PhD Topics for Entry September 2025

There are three projects involving thefosterlab both with a deadline Wednesday 8th January 2025.  Here is a link of how to apply: https://inspire-dtp.ac.uk/how-apply.  NB it is open to overseas applicants (although the DTP has a cap on how many overseas students it can take).

These projects are fully funded but will be offered on a competitive basis with interviews in February 2025.  Please get in touch with Gavin if you want to know more (g.l.foster@soton.ac.uk).

Project 1: It’s getting hot in here – coral-based reconstructions of ocean warming

When the Earth’s temperature breaches the Paris climate targets of +1.5 and +2 C depends on the choices we make in terms of emissions but also on the temperature of the Earth during the “pre-industrial” era – a loose and undefined period before the 1900s.  While we have a good idea of the temperature of the surface of the Earth today, our uncertainties increase as we go back in time.  This is largely due to changes in observation technology and data coverage associated with measuring ocean temperature (Voosen et al., 2024).  The upshot being that although 2023 was agreed to be the hottest year on record, one data product placed it at +1.34 C warmer than pre-industrial, the other at +1.54 C!  That’s a big error in the global mean that is largely due to the slightly different pre-industrial ocean temperatures in the products used. 

In this project we will improve our reconstructions of ocean temperature during the pre-industrial by turning to palaeoclimate, and coral based proxies in particular.  If you like lasers and corals, and firing lasers at corals to improve our understanding of the magnitude of historic climate change – then this is the project for you!

Click here to find out more

Project 2: Exploring the eruptive behaviour of a rare young stratovolcano

Subduction zone volcanoes are notoriously dangerous and unpredictable. Volcanoes in these settings tend to have a mature plumping system that can produce a diversity of magma compositions and explosivities.  This diversity of eruption styles (effusive/explosive), sizes, and pre-eruptive unrest periods (days/decades) pose fundamental challenges to volcanic risk reduction.  By contrast, the plumbing systems of young, immature stratovolcanoes are less complex, resulting in potentially less diverse eruption mechanisms and styles. However, due to their scarcity, young stratovolcanoes remain poorly understood. This project will overcome this limitation by studying a young, persistently active stratovolcano (Bagana, Papua New Guinea) to catalogue its eruptive history and characterize the dynamics and timescales of magma assembly prior to eruptions. This unique dataset will be compared with a mature reference volcano (Etna, Italy; fieldwork optional) and with published data from other arc volcanoes.

In this project, led by Dr Martin Mangler, we use novel imaging tools, that include laser ablation time of flight ICPMS (e.g. Standish et al., 2024), in a correlative framework to reveal the full complexity of the plumbing systems of these volcanoes. 

Click here to find out more

Project 3: Are extreme rainfall events more frequent in a warmer world?

Have you ever wondered what the weather was like 56 million years ago during the Paleocene-Eocene Thermal Maximum (PETM)? Yes? Well this project is for you!

Predicting future rainfall patterns remains highly challenging and there is a profound disagreement amongst climate model projections. In this project, you reconstruct the hydrological cycle during the PETM using the hydrogen isotopic composition of leaf waxes in terrestrial sediments. A geochemical characterisation of the sediments will also help reveal leaf wax provenance and sediment transport histories. Together this will provide vital constraints on the response of the hydrological cycle under higher CO2 concentrations. 

Click here to find out more

PhD projects entry September 2024

There are two projects this year involving my research group, both with a deadline of 3rd Jan 2024, here is a link to how to apply (https://inspire-dtp.ac.uk/how-apply).

 Project 1: The Acid Test – high-resolution records of climate change across the PETM and other hyperthermals (link for more details).

The most recent time in the geological past when Earth’s climate changed as fast as it is doing today was during the PETM – the Paleocene-Eocene Thermal Maximum – 56 million years ago.  In this project you will generate new records of ocean acidification (OA) and warming across this event using laser ablation of individual foraminifera.  Each foram grows in the upper ocean over a couple of weeks to a month, so in its shell is encapsulated a super high-resolution picture of past climate.  Unfortunately, that high-resolution picture of climate is scrambled by the slowly accumulating sediment record as the foram gets mixed up with and churned around by benthic organisms.  By combining single foram analysis of boron isotopes, trace element composition and carbon and oxygen isotopes with a sediment mixing model and outputs of the GENIE Earth system model (as part of a wider project called C-FORCE) you will “see-through” the mixing to reveal the true nature of the OA across the PETM and other hyperthermals of the Eocene.  This project will also enable you to take part in International Continental Scientific Drilling occurring in the US to collect more material across these key climate events.

 Project 2: It’s getting hot, sour and breathless – impacts of climate change on carbon(ate) fixation by foraminifera (link for more details)

Foraminifera are not just archives of past climate change (see Project 1) but form a key aspect of the ocean carbon(ate) pump.  How this key long-term sink of CO2 out of the atmosphere will be impacted by future climate change will depend on how the calcification of forams responds to the oceans getting hot, sour and breathless.  This project is led by David Evans and involves using cutting edge techniques to analyse cultured foraminifera as well as forams from unique museum collections to determine the response of forams of various species to OA, warming, and changes in O2.

Please get in touch with Gavin (g.l.foster@soton.ac.uk) if you want to know more and are interested in these projects.

Project 3: How do foraminifera grow? Determining the role of cellular ion transport processes in biogenic marine calcite formation (link for more details)

How foraminifera actually calcify (make their shells) is only poorly understood. Here the role of Mg ion transport and amorphous precursor phases in foraminiferal calcification will be explored using a suite of techniques to study live foraminifera. This project is also led by David Evans as part of his ERC.

Laser Ablation System and Neptune MC-ICPMS

in our Geochemistry Lab in Southampton

live planktonic foram

live planktonic foram with calcite spines, streaming pseudopods and photosynthetic symbionts. Credit: Dr. Howard J. Spero, University of California, Davis/ Smithsonian NMNH

Image of a sediment core showing the PETM

Red clay band in deep-sea sediment cores marks the onset of the PETM. Image courtesy of J. Zachos.

Our Neoma MS/MS MC-ICPMS

The Neoma is a state of the art mass spec capable of removing interfering Ca ions that make boron by laser ablation difficult.

Amoeboid foraminifera

A confocal image of an amoeboid decalcified but living planktic foraminifera (see Bentov and Erez, 2005, Geology). The bright yellow areas are calcein stained, the red areas are symbionts. Image credit: David Evans

Rushing to save Coral Reefs

Gavin was interviewed last month about how a better understanding of the mechanisms involved in coral skeleton formation can help conserve this really important ecosystem. You can read the article here

PhD Opportunities @theFosterlab for entry October 2023

We have four projects this year. For projects 1-3 the deadline for application is 3rd of January 2023 and for project 4 its the 9th of January 2023. To apply for projects 1-3 here and projects 4 here.

Project 1.  Hot, acidified and breathless – biomineralisation of deep sea corals in the oceans of the future. 

Deep sea stony corals form the foundations for large reefs 100s to 1000s of metres below the surface of the ocean, providing a key habitat for marine life.  Yet even this habitat deep in the abyss is threatened by anthropogenic climate change.  In order to better protect this precious environment and see what the future has instore for it, we aim here to understand the process of skeleton building (biomineralization) in the deep-sea coral species Lophelia pertusa using a range of cutting edge approaches analytical and imaging approaches (from genes to geochemistry).  Opportunities exist to take part in coral culturing work going on at St. Abbs Marine Station (https://marinestation.co.uk/) and to go to sea to collect live species.  Experience/knowledge of geochemistry/chemistry as well as an interest and/or experience with coral biology would be useful prerequisites.

This project is led by Gavin and co-supervised by Sumeet Mahajan from Chemistry at Southampton, Cecilia D’Angelo from Southampton’s Coral Reef Laboratory and Murray Roberts from Edinburgh. It is closely aligned with Gavin’s ERC Advanced Grant Microns2Reefs

More details here

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Project 2. Exploring the mechanisms of microplastics incorporation and their influence on the functioning of coral holobionts.

Microplastics are found everywhere from the top of Everest to the Marina Trench.  The influence of microplastics on corals and the reefs they construct is largely uncertain.  This project aims to use a combination of advanced laboratory study and novel analytical approaches to examine the mechanisms of microplastic incorporation into the coral holobiont and therefore determine how and why microplastics impact coral health.  Experience/knowledge of Raman imaging techniques as well as an interest and/or experience with coral biology would be useful prerequisites.

This project is led by Prof Sumeet Mahajan and is co-supervised by Gavin, Joerg Wiedenmann and Cecilia D’Angelo from Southampton’s Coral Reef Laboratory. 

More details here

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Project 3. Unraveling oceanic multi-element cycles using single cell ionomics. 

Oceanic elemental cycles are strongly influenced by marine microbes, including phytoplankton.  However our picture of such elemental cycling is typically only based on a few elements and is averaged across mixed communities of species.  Here we will apply a new analytical tool (Time of Flight Inductively Coupled Plasma Mass Spectrometry, ToF-ICPMS) to facilitate rapid multi-element analysis of individual marine phytoplankton cells and zooplankton.  By applying a multi-element “ionomic” approach this project will facilitate a deeper understanding of multi-elemental ocean biogeochemical cycles.  Experience with marine biogeochemistry and a desire to develop a new analytical approach are important prerequisites. 

The project is being led by Mark Moore from Southampton, and co-supervised by Gavin and Maeve Lohan from Southampton and Kate Hendry from the British Antarctic Survey.  Opportunities exist to sample natural plankton communities around the UK and further afield (e.g. the Southern Ocean). 

More details here

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Project 4. Imaging the metallome using correlative laser ablation mass spectrometry.  

Many metallic elements are critical to cellular functioning and inappropriate concentration of metals can be toxic. Thus regulation of cellular metal concentrations (the metallome) is critical.  Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) based approaches have emerged as the most suitable techniques to achieve this.  However, current approaches only provide a limited picture of metal distribution in 2D. Here, the student will exploit two new technologies to develop an imaging pipeline to enable the rapid (<1 hour) generation of high resolution (<5 µm) 2D images of the full metallome (from H to U) of mm-scale biological tissues. The rapidity enables serial sections to be measured allowing 3D images to be constructed, thereby yielding new understanding of metallomic regulation, its perturbation, and its role in disease or toxicity.  A desire to develop a multidisciplinary skillset is an important prerequisite and a good level of knowledge about geochemistry, chemistry and biology would be desirable.

This project is being led by Gavin, and is co-supervised by Matthew Loxham in Medicine at Southampton and Craig Storey from Portsmouth. 

More details here

Record breaking CO2 AGAIN

Once again atmospheric CO2 reached its yearly maximum in May, this time hitting 420 ppm. Its been a while since I posted this update (mainly because I find it too depressing!) but here is the latest palaeo-CO2 compilation (from the IPCC Figure 2.3 - data and sources here, script here). As you can see from the plot, as far as we can tell, CO2 hasn’t been this high for at least the last 2 million years (one of the headline statements in the AR6 - based on this data). Uncertainties for this palaeo-CO2 is obviously relatively high and our data coverage is relatively poor compared to the ice core, but I wouldn’t mind betting that CO2 actually hasnt been this high for at least 3 million years. Clearly we live in unusual times!

Atmospheric CO2 reconstructed from Marine proxies and ice core methods for the last 3.5 million years. Also shown is the CO2 for May 2022 (420 ppm) and the atmospheric record from mUana Loa

PhD opportunities @theFosterlab 2022 Start

We have 2 fully funded PhD projects available this year. Please click on the links below for more details and go to GSNOCS (our graduate school) for details how to apply. The deadline is 4th January 2022. Note that both projects are available to UK, EU and overseas students as there is a fee waiver on offer. Please contact Gavin through this website (here) or email: gavin.foster@noc.soton.ac.uk if you want to chat about either of them

Project 1. The Acid Test: revolutionizing the record of abrupt changes in ocean pH through novel laser analysis of marine microfossils

Do you like lasers?

Do you want to study the closest analogues to anthropogenic climate change in the last 56 million years?

Do you want to study the closest analogue to anthropogenic climate change in the last 56 million years with lasers?

Then we have a PhD that is perfect for you!

In this project the student (i.e. you) will use cutting edge laser ablation and mass spectrometry techniques to ablate SINGLE foraminifera for their boron isotopic and trace element composition (following the method outline here and new approaches we are working on).  Then what is left of the foram shell will be measured by gas source mass spec for d18O/d13C.  So from the same single foram you get information about the pH it experienced during its life time, the temperature (from Mg/Ca), what ice was doing (d18O) and the carbon cycle (d13C) – all from 50 odd million years ago!

You will apply this tool kit to study two key events that have been difficult thus far because foram abundance is low and/or we want to look at them at super high resolution: the Paleocene Eocene Thermal Maximum and Eocene Thermal Maximum-2 (with the legend that is Jim Zachos at UCSC).

Get in touch with me (gavin.foster@noc.soton.ac.uk) if you want to know more.

Project 2. Unravelling oceanic multi-element cycles using single cell ionomics.

Do you want to start a revolution?

Then this project is for you!

Ionomics is the measurement of the total elemental composition of an organism to address a biological problem. In this project we want to quantify how the variability in co-limiting oceanic nutrients influences the multi-elemental cellular composition of non-limiting nutrients – something that is essential to understand coupled cycling of nutrients like carbon, nitrogen and phosphorous in the ocean.  Although single-cell analysis has become increasing important for cellular biologists its application in the marine sciences remains rather limited because of the lack of suitable analytical techniques.

In this project you will exploit the new Time of Flight ICPMS installed at Southampton (https://www.southampton.ac.uk/oes/research/facilities/time-of-flight-icp-ms.page) to overcome this analytical bottle neck.   By using single cell analysis and laser ablation approaches you will generate some truly novel data to provide insights into how nutrient limitations by one element influences the cellular composition of other elements and how this varies between taxa and sub-populations. 

This project is led by Prof Mark Moore and involves scientists from the British Antarctic Survey (BAS) and includes the possibility of field work in coastal waters around Antarctica. 

Get in touch with me (gavin.foster@noc.soton.ac.uk) or Mark Moore (c.moore@noc.soton.ac.uk) if you want to know more. 

Job Vacancy @thefosterlab

We are looking to fill a 3 year Post-Doc position funded via Gavin’s Microns2Reefs ERC grant (click here).  The post will be line managed by Gavin and Dr Cecilia D’Angelo from the Coral Reef Laboratory (click here and see picture below)  at the School of Ocean and Earth Sciences.

The job advert is here 

The closing date is the 15th November 2021. Please get in touch if you want to know more. Contact details here

The skeletons of corals can store information about past climate (Credit Wiedenmann D'Angelo)

Coral Reef Auquarium Facility at the UoS Waterfront Campus (Credit WIedenmann D'Angelo)

PhD opportunities @theFosterLab start 2021 still available!

We still have 1 fully funded PhD project available this year. Please click on the links below for more details and go to GSNOCS (our graduate school) for details on how to apply. The deadline is 16th June 2021. Please contact Gavin through this website (here) or email: gavin.foster@noc.soton.ac.uk if you want to chat about them.

How do corals make their skeletons? Insights from boron geochemistry

Tropical coral reefs are diversity hotspots and provide many ecosystem services that sustain important economic activities.  Both of these depend on the 3D framework of the reef that is constructed within a micron-sized space sandwiched between the coral animal and its existing skeleton.  If we are to better predict what the coming decades have in stall for corals and the reefs they make we need to understand this calcification process better. One way to do this is with the boron based proxies that reveal the state of the carbonate system in the calcifying space.

In this project you will use laboratory experiments to grow aragonite (the CaCO3 polymorph corals use) under controlled conditions to better understand exactly how boron geochemistry reflects the carbonate system. The improved understanding you will develop will then be tested using careful measurements of the calcifying fluid using micro-electrodes and pH sensitive dyes and will feed into mechanistic models of calcification that can be used to understand how environmental change influences how corals build their skeletons.

For more details go here. Gavin is the lead supervisor for this PhD project is funded by the European Research  Council as part of Prof Gavin Foster’s recently funded Advanced Grant Microns2Reefs.  The project includes an extended stay in the laboratory of Prof Jonathan Erez in Jerusalem and potentially field work in the Red Sea to collect suitable coral species for culturing. 

Coral Reefs are the largest bioconstructions on the planet. The 3d Framework of a reef is made by the skeletons of colonial scleractinian corals. Each colonies skeleton is constructed in a micron-sized space sandwiched between the existing skeleton and the coral animal. Schematic anatomy of colonial coral from Tambutte et al. (2011) labelled A and B

PhD opportunities @theFosterLab 2021 Start

We have 3-fully funded PhD projects available this year (and we are involved with one project with Glasgow - see below). Please click on the links below for more details and to to GSNOCS (our graduate school) for details on how to apply. The deadline is 04 January 2021. Please contact Gavin through this website (here) or email: gavin.foster@noc.soton.ac.uk if you want to chat about them. Note for this year, Project 1 and 3 are suitable for UK, EU and overseas students as there is a fee waiver on offer. So where ever you are - please apply!

Project 1. Forams in the laser sights – time capsules of monthly-scale pH and temperature fluctuations.

If you like lasers and you like forams (and who doesn’t?) then this is the project for you!

We all know forams are great archives of past climates, but unfortunately their life processes and the mechanics of biomineralisation (how they make their shells) complicates how well they trace past environmental change (so called “vital effects”).  The current method of analysis, where 10s to 100s of forams are crushed and analysed together, also represents a missed opportunity of reconstructing past climate change at a much higher resolution as each foram only lives for around a month and thus is potentially a high temporal resolution archive of climate change in the past.

In this project you will use new in situ laser ablation techniques to analyse Mg/Ca (for temperature) and d11B (for pH) at a fine-scale to improve our understanding of vital effects and unlock the potential of foraminifera to record temperature and pH at monthly scales.

For more details click here.   Gavin is the lead supervisor for this project and it is funded by our INSPIRE DTP and includes the opportunity for field work in Bermuda to collect plankton tows and will use a number of new mass spectrometers we have recently purchased – including a time of flight ICPMS (the only one in a geoscience department in the UK)

Project 2.  How do corals make their skeletons? Insights from boron geochemistry

Tropical coral reefs are diversity hotspots and provide many ecosystem services that sustain important economic activities.  Both of these depend on the 3D framework of the reef that is constructed within a micron-sized space sandwiched between the coral animal and its existing skeleton.  If we are to better predict what the coming decades have in stall for corals and the reefs they make we need to understand this calcification process better. One way to do this is with the boron based proxies that reveal the state of the carbonate system in the calcifying space.

In this project you will use laboratory experiments to grow aragonite (the CaCO3 polymorph corals use) under controlled conditions to better understand exactly how boron geochemistry reflects the carbonate system. The improved understanding you will develop will then be tested using careful measurements of the calcifying fluid using micro-electrodes and pH sensitive dyes and will feed into mechanistic models of calcification that can be used to understand how environmental change influences how corals build their skeletons.

For more details go here. Gavin is the lead supervisor for this PhD project is funded by the European Research  Council as part of Prof Gavin Foster’s recently funded Advanced Grant Microns2Reefs.  The project includes an extended stay in the laboratory of Prof Jonathan Erez in Jerusalem and potentially field work in the Red Sea to collect suitable coral species for culturing. 

Coral Reefs are the largest bioconstructions on the planet. The 3d Framework of a reef is made by the skeletons of colonial scleractinian corals. Each colonies skeleton is constructed in a micron-sized space sandwiched between the existing skeleton and the coral animal. Schematic anatomy of colonial coral from Tambutte et al. (2011) labelled A and B

Project 3: Atmospheric CO2 variability and climate sensitivity during past warm climates - a lesson for the future?

The lead supervisor for this project is Dr Gordon Inglis here at Southampton and, as well as Gavin, it also involves Drs Jessica Whiteside (Southampton) and Jess Tierney (Arizona). By examining both the boron isotopic composition of foraminifera and the d13C of marine phytoplankton lipids during the Mid-Miocene (14 to 17 million years ago) this project aims to generate a high-fidelity, high-resolution multi-proxy CO2 record for this interval of global warmth. By comparing this new CO2 record to climate reconstructions at the time the student will be able to fully characterise the sensitivity of the Miocene Earth System to warming. This project is also funded through our INSPIRE DTP, for more details see Gordons website here.

Project 4: Understanding coral bleaching using multi-proxy bleaching reconstruction

Coral health is significantly impacted by coral bleaching (i.e. loss of symbionts). Coral bleaching is caused by a number of stressors such as thermal perturbations, disease, and freshwater runoff. This project aims to reconstruct past coral bleaching using a multiproxy approach applied to their skeletons, putting observationaly records of bleaching into a longer context to better evaluate the relevance of current bleaching trajectories. The lead supervisor of this project is Dr Nick Kamenos from The Univesrity of Glasgow, where the student will be based. The studentship is funded through the IAPETUS DTP - see here for more details. Note the deadline for the IAPETUS is Friday 8th Jan 2021 at 5pm.

CO2 in May 2020 at 417 ppm – highest in at least 2.5 million years

Despite the world grinding to a COVID-19 related halt in 2020, CO2 continues its inexhaustible rise.  Around this time of year the Mauna Loa CO2 record reaches its annual maximum and this year it is around 417 ppm (a 2 ppm increase on last year; see here).  As something of a tradition I have updated our plot of CO2 over the last 3.5 millions of years to reflect this. 

Plio-Pleistocene CO2 from ice core (red) and boron isotopes (blue). Sources indicated on text and listed here. Data downloadable here and Rscript here to make your own version of this figure.

While the CO2 rise we have seen thus far this year may well be a little bit smaller than expected because of the impact of COVID-19 (see this great analysis by Richard Betts and others for Carbon Brief here), it remains the case that atmospheric CO2 is higher NOW than it has been for around 2.5 million years.  As the economies of the world recover, CO2 will no doubt continue to increase in years to come.  Although Pliocene CO2 remains uncertain (watch this space!), with each passing year we are closer and closer to exceeding the CO2 levels last experienced 3 million years ago. 

Additional PhD opportunity 2020 start!

Do you lasers?

Do you want to study the closest analogue to anthropogenic climate change in the last 56 million years?

Do you want to study the closest analogue to anthropogenic climate change in the last 56 million years with lasers?

Then we have a PhD that is perfect for you!

In addition to the projects offered through our DTP (here) we have one other opportunity funded via the University of Southampton (click here for details)

The Acid Test: revolutionizing the record of abrupt changes in ocean pH through novel laser analysis of marine microfossils

In this project the student (i.e. you) will use cutting edge laser ablation techniques to ablate SINGLE benthic foraminifera for their boron isotopic composition (following the method outline here).  You will also develop an approach where you can measure trace element composition of the foram from the same ablation (called split-streaming, see here for more details).  Then what is left of the foram will be measured by gas source mass spec for d18O/d13C.  So from the same single benthic foram you get information about the pH it experienced during its life time (1-10 years), the temperature (from Mg/Ca), what ice was doing (d18O) and the carbon cycle (d13C).

You will apply this tool kit to study two key events that have been difficult thus far because foram abundance is low and/or we want to look at them at super high resolution: the Paleocene Eocene Thermal Maximum (with the legend that is Jim Zachos at UCSC) and the Eocene-Oligocene Transition.

Get in touch with me (Gavin.Foster@noc.soton.ac.uk) if you want to know more.  The deadline is 3rd of Jan.  Follow the link to the project above to see how to apply and to learn more about it etc.

Importantly this opportunity is open to overseas applicants!

PhD opportunities @theFosterLab 2020 start

Through our new DTP at Southampton (INSPIRE) we have 3-fully funded PhD projects available this year. Please click on the links below for more details and how to apply through GSNOCS (our graduate school). The deadline is 03 January 2020. Please contact Gavin through this website (here) or email: gavin.foster@noc.soton.ac.uk

Project 1. Multimodal-imaging of airborne particulate matter (PM) pollution as a means of source apportionment (here for more)

Airborne particulate matter (PM) is a key risk factor for premature death (8.9 million per annum worldwide) and reduced quality of life due to a range of diseases of the respiratory and cardiovascular system (e.g. more detail here).  In  order to do anything about this problem though we need to know what is causing the air pollution.  To do that we need to work out where it is coming from.  In this project the student will use the latest laser ablation technology, including our new time of flight inductively coupled plasma mass spectrometer (TOF-ICPMS), to carry out elemental analysis of airborne PM to apportion its source.  The TOF-ICPMS is a unique facility in the UK recently funded by NERC and, when coupled with laser ablation, will allow us to identify the source of air pollution in the port city of Southampton.  This work is part of cross university network of scientists from a range of disciplines tackling this important issue.

Figure showing element maps of urban PM made using laser ablation ICPMS from Gligorovski et al. (2008).

Photo showing the smoke plume from a cruise ship in dock in Southampton. The city has a diverse series of pollution sources that make mitigation a challenge that can be solved by the technical innovation offered by this project.

Project 2. Forams in the laser sights – getting the most out of laser ablation ICPMS analysis of planktic foraminifera (more info here)

Foraminifera are the preferred archive of past climate change. They secrete their shells from CaCO3 and different species live throughout the water column, allowing for detailed reconstructions of the past ocean. They live for around 4 weeks and when they die their shells accumulate on sea floor where they form a major component of deep ocean sediments. The standard way to analyse foraminifera is to aggregate 10-100 individuals, but this averages over time and obscures individual level variability in life cycle (and environment). Laser ablation approaches allow us to analyse individual chambers of the shells potentially providing environmental reconstruction at a much finer granularity. This project will couple standard laser ablation approaches with our new time of flight inductively coupled plasma mass spectrometer (TOF-ICPMS). This will allow us to unpick environmental from physiological signals with unprecedented spatial and temporal resolution. This work is closely associated with the NERC-funded multidisciplinary project PISTON (here)

Project 3. Novel microprobes for the geochemical gradients in diffusive boundary layers around marine calcifiers (here for more info)

Marine organisms, like corals and foraminifera, sense their environment through micron-scale diffusive boundary layers (DBL). Changes in external environment (temperature, pH, water chemistry) influence key physiological processes that determine O2 and pH gradients in the diffusive boundary layer around living organisms. The sensitivity of these processes in turn governs the impact of environmental changes on the organism, potentially offering a source of understudied resilience to climate change, but also influencing how environmental signals are encoded in the skeletons of many marine organisms as proxies of past climate (e.g. boron isotopes).  This project will develop new robust and accurate microelectrodes to study the microenvironment around living foraminifera in unprecedented detail.  This will allow us to gain unique insights into how future climate change will impact calcification in foraminifera and provide new constraints on the cause of proxy “vital effects”. This will is closely associated with the NERC funded SWEET grant (here)

Orbulina Universa being probed with microelectrodes

The microenvironment around a foraminfera being probed

There is also this opportunity that is not funded through our DTP but is open to all overseas candidates: http://www.thefosterlab.org/blog/2019/11/28/additional-phd-opportunity-2020-start

415 ppm CO2 threshold crossed May 2019

Some things in climate science are worryingly unpredictable – like when will the next ice shelf collapse off Antarctica? Or whether tropical storms will increase in frequency and strength in a warm world? Etc etc. However some things, like the ever increasing levels of CO2 in our atmosphere are getting all too predictable – Yesterday CO2 reached its annual maximum in the Mauna Loa Observatory, Hawaii crossing 415 ppm (13th May 2019).  Not that 415 ppm is an important figure, rather just a symbolic one.  Nonetheless, to honour this event I have updated our plot of CO2 over the last 3.5 million years.  And just to confirm, as has been the case for every May/June since the 1950s, atmospheric CO2 is higher NOW than it has been for around 2.5 million years. 

Plio-Pleistocene CO2 from ice core (red) and boron isotopes (blue). Sources indicated on text and listed here. Data downloadable here and Rscript here to make your own version of this figure.

To put this in context, this is a long time ago, e.g. this is what our human ancestors looked like back then (here).

New this year to the Pliocene to Pleistocene CO2 compilation: (i) new data from Dyez et al. (2018) for the interval around 1.5 million years ago; (ii) recalculation of Pliocene CO2 by Sosdian et al. (2018) and this.  This recalculation makes the data more accurate but also a little more uncertain. It also lowers the mean by 22 ppm – this doesn’t sound like a huge deal but makes the current CO2 higher than nearly all of the Pliocene.  Despite lots of talk it is still growing at 2-3 ppm per year - so I reckon by the time my kids leave school (ten years time) we will be outside of the Pliocene envelope and will have to go back 15 million years to the Miocene to see similar levels of CO2. It’s obviously not too late to act but we need to act fast!

Gavin takes part in award winning Radio programme

A BBC radio programme featuring Southampton Professor Gavin Foster has won an international award for science journalism.

The programme, broadcast on the BBC’s World Service in October 2017, was based around a listener’s question about ancient carbon dioxide levels compared to what they are today. Producer Cathy Edwards complimented Professor Foster on his contribution which she said was a “real highlight and played a part in the programme’s success”.

During his interview, Professor Foster, a specialist in Isotope Geochemistry, described how he is able to determine historic CO2 levels going back millions of years by studying ancient sea fossils drawn from sediment samples recovered from the sea floor. You can read more about this research here, and further information is also available here.

The Science Journalism Awards have been administered by the American Association for the Advancement of Science (AAAS) since their inception in 1945 to honour distinguished reporting for a general audience around the world. The awards are endowed by The Kavli Foundation which is dedicated to advancing science for public benefit and understanding.

You can listen to the full programme via the BBC website here.

PhD opportunities @theFosterlab

Through our new DTP at Southampton (INSPIRE) we have 3-fully funded PhD projects available this year. Please click on the links below for more details and how to apply through GSNOCS (our graduate school). The deadline is 04 January 2019. Please contact Gavin through this website (here) or email: gavin.foster@noc.soton.ac.uk

Boron isotopic composition of coralline algae at super-high resolution determined using laser ablation by Fietzke et al. (2015, PNAS). Examining the boron & carbon isotope variability at this scale in Project 1 is key for unpicking the health of coral reefs.

Project 1. Reconstructing the health and productivity of coral reef systems at high resolution: Laser ablation analysis of boron and carbon isotopes in corals. Here the student will develop and apply novel laser ablation methods to analyse boron and carbon isotopes in situ in corals (and potentially other carbonates) to determine the evolution of the ocean carbonate system at super high temporal resolution.

The Li, Sr and Os isotopic composition of the oceans over the last 70 million years from Misra et al. (2012). Project 2 investigates the role of the changing carbonate system in driving d7Li. Project 3 revisits the variability in 87Sr/86Sr over the Cenozoic to better determine the relationship between silicate weathering and climate.

Project 2. Lithium isotopes in foraminifera: a new proxy for the ocean carbonate system? Li isotopes in carbonates may be a tracer of weathering, but do they also reflect changes in the carbonate system? This project will examine this question through a combination of field, laboratory and culturing studies.

Project 3. Old proxy, New techniques: Reshaping the seawater strontium curve and resolving its implications for climate feedback processes. Sr isotopic composition of marine carbonates has long been used as a tracer of silicate weathering, new analytical techniques developed at Southampton offer the potential to use Sr to open a new window into the relationship between weathering and climate.

Hyperthermals - insights into our warm future from past rapid changes in climate

There are few, if any, direct analogues for anthropogenic climate change in the geological record.  This is because it is occurring at a pace that is rarely seen naturally, short of those rare times when the Earth is hit by an asteroid (e.g. 66 million years ago). There are events that occur natural that are however relatively similar - these are known as the “hyperthermals”.  These are geological rapid, relatively short events (<1 million years) characterised by rapid warming and caused by the injection of carbon to the climate system – typically a doubling or more of CO2 (see table below for a list of the most recent ones).

A summary of the most significant hyperthermals of the last 300 million years.  Italics indicate a high degree of uncertainty.  From Foster et al. (2018) - click here, also see original paper for references.

We @thefosterlab, with Celli Hull, Dan Lunt, and Jim Zachos organised a discussion meeting at the Royal Society last September to bring together scientists from many branches of the Earth Sciences to advance our understanding of these events and crucially try and fathom what they can tell us about our warm future.  This research has now been written up and turned into a special volume of the Philosophical Transactions of the Royal Society (here). I recommend you go and read them as many are open access and free to download. 

(Briefly) What can we learn from hyperthermals?

Exactly how the climate will respond to anthropogenic forcing is currently uncertain because our understanding of the climate system is incomplete. Hyperthermals, however paint a very consistent picture of how the Earth has responded in the past intervals of rapid and massive carbon addition (see table above).  These features include:   

(i) rapid global warming of >3 C. 

(ii) a reduction in oceanic oxygen content leading to ocean anoxia and/or euxinia. 

(iii) ocean acidification of around 0.3 to 0.4 pH units. 

(iv) the hydrological cycle intensified with wet regions generally getting wetter and dry regions drier.

(v) continental erosion/weathering rates were enhanced.

(vi) relatively large biotic responses occurred in the first half of the Phanerozoic (Paleozoic and early Mesozoic mass extinctions often associated with hyperthermals), and muted or mixed responses in the latter half of the Phanerozoic. But in each case the hyperthermals are associated with biotic disruptions. 

(vii) the Earth system takes 100's of thousands of years to recover once C-emissions have stopped.

These changes to the system were likely caused by the introduction of 10,000 to 40,000 Pg of C over a couple of millennia.  Where this carbon came from is debatable but CO2 from flood basalt eruption and emplacement is likely involved (see here and here).  Although this is rapid for geology, the rates of carbon addition are still likely 10x less than current rates (i.e. less than 1-2 Pg C per year vs. 10 Pg C per year; though this is controversial – see this paper in our special volume). 

As the figure above from Gattuso et al. (2015, Science) shows, we have seen a very similar response to the Earth System to current anthropogenic emissions, for instance in response to increasing atmospheric CO2 by 40% over the last 150 years we have seen sea surface temperature increase by 0.5 C, ocean acidification by 0.1 pH unit and a decrease in ocean oxygen content.  Projections by the IPCC and others suggest we are heading on a similar path as the ancient hyperthermal events (see figure above). 

A key difference between what we are currently doing to the Earth System and what happened during these hyperthermal events however is the rate of current change is much much faster.  The magnitude of CO2 change from any C emission, and hence the full magnitude of warming, anoxia, ocean acidification and extinction that occurs, is a function of rate, due to the timescales of a number of key negative feedbacks (see this paper).  Why the Palaeozoic hyperthermals are associated with significantly greater extinction rate than more recent hyperthermals is currently not known (see table above).  However, a consensus is emerging that it is the extreme heat and anoxia that are the likely “kill mechanisms” (see this paper in our special volume).  Given that the rate of carbon addition during our “anthropogenic hyperthermal” eclipses that of the Palaeocene Eocene Thermal Maximum (PETM), at the very least we are likely looking at a potential future with a more severe impact on life on Earth than any climate change event of the last 56 million years.  Exactly how severe however remains perhaps the biggest unknown.       

An unprecedented degree of undersaturation?

Many people are familiar with Michael Mann’s famous Hockey Stick of global surface temperature over the last 2000 years, clearly showing the influence of anthropogenic climate change.  In a recent paper published in Earth and Planetary Science letters this week led by Sindia Sosdian from Cardiff University we show a series of “ocean carbonate system” hockey sticks showing how anthropogenic and future change in CO2, pH and aragonite saturation compare to what the Earth has experienced over the last 20 million years or so.

Surface water pH (A), atmospheric CO2 (B) and surface water aragonite saturation state (C) over the last 20 million years.  Bands encompass the mean and 1sigma uncertainty.  The different colours represent different scenarios (see the paper for more detail).  The plots on the right-hand side show historical (grey) and future projections from Winklemann et al. (2015). 

From the long-term trends in the above figure, pH (the –log10 of the H+ concentration) has increased and CO2 decreased, on the whole, over the last 20 million years (with some interesting structure that is for another post for another day).  CO2 and pH are clearly tightly coupled over this time, the reason is actually a bit complex, but can be simply thought of arising because CO2 is an acidic gas, so more CO2 = lower pH and vice versa.  Furthermore, the CO2 content of the ocean dictates the CO2 content of the atmosphere, so this tight coupling between pH and CO2 is not a surprise.  We are not sure why CO2 declined and pH increased through the last 20 million years but it most likely relates to a long term decline in CO2 outgassing from the mantle or a gradual increase in the weathering of silicate rocks in the Himalaya.

The key new record in this latest study however is the evolution of the saturation state of calcium carbonate (CaCO3) over the last 20 million years (in figure above expressed as omega aragonite – the saturation state of the aragonite polymorph).   When saturation state is greater than 1 CaCO3 can precipitate easily, when its below 1 CaCO3 dissolves.   Organisms that make their shells and skeletons out of calcium carbonate, like corals and shell-fish, require a high degree of CaCO3 oversaturation.  Similarly, carbonate structures like coral reefs exist in a delicate balance between dissolution and accretion, so any decline in saturation state can start to weaken and dissolve the reef. 

This really great figure below from Honisch et al. (2012; Science), firstly shows the close relationship between atmospheric CO2 (panel A) and surface ocean pH (panel B) in a model where you double CO2 on different timescales (warm colours – fast, cold colours – slow). In panel C the mean surface ocean saturation state of aragonite is shown.  Although it looks similar to the other two on short timescales, on long timescales of CO2 addition it becomes decoupled from pH and CO2 and doesnt change very much.  This is perhaps more clearly shown in panel D.  It’s not easy to explain why this happens and those of you interested should look at the Honish et al. (2012) paper in more detail (or see wiki or this Royal Society report)   

Our new record of aragonite saturation state shows that as predicted, there isn’t much of a trend over the last 20 million years, consistent with this idea of a decoupling of pH and CO2 from saturation state when CO2 change is slow – i.e. on thousands to million year timescales.

However, over the last 150 years or so, CO2, ocean pH and saturation state have all changed in tandem because the changes are so fast.  What the figure from our new paper shown above shows is that attempts to mitigate the effects of climate change by restricting CO2 rise at 2100 to <500 ppm (RCP2.5) or so keeps ocean pH and saturation state to well within the range of the last 5 million years or so.  The RCP8.5 scenario – the often called “business as usual” – risks tipping saturation state to lower values than have been seen in the last 14 million years, and maybe longer.

What does this mean for calcifying organisms? Well I guess we just don’t know for sure without further study. But the message is clear – if we continue to emit CO2 at the current rates we risk taking the Earth to a state not seen for many millions of years…

410 ppm CO2 for April 2018 - first time in millions of years....

So with spring having sprung we reach the highest monthly CO2 at the Mauna Loa for 2018 - April 2018 was 410.26 ppm, thats 1.26 ppm above last years peak (Mauna Loa data here). 

@thefosterlab we determine the levels of CO2 over the last 50-60 million years using the boron isotope proxy.  It is often said that at 410 ppm CO2 is now higher than any level the Earth has seen for at least 3 million years.  As this revised plot shows (see here for Rscript and here for data), this is likely true, but we are now beginning to creep over even the highest values in the Pliocene 3 million years ago.

Atmospheric CO2 from AD 1000 to AD 2018 (right) from a mix of ice core records and measuresments of the astmosphere from Mauna Lao.  On the left is a compilation of ice core CO2 (red) and boron isotope based estimates (blue).  Note the age scales are different but y-axis is the same. See this document for references.

Beyond the Pliocene we have to go to the Middle Miocene Climatic Optimum around 16 million years ago to see CO2 >450 ppm. There have been several papers recently on this topic (e.g. this one by James Super of Yale) and I desparately need to find time to update the compilation on p-CO2.org...at current rates of CO2 rise though I probably have a couple of years before Earth crosses 450 ppm....
 

Research Experience Placement for Summer 2018

The micro-environment around the planktic foram O.Universa being analysed for O2 and pH (top).  A close up of a live O. universa collected Nov 2017 from the Sargasso Sea, Bermuda (bottom)

Larger view of the O. universa being probed in the laboratory using micro-electrodes

TheFosterLab has a fully funded Research Experience Placement for the summer of 2018 (17 June to 21 September 2018).  We are looking for a quantitative student from a discipline not normally funded by NERC (e.g. from chemistry, physics, engineering, biology NOT geology, earth science, environmental science) who is keen to apply their skill set to help understand foraminifera vital effects.

Details of the scheme which is run out of our NERC DTP can be found here: (http://www.spitfire.ac.uk/spitfire-dtp-research-experience-placement-scheme-2018), the project is described below. Please contact Gavin if you are interested (gavin.foster@noc.soton.ac.uk) or have any questions. 

Opening the black box: the influence of environment on foraminiferal physiology

The foraminifera are a group of amoeboid sub-mm sized protists with an extensive fossil record that play an important role in global carbon cycling due to their ability to form calcium carbonate shells (known as tests).  The chemical composition of their tests is predominantly determined by: (i) the composition of the seawater they grew in and (ii) a number of environmental factors (e.g. temperature, salinity, and pH).  The latter forms the basis of many quantitative reconstructions of climate over the last 140 million years.  Such reconstructions inform our understanding of how the climate system works and help to improve our predictions of future climate in the face of anthropogenic climate change.  Assessing the reliability and uncertainty of our quantitative reconstructions of past climate using the chemical and isotopic composition of foraminifera is therefore key.

However, rather than being passive recorders of the environment they live in, the composition of the foram tests are heavily influenced by the physiology (i.e. life processes) of the foram and its photosymbionts.  Indeed, it is the influence of environment on physiology that often imparts an environmental sensitivity to test composition. This influence comes about predominantly because foraminiferal calcification and respiration and symbiont photosynthesis modify the pH in the immediate 1 mm or so around the growing foram, such that it is no longer simply growing in seawater but seawater with a composition that is modified by the growth of the foram itself.

This short project will aim to better understand the role of the external environment on the physiology of foraminifera, and hence test composition, by using microelectrodes to make measurements of the pH, [Ca2+], and O2 in the micro-environment around growing foraminifera under controlled conditions. The student will therefore gain experience in the maintenance and study of foraminifera in laboratory culture and in the development and use of ion-selective microelectrodes to measure pH, Ca and O2 at micron-scale resolution in biological samples.

Experiments will be performed at the National Oceanography Centre under the guidance of Prof. Gavin Foster, Dr. Tali Babila (OES), Dr Glen Wheeler (MBA), Dr Gerald Langer (MBA). The results of this study will feed into a larger  NERC funded project SWEET aimed at reconstructing climate 50  million years ago.  

The task the student will be to perform the measurement of pH, O2 and Ca2+ gradients in the micro-environment around multiple specimens of two benthic foraminifera species Ammonia sp. (non-symbiont bearing) and Amphistegina (symbiont bearing). The magnitude of the chemical gradients measured are indicative of the fluxes of ions and molecules in the micro-environment allowing a quantification of the magnitude of calcification, respiration and photosynthesis for each individual.  By manipulating the environment the foraminifera are inhabiting, e.g. by changing the temperature, pH and chemical composition of the culture media, we will gain unique insights into how environment influences foram physiology. 

An approximate plan is:

Weeks 1-2: ambient conditions

Weeks 2-5: modified temperature

Weeks 5-7: modified pH

Weeks 7-10: modified chemical composition

No prior knowledge of foraminiferal biology is required but experience with the use of micro-electrodes and an understanding of how they work is desirable. The candidate should also be numerate and comfortable with data processing.

Narrowing in on Equilibrium Climate Sensitivity

A post by Gavin, Phil Goodwin and Eelco Rohling

A fundamental variable in describing how warm our future will be is the equilibrium climate sensitivity (ECS) – the global mean surface temperature change in response to a doubling of atmospheric CO2, once the system has reached equilibrium.  Assessing the impact of anthropogenic climate change has been framed in these terms for nearly 120 years since Svante Arrhenius in 1896 (LINK). However, a precise value for Earth’s ECS has stubbornly resisted determination over this time – see this figure I have modified from Steve Schwartz. 

The evolution of the estimates of equilibrium climate sensitivity over the last 130 years.  From Steve Schwartz with the addition of the 2013 AR5 IPCC report.  http://www.ecd.bnl.gov/steve/schwartz.html

This apparently lack of scientific progress was exemplified in the last IPCC report in 2013 when, instead of quoting a most likely value as previous reports had done, the best estimate of ECS based on multiple methods was that it was likely (i.e. with a 66% probability) in the range of 1.5 to 4.5 C per CO2 doubling.  This is arguably something we have known since the late 70s (although by luck rather than judgement; see figure above).  With the international agreement in Paris in 2015 to limit global warming to 1.5 or 2 C this uncertainty in the true value of ECS has come into sharp focus - quite simply in order to ensure we don’t go above 1.5 or 2 C we first need to know how sensitive the climate system is.

In the last year, with an eye on these targets, there have been a number of attempts to narrow in on the real value of the Earth’s ECS.  For instance, Armour (2017; doi:10.1038/NCLIMATE3278) showed that because climate feedbacks operate on different spatial and temporal scales, simple energy balance approaches, though elegant, tend to biased low (by ~26%).  Brown and Caldeira (2017; doi:10.1038/nature24672), confronted climate model output with a series of observations, and those models that best matched the observations were found to describe a narrower range in ECS.  Finally, last week Cox et al. (2018, doi:10.1038/nature25450) found that only a subset of the available climate models exhibited a similar level of year-on-year variation in climate to what is observed in the historical record.  Interestingly, this subset of models also had similar and narrow range of ECS.  Taken together, these recent advances suggest that an ECS of <2 or >4.5 is unlikely (summarised nicely by a Nature news and views article by Piers Forster and this figure below).

Recent estimates of equilibrium climate sensitivity.  The estimate from the IPCC (2013) is based on several lines of evidence.  Bars depict the ranges for which there is a 66% likelihood of the value being correct.  Best estimate is a blue line.  From Forster (2018).

Our latest paper, published today (22/01/2018; Goodwin et al. 2018, doi:10.1038/s41561-017-0054-8), continues this recent trend of narrowing in on the real value of ECS for the Earth in its current state.  In contrast to these other studies we used a much simpler model (the WASP Earth System model, http://www.waspclimatemodel.info) but one that could be run many times with different input parameters.  The accuracy of the outputs could then be tightly constrained by observations of anthropogenic climate change (e.g. surface warming, ocean heat up take etc.), thereby identifying the most realistic parameter sets and so most accurate model runs.  We started from the premise that the geologically constrained estimates of ECS from the Palaeosens study (Rohling et al., 2012, doi:10.1038/nature11574), represent a good, if uncertain, approximation of the Earth’s true sensitivity (in Bayesian terms this is our prior).  We found that, given the uncertainties in climate forcing over the last 100 years, only a subset of the initial geologically-determined ECS was able to generate climate change in WASP that adequately agreed with the available observational datasets (e.g. ocean heat uptake and surface warming).  Like in the other studies discussed above, this subset (our posterior) had a much narrower distribution of ECS: a most likely value of around 2.7 C per CO2 doubling and a 66% likelihood range of 2.3 to 3.2 C.  This agrees remarkably well with estimates of Cox et al. (2018) as shown in this figure.

Estimates of ECS from Goodwin et al. (2018) and Cox et al. (2018).  NB – for plotting we have assumed a normal distribution from Cox et al. (2018).  Our 66% range is 2.3 to 3.2 C per CO2 doubling with a most likely value of 2.7.  Cox's 66% range is 2.2 to 3.2 C with a most likely value of 2.8 C per CO2 doubling..

At face value, this appears to be great news.  For instance, the extreme global warming implied by an ECS >5 C now appears to be very unlikely, as does the possibility of a “lukewarm” sensitivity.  However, there is a downside too, because by reducing uncertainties in ECS we are also reducing our “wiggle room” in climate negotiations and emission-reduction actions.  To illustrate this in Goodwin et al. (2018), we take our subset of observationally consistent models and see how quickly they approached 1.5 and 2 C above pre-industrial, given current emission rates (see figure below).  What we find is startling – within 17-18 years we are likely to have reached the 1.5 C target and by 35-41 years we will have reached 2 C above pre-industrial levels.  So, rather than being relieved that our study rules out extreme climate change on century timescales, we place the need to rapidly decarbonise our society into ever more sharp focus. 

Cumulative carbon emissions and warming projects from our observationally consistent ensemble.  From these plots, given a known rate of emissions, the time at which a target T is crossed can be calculated. From Goodwin et al. (2018).