Forward modelling of past abrupt climate transitions
Lead Research Organisation:
University of Leeds
Department Name: School of Earth and Environment
Abstract
Ocean circulation plays an important role in redistributing heat around the Earth and regulating its climate. However, there remains considerable uncertainty over the interactions between ocean and climate during abrupt transitions that are known to have occurred in the past. One such example is the rapid warming and sudden change in ocean circulation associated with the start of the Bolling-Allerod around 14.6 thousand years ago. The proxy-archives used to understand these shifts (including chemical ocean circulation tracers such as d18O, d13C, radiocarbon, Pa/Th and eNd) seems to disagree at times, suggesting that we are missing fundamental knowledge for interpreting this data. In addition, it remains unknown what chain of events led to these abrupt changes; were they forced by gradual changes in atmospheric CO2? Was a critical threshold crossed in ice-sheet dynamics, atmospheric physics or ocean circulation? To what extent were the concurrent shifts in atmospheric and oceanic processes linked, or were they entirely separate? With this limited understanding, we cannot know if similar rapid transitions could occur again in the near-future; our projections could be lacking crucial mechanistic understanding of climate and ocean dynamics.
Great advancements have recently been made in both the fields of palaeoclimate reconstruction and climate modelling. However, we are reaching the limits of what can be achieved by applying these specialist methods in relative isolation. I propose to make the next logical step and combine these fields of expertise in this fellowship. Using state of the art facilities, this fellowship aims to incorporate cutting-edge knowledge of ocean circulation proxies into some of the most powerful tools for understanding climate dynamics; high complexity atmosphere-ocean general circulation models, the same IPCC-class models that are used to make projections of future change. The exciting multi-proxy, multi-model approach is designed for robustness and to explore uncertainty in both the methods employed and the results produced. With these new multidisciplinary tools, I hope to not only answer specific questions such as 'what caused the abrupt Bolling-Allerod warming?' and 'was the deglacial ocean ever in a bistable mode?', but also to equip earth system scientists with an improved, more holistic understanding of climate-ocean interactions that can be applied to a range of timescales for past, present and future scenarios.
This fellowship answers a call in the field of climate science for multidisciplinarity. The scientific community have expressed enthusiasm and excitement for the development of these tools, the expertise that I am training in and the chance to shift some of the existing paradigms of past climate-ocean dynamics. In order to achieve these goals, I have built a network of collaborators who are world leaders in their specific fields of research; Valdes and Otto-Bliesner in GCM modelling (respectively expert in the UM and CESM models), McManus in Pa/Th, Robinson in radiocarbon, Barker in d18O and d13C, Gutjahr in eNd and essentially, all collaborators have overlapping expertise. The collaborators have been involved in developing some of the hypotheses tested in this fellowship and will make world leading facilities available to me, helping to keep the project at the cutting-edge of current understanding. Their research groups will broaden my network and establish me as a high-profile, internationally-renowned researcher with unique and highly sought after expertise; the ideal foundation for crafting my own research group.
Great advancements have recently been made in both the fields of palaeoclimate reconstruction and climate modelling. However, we are reaching the limits of what can be achieved by applying these specialist methods in relative isolation. I propose to make the next logical step and combine these fields of expertise in this fellowship. Using state of the art facilities, this fellowship aims to incorporate cutting-edge knowledge of ocean circulation proxies into some of the most powerful tools for understanding climate dynamics; high complexity atmosphere-ocean general circulation models, the same IPCC-class models that are used to make projections of future change. The exciting multi-proxy, multi-model approach is designed for robustness and to explore uncertainty in both the methods employed and the results produced. With these new multidisciplinary tools, I hope to not only answer specific questions such as 'what caused the abrupt Bolling-Allerod warming?' and 'was the deglacial ocean ever in a bistable mode?', but also to equip earth system scientists with an improved, more holistic understanding of climate-ocean interactions that can be applied to a range of timescales for past, present and future scenarios.
This fellowship answers a call in the field of climate science for multidisciplinarity. The scientific community have expressed enthusiasm and excitement for the development of these tools, the expertise that I am training in and the chance to shift some of the existing paradigms of past climate-ocean dynamics. In order to achieve these goals, I have built a network of collaborators who are world leaders in their specific fields of research; Valdes and Otto-Bliesner in GCM modelling (respectively expert in the UM and CESM models), McManus in Pa/Th, Robinson in radiocarbon, Barker in d18O and d13C, Gutjahr in eNd and essentially, all collaborators have overlapping expertise. The collaborators have been involved in developing some of the hypotheses tested in this fellowship and will make world leading facilities available to me, helping to keep the project at the cutting-edge of current understanding. Their research groups will broaden my network and establish me as a high-profile, internationally-renowned researcher with unique and highly sought after expertise; the ideal foundation for crafting my own research group.
Planned Impact
Who:
This project aims to develop new tools for improving scientific understanding of abrupt climate change and ocean-climate dynamics, working within a multidisciplinary framework to improve our knowledge of climate projection uncertainty. The beneficiaries are many because this topic is a focus of the Earth system science research agenda and it holds great topical interest for the wider public as concerns grow about modern climate change. The project will deliver fundamental knowledge on the causes/consequences of past climate change, develop new modelling tools and improve cross-discipline channels of communication, benefitting a broad range of scientists, including model-developers and any individual/group with an interest in understanding mechanisms of climate change, reducing uncertainty in future climate projections and implementing policy to adapt to these changes. Therefore, postgraduates and undergraduates; model end-users (policy makers/stake holders); the scientifically-, socially- and politically-engaged general public; school teachers and pupils will also benefit from this research.
How:
Model developers worldwide, and particularly at the UK Met Office, will benefit from my isotope implementation into the UM and my assessment of its physical parametric uncertainty. This fellowship research will improve our understanding and analysis of model uncertainty and provide an improved framework for the effective and transparent transfer of knowledge to end users. This is a theme that I have been engaged with since the outset of my research career (see Ivanovic and Freer, 2009) and is one I am keen to bring to the fore in the future. The general public and schools will benefit from my continued leadership and participation in numerous outreach schemes, which to date has had several purposes: (i) to inspire, (ii) to open doors to higher education and academia, (iii) to make reported scientific findings accessible to the public, (iv) to shatter the black-box perception of the methodologies employed, (v) to dispel the illusions of scientists as 'them' or 'other' (vi) to educate. In addition, the public will have the opportunity to read about my work, should they wish.
Practical strategies to ensure the benefit:
1. Become a highly visible research leader and establish new international working groups to bring to the fore the multidisciplinary techniques I will employ.
2. Publish results, methodologies and model development code in high profile, peer-reviewed journals (open access wherever possible). 10 publications are anticipated.
3. Present work at 2 major, international conferences per year, in the departments I will be working in, as well as at other UK and international institutes.
4. Convene at least one session at Goldschmidt and one session at AGU Fall Meeting.
5. Make my model data freely available on a website with a non-specialist, user-friendly interface.
6. Create and maintain a wiki user-manual for running the UM with the geochemical ocean tracers I will implement.
7. Contribute towards a website with online resources for learning about science.
8. Employ mass; press releases targeting newspapers, television and other popular media outlets, e.g. NERC Planet Earth publication and podcasts.
9. Run a high profile public debate or panel discussion involving 6 experts (with different specialism) on the extent to which uncertainty in climate science fetters policy making in public and private domains.
10. Integrate my research into undergraduate/postgraduate teaching and research project supervision.
11. Establish an innovative, multidisciplinary and expert research group.
This project aims to develop new tools for improving scientific understanding of abrupt climate change and ocean-climate dynamics, working within a multidisciplinary framework to improve our knowledge of climate projection uncertainty. The beneficiaries are many because this topic is a focus of the Earth system science research agenda and it holds great topical interest for the wider public as concerns grow about modern climate change. The project will deliver fundamental knowledge on the causes/consequences of past climate change, develop new modelling tools and improve cross-discipline channels of communication, benefitting a broad range of scientists, including model-developers and any individual/group with an interest in understanding mechanisms of climate change, reducing uncertainty in future climate projections and implementing policy to adapt to these changes. Therefore, postgraduates and undergraduates; model end-users (policy makers/stake holders); the scientifically-, socially- and politically-engaged general public; school teachers and pupils will also benefit from this research.
How:
Model developers worldwide, and particularly at the UK Met Office, will benefit from my isotope implementation into the UM and my assessment of its physical parametric uncertainty. This fellowship research will improve our understanding and analysis of model uncertainty and provide an improved framework for the effective and transparent transfer of knowledge to end users. This is a theme that I have been engaged with since the outset of my research career (see Ivanovic and Freer, 2009) and is one I am keen to bring to the fore in the future. The general public and schools will benefit from my continued leadership and participation in numerous outreach schemes, which to date has had several purposes: (i) to inspire, (ii) to open doors to higher education and academia, (iii) to make reported scientific findings accessible to the public, (iv) to shatter the black-box perception of the methodologies employed, (v) to dispel the illusions of scientists as 'them' or 'other' (vi) to educate. In addition, the public will have the opportunity to read about my work, should they wish.
Practical strategies to ensure the benefit:
1. Become a highly visible research leader and establish new international working groups to bring to the fore the multidisciplinary techniques I will employ.
2. Publish results, methodologies and model development code in high profile, peer-reviewed journals (open access wherever possible). 10 publications are anticipated.
3. Present work at 2 major, international conferences per year, in the departments I will be working in, as well as at other UK and international institutes.
4. Convene at least one session at Goldschmidt and one session at AGU Fall Meeting.
5. Make my model data freely available on a website with a non-specialist, user-friendly interface.
6. Create and maintain a wiki user-manual for running the UM with the geochemical ocean tracers I will implement.
7. Contribute towards a website with online resources for learning about science.
8. Employ mass; press releases targeting newspapers, television and other popular media outlets, e.g. NERC Planet Earth publication and podcasts.
9. Run a high profile public debate or panel discussion involving 6 experts (with different specialism) on the extent to which uncertainty in climate science fetters policy making in public and private domains.
10. Integrate my research into undergraduate/postgraduate teaching and research project supervision.
11. Establish an innovative, multidisciplinary and expert research group.
People |
ORCID iD |
| Ruza Ivanovic (Principal Investigator / Fellow) |
Publications
Boyd J
(2018)
The relationship between Neogene dinoflagellate cysts and global climate dynamics
in Earth-Science Reviews
Cooper C
(2020)
Is there a climatic control on Icelandic volcanism?
in Quaternary Science Advances
Dentith J
(2020)
Simulating stable carbon isotopes in the ocean component of the FAMOUS general circulation model with MOSES1 (XOAVI)
in Geoscientific Model Development
Dentith J
(2018)
Ocean circulation drifts in multi-millennial climate simulations: the role of salinity corrections and climate feedbacks
in Climate Dynamics
Di Nezio P
(2016)
The climate response of the Indo-Pacific warm pool to glacial sea level
in Paleoceanography
Emery A
(2020)
Ice sheet and palaeoclimate controls on drainage network evolution: an example from Dogger Bank, North Sea
in Earth Surface Dynamics
Erb M
(2022)
Reconstructing Holocene temperatures in time and space using paleoclimate data assimilation
in Climate of the Past
| Title | Interactive map of BIS and future sea level rise over Yorkshire |
| Description | An interactive 'jigsaw' 3D map of future sea level rise, past sea level and past ice sheet cover of the North of England. |
| Type Of Art | Artistic/Creative Exhibition |
| Year Produced | 2017 |
| Impact | By building the map and being able to visualise the sea level changes that have happened in the past and could occur in the future, the public and school children were able to contextualise what they learned and already knew (from School, or from the news etc.) about rates of sea level rise (current and near future). By examining the configurations of past ice sheets, they were better able to understand how their local/regional landscape was sculpted, and better understand the processes that control ice sheet evolution (past and future) in a tangible way. |
| Title | James MacKay Palaeo Art |
| Description | Series of artists' impressions that seek to accurately represent specific landscapes during the geological past, including events/time periods that my research has shed light on. James macKay produces the artwork and I advised him on scientific elements. |
| Type Of Art | Image |
| Year Produced | 2017 |
| Impact | Visualising what we explain helps undergraduates and the general public to understand the processes we describe, and how major climate changes can sculpt the landscape. |
| Description | The first major achievement was to establish an internationally coordinated working group under the auspices of the Paleoclimate Modelling Intercomparison Project (PMIP) to investigate processes of deglaciation. The working group, which I lead, has established multi-model simulation protocols for the last deglaciation to present (spanning 26-0 thousand years ago) and for the penultimate deglaciation (~140 to 130 thousand years ago). We are also collating climate and other environmental proxy data for these periods for comparison to the model simulations. These simulations and data gathering efforts are major undertakings across the whole community and it will take time for the results of the work to emerge. We are now starting to see the first fruits of these efforts across the community, learning about the mechanisms that can lead to deglaciations and abrupt climate changes within the longer term trends, and also the carbon cycle dynamics during these time periods. This work is a major achievement of the fellowship with far-reaching impacts across the scientific community. It has also led to my contributing role to defining PMIP's role in the sixth Coupled Model Intercomparison Project (CMIP6). In total, this work has directly yielded three publications so far, but through the knowledge I gained in order to lead the working group and produce these manuscripts, I was also able to establish a new collaboration developing our understanding of how the global ocean silicon cycle is impacted by ice sheet melting (one further publication). For the fellowship, I developed a novel, mechanistically robust framework for tracking through the physical processes of ice sheet melting and ocean circulation/climate change to examine the chains of past events. This has been important because many of the explanations for the past events offered by the community so far have proven flaws that render them unfeasible. How then could the well documented series of rapid warmings, coolings and sea level rises have taken place? What was the link between ice sheet evolution, ocean circulation and surface climate? My new methodology has so far enabled me to examine four key events during the last deglaciation, when the vast ice sheets that once covered the Northern Hemisphere (in particularly North America and northwestern Eurasia) melted away until present day conditions were reached. Through this modelling work, and working with new collaborators to generate new observational climate/ocean proxy data, my team and I have established: - that the 8.2 ka event (widespread northern hemisphere cooling of several degrees 8,200 thousand years ago) was likely caused by the longer term melting of the North American ice sheet, and not by an abrupt lake release to the ocean (the long standing and widely held view), or a re-organisation of atmospheric circulation following the collapse of the ice sheet (another popular hypothesis). The main results of this work are provided in two publications. - that melting of the North American ice sheet most likely made a significant contribution to Meltwater Pulse 1a (the largest, rapid sea level rise ever recorded: 12-22 m in < 350 years, around 14 thousand years ago), that there is sound mechanistic underpinning for this melting to have been caused by the abrupt Bolling Warming (several degrees of Northern Hemisphere warming in a few decades, around 15 thousand years ago), that the melting must have caused a subsequent reduction in the strength of Atlantic Ocean Overturning and through this mechanism widespread northern hemisphere cooling of a few degrees (which could be the Older Dryas Cooling, around 14 thousand years ago). My simulations also demonstrate that it is very unlikely that roughly concurrent melting from Antarctica could have caused the Bolling Warming event, or reduced/reversed the cooling caused by Northern Hemisphere melting. This remains a contentious debate, and the series of three publications we produced on the topic make an important knowledge contribution to one of the least well understood periods of the last deglaciation, when rapid sea level rise, warming and cooling are all known to have occurred, but have hitherto been poorly linked, mechanistically. - that the onset of an abrupt weakening of Atlantic Ocean overturning and Northern Hemisphere cooling (i.e. the beginning of Heinrich Stadial 1, ~ 18.5 thousand years ago) was feasibly triggered by the acceleration of Northern Hemisphere (most likely Eurasian) ice sheet melting. This had never been achieved before with a climate model, and challenges the largely discredited yet persistently popular view that the event was linked to iceberg discharge or an impossibly large amount of ice melting. The main results of this work are provided in two publications, including a new composite data set for the protactinium/thorium proxy for ocean circulation. Carbon-isotope implementation in UM version 4.5 has been completed (PhD thesis by J. Dentith, 2019: http://etheses.whiterose.ac.uk/25427/; Dentith et al., in review for GMD; Dentith et al., in revision for Biogeosciences). Carbon isotopes were prioritised over other isotope systems due to their having the widest available database for the key timeperiod of interest for the fellowship (last 21 thousand years) and the use of carbon-13 further back in time. Furthermore, as the most extensively studied isotope system of those mentioned in the fellowship proposal, they are the best understood system, thus making their implementation a robust procedure. The work was delayed by the discovery of scientific problems with the model version that I planned to use for the isotope implementation development. This took two years to resolve, but led to an unforeseen publication. Following the successful implementation of carbon isotopes, neodymium isotope implementation has begun (PhD by Suzanne Robinson), building on the carbon isotope code. The scheme is simpler to implement, but neodymium isotopes are less well understood. One reason for delaying the neodymium isotope implementation was the emergence of new questions regarding how the system operates following the proliferation of measurements being undertaken by the GEOTRACES program. I needed to be sure that we understand the system well enough to carry out a scientifically rigorous implementation of the scheme. One advantage to the delay is that the new measurements provide yet more data to initialise and validate simulations of neodymium isotopes. Furthermore, I am now in a position to take a leading role to contribute to the debate over how neodymium isotopes operate in the ocean system and directly tackle the key controversies that are being debated in the field (neodymium cycling in the ocean, discussion on whether there is a benthic source and balance between different sources/sinks). The model will be an ideal and extremely useful tool for achieving this, and it is only possible because of new thinking that has arisen since the fellowship began. I will therefore lead modelling efforts to resolve the debate. I have delayed protactinium/thorium implementation because it is an even less well understood system and hence is lower priority. I am also able to use the new carbon isotope system to re-tune aspects of the model that will be important for the protactinium/thorium isotope schemes, and therefore improve model performance and ability to simulate these isotope systems robustly. I have identified that the protactinium/thorium code will be heavily based on the neodymium and carbon isotope schemes and therefore should be relatively straightforward to implement, technically, when those systems are validated in the model. New unforeseen collaborations with a group of scientists investigating terrestrial biogeochemical evolution over the past 21 thousand years, specifically peatlands, also led to new work linking climate change over the period to the evolution of peatlands. This works provides valuable insight into the controlling mechanisms on peatland initiation and health, with valuable insight gained for understanding how peatlands, which are currently a major natural carbon sink in the environment, may develop in the future under changing climate conditions. This research produced two high profile publications. Furthermore, with new collaborators, I was able to work with a different climate model whilst on my planned secondment to the National Center for Atmospheric Research (NCAR, Boulder, USA) to establish the role of sea level in tropical climate change at the last glacial maximum, 21 thousand years ago (one publication). I have also contributed to an investigation of the mechanisms governing marine ice sheet instabilities, with a specific case study of the British-Irish Ice Sheet during the last deglaciation (one publication). Through my new role as Principle Investigator, I was also able to supervise PhD research with broader scope, examining the evolution of Antarctic climate (one publication) and the performance of dinoflagellate cysts as a proxy for climate change (one publication) through the Neogene (approx. 23-2.5 million years ago); all providing valuable context for my more focused work on the last deglaciation and generating new climate proxy tools for investigating past climate. Throughout the fellowship my work has aimed to develop my skills in using both climate models and proxies to reach a better mechanistic understanding of climate-ice-ocean interactions, using case studies from the last deglaciation to better understand Earth's recent climate history. All of my work (as evidenced by the publications) have contributed towards this aim, developing forward modelling techniques, running hypothesis driven simulations, assessing uncertainty through multi-model and intra-model ensemble experiments, carrying out climate model-proxy comparisons to understand the drivers of observed changes and biases in the model, developing our knowledge of climate proxies and generating new climate proxy datasets. |
| Exploitation Route | My PMIP leadership role, including my work on model experiment protocols, has supported anyone running or wishing to analyse simulations of the last deglaciation, last glacial maximum and penultimate deglaciation. Clear guidelines are provided, and I remain the first point of contact for advice and to coordinate related initiatives for the last deglaciation, internationally. Because of the length of these simulations, most groups are still running the simulations, or are yet to start them, and they will use the information provided and support from me to do this. I will continue to lead the efforts. Simulations of the past 26 thousand years have been utilised in several other processed-based studies investigating climate, ecological and geomorpholoigcal evolution over this time period (e.g. to date: Swindles et al., 2018; Morris et al., 2018; Gandy et al., 2018; 2019; McKeown et al., 2019; Fewster et al., in revision; Cooper et al., in review; Emery et al., submitted; Gray et al., in revision...). I have provided the output data to researchers in the UK, Europe, US, Canada, New Zealand; and am contributing to new projects hosted in all of these regions. My work on the chains of abrupt climate events and ice-ocean-climate interactions has attracted wide interest from the community, leading to several high profile conference talks and publications. These are controversial debates, and our findings provide some answers, as well as clearer questions to specifically target to establish definitively what happened with the ice sheets, climate and ocean circulation over the past 26 thousand years. Furthermore, some of the mechanisms (i.e. interactions between ocean and ice sheets) are very relevant for processes going on today. Further rigorous examination of past occurrences of these events will yield valuable test cases for the climate models and our process-understanding, to improve models of and form new hypotheses for ice-ocean-climate interactions. |
| Sectors | Environment |
| Description | Abrupt climate transitions using geological tracers of ocean circulation |
| Amount | £80,000 (GBP) |
| Funding ID | 1652094 |
| Organisation | Natural Environment Research Council |
| Sector | Public |
| Country | United Kingdom |
| Start | 10/2015 |
| End | 06/2019 |
| Description | Collaborative Research: Terrestrial hydrology during the last deglaciation |
| Amount | $706,342 (USD) |
| Organisation | National Science Foundation (NSF) |
| Sector | Public |
| Country | United States |
| Start | 07/2019 |
| End | 06/2022 |
| Description | Constraining projections of ice sheet instabilities and future sea level rise |
| Amount | £1,249,738 (GBP) |
| Funding ID | MR/S016961/1 |
| Organisation | Medical Research Council (MRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 05/2019 |
| End | 04/2024 |
| Description | North American ice sheet collapse and abrupt climate change |
| Amount | £80,000 (GBP) |
| Funding ID | 1506596 |
| Organisation | Natural Environment Research Council |
| Sector | Public |
| Country | United Kingdom |
| Start | 10/2014 |
| End | 03/2018 |
| Title | C-isotope implementation in the UK Met Office Unified Model version 4.5 |
| Description | Implemented d13C and d14C (biotic and abiotic) ocean tracer in the UK Met Office Unified Model version 4.5. Tested with FAMOUS version of the model. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2019 |
| Provided To Others? | No |
| Impact | Scientific impact: new research tool for interpreting palaeo ocean circulation, advancing knowledge of mechanisms of past climate/ocean/carbon-cycle changes. Provides an additional, rigorous technique for validation of the performance of the model. |
| Title | Climate model data presented in 'Acceleration of northern ice sheet melt induces AMOC slowdown and northern cooling in simulations of the early last deglaciation' |
| Description | Climate model data presented in: Ivanovic, R. F., Gregoire, L. J., Burke, A., Wickert, A. D., Valdes, P. J., Ng, H. C., Robinson, L. F., McManus, J. F., Mitrovica, J. X., Lee, L. and Dentith, J. E.: Acceleration of northern ice sheet melt induces AMOC slowdown and northern cooling in simulations of the early last deglaciation, Paleoceanography and Paleoclimatology, 33(7), 807-824, doi:10.1029/2017PA003308, 2018. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2018 |
| Provided To Others? | Yes |
| Impact | Academic use of data |
| URL | http://archive.researchdata.leeds.ac.uk/407/ |
| Title | Climate model data presented in 'Climatic effect of Antarctic meltwater overwhelmed by concurrent Northern hemispheric melt'. |
| Description | Climate model data presented in: Ivanovic, R. F., Gregoire, L. J., Wickert, A. D. and Burke, A.: Climatic Effect of Antarctic Meltwater Overwhelmed by Concurrent Northern Hemispheric Melt, Geophysical Research Letters, 45(11), 5681-5689, doi:10.1029/2018GL077623, 2018. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2018 |
| Provided To Others? | Yes |
| Impact | academic use of climate model data |
| URL | http://archive.researchdata.leeds.ac.uk/390/ |
| Title | Climate model data presented in 'Holocene lowering of the Laurentide ice sheet affects North Atlantic gyre circulation and climate' |
| Description | Climate model data presented in: Gregoire, L. J., Ivanovic, R. F., Maycock, A. C., Valdes, P. J. and Stevenson, S.: Holocene lowering of the Laurentide ice sheet affects North Atlantic gyre circulation and climate, Clim Dyn, 51(9), 3797-3813, doi:10.1007/s00382-018-4111-9, 2018. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2018 |
| Provided To Others? | Yes |
| Impact | Academic use of climate model output |
| URL | http://archive.researchdata.leeds.ac.uk/310/ |
| Title | Simulations of the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk r3298) |
| Description | This dataset presents the input and output data from a set of sensitivity experiments to simulate the evolution of the Laurentide ice sheet in the Early Holocene (10-7 thousand years ago). These data are presented in the manuscript "Simulating the Early Holocene demise of the Laurentide Ice Sheet with BISICLES (public trunk revision 3298)". Simulating the demise of the Laurentide Ice Sheet covering the Hudson Bay in the early Holocene is important for understanding the role of accelerated changes in ice sheet topography and melt in the '8.2 ka event', a century long cooling of the Northern Hemisphere by several degrees. Freshwater released from the ice sheet through a surface mass balance instability (known as the saddle collapse) has been suggested as a major forcing for the 8.2 ka event, but the temporal evolution of this pulse has not been constrained. Dynamical ice loss and marine interactions could have significantly accelerated the ice sheet demise, but simulating such processes requires computationally expensive models that are difficult to configure and are often impractical for simulating past ice sheets. Here, we developed an ice sheet model setup for studying the Laurentide Ice Sheet's Hudson Bay saddle collapse and the associated meltwater pulse in unprecedented detail using the BISICLES ice sheet model, an efficient marine ice sheet model of the latest generation, capable of refinement to kilometre-scale resolution and higher-order ice flow physics. The setup draws on previous efforts to model the deglaciation of the North American Ice Sheet for initialising the ice sheet temperature, recent ice sheet reconstructions for developing the topography of the region and ice sheet, and output from a general circulation model for a representation of the climatic forcing. The modelled deglaciation is in agreement with the reconstructed extent of the ice sheet and the associated meltwater pulse has realistic timing. Furthermore, the peak magnitude of the modelled meltwater equivalent (0.07-0.13 Sv) is compatible with geological estimates of freshwater discharge through the Hudson Strait. The results demonstrate that while improved representation of the glacial dynamics and marine interactions are key for correctly simulating the pattern of early Holocene ice sheet retreat, surface mass balance introduces by far the most uncertainty. The new model configuration presented here provides future opportunities to quantify the range of plausible amplitudes and durations of a Hudson Bay ice saddle collapse meltwater pulse and its role in forcing the 8.2 ka event. Ilkka Matero was funded by the Leeds-York Natural Environment Research Council (NERC) Spheres Doctoral Training Partnership (NE/L002574/1). The contribution from Ruza Ivanovic was partly supported by NERC grant NE/K008536/1. Lauren Gregoire is funded by a UKRI Future Leaders Fellowship (MR/S016961/1). The work made use of the N8 HPC facilities, which are provided and funded by the N8 consortium and EPSRC (EP/K000225/1) and co-ordinated by the Universities of Leeds and Manchester. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2019 |
| Provided To Others? | Yes |
| Description | CLIVAR Atlantic Region Panel |
| Organisation | World Climate Research Programme |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | I am panel member and make contributions towards the panel's activities. See below. |
| Collaborator Contribution | The panel seeks to direct international Atlantic climate and ocean research through white papers, endorsement of projects, creating international collaborations. The panel takes a strong leadership role in international observational networks and reports on international initiatives and projects to WCRP. |
| Impact | Numerous white papers, reports, endorsed grant applications, publications arising from research supported by the panel. |
| Start Year | 2015 |
| Description | Application open days |
| 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 | Undergraduate students |
| Results and Impact | Talks, interviews and discussion at University Open Days for prospective students and their families to educate them on the opportunities of higher education and provide a positive scientist role model experience, particularly for female applicants, who we noticed were often not following through with their application. Since starting this female applications have gone up. Furthermore, students and parents express an excitement about my research topic and cite it as a reason they select to attend the university. |
| Year(s) Of Engagement Activity | 2014,2016,2017,2018,2019 |
| Description | BeCurious |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Interactive and visual displays to educate on the recent geological past, current climatological state and near future projections/possibilities for the Yorkshire area. Received very positive feedback from event organisers and the public, particularly children who felt that the activities helped them to contextualise cliamte change and udnerstand what has happened in the past, why our landscape looks as it does, and what may happen again in the future. |
| Year(s) Of Engagement Activity | 2017 |
| URL | http://www.leeds.ac.uk/info/4000/around_campus/460/be_curious_festival-about_leeds_and_yorkshire |
| Description | Palaeo artwork |
| Form Of Engagement Activity | Engagement focused website, blog or social media channel |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Consulted with local artist (James MacKay) to produce scientifically accurate and visually stimulating art work as an impression of how the environment looked at various stages in the past, mostly my own research time period and events. |
| Year(s) Of Engagement Activity | 2017,2018 |
| Description | Pint of Science |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Public/other audiences |
| Results and Impact | This is an annual event where members of the public come to listen to current topics in research, and enjoy an interactive and relaxed evening while learning about cutting edge research to inform them about topical issues. |
| Year(s) Of Engagement Activity | 2019 |
| Description | RMetS Meeting on the last deglaciation |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Study participants or study members |
| Results and Impact | The Meltdown: Abrupt Climate Change since the Last Ice Age: this ticketed event was sold out, with invited speakers from across the country and an expert panel debate. I organised the event, which was chaired by Prof. Dame Jane Francis, and attracted both an academic, other professional, and interested general public audience. The purpose was to educate, explore and challenge critically the notion that the past can tell us about the future, with specific reference to 21st C climate change. Bringing experts and general public together to do this was highly educational, but also changed the way we think in this field. It was widely reported as a high success and hailed as one of the most interesting meetings of the year by attendees. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.rmets.org/event/meltdown-abrupt-climate-change-last-ice-age |
| Description | Rotunda Geological Society |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Public/other audiences |
| Results and Impact | Outreach activity: invited talk and Q&A to this amateur geological society (30-50 members present) on my fellowship research. The organisers reported high interest in the topic with record attendance at the talk and rejuvenated enthusiasm for the group. |
| Year(s) Of Engagement Activity | 2017 |
| URL | http://www.rotundageologygroup.org/ |
| Description | Yorkshire Fossil Festival |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Annual event with hands-on activities, talks, Q&A and educational information on local geology and links to research undertaken within the group at the University of Leeds. |
| Year(s) Of Engagement Activity | 2017,2018 |
| URL | https://yorkshirefossilfestival.co.uk/ |