iSTAR-D: The contribution to sea-level rise from the Amundsen Sea sector of Antarctica

Lead Research Organisation: NERC British Antarctic Survey
Department Name: Science Programmes

Abstract

The notions of a warming climate, melting ice and rising sea levels are firmly rooted in the public consciousness. In fact, today, while sea level is rising at some 3 cm per decade, the great ice sheets of Greenland and Antarctica are only contributing a small component, perhaps some 0.5 cm per decade. Nonetheless, it is also established that their contribution to sea level rise is accelerating, by perhaps as much as 0.1 cm per year. In Antarctica, this acceleration is result, in part, of the warming Antarctic Peninsula, but of greater concern, because of the vast quantities of ice backed up in their basins, are the Amundsen sector ice streams; one of which, the Pine Island Glacier, has quadrupled its mass loss in the past decade. What we know about the behaviour of these large ice sheets has been established over the past two decades through measurements from successive Earth-orbiting satellites: ERS-1, ERS-2, ENVISAT, GRACE and most recently CryoSat-2. Equally, the satellite estimates remain uncertain; an uncertainty that, as concern increases as to the magnitude of the rising contribution, it is increasingly important to close down. This proposal aims to attack this problem directly for the Amundsen sector ice streams.

The uncertainties arise because the satellites do not directly observe the mass loss of the ice sheets. There are three different instruments and techniques, satellite altimetry, satellite gravimetry, and SAR interferometry, and each of them contains a bete noir. Satellite altimetry measurements cannot distinguish changes in density from changes in mass. Satellite gravimetry cannot distinguish those changes due to mass loss from the ice from those due to the motion of the underlying solid Earth. SAR interferometry is reliant on an uncertain combination of patchy surface measurements and forecast models. These uncertainties can only be unraveled by other, ground observations that, together with the satellite measurements, can provide a complete picture of the mass loss. This proposal aims to provide these 'missing' measurements, of snow accumulation, of density, and solid Earth motion, over the two decades of the satellite measurements, for the Amundsen sector ice streams.

At its heart is a 800 km traverse of the Pine Island glacier basin in the austral summers of 2012/3 and 2013/4. Two tracked vehicles, will progress around the tributaries of the Pine Island Glacier, carrying with them scientists and their equipment. Through a combination of shallow and deeper ice cores, along the traverse, we will obtain a continuous record of the snowfall and its density. We will extrapolate the dated, annual accumulation layers and their density throughout the traverse through an airborne over-flight of a very high resolution, 'snow' radar. In parallel, a separate party, flying out from Union Glacier in West Antarctica, will make annual visits from 2012/3 to rare exposures of the Earth's crust ('nunataks') south of the Pine Island Basin. Using automated GPD stations attached to the nunataks, the motion of the solid Earth can be determined.

These observations will be used to, first, evaluate the quality of the models of Antarctic accumulation, density and solid Earth motion that are presently used with the satellite data. With this information, we will be able to determine the errors in the historical (from 1992) and on-going series of altimeter, SAR and gravimeter satellites. Second, the data we collect (and other data of Project Partners and beyond) will be used to update these models. Finally, we will generate the best estimate of the contribution to sea level, and its trend in time, throughout the Amundsen sector basins of the West Antarctic ice sheet. The result will also, when combined with the outcome of the 'sister' program of ISTAR-D, provide the best available prediction into the future of these great glacier basins.

Planned Impact

This proposal (ISTAR-D) is aimed at determining the recent past, and present contribution to sea level of the Amundsen sector drainage basins. It will run along side the second activity of this NERC opportunity, ISTAR-C, that will focus on the dynamical behaviour of the sector's ice streams. Together, the two activities will provide the best knowledge, and prediction of this sector's contribution to sea level. We intend to pursue a common impact plan with ISTAR-C, as our contribution to the wider impact plan of the ISTAR program as a whole. The following groups are identified as key stakeholders in iSTAR-C/D science, and will be specifically targeted by our Knowledge Exchange activities:

1. Intergovernmental Panel on Climate Change (IPCC). The IPCC is by far the most authoritative group synthesising scientific knowledge and predictions of sea-level rise. It is therefore essential that l group synthesising and delivering sea-level rise projections to policy-makers, it is essential that iSTAR-C/D science is delivered to IPCC. Science to be included in the IPCC 5th Assessment Report has to be submitted for peer review by July, 2012, iSTAR-C/D science will only be available to subsequent reports. Since IPCC reports relies almost exclusively on peer-reviewed literature, delivery to IPCC must be achieved through such publications. PI ISTAR-C is a Coordinating Lead Author for IPCC 4th and 5th Assessment Report, and ISTAR-D PI & Co-Is have acted as Collaborating Authors and can direct ISTAR-C and -D investigators to ensure ISTAR C and D fully contribute to the IPCC.
2. UK Environment Agency. Because of limitations of the IPCC sea-level rise projections, the UK Environment Agency have found the need to develop its own UK specific sea-level rise scenarios. These were developed in conjunction with the Hadley Centre and BAS. A regular dialogue with the key Programme Managers at the Environment Agency (e.g. TE2100) will ensure that the Environment Agency is fully able to use science outcomes.
3. Living With Environmental Change (LWEC). LWEC is a UK government initiative to optimize the coherence and effectiveness of UK environmental research funding and ensure government, business and society have the foresight, knowledge and tools to mitigate, adapt to and capitalise on environmental change. The ISTAR-C PI currently leads an Accredited Activity ("Ice sheets and sea-level rise") within the Living With Environment Change programme (LWEC). Early discussions, indicate that the activities described in iSTAR-C/D are welcome as a substantial addition to this activity. LWEC is proving to be an effective method of delivery to UK government departments and iSTAR-C/D will be well-positioned to contribute, especially to the activities such as LWEC's development of the UK First Flood Research Strategy.
4. Space and Meteorological Operational Agencies & Supply Industry. The CryoSat-2 radar design, that originated with the ISTAR-D PI, has been adopted as standard for future European operational meteorological and oceanographic satellites, and in particular the GMES Sentinel 3 and NOAA/Eumetsat/CNES Jason-CS missions. ISTAR-D will provide the proving ground for the scientific data processing of these data. The ISTAR-D PI is actively involved in the provision, with industry, of ground processing software for these missions. ISTAR-C and D Co-I's are also advising the European Space Agency operational 'Essential Climate Variables' programme.

We will also organise and host a summary policymaker workshop to which all key stakeholders will be invited. Early career staff will be trained in the public communication of science. A website and newsletter will be created to promote wider engagement with stakeholders and the wider public.
 
Title Ice Floor by Wayne Binitie, Royal College of Arts. Art installation British Antarctic Survey and Arup Architects 
Description Arup presents Ice Floor, a new Phase 2 commission about climate change that has been developed by UK born artist Wayne Binitie in collaboration with the British Antarctic Survey, a world leading centre for polar science. Since 1979 summer sea-ice extent in the Arctic has reduced at 10% per decade. Some major glaciers that drain the Antarctic and Greenland ice sheets have accelerated by as much as 50%, adding to sea level rise. The installation explores the vulnerability of these regions to global warming and how they are subject to conditions like 'calving' (large chunks of ice breaking away at random moments). Deep ice cores from the polar regions have revealed more about the link between climate change and the atmosphere than any other scientific technique. In a cold room, specially created for the exhibition, slices taken from Antarctic ice cores appear to float on a solid ice floor. The exhibition has been made possible through collaboration with the British Antarctic Survey and the kind support of ISOVER. 
Type Of Art Artwork 
Year Produced 2019 
Impact The Ice Floor art installation comprised 360 discs, each 100 mm diameter and 20mm thick, of ancient Antarctic ice cores placed on a 2 meter diameter slab of frozen water in a dark and sound-proofed room, kept at -5 degrees Celsius, situated in the reception area of Arup Architects in London. The slab of ice was lit from below to cast an eerie light into the darkened room. Speakers set into the concrete floor projected the sounds of pre-industrial air being released from ice cores, which tell us the levels of greenhouse gases in the past. The exhibition was open to the public, with free access. Many thousands of visitors were entranced by the sight of the ice samples from Antarctica, slowly subliming away, evoking the fragility of the Antarctic ice landscape, yet providing mankind with the fundamental knowledge of the history of climate and the composition of the atmosphere. 
URL https://www.arup.com/news-and-events/ice-floor
 
Title Solid Liquid Gas 
Description Audio visual field recording of Antarctic ice core air bubbles. 1, 500 years old. Glass sculpture. V&A Museum 
Type Of Art Artwork 
Year Produced 2018 
Impact Exhibition of glass sculptures, set to the sound of air bubbles being released from deep ice cores. Set in the courtyard of the V&A museum, it was visited by many thousands of visitors. Sculptures evoked natural polar ice. Artist provided narrative linking sculptures and sound of ancient air to modern anthropogenic changes in the climate and atmosphere. 
URL https://vimeo.com/248285560
 
Description We have now completed the primary data for the iSTAR project.

The motivation for the project is to understand the impact on sea level of ice loss from the Pine Island Glacial basin in Antarctica. Satellite observations indicate that Pine Island Glacier is losing elevation; this is interpreted as mass loss of ice, with a consequential rise in sea level. The NERC iSTAR Ice Sheet Stability Programme seeks to understand the cause and extent of ice loss via four major projects: two are ocean focussed investigations in the Amundsen Sea utilising ship operations; two are ice focussed research on the Pine Island Glacier using over-snow tractor traverses.

One of the specific aims of iSTAR was to determine the contribution to mass balance arising from changes in local accumulation rate and climate in the past few decades. We have tackled this using a tractor-train based over-snow traverse in the 2014/15 austral field season. Ten 50m deep ice cores were recovered from a wide geographical area of Pine Island Glacier, each incorporating a period of about 70 years of snow accumulation. The cores were returned frozen to laboratories in the UK for analysis.

We have measured the cores by Continuous Flow Analysis in Cambridge, including: H2O2, dust, anions (fast ion chromatography), trace elements (ICP-MS) and water isotopes. Analysis of all ten cores are now completed.
Annual accumulation has been derived from picking annual layer horizons in the hydrogen peroxide records, and converting to water equivalent annual accumulation using the density profile from each site. This enables us to generate a history of annual accumulation over the past 70 years - some sites are showing increased snowfall, while others have decreasing. The data can be compared, and used to test, climate models of snowfall in this region. Currently we compare to climate reanalysis models (ERA-I), and high resolution climate models (RACMO).

The density profile of the firn column was obtained for all ten 50m ice cores by the classical gravimetric technique, plus another 21 x 12m boreholes by a neutron probe technique. This type of snow density data is becoming increasingly important to the understanding of satellite altimetry of the Antarctic surface elevation, and the calculation of ice mass loss from the polar regions. We contributed the data to a global database of firn density data, and to further iSTAR project publications on the densification of firn on the Pine Island Glacier.

Several papers describing the results, and contributing to the knowledge of the mass balance of the Pine Island glacial basin, are either published or currently in preparation.
Exploitation Route Academics in other areas of palaeoclimate, climate modelling etc. Sea level experts interested in how future ice loss from the Pine Island Glacial basin might affect sea level. The public who are interested in past Antarctic climate and ice core research.
Sectors Education,Environment,Government, Democracy and Justice

 
Title Borehole derived Pine Island Glacier mean annual temperatures - collected 2014-2015 
Description Table with measurements of mean annual temperature in degrees Celsius at 22 sites in Pine Island Glacier, located by hand held Garmin GPS position, and altitude recorded by survey quality Leica GPS. The mean annual temperature of a remote ice sheet site is generally agreed to be equivalent to the temperature measured at 10m depth in a borehole. This dataset records the 10m temperatures at 22 remote sites in the Pine Island Glacier region of the West Antarctic Ice Sheet. Data were recorded on a single thermistor logging thermometer for a period of 12 to 24 hours on the date noted in table (marked in table as 'Single thermistor') or as the mean of two cables with parallel triple thermistors measured at a single time (date/time noted in table) after a minimum of 12 hours settling in the borehole (marked in table as 'Average of six thermistors'). Measurements were made independently in two boreholes: one drilled to approximately 12m for deployment of a neutron source ice density probe (marked in table as '10m temperature Neutron Probe borehole'); one drilled to approximately 50m during recovery of an ice core (marked in table as '10m temperature Ice Core borehole'). Some have argued that the mean annual temperature is better measured at 15m in a borehole to remove any trace of the seasonal surface temperature cycle. In the table we additionally record the temperature in the ice core borehole at 15m (marked in table as '15m temperature Ice Core borehole') using a logging PT-100 temperature device (marked in table as 'Single PT-100'). 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Description Collaboration with Alfred Wegener Institute 
Organisation Alfred-Wegener Institute for Polar and Marine Research
Country Germany 
Sector Private 
PI Contribution Exchange of data.
Collaborator Contribution Exchange of data.
Impact On-going research.
Start Year 2017
 
Description Ad hoc climate and atmospheric change briefings 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Briefings to visitors to BAS on climate and atmospheric change, and tours of the NERC/BAS ice core facilities.

Highest impact comes from allowing visitors to handle small samples of ice that originates from the pre-industrial period, and allow them to feel and hear the escape of pre-industrial air, with levels of carbon dioxide significantly lower than present day.
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020
 
Description Antarctic ice core display - Science Museum, London 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Display of an Antarctic ice core in the 'Atmospheres' gallery of the Science Museum in London, with a caption showing 800,000 years of climate change and atmospheric carbon dioxide levels, and explanation of the interaction between carbon dioxide and climate. Display has been in place for ten years, and has been renewed for another five years, and possibly longer.

https://www.sciencemuseum.org.uk/see-and-do/atmosphere, accessed 10th March 2021, records the following:

Step into a virtual world, with its own oceans, land and atmosphere, and go back in time to discover key moments in the Earth's multibillion-year climate history.

The Atmosphere gallery is an exciting place to make sense of the climate-the science of how it works, what it's doing now and what it might do next. Uncover the secrets of ice cores and stalagmites, then head for the future to wonder at the latest ideas for a low-carbon life.

Fascinating objects include a real Antarctic ice core, tree rings and scientists' instruments. Come to this gallery to get to grips with the latest climate news and investigate the important issue of climate change.

The Science Museum developed the content for this gallery through extensive research and engagement with scientists and experts, including expertise from the Met Office as principal content contributor.
Year(s) Of Engagement Activity 2021
URL https://www.sciencemuseum.org.uk/see-and-do/atmosphere
 
Description Cambridge Institute for Sustainable Leadership 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Regular (4 - 8 times per year) briefings on climate change, and the longer term changes over millennia of global climate and greenhouse gases, together with demonstrations of the NERC/BAS ice core facilities . Audiences range from Politicians/Ministers, to senior business leaders in sectors such as international banking (World Bank, IMF), insurance, motor industry, food industry, building industry. Politicians include those from the UK, and from overseas (particularly China).
Year(s) Of Engagement Activity 2010,2011,2012,2013,2014,2015,2016,2017,2018
 
Description Demonstration of climate research from ice cores to Duke and Duchess of Cambridge and Sir David Attenborough 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Demonstrated ice cores and discussed climate research with the Duke and Duchess of Cambridge and Sir David Attenborough. Discussion was filmed and aired on national TV as a news item, and then later included as a segment in a BBC programme presented by Sir David Attenborough. Reach is thought to have been global.
Year(s) Of Engagement Activity 2019
 
Description Documentary interview for television: global climate effects of super-eruptions 
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 Media (as a channel to the public)
Results and Impact Documentary interview for television programme on the climate effects of a volcano super eruption. Supplied both face to face interview, and high quality footage of drilling ice cores in Antarctica from personal video assets. UK programme maker commissioned by US channel. Likely to be sold on and screened globally.
Year(s) Of Engagement Activity 2020
 
Description Prince's Teaching Institute 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Teaching climate change science to GCSE and A-Level school science teachers.
Year(s) Of Engagement Activity 2010,2011,2013,2015,2016,2018
URL http://www.princes-ti.org.uk/what-we-do/new-teacher-subject-days
 
Description iSTAR Final Meeting 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other audiences
Results and Impact Presented project data and results relating to regional accumulation rate to audience interested in the potential loss of mass balance/sea level change from the West Antarctic Ice Sheet.
Year(s) Of Engagement Activity 2017