M. PI Grant Bigg (University of Sheffield). Submitted March 2017. 'Iceberg calving and runoff - linking the Greenland Ice Sheet to regional seas and the Atlantic (ILULISSAT)'
? NERC Large Grant, £3.5 M. PI Nick Kamenos (University of Glasgow). Submitted March 2017. 'Glacially-driven inshore Arctic marine production (GLEAM)'
Exploitation Route We have started the process of submitting IcePlume to become an official part of MITgcm. This takes some time as conflicts with other modules must be identified and solved. In the meantime, several MITgcm developers/users are utilising IcePlume. For example Dustin Carroll (University of Oregon), Neil Fraser (SAMS). We expect this tool to be used extensively by glaciologists and oceanographers interested in ice-ocean interactions, particularly in Greenland, Alaska and Arctic Canada. This will lead both to developments of the parameterisation and its incorporation into larger-scale models which seek to simulate the future mass balance (and thus sea level contribution) of glaciers and ice sheets.

Results from the near-terminus hydrology work highlight the need to constrain near-terminus subglacial hydrology at tidewater glaciers if we are to simulate ocean forcing accurately. This novel finding will likely encourage glacial hydrologists and oceanographers alike to improve the representation of these processes in ice sheet and ice-ocean interaction models.

The two papers published so far as part of NE/K014609/1 have been cited several times:
Cowton et al. (2015): 6 citations as of 6/3/2016
Slater et al. (2015): 2 citations as of 6/3/2016

MARCH 2017 Update
The six papers published so far have been cited as follows:
Cowton et al. (2015): 7 (Scopus) citations as of 8/3/2017
Slater et al. (2015): 17 (Scopus) citations as of 8/3/2017
Cowton et al (2016): none yet
Slater et al (2016): 2 citations as of 8/3/2017
Slater et al (2017a): none yet
Slater et al (2017b): none yet

March 2019 UPDATE
The eight key papers published as part of NE/K014609/1 have continued to gain citations (google scholar):
Cowton et al. (2015): 51 citations as of 12/3/2019
Slater et al. (2015): 57 citations as of 12/3/2019
Cowton et al (2016): 16 citations as of 12/3/2019
Slater et al (2016): 23 citations as of 12/3/2019
Slater et al (2017a): 18 citations as of 12/3/2019
Slater et al (2017b): 16 citations as of 12/3/2019
Nienow et al 2017: 12 citations as of 12/3/2019
Cowton et al (2018): 2 citation as of 15/2/2019

MARCH 2021 Update
The 'iceplume' package developed in this grant has been developed further and is now being used to investigate the melt of icebergs in Greenlandic fjords.
e.g. Davidson et al, 2020. Nat. Communications, https://doi.org/10.1038/s41467-020-19805-7

The modelling developments during this grant have been utilised by Dr Donald Slater and he has now been awarded a NERC Independent Research Fellowship, starting at the University of Edinburgh in March 2022 investigating ice-ocean interactions in Greenland.

Eight key papers published as part of NE/K014609/1 have continued to gain citations (data from Scopus):
Cowton et al. (2015): 58 citations as of 9/3/2021
Slater et al. (2015): 68 citations as of 9/3/2021
Cowton et al (2016): 19 citations as of 9/3/2021
Slater et al (2016): 41 citations as of 9/3/2021
Slater et al (2017a): 23 citations as of 9/3/2021
Slater et al (2017b): 25 citations as of 9/3/2021
Nienow et al 2017: 27 citations as of 9/3/2021
Cowton et al (2018): 19 citation as of 9/3/2021
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Education,Environment

URL https://www.donaldslaterglaciers.com/research
 
Description Please see various boxes above with respect to Nienow's contribution to the Arctic Circle Assembly (http://www.arcticcircle.org/assemblies/2016) via the Scottish Government's chief scientific adviser (see more detailed description in 6. Influence on Policy, Practice, Patients & the Public)
First Year Of Impact 2016
Sector Other
Impact Types Societal

 
Description Feedback to the Chief Scientific Adviser Rural Affairs and Environment for The Scottish Government
Geographic Reach Multiple continents/international 
Policy Influence Type Gave evidence to a government review
 
Description Edinburgh University PhD Scholarships
Amount £60,000 (GBP)
Organisation University of Edinburgh 
Sector Academic/University
Country United Kingdom
Start 01/2016 
End 12/2018
 
Description NERC E3 DTP studentship
Amount £80,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2016 
End 08/2020
 
Description Scottish Alliance for Geoscience, Environment and Society (SAGES)
Amount £60,000 (GBP)
Organisation Scottish Alliance for Geoscience, Environment and Society (SAGES) 
Sector Academic/University
Country United Kingdom
Start 09/2017 
End 02/2025
 
Title Observed terminus position and modelled ocean temperature, air temperature and runoff for 10 tidewater glaciers in east Greenland, 1990-2015 
Description The data consists of observed terminus position and modelled ocean temperature, air temperature and runoff for 10 tidewater glaciers in east Greenland, 1990-2015. The glaciers are (listed from south to north) Mogens 3, Tingmjarmiut 1, AP Bernstorffs Glacier, Helheim Glacier, Kangerdlugssuaq Glacier, Borggraven, Vestfjord Glacier, Daugaard-Jensen Glacier, Waltershausen Glacier, Heinkel Glacier. Values are given as annual means. Glacier terminus positions are derived directly from remote sensing observations. Ocean temperature is based on the mean 200-400m temperature from GLORYS2V3 1/4 deg ocean reanalysis, obtained from the nearest cell of sufficient depth and adjusted to better agree with available in situ observations. Air temperature is based on the May-September mean of monthly temperatures from European Reanalysis (ERA)-Interim global atmospheric reanalysis, while Q is obtained from a 1-km surface melting, retention, and runoff model forced using ERA-Interim reanalysis. These data were compiled to study the relationship between environmental forcings and tidewater glacier retreat in east Greenland, as published by Cowton et al (2018). 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
 
Description DMI melt model collaboration 
Organisation Danish Meteorological Institute (DMI)
Country Denmark 
Sector Public 
PI Contribution Ruth Mottram and Peter Langen (Danish Meteorological Institute) provided ice sheet surface mass balance model output for use in a paper (Slater, D., Nienow, P., Sole, A., Cowton, T., Mottram, R., Langen, P. and Mair. D. 2017. Spatially distributed runoff at the grounding line of a large Greenlandic tidewater glacier inferred from plume modelling, Journal of Glaciology, doi: 10.1017/jog.2016.139.) relating plume visibility at the fjord surface, ice sheet runoff and near-terminus subglacial hydrology.
Collaborator Contribution Ruth Mottram and Peter Langen (Danish Meteorological Institute) provided ice sheet surface mass balance model output for use in a paper (Slater, D., Nienow, P., Sole, A., Cowton, T., Mottram, R., Langen, P. and Mair. D. 2017. Spatially distributed runoff at the grounding line of a large Greenlandic tidewater glacier inferred from plume modelling, Journal of Glaciology, doi: 10.1017/jog.2016.139.) relating plume visibility at the fjord surface, ice sheet runoff and near-terminus subglacial hydrology.
Impact Slater, D., Nienow, P., Sole, A., Cowton, T., Mottram, R., Langen, P. and Mair. D. 2017. Spatially distributed runoff at the grounding line of a large Greenlandic tidewater glacier inferred from plume modelling, Journal of Glaciology, doi: 10.1017/jog.2016.139.
Start Year 2015
 
Description Nuuk Tidewater glacier interaction 
Organisation Greenland Institute of Natural Resources
Country Greenland 
Sector Public 
PI Contribution In Sept 2016, Nienow and Sole were invited to GNIR/ASIAQ in Nuuk, Greenland, to talk about their research in Greenland associated with this grant. This has led to ongoing discussions between us and colleagues in Nuuk about future work in Greenland (including work incorporated in the imminent GLEAM NERC large grant submission (see elsewhere)).
Collaborator Contribution In Sept 2016, Nienow and Sole were invited to GNIR/ASIAQ in Nuuk, Greenland, to talk about their research in Greenland associated with this grant. This has led to ongoing discussions between us and colleagues in Nuuk about future work in Greenland (including work incorporated in the imminent GLEAM NERC large grant submission (see elsewhere)).
Impact A NERC Large Grant outline bid, £3.5 M. PI Nick Kamenos (University of Glasgow). Submitted March 2017. 'Glacially-driven inshore Arctic marine production (GLEAM)' with PP from GINR
Start Year 2016
 
Description Sheffield runoff modelling 
Organisation University of Sheffield
Country United Kingdom 
Sector Academic/University 
PI Contribution As part of the modelling experiments, an effective collaboration was developed with Prof Edward Hanna (now at the University of Lincoln) and Dr David Wilton (University of Sheffield), who provided newly-developed high resolution surface melt model outputs from which to calculate runoff inputs to the fjord. This collaboration formed an important part of one publication (Cowton et al, 2016, Journal of Glaciology v62) and two conference presentations (AGU 2015; IGS Symposium on Ice Sheet Dynamics).
Collaborator Contribution As part of the modelling experiments, an effective collaboration was developed with Prof Edward Hanna (now at the University of Lincoln) and Dr David Wilton (University of Sheffield), who provided newly-developed high resolution surface melt model outputs from which to calculate runoff inputs to the fjord. This collaboration formed an important part of one publication (Cowton et al, 2016, Journal of Glaciology v62) and two conference presentations (AGU 2015; IGS Symposium on Ice Sheet Dynamics).
Impact Cowton, T., Sole, A., Nienow, P., Slater, D., Wilton, D. and Hanna, E. 2016. Controls on the transport of oceanic heat to Kangerdlugssuaq Glacier, east Greenland, Journal of Glaciology, 62(236) 1167-1180 doi: 10.1017/jog.2016.117.
Start Year 2015
 
Description Tidewater glacier collaborations 
Organisation University of St Andrews
Department School of Geography & Geosciences
Country United Kingdom 
Sector Academic/University 
PI Contribution Expertise developed during the project has led to the development of collaboration between Tom Cowton and Prof Doug Benn (University of St Andrews) and Prof Adrian Luckman (University of Swansea) to examine the role of submarine melting as a driver of calving at tidewater glaciers. This has culminated in the successful application for NERC funding for a new 3-year project Calving Laws for Ice Sheet Models (CALISMO; £764,330), to start April 2017. Similarly, Tom Cowton has developed a role as a collaborator on the TIGRIF project led by Dr Jack Kohler of the Norwegian Polar Institute, investigating the importance of marine terminating glaciers for fjord ecosystems. In this capacity he has attended project meetings in Tromsø, Norway, and is working with Paul Budgell (Institute of Marine Resources, Norway) and Alistair Everett (Norwegian Polar Institute) to improve their capacity to include glacially-driven plumes in their fjord modelling set-up.
Collaborator Contribution Expertise developed during the project has led to the development of collaboration between Tom Cowton and Prof Doug Benn (University of St Andrews) and Prof Adrian Luckman (University of Swansea) to examine the role of submarine melting as a driver of calving at tidewater glaciers. This has culminated in the successful application for NERC funding for a new 3-year project Calving Laws for Ice Sheet Models (CALISMO; £764,330), to start April 2017. Similarly, Tom Cowton has developed a role as a collaborator on the TIGRIF project led by Dr Jack Kohler of the Norwegian Polar Institute, investigating the importance of marine terminating glaciers for fjord ecosystems. In this capacity he has attended project meetings in Tromsø, Norway, and is working with Paul Budgell (Institute of Marine Resources, Norway) and Alistair Everett (Norwegian Polar Institute) to improve their capacity to include glacially-driven plumes in their fjord modelling set-up.
Impact NERC funding for a new 3-year project Calving Laws for Ice Sheet Models (CALISMO; £764,330), to start April 2017.
Start Year 2016
 
Description WHOI 
Organisation Woods Hole Oceanographic Institution
Country United States 
Sector Charity/Non Profit 
PI Contribution As a result of this grant and the modelling work related to MITgcm, Donald Slater, a NERC funded PhD student working as part of our wider team conducted a two month exchange visit to Woods Hole Oceanographic Institute (WHOI), USA, to work with Fiamma Stranneo, a world leader in ice-ocean interactions. The work is now nearing completion and journal submission and is being presented at the upcoming EGU conference in Vienna as contribution EGU2017-8326; "Fjord circulation promotes significant glacier-wide submarine melting at a west Greenland tidewater glacier". The initial collaboration started through Peter Nienow's involvement, from 2014, on the Acting Committee of the US led Greenland Ice Sheet Ocean Science Network (GRISO).
Collaborator Contribution As a result of this grant and the modelling work related to MITgcm, Donald Slater, a NERC funded PhD student working as part of our wider team conducted a two month exchange visit to Woods Hole Oceanographic Institute (WHOI), USA, to work with Fiamma Stranneo, a world leader in ice-ocean interactions. The work is now nearing completion and journal submission and is being presented at the upcoming EGU conference in Vienna as contribution EGU2017-8326; "Fjord circulation promotes significant glacier-wide submarine melting at a west Greenland tidewater glacier".
Impact Fjord circulation promotes significant glacier-wide submarine melting at a west Greenland tidewater glacier Donald A. Slater (1), Fiamma Straneo (2), Sarah B. Das (2), and Peter W. Nienow (1) 1 - GeoSciences, Edinburgh, UK 2 - WHOI, USA
Start Year 2014
 
Title IcePlume 
Description We have developed IcePlume: a sub grid-scale buoyant plume parameterisation for the widely used Massachusetts Institute of Technology General Circulation Model (MITgcm). IcePlume is detailed in a manuscript currently under review in the Journal of Geophysical Research - Oceans, entitled 'Modeling the impact of glacial runoff on fjord circulation and submarine melt rate using a new subgrid-scale parameterization for glacial plumes'. This development enables three-dimensional simulation of large (500 km2) glacial fjords on annual to decadal timescales. Previously this was computationally impractical because it was necessary to incorporate both the fine scale, highly non-hydrostatic dynamics of the turbulent glacial outflow plume as well as the wider circulation of fjords that may be hundreds of square kilometres in area. 
Type Of Technology Software 
Year Produced 2015 
Open Source License? Yes  
Impact The software has been used by a number of leading groups investigating the impact of fjord circulation on tidewater glacier terminus melt and behaviour 
 
Description Boat of Garten 'Boat talks' - 'The stability of the Greenland Ice Sheet' 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I was invited to give a talk to the series of talks at Boat of Garten entitled 'Boat talks' - 'The stability of the Greenland Ice Sheet'
Year(s) Of Engagement Activity 2018
URL https://www.eventbrite.co.uk/e/boat-talks-the-stability-of-the-greenland-ice-sheet-with-professor-pe...
 
Description Exhibitions at our Dynamic Earth, Edinburgh 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact We undertook two outreach events to showcase our research to the public at the geosciences museum Our Dynamic Earth in Edinburgh. The first of these (March 15th, 2016) was attended by a number of secondary school groups, while the second (October 16-17th 2016) was aimed at families. We presented images and videos to showcase our research, and discussed the underlying science and policy questions with visitors to the exhibition.
Year(s) Of Engagement Activity 2016
 
Description Midlothian Science Festival talk at IKEA - 'The Greenland Ice Sheet in a warming world'. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact About 30 members of the public attended my talk, 'The Greenland Ice Sheet in a warming world' at IKEA as part of the Midlothian Science Festival.
Year(s) Of Engagement Activity 2018
URL https://midlothiansciencefestival.com/event/climate-change-greenlands-ice-sheet/
 
Description Research seminar 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Seminar to Bristol University School of Geography on Greenland research and tidewater glaciers
Year(s) Of Engagement Activity 2020
 
Description Royal Society of Edinburgh - 'Winter Wonders' public event - talk and discussion. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Royal Society of Edinburgh - 'Winter Wonders' public event - talk and discussion. Invited talk with Prof David Sugden whom spoke about Antartica, I spoke about the Greenland Ice Sheet and we discussed and answered questions from the floor.
Year(s) Of Engagement Activity 2018
URL https://www.scottishfield.co.uk/culture/whatson/enjoy-the-wonders-of-nature-in-the-winter/
 
Description Royal Society of Edinburgh public outreach talk event 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact It was a presentation and then open debate, with questions on climate change, with my role as an expert on glacier and ice sheet change in a warming world.

The open public event was held by the Royal Society of Edinburgh and hosted online. More details at https://www.rse-curious.com/our-planet-panel/
Year(s) Of Engagement Activity 2020
URL https://www.rse-curious.com/our-planet-panel/
 
Description Science advisor to "Aquarela", a cinematic climate science documentary 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I contributed expert glacial knowledge to the film/documentary 'Aquarela' on water, ice and climate change - I am acknowledged in the credits and attended the UK premier as a guest
Year(s) Of Engagement Activity 2019
URL https://www.theguardian.com/film/2019/dec/11/aquarela-review-victor-kossakovsky-climate-crisis-docum...
 
Description Talk at Art Festival 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Talk and panellist at Sonica-Cryptic Art Festival, Glasgow Centre for Contemporary Art (CCA) - 'Are we at the Tipping Point?'. Talk focussed on whether the Greenland Ice Sheet is at a tipping point regarding ice mass loss in response to climate change. The talk and panel was linked to an art installation at the Sonica-Cryptic Art Festival by artist Kathy Hinde that was addressing ice mass loss and climate change issues. The Art Festival wanted a scientist to discuss the issues regarding ice mass loss and climate change.
Year(s) Of Engagement Activity 2017
URL http://sonic-a.co.uk/talks-tours-workshops/
 
Description Talk at Kingussie High School - 'Climate change, ice-sheets and satellites' 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Invited talk at Kingussie High School to their S4 and S5 Geography Higher class - 'Climate change, ice-sheets and satellites'
Year(s) Of Engagement Activity 2019
 
Description Talk at a science festival 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Evening talk at IKEA, Edinburgh as part of the Midlothian Science Festival entitled 'Science in Extreme Conditions'. Talk focussed on investigations of Greenland Ice Sheet stability, especially with respect to the importance of collecting hard won field based data sets to support the science.
Year(s) Of Engagement Activity 2017
 
Description Talk to the Probus Club of Lomond, Drymen - 'The stability of the Greenland Ice Sheet' 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Invited to give a talk to the Probus Club of Lomond in Drymen, Scotland - talk title 'The stability of the Greenland Ice Sheet'
Year(s) Of Engagement Activity 2018