SWEET:Super-Warm Early Eocene Temperatures and climate: understanding the response of the Earth to high CO2 through integrated modelling and data
Lead Research Organisation:
University of Bristol
Department Name: Geographical Sciences
Abstract
The Earth's climate is currently changing rapidly, primarily due to emissions of greenhouse gases caused by human industrialisation. These emissions are projected to increase through this century, and under some scenarios atmospheric carbon dioxide (CO2) concentrations could reach more than 1000 parts per million (ppm) by the year 2100, compared with 280 ppm prior to industrialisation. In order to predict the sociological, environmental, and economic impacts of such scenarios, and thus to better prepare for them, the only tool at our disposal is climate modelling. In order to assess our confidence in predictions from climate models, they are routinely tested under conditions of known climate. However, this testing (and associated tuning of the models) is almost exclusively carried out under modern climate conditions, and relative to recently observed climate change, for which CO2 concentrations are less than 400 ppmv. As such, our state-of-the-art climate models have never been tested under the high CO2, super-warm climate conditions to which they are primarily applied, and upon which major policy decisions are made.
However, there exist time periods in Earth's deeper past (for example the Eocene, about 50 million years ago) when CO2 concentrations were similar to those expected by the end of this century; but climatological information from these time periods is currently sparse and is associated with large uncertainties, and the exact concentrations of CO2 are only poorly known. Recent changes in our understanding of how the geological record preserves climate signals, and developments in laboratory techniques, mean that for the first time there exists a new and exciting opportunity to remedy this situation and provide a much-needed evaluation of our very latest climate models in a super-warm world.
In SWEET, we will apply these emerging techniques, and develop new methodologies and tools, to produce a global dataset of Eocene temperatures. Coupled with new and high-fidelity reconstructions of Eocene CO2 concentrations, and state-of-the-art maps of the 'palaeogeograpy' (continental positions, mountain ranges, ocean depths etc.), we will use this dataset to test a state-of-the art climate model under high atmospheric CO2, Eocene conditions. The model, UKESM, is identical to that being used by the UK Met Office in the international 'CMIP6' project, which itself will be the primary input to the next Intergovernmental Panel on Climate Change (IPCC) assessment report. We will also use our data and additional model simulations (running at high spatial resolution) to investigate the relative importance of the various mechanisms which determine the response of the Earth system to high CO2 and to changes in palaeogeography.
A characteristic of SWEET is that we will take full account of uncertainties in the geological data and the modelling, and our model-data comparisons will be underpinned by a statistical framework which incorporates these uncertainties. We will also adopt a 'multi-proxy' approach by using several independent geological archives to reconstruct temperature. For one of these archives, namely the oxygen isotopic composition of the fossilised shells of microscopic marine creatures from the Eocene, we will apply a particularly innovative approach which will enable us to 'resurrect' previously discredited data, by using an extremely fine-scale 'ion probe' to investigate how these isotopic signatures of past climate change are recorded in individual fossils.
SWEET has strong links to UK Met Office, and to the international DeepMIP project, which is part of the 'Palaeoclimate Modelling Intercomparison Project', itself part of CMIP6. We expect our results to feed into the next IPCC assessment reports and therefore to ultimately inform policy.
However, there exist time periods in Earth's deeper past (for example the Eocene, about 50 million years ago) when CO2 concentrations were similar to those expected by the end of this century; but climatological information from these time periods is currently sparse and is associated with large uncertainties, and the exact concentrations of CO2 are only poorly known. Recent changes in our understanding of how the geological record preserves climate signals, and developments in laboratory techniques, mean that for the first time there exists a new and exciting opportunity to remedy this situation and provide a much-needed evaluation of our very latest climate models in a super-warm world.
In SWEET, we will apply these emerging techniques, and develop new methodologies and tools, to produce a global dataset of Eocene temperatures. Coupled with new and high-fidelity reconstructions of Eocene CO2 concentrations, and state-of-the-art maps of the 'palaeogeograpy' (continental positions, mountain ranges, ocean depths etc.), we will use this dataset to test a state-of-the art climate model under high atmospheric CO2, Eocene conditions. The model, UKESM, is identical to that being used by the UK Met Office in the international 'CMIP6' project, which itself will be the primary input to the next Intergovernmental Panel on Climate Change (IPCC) assessment report. We will also use our data and additional model simulations (running at high spatial resolution) to investigate the relative importance of the various mechanisms which determine the response of the Earth system to high CO2 and to changes in palaeogeography.
A characteristic of SWEET is that we will take full account of uncertainties in the geological data and the modelling, and our model-data comparisons will be underpinned by a statistical framework which incorporates these uncertainties. We will also adopt a 'multi-proxy' approach by using several independent geological archives to reconstruct temperature. For one of these archives, namely the oxygen isotopic composition of the fossilised shells of microscopic marine creatures from the Eocene, we will apply a particularly innovative approach which will enable us to 'resurrect' previously discredited data, by using an extremely fine-scale 'ion probe' to investigate how these isotopic signatures of past climate change are recorded in individual fossils.
SWEET has strong links to UK Met Office, and to the international DeepMIP project, which is part of the 'Palaeoclimate Modelling Intercomparison Project', itself part of CMIP6. We expect our results to feed into the next IPCC assessment reports and therefore to ultimately inform policy.
Planned Impact
Our exciting and innovative Impact Plan has three components, which are focussed on public outreach and engagement with policy-makers through the Intergovernmental Policy on Climate Change (IPCC).
Our public outreach will be centred on the SWEET project website, which we will promote via the participating universities' extensive media contacts (both traditional media and social media). Through the website we will produce regular blog postings from the postdoctoral researchers and the PhD student, charting progress through the project. The innovation here is that in addition to highlighting exciting new scientific results, the blogs will also focus on the process of actually carrying out science, including highs and lows, excitements and disappointments. As such, they will document the complete scientific process from a human perspective, and it is our hope that this will inspire undergraduates and schoolchildren to engage with science, in particular those who otherwise may have viewed science and scientists as unapproachable.
Another central aspect of our engagement with the general public will be via the first ever (to our knowledge) climate model simulations of the world of 'Game of Thrones' - a hugely popular book and television series (single episodes of which attract viewing figures in the 10's of millions). We previously had great success with a similar exercise as part of the Impact Plan of a previous NERC grant, in which we simulated the climate of J.R.R. Tolkien's Middle Earth (and which received a total of 100,000 Tweets/reTweets in the first 8 hours alone), and we anticipate that this new activity will have a similar, if not greater, global impact. The primary aim is to excite the general public about climate science and climate models, and to emphasise that climate models have the flexibility, because of their grounding in fundamental scientific principles, to be applied beyond just the modern Earth. As such, we will tackle the commonly held myth that climate models are just constructed for and tuned, to, the modern world. Note that we do not request any resource to carry out this activity.
Finally, we will aim to communicate our findings to policymakers via their inclusion in forthcoming reports of the IPCC (AR6, and AR7 if appropriate; note that five of the SWEET team were Contributing Authors to AR5). The work in SWEET represents a step-change in terms of evaluation of deep-time warm climates compared with what was presented in AR5. As such, we are confident that our work will be included in AR6. However we will facilitate this by sending copies of our papers to the appropriate IPCC authors, and by presenting our work at international conferences.
Our public outreach will be centred on the SWEET project website, which we will promote via the participating universities' extensive media contacts (both traditional media and social media). Through the website we will produce regular blog postings from the postdoctoral researchers and the PhD student, charting progress through the project. The innovation here is that in addition to highlighting exciting new scientific results, the blogs will also focus on the process of actually carrying out science, including highs and lows, excitements and disappointments. As such, they will document the complete scientific process from a human perspective, and it is our hope that this will inspire undergraduates and schoolchildren to engage with science, in particular those who otherwise may have viewed science and scientists as unapproachable.
Another central aspect of our engagement with the general public will be via the first ever (to our knowledge) climate model simulations of the world of 'Game of Thrones' - a hugely popular book and television series (single episodes of which attract viewing figures in the 10's of millions). We previously had great success with a similar exercise as part of the Impact Plan of a previous NERC grant, in which we simulated the climate of J.R.R. Tolkien's Middle Earth (and which received a total of 100,000 Tweets/reTweets in the first 8 hours alone), and we anticipate that this new activity will have a similar, if not greater, global impact. The primary aim is to excite the general public about climate science and climate models, and to emphasise that climate models have the flexibility, because of their grounding in fundamental scientific principles, to be applied beyond just the modern Earth. As such, we will tackle the commonly held myth that climate models are just constructed for and tuned, to, the modern world. Note that we do not request any resource to carry out this activity.
Finally, we will aim to communicate our findings to policymakers via their inclusion in forthcoming reports of the IPCC (AR6, and AR7 if appropriate; note that five of the SWEET team were Contributing Authors to AR5). The work in SWEET represents a step-change in terms of evaluation of deep-time warm climates compared with what was presented in AR5. As such, we are confident that our work will be included in AR6. However we will facilitate this by sending copies of our papers to the appropriate IPCC authors, and by presenting our work at international conferences.
Organisations
- University of Bristol (Lead Research Organisation)
- Purdue University (Collaboration)
- Getech (United Kingdom) (Project Partner)
- Université Libre de Bruxelles (Project Partner)
- Bermuda Institute of Ocean Sciences (Project Partner)
- University of California, Santa Cruz (Project Partner)
- Yale University (Project Partner)
- Met Office (Project Partner)
- Marine Biological Association of the United Kingdom (Project Partner)
Publications
Lunt D
(2021)
Multi-variate factor separation of numerical simulations
Hollis C
(2019)
Reply to Reviewer 2
Babila T
(2022)
Surface ocean warming and acidification driven by rapid carbon release precedes Paleocene-Eocene Thermal Maximum
in Science Advances
Tierney JE
(2020)
Past climates inform our future.
in Science (New York, N.Y.)
Burke KD
(2018)
Pliocene and Eocene provide best analogs for near-future climates.
in Proceedings of the National Academy of Sciences of the United States of America
Zhang Y
(2022)
Early Eocene Ocean Meridional Overturning Circulation: The Roles of Atmospheric Forcing and Strait Geometry
in Paleoceanography and Paleoclimatology
Cramwinckel M
(2023)
Global and Zonal-Mean Hydrological Response to Early Eocene Warmth
in Paleoceanography and Paleoclimatology
Goudsmit-Harzevoort B
(2023)
The Relationship Between the Global Mean Deep-Sea and Surface Temperature During the Early Eocene
in Paleoceanography and Paleoclimatology
Greene SE
(2019)
Early Cenozoic Decoupling of Climate and Carbonate Compensation Depth Trends.
in Paleoceanography and paleoclimatology
Reichgelt T
(2022)
Plant Proxy Evidence for High Rainfall and Productivity in the Eocene of Australia
in Paleoceanography and Paleoclimatology
Williams CJR
(2022)
African Hydroclimate During the Early Eocene From the DeepMIP Simulations.
in Paleoceanography and paleoclimatology
Dunne E
(2020)
Climatic drivers of latitudinal variation in Late Triassic tetrapod diversity
in Palaeontology
Inglis G
(2020)
A long-term, high-latitude record of Eocene hydrological change in the Greenland region
in Palaeogeography, Palaeoclimatology, Palaeoecology
Fischer H
(2018)
Palaeoclimate constraints on the impact of 2 °C anthropogenic warming and beyond
in Nature Geoscience
Naafs B
(2018)
High temperatures in the terrestrial mid-latitudes during the early Palaeogene
in Nature Geoscience
Cavalheiro L
(2021)
Impact of global cooling on Early Cretaceous high pCO2 world during the Weissert Event.
in Nature communications
Anagnostou E
(2020)
Proxy evidence for state-dependence of climate sensitivity in the Eocene greenhouse.
in Nature communications
Feng R
(2022)
Past terrestrial hydroclimate sensitivity controlled by Earth system feedbacks.
in Nature communications
Ayesiga G
(2022)
Linking Equatorial African Precipitation to Kelvin Wave Processes in the CP4-Africa Convection-Permitting Regional Climate Simulation
in Journal of the Atmospheric Sciences
Dutta D
(2021)
A multimodel investigation of atmospheric mechanisms for driving Arctic amplification in warmer climates
in Journal of Climate
Ayesiga G
(2020)
The observed synoptic scale precipitation relationship between Western Equatorial Africa and Eastern Equatorial Africa
in International Journal of Climatology
Niezgodzki I
(2022)
Simulation of Arctic sea ice within the DeepMIP Eocene ensemble: Thresholds, seasonality and factors controlling sea ice development
in Global and Planetary Change
Adloff M
(2021)
Inclusion of a suite of weathering tracers in the cGENIE Earth system model - muffin release v.0.9.23
in Geoscientific Model Development
Lunt D
(2021)
Multi-variate factorisation of numerical simulations
in Geoscientific Model Development
Hollis C
(2019)
The DeepMIP contribution to PMIP4: methodologies for selection, compilation and analysis of latest Paleocene and early Eocene climate proxy data, incorporating version 0.1 of the DeepMIP database
in Geoscientific Model Development
Farnsworth A
(2019)
Climate Sensitivity on Geological Timescales Controlled by Nonlinear Feedbacks and Ocean Circulation
in Geophysical Research Letters
Vervoort P
(2019)
Negative carbon isotope excursions: an interpretive framework
in Environmental Research Letters
Adloff M
(2020)
Unravelling the sources of carbon emissions at the onset of Oceanic Anoxic Event (OAE) 1a
in Earth and Planetary Science Letters
Wang Canfa
(2019)
Speleothem biomarker evidence for a negative terrestrial feedback on climate during Holocene warm periods
in EARTH AND PLANETARY SCIENCE LETTERS
Zhang Z
(2021)
Mid-Pliocene Atlantic Meridional Overturning Circulation simulated in PlioMIP2
in Climate of the Past
Williams C
(2020)
CMIP6/PMIP4 simulations of the mid-Holocene and Last Interglacial using HadGEM3: comparison to the pre-industrial era, previous model versions and proxy data
in Climate of the Past
Oldeman A
(2021)
Reduced El Niño variability in the mid-Pliocene according to the PlioMIP2 ensemble
in Climate of the Past
Berntell E
(2021)
Mid-Pliocene West African Monsoon rainfall as simulated in the PlioMIP2 ensemble
in Climate of the Past
Dunkley Jones T
(2020)
OPTiMAL: a new machine learning approach for GDGT-based palaeothermometry
in Climate of the Past
Lunt D
(2021)
DeepMIP: model intercomparison of early Eocene climatic optimum (EECO) large-scale climate features and comparison with proxy data
in Climate of the Past
Williams C
(2021)
Simulation of the mid-Pliocene Warm Period using HadGEM3: experimental design and results from model-model and model-data comparison
in Climate of the Past
Han Z
(2021)
Evaluating the large-scale hydrological cycle response within the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) ensemble
in Climate of the Past
Weiffenbach J
(2023)
Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2
in Climate of the Past
| Description | We are currently building our model capability using UKESM. Our Eocene model simulations are currently being run. We have also carried out HadCM3 simulations with a perturbed parameter set. We have also carried out Pliocene HadGEM3 simulations as a stepping-point towards the Eocene. These are currently published, and have been included in the IPCC AR6. A large number of papers are currently in prep/press arising from the overall DeepMIP project, to which SWEET is aligned. See https://www.deepmip.org/publications-eocene/ . |
| Exploitation Route | It will be incredibly useful for the UK paleoclimate modelling community, who will benefit from our expertise with UKESM. The Pliocene simulations that we have carried out have contributed to the wider PlioMIP community. |
| Sectors | Environment |
| URL | https://www.deepmip.org/sweet/ |
| Description | Climate of Game of Thrones. See e.g. https://www.paleo.bristol.ac.uk/~ggdjl/westeros/game_thrones_1.0.pdf https://www.theguardian.com/science/blog/2018/jan/23/why-the-climate-of-game-of-thrones-is-about-more-than-the-arrival-of-winter |
| First Year Of Impact | 2018 |
| Sector | Education,Leisure Activities, including Sports, Recreation and Tourism |
| Impact Types | Cultural Societal |
| Description | IPCC activities |
| Geographic Reach | Multiple continents/international |
| Policy Influence Type | Participation in a guidance/advisory committee |
| Impact | Influence through IPCC report. |
| URL | https://www.ipcc.ch/assessment-report/ar6/ |
| Title | Age model of the Mossy Grove sediment core |
| Description | |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://doi.pangaea.de/10.1594/PANGAEA.960397 |
| Title | BIT Index, GDGT-derived OPTiMAL and BAYSPAR paleotemperatures for the Mossy Grove sediment core |
| Description | Samples were processed for GDGTs at the Birmingham Molecular Climatology Laboratory, University of Birmingham. Lipids were extracted from ~10-15 g of homogenized sediment by ultrasonic extraction using dichloromethane (DCM):methanol (3:1). The total lipid extract was fractionated by silica gel chromatography using n-hexane, n-hexane:DCM (2:1), DCM, and methanol to produce four separate fractions, the last of which contained the GDGTs. Procedural blanks were also analyzed to ensure the absence of laboratory contaminants. Samples were filtered using hexane:isopropanol (99:1) through a 0.4 µm PTFE filter (Alltech part 2395), before being dried under a continuous stream of N2. Samples were then sent to the University of Bristol for analysis by LC-APCI-MS. HPLC-APCI-MS analyses were conducted at the National Environmental Isotope Facility, Organic Geochemistry Unit, School of Chemistry, University of Bristol, with a ThermoFisher Scientific Accela Quantum Access triple quadrupole MS in selected ion monitoring (SIM) mode. Normal phase separation was achieved using two ultra-high performance silica columns (Acquity UPLC BEH HILIC columns, 50 mm × ID 2.1 mm × 1.7 µm, 130 Å; Waters) were fitted with a 2.1 mm × 5 mm guard cartridge after Hopmans et al. (2016). The HPLC pump was operated at a flow rate of 200 µL min-1. GDGT determinations were based on single injections. A 15 µL aliquot was injected via an autosampler, with analyte separation performed under a gradient elution. The initial solvent hexane:iso-propanol (IPA) (98.2:1.8 v/v) eluted isocratically for 25 min, followed by an increase in solvent polarity to 3.5 % IPA in 25 min, and then by a sharp increase to 10 % IPA in 30 min (Hopmans et al., 2016). A 45 min washout period was applied between injections, whereby the column was flushed by injecting 25 µL hexane:isopropanol (99:1 v/v). GDGT peaks were integrated manually using Xcalibur software. In-house generated standard solutions were measured daily to assess system performance. One peat standard was run in a sequence for every 10 samples and integrated in the same way as the unknowns. Selected ion monitoring (SIM) was used to monitor abundance of the [M+H] + ion of the different GDGTs instead of full-scan acquisition in order to improve the signal-to-noise ratio and therefore yield higher sensitivity and reproducibility. SIM parameters were set to detect the protonated molecules of isoprenoid and branched GDGTs using the m/z (Schoon et al., 2013). The majority of sediments were found to contain a full range of both isoprenoid and branched GDGTs. Sea surface temperature (SST) estimations from GDGT assemblages are show based on two methodologies: the BAYSPAR Bayesian regression model of Tierney and Tingley (2014, 2015) using the 'analogue' version for deep-time applications; and, the OPTiMAL Gaussian process model of Dunkley Jones et al. (2020). When plotting BAYSPAR SSTs we distinguish samples with BIT indices greater than and less than 0.4, as high BIT can be associated with a small warm bias (Weijers et al., 2006). For the OPTiMAL model we apply its own internal screening criteria that quantifies the extent that fossil GDGT assemblages are non-analogue relative to the modern calibration data, using the Dnearest criteria with a cut-off value of 0.5. All but one pre-NIE GDGT assemblages have Dnearest values that exceed 0.5, whereas eight samples above this level have values less than 0.5.Only OPTiMAL SST data that pass the Dnearest screening criteria are shown. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://doi.pangaea.de/10.1594/PANGAEA.960406 |
| Title | Benthic foraminifera stable isotope data for the Mossy Grove sediment core |
| Description | Sample preparation for benthic foraminiferal stable-isotope analyses: Sediment amples were prepared and analyzed at Kochi University. Samples were washed through a 63 µm screen with Calgon in tapwater, and the residue was dried at 50 °C. Specimens of U. jacksonensis were picked from the >150 µm fraction of the residues, and were found to be present in 38 sediment samples. The specimens are well-preserved appearing transparent to translucent in color under the light microscope (Figure S2). Using a Keyence VHX-2000 digital microscope and a JEOL JSM-6500F scanning electron microscope, the preservation of examined specimens was assessed. The light microscopic image is focus stacking. To extend this record down core, a further five samples were prepared at the University of Birmingham. These samples were dried in a low-temperature oven at 40°C for approximately one week in order to obtain a dry bulk sediment weight and then washed over a 63 µm sieve with de-ionised water. The coarse fraction (>63 µm) was dried in the oven and then dry sieved at 250-300 µm and individuals of the infaunal benthic foraminifera genus Uvigerina picked (wherever possible U. jacksonensis was selected). Any sample with more than two individuals was analyzed for stable isotopes (>10 µg).The stable carbon (d13C) and oxygen (d18O) isotope analysis of five benthic foraminiferal samples prepared at the University of Birmingham were performed at the British Geological Survey, Keyworth, UK on a dual inlet, gas source, isotope ratio mass spectrometer. The carbonate analysis method involves reacting the carbonate sample with anhydrous phosphoric acid to liberate CO2. All data are reported against Vienna Pee Dee Belemnite standard (VPDB). Calibration of the in-house standard with NBS-19 shows the analytical precision is < ±0.01‰ for both isotope ratios. For the 38 benthic foraminifera samples prepared at Kochi University, we used a Finnigan MAT253 mass-spectrometer system with a Kiel III carbonate device in the Center for Advanced Marine Core Research/Kochi Core Center (CMCR/KCC), Kochi University. Between 2-7 individuals were measured in each sample and were cleaned at least three times, using milli-Q and methanol in a sonic bath. NBS-19 and ANU-m2 were used as stable isotopes standards. The precisions of the measurements (1s) were 0.18‰ and 0.08‰ for d13C and d18O respectively, calculated using 24 repeat measurements of the standard. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://doi.pangaea.de/10.1594/PANGAEA.960399 |
| Title | Data supplement to: Plant proxy evidence for high rainfall and productivity in the eocene of Australia |
| Description | During the early to middle Eocene, a mid-to-high latitudinal position and enhanced hydrological cycle in Australia would have contributed to a wetter and "greener" Australian continent where today arid to semi-arid climates dominate. Here, we revisit 12 Australian plant megafossil sites from the early to middle Eocene to generate temperature, precipitation and seasonality paleoclimate estimates, as well as net primary productivity (NPP) and vegetation type, based on paleobotanical proxies and compare to early Eocene global climate models. Temperature reconstructions are uniformly subtropical (mean annual, summer, and winter mean temperatures 19-21 °C, 25-27 °C and 14-16 °C, respectively). This indicates that southern Australia was ~5 °C warmer than today, despite a >20° poleward shift from its modern geographic location. Precipitation was less homogeneous than temperature, with mean annual precipitation of ~60 cm over inland sites and >100 cm over coastal sites. Precipitation may have been seasonal with the driest month receiving between 2-7× less precipitation as mean monthly precipitation. Proxy-model comparison is favorable with an 1680 ppm CO2 concentration. However, individual proxy reconstructions can disagree with models as well as with each other. In particular, seasonality reconstructions have systemic offsets. NPP estimates were up to 1000 gC m-2 yr-1 higher than modern, implying a more homogenously "green" Australian continent in the early to middle Eocene and larger carbon fluxes to and from the Australian biosphere. The most similar modern vegetation type is modern-day eastern Australian subtropical forest, although distance from coast and latitude may have led to vegetation heterogeneity. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2022 |
| Provided To Others? | Yes |
| URL | http://datadryad.org/stash/dataset/doi:10.5061/dryad.59zw3r294 |
| Title | Fine fraction (<20 µm) bulk stable isotope data for the Mossy Grove sediment core |
| Description | Sample preparation for carbonate fine-fraction stable-isotope data: A total of 444 bulk sediment samples, taken at ~30 cm spacing from the Mossy Grove Core (MGC), were processed at the University of Birmingham. The sediment was sieved over a 20 µm stainless steel mesh, with the fine fraction passing through the sieve captured on ultra-fine-grade filter paper and air dried. The sediment residue (>20 µm) was then transferred to 50 ml centrifuge tubes and organic matter within this fine fraction removed by overnight reaction with 5% sodium hypochlorite (NaClO) solution. The sample was then spun down at 4,500 rpm (6,800 × g) and the supernatant discarded. The sample was then washed 2-3 times with de-ionized water - each wash consisting of resuspension, agitation and then centrifuging and discarding of the solution as above - until a neutral pH was established. Samples were then weighed to provide sufficient sample mass for sample analysis.The stable carbon (d13C) and oxygen (d18O) isotope analysis of 444 fine-fraction sediment samples prepared at the University of Birmingham were performed at the British Geological Survey, Keyworth, UK on a dual inlet, gas source, isotope ratio mass spectrometer. The carbonate analysis method involves reacting the carbonate sample with anhydrous phosphoric acid to liberate CO2. All data are reported against Vienna Pee Dee Belemnite standard (VPDB). Calibration of the in-house standard with NBS-19 shows the analytical precision is < ±0.01‰ for both isotope ratios. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://doi.pangaea.de/10.1594/PANGAEA.960398 |
| Title | Selected palynomorph-based indicators for the Mossy Grove sediment core |
| Description | Palynology: Altogether, 112 samples collected at ~1.2 m intervals from the Mossy Grove borehole between ~17.0 and 152.0 m were treated with 40% HCl for 30 minutes and 60% HF for 24 hours to dissolve carbonates and disaggregate the rock matrix, and sieved over a 10 µm nylon mesh to retain the HF effluent from the material. A second HCl treatment was applied to remove any precipitate, followed by a final sieving over a 10 µm mesh. The remaining sample material (>10 µm) was subjected to oxidation (70% HNO3 for exactly two minutes) to remove pyrite, debris and any unstructured organic material from the palynomorphs, followed by another sieving over a 10 µm mesh to remove any HNO3 effluent. A final cleaning treatment was undertaken with a combination of domestic and industrial detergents. Using swirling techniques, palynomorphs in each sample were then concentrated and Bismark brown was added to make them more visible with light microscopy. Finally, the samples were sieved into two size fractions, 10-30 µm (concentrating spores and pollen) and 30 µm+ (concentrating dinocysts), and then mounted on separate 22x22 mm coverslips, which were glued to a glass slide using Norland optical adhesive. In this work, only the coarse-fraction content of each slide was analyzed. A pilot survey of these slides revealed that the acid and oxidizing technique yielded higher diversity than their non-acid and non-oxidizing counterparts61. The coarse/fine-fraction sorting follows the premise that pollen and spores size mostly ranges between 11 and 44 µm, whereas dinocysts range between 20 and 150 µm62. All slides are stored in the collection of the School of Geography, Earth and Environmental Sciences, University of Birmingham, and are available upon request from Tom Dunkley Jones.Palynomorph components: In this work, the coarse-fraction content of each slide was analyzed with a Zeiss transmitted light microscope (400x magnification). Two hundred dinocyst specimens were counted in each sample, along with any spores, pollen, algae (prasinophyceae and chlorophyceae), zoomorphs/zooclasts, phytoclasts and amorphous organic matter. Only palynomorphs that were more than 50% complete and not obscured either by air bubbles or organic debris were considered 63. Reworked acritarchs and amorphous organic matter were excluded from the final sum of palynomorphs and thereby from the percentage calculations. Palynomorph-based paleoenvironmental indicators include the peridinioid/gonyaulacoid dinocyst (P/G) ratio 64-70, and salinity reconstructions based on the relative abundance of the high-salinity favoring Homotryblium spp. 43,71-73 and in the ratio of short-to-long process of dinocyst genus Spiniferites 74-78. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://doi.pangaea.de/10.1594/PANGAEA.960400 |
| Title | X-ray fluorescence data for the Mossy Grove sediment core |
| Description | Elemental composition of the sediment core was determined using two XRF techniques. 2,098 samples on the original core section were directly analyzed at a resolution of ~1.2 cm across the interval 17.1-109.4 m with a hand-held XRF analyzer at the core store of the Mississippi Department of Environmental Quality, in Jackson, Mississippi. A further 179 samples were collected every 20-30 cm downcore, spanning the interval 106.8-151.6 m, and were subsequently finely ground and dried before analysis as pressed powders in wax pellets. Pellets were analyzed with a Bruker S8 TIGER XRF spectrometer with an 8 min analysis time, at the School of Chemistry, University of Birmingham. We selected the (Al+Fe+K+Ti)/Ca ratio as a paleoenvironmental indicator of terrigenous-derived versus marine planktonic carbonate sediment 79,80. The two methodologies were cross-calibrated over an interval of overlap between 106.8 and 109.4 m, with a total of ~80 samples, spanning a range of compositions, cross-correlated from both analysis methods. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| URL | https://doi.pangaea.de/10.1594/PANGAEA.960404 |
| Description | The DeepMIP community |
| Organisation | Purdue University |
| Department | Department of Earth, Atmospheric and Planetary Sciences |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | I founded DeepMIP and am the lead organiser. |
| Collaborator Contribution | All members of the DeepMIP community contribute. |
| Impact | Multidisciplinary. www.deepmip.org for more info. |
| Start Year | 2015 |
| Title | carbonatefan/OPTiMAL: First release. |
| Description | OPTiMAL code in support of: Eley, Y. L., Thompson, W., Greene, S. E., Mandel, I., Edgar, K., Bendle, J. A., and Dunkley Jones, T.: OPTiMAL: A new machine learning approach for GDGT-based palaeothermometry, Clim. Past Discuss., https://doi.org/10.5194/cp-2019-60, in review, 2019. |
| Type Of Technology | Software |
| Year Produced | 2020 |
| Open Source License? | Yes |
| URL | https://zenodo.org/record/4293850 |
| Description | Game of Thrones model simulations |
| Form Of Engagement Activity | Engagement focused website, blog or social media channel |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Public/other audiences |
| Results and Impact | We started a Twitter account for @ClimateSamwell, where we described the process of running a climate model simulation of Game of Thrones. We also wrote a mock paper. there was significant media interest. |
| Year(s) Of Engagement Activity | 2017,2018,2019 |
| URL | https://twitter.com/ClimateSamwell |