Wed 29 Apr 14:00: Polar Oceans Seminar Talk: Exploring state dependence of the climate response to radiative forcing using two idealized coupled climate models If you are external to BAS and would like to attend please reach out to the organisers...
Studies of climate sensitivity and feedbacks typically employ a suite of models with similar base climates but different model physics. Such an approach is useful for uncovering how changes to physical processes affect the climate response to changes in radiative forcing, but obscures the dependence of the climate response on the initial state of the climate itself. In order to better understand this dependence, we study the response to radiative forcing of two nearly identical configurations of the Community Earth System Model (CESM) with production-grade physics and resolutions that have dramatically different climates. The first, called Aqua, is completely covered with a uniform-depth ocean except for two 10º-wide polar continents to avoid the polar singularities in the ocean. The second, Ridge, is identical to Aqua except for the presence of a thin ridge continent connecting the two polar caps. The ridge supports gyres in the ocean and leads to a warm, ice-free climate resembling a global Pacific Ocean, with a warm pool and cold tongue in the tropical ocean connected by a Walker circulation in the atmosphere. In contrast, the mean climate of Aqua is zonally symmetric and dominated by a global cold belt in the ocean driven by vigorous equatorial upwelling. The lack of gyres leads to a deep oceanic thermocline and reduces meridional heat transport, which allows for the development of persistent sea ice at high latitudes.
These two mean climates are perturbed by increasing atmospheric CO2 concentration at a rate of 1% per year until quadrupling. Aqua initially warms more slowly than Ridge, with the transient climate response (TCR) at doubling 23% smaller for Aqua than Ridge. After doubling, however, Aqua begins to warm faster than Ridge and Aqua’s global mean temperature surpasses Ridge’s at quadrupling. A linear feedback analysis is used to gain insight into the time-evolving responses of these two configurations to increased CO2 concentration. At all stages, Aqua’s net top-of-the-atmosphere heating is greater than Ridge’s. At early times, this is due to high clouds replacing low clouds in Aqua’s high latitudes, but decreasing surface albedo due to sea-ice loss eventually becomes a dominant factor. Aqua’s deep thermocline supports a higher ocean heat uptake (OHU) efficiency relative to Ridge that initially offsets these positive feedbacks and results in Aqua’s lower TCR . As CO2 concentration approaches quadrupling, the combined effects of declining OHU efficiency and a strengthening ice-albedo feedback drive Aqua’s warming to temperatures compatible to Ridge. In the century following quadrupling, Aqua warms several Kelvin more than Ridge. Such idealized systems can shed light on the fundamental aspects of Earth’s climate system—such as how the response to radiative forcing depends on the base climate—that might be obscured in more complex configurations.
If you are external to BAS and would like to attend please reach out to the organisers before the talk and arrive at reception 10 minutes before so we can let you in.
- Speaker: Christopher Wolfe (University of Liverpool)
- Wednesday 29 April 2026, 14:00-15:00
- Venue: BAS Seminar Room 1.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Katherine Turner.
Thu 21 May 11:30: TBC
Abstract not available
- Speaker: Reshma Rao, Imperial College London
- Thursday 21 May 2026, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Thu 14 May 11:30: TBC
Abstract not available
- Speaker: Prof. John R. Taylor (University of Cambridge)
- Thursday 14 May 2026, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Thu 30 Apr 11:30: TBC
Abstract not available
- Speaker: Ali Mashayek (University of Cambridge)
- Thursday 30 April 2026, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Thu 11 Jun 15:00: From Plate to Brain: Global Diet, Cognitive Function and Neuroimaging in Diverse Populations
Drawing on findings from the Canadian Alliance for Healthier Hearts and Minds (CAHHM) and the Prospective Urban Rural Epidemiology (PURE) study, this seminar will examine how global dietary patterns influence cognitive performance and brain structure across diverse populations. Dr. Anand will highlight evidence linking diet quality and cardiometabolic risk to cognition and neuroimaging markers of brain health in multi‑ethnic and international cohorts. The presentation will discuss implications for prevention strategies that connect nutrition, vascular health, and brain aging from a global perspective.
- Speaker: Professor Sonia Anand
- Thursday 11 June 2026, 15:00-16:00
- Venue: Large Seminar Room, East Forvie Building, Forvie Site Robinson Way Cambridge CB2 0SR..
- Series: Bradford Hill Seminars; organiser: Pam Mungroo.
Thu 18 Jun 11:30: Atmospheric Methane - rise, surge, and ongoing post-surge growth. Can we mitigate the rise, and can anything be done to reduce emissions? Microsoft Teams meeting Join: https://teams.microsoft.com/meet/354163162980400?p=wJWyEtLmSa0qBUgRA6
Abstract:
Methane was discovered 250 years ago by Alessandro Volta in 1776, but its atmospheric budget is still not understood. There is evidence for a strong rise in wetland, agricultural and waste emissions, especially natural emissions from regions in tropical Africa such as South Sudan’s Sudd wetland, as well as in the boreal/Arctic realm. 14CO data suggest an increasing OH sink since 1997, implying the rise in methane emissions was even stronger than previously thought. Following more than a decade of strong growth, 2020-2022 brought a major surprise: the highest growth in the observational record. The causes of the surge seem to include a transient decline in the oxidative power of the atmosphere, coupled with rising wetland emissions. The implications are profound: it’s going to be very hard to bring methane’s growth under control. Growth in emissions from wetlands and tropical agriculture makes the Global Methane Pledge’s goal of cutting the total atmospheric methane burden harder to achieve. However, there are many easy wins – coal mine vents in China and India, livestock manure, landfills, sewage and biomass fires. In Africa and India landfill management is very poor and rural crop waste burning is widespread, despite the damaging impact of air pollution on public health: much can be done here. In the dairy industry of Europe, the US, China and temperate Southern Hemisphere emission mitigation is increasingly feasible. Overall, meeting the targets of the Global Methane Pledge looks very difficult: but there’s hope that much can change, especially in China.
Biography:
Euan Nisbet is emeritus professor of Earth Sciences, at Royal Holloway, Univ. of London. After studying at Univ. Zimbabwe and at Sidney Sussex college, his geology PhD was in Darwin College, After a NERC Independent fellowship in Oxford and a Royal Society postdoc in ETH Zurich, he joined the staff of Mineralogy and Petrology in Cambridge, prior to the merger into Earth Sciences. For many years he and CMR Fowler, his wife, both taught in the Earth Sciences Dept., Univ. of Saskatchewan (he has prairie ancestry). He led the Canadian Lithosphere Committee for many years, advising the government on natural hazards, including methane hydrate. From 1985-7 he held a Steacie Fellowship from the Governor-General which, with help from Paul Crutzen and Ralph Cicerone, prompted a switch from hard rock geology to atmospheric methane, much to the annoyance of the funding agency who halved his grant. At Royal Holloway he led or co-led many large European consortia, such as Meth-MoniEUr, the West European Methane Budget experiment, EuroHydros, Geomon, MEMO etc. etc. and many NERC projects, including the UK MOYA Global Methane Budget consortium (2016-2022). Many projects were in collaboration with John Pyle. Now retired, he serves on the scientific advisory panel for the United Nations International Methane Emissions Observatory. His input was used in the 2021 Global Methane Assessment underpinning the Global Methane Pledge, and he is a co-author of the 2025 UNEP Global Methane Status report.
Microsoft Teams meeting Join: https://teams.microsoft.com/meet/354163162980400?p=wJWyEtLmSa0qBUgRA6
- Speaker: Prof Euan Nisbet, Department for Earth Sciences, Royal Holloway, University of London
- Thursday 18 June 2026, 11:30-12:30
- Venue: Chemistry Dept, Unilever Lecture Theatre and Teams.
- Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Yao Ge.
Thu 21 May 11:30: TBC
Abstract not available
- Speaker: Rashma Rao, Imperial College London
- Thursday 21 May 2026, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Thu 14 May 11:30: TBC
Abstract not available
- Speaker: Quentin Kriaa, University of Cambridge
- Thursday 14 May 2026, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Thu 30 Apr 11:30: TBC
Abstract not available
- Speaker: Prof. John R. Taylor (University of Cambridge)
- Thursday 30 April 2026, 11:30-12:30
- Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
- Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.
Thu 14 May 11:00: Laser tomography for wide area gas emission spatio-temporal reconstruction Microsoft Teams meeting: https://teams.microsoft.com/meet/355090881827880?p=ctQq7LD4cdHo0p85nw
Abstract: Through injection of gas phase chemicals such as greenhouse gases (GHGs) and pollutants, the composition of the Earth’s atmosphere is changing, affecting radiative, chemical, and transport processes within the atmosphere, and the health of bio-receptors and ecosystems. Understanding natural and anthropogenic processes leading to gas emissions requires quantitative observations at the scale of the emitting unit, with a temporal and spatial resolutions allowing to resolve dynamic emission behaviours and their spatial patterns. In the case of anthropogenic GHG emissions from the energy, the waste management, or the agricultural sectors, spatio-temporal quantification of gas emitted at the facility scale is also critical to the implementation of sustainable climate policies, such as the Net Zero agenda, to allow for fair and transparent reporting, monitoring and verification. Considering methane, great progress has been made towards improved quantitative emission monitoring to reconcile bottom-up emission inventories and top-down estimates. Novel measurement systems, particularly satellite-borne ones, now provides global coverage when the cloud cover allows, and can ‘focus’ on large facilities to provide snapshot quantitative estimates. However, this way only fairly large emissions can be measured (~100kg/h), and a snapshot measurement does not provide the temporal patterns of emissions often associated to facility operations. Satellite-borne measurements also need robust ground-based validation to demonstrate their data quality.
In this context, the need for continuous gas emission monitoring systems capable of characterising the emitting behaviour of an entire facility, in space and time, remains acute. To address the need, we have developed the concept of gas emission laser tomography made of 1) high-resolution spectroscopic measurements of atmospheric transmission over multiple open-paths, and 2) a inversion scheme to reconstruct, from the time series of multi-path integrated concentrations, the evolution of three dimensional gas plumes and associated emission sources. Field deployments at oil and gas, waste treatment, and agricultural facilities, together with controlled gas released tests, have established the highly promising capabilities of gas emission laser tomography for methane characterisation. We will describe the system, present some example of deployments and results, and discuss the current developments to additional trace gases, as well as improvements of the inversion framework based on Bayesian state estimation.
Biography: Damien Weidmann heads the Spectroscopy programme of the Space Science and Technology Department of the STFC Rutherford Appleton Laboratory (aka RAL Space). He has been conducting research and development for more than 30 years in molecular spectroscopy and atmospheric sensing, in France, the USA and the UK. He has a particular interest in the development and application of novel high resolution chemical sensing concepts enabled by spectroscopy, covering technologies, algorithms, systems, and mission concepts. DW is also co-founder and chief scientific officer of MIRICO Ltd, a company exploiting high-precision gas sensing for terrestrial applications.
Microsoft Teams meeting: https://teams.microsoft.com/meet/355090881827880?p=ctQq7LD4cdHo0p85nw
- Speaker: Dr Damien Weidmann, Space Science & Technology Dept (RAL Space)
- Thursday 14 May 2026, 11:00-12:00
- Venue: Chemistry Dept, Unilever Lecture Theatre and Teams.
- Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Yao Ge.
Mon 01 Jun 19:30: CSAR lecture: Beyond Net Zero: Can We Repair The Climate?
Climate change arises from a fundamental imbalance in the Earth’s energy budget. While renewable energy technologies are essential for reducing emissions, the slow response of the climate system has led to growing interest in approaches that directly influence how energy is absorbed and reflected by the planet. This talk introduces the concept of climate repair, including methods such as marine cloud brightening, sea ice thickening, and stratospheric aerosol injection. It will explore how these approaches may complement existing climate strategies, alongside the key challenges and uncertainties that remain.
- Speaker: Dr. Luke Haworth, Centre for Climate Repair, University of Cambridge
- Monday 01 June 2026, 19:30-21:00
- Venue: Location: Wolfson Lecture Theatre, Churchill College, and Zoom.
- Series: Cambridge Society for the Application of Research (CSAR); organiser: John Cook.
Tue 16 Jun 12:30: Energy patterns among residential consumers
Abstract not available
- Speaker: Raine Zhang (Beijing Institute of Technology) and Yunfeng Den (Tsinghua University)
- Tuesday 16 June 2026, 12:30-13:30
- Venue: Judge Business School, W2.01.
- Series: EPRG Energy & Environment Seminars ; organiser: Mariana Soberon.
Tue 05 May 12:30: Centralized Demand, Decentralized Supply: Scenario Analysis of South Korea's Spatial Electricity Mismatch
Abstract not available
- Speaker: Manseok Jo, Korea Research Institute for Human Settlements (KRIHS)
- Tuesday 05 May 2026, 12:30-13:30
- Venue: Judge Business School, W4.05.
- Series: EPRG Energy & Environment Seminars ; organiser: Mariana Soberon.
Tue 12 May 12:30: Toward efficient resource adequacy: The role of shared reserves in China's power grid
Abstract not available
- Speaker: Prof Jiang Lin (UC Berkeley / LBNL)
- Tuesday 12 May 2026, 12:30-13:30
- Venue: Judge Business School, W4.05.
- Series: EPRG Energy & Environment Seminars ; organiser: Mariana Soberon.
Wed 15 Apr 13:00: Polar Oceans Seminar Talk - Christina Schmidt (BAS): Antarctic Bottom Water formation and its dynamics in a changing climate If you are external to BAS and would like to attend please reach out to the organisers before the talk and...
Antarctic Bottom Water (AABW) is an important part of the climate system as it occupies about one-third of the ocean’s volume, ventilates the abyss, and stores heat and carbon for centuries. The formation of AABW at the Antarctic continental margin is therefore a key process in the global ocean circulation but observing and accurately modelling AABW remains an ongoing challenge. The aim of my PhD thesis has been to deepen our understanding of AABW dynamics, motivated by its critical role in the global ocean and declining AABW volume in a warming climate. Using ocean–sea ice models, I investigate the interannual variability of AABW formation and its underlying drivers. I then examine the response of salinity in the Ross Sea to wind and meltwater variability to advance our understanding of the physical mechanisms behind the recent salinity rebound in the Ross Sea. Finally, I assess the horizontal model resolution required to accurately simulate AABW formation. By improving our understanding of past AABW variability and identifying the model resolution required to simulate AABW , this work contributes to more reliable future projections of AABW formation and the evolution of the global overturning circulation.
If you are external to BAS and would like to attend please reach out to the organisers before the talk and arrive at reception 10 minutes before so we can let you in.
- Speaker: Christina Schmidt
- Wednesday 15 April 2026, 13:00-14:00
- Venue: BAS Seminar Room 1.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Katherine Turner.
Wed 01 Apr 14:00: Polar Oceans Seminar Talk - Yavor Kostov If you are external to BAS and would like to attend please reach out to the organisers before the talk and arrive at reception 10 minutes before so we can let you in.
Water mass transformation in the supbolar North Atlantic is sensitive to the combined effects of wind stress and surface buoyancy anomalies, which trigger a signal that gets communicated southward and impacts the subtropical AMOC . We explore historical variability in the volume of accumulated Labrador Sea Water (LSW) using ECCO , an ocean state estimate configuration of the Massachusetts Institute of Technology general circulation model (MITgcm). The model’s adjoint, a linearization of the MITgcm, is set up to output the lagged sensitivity of the water mass volume to surface boundary conditions. This allows us to reconstruct the evolution of LSW volume over recent decades using historical surface wind stress, heat, and freshwater fluxes. Each of these boundary conditions contributes significantly to the LSW variability that we recover, but these impacts are associated with different geographical fingerprints and arise over a range of time lags. We show that the volume of LSW accumulated in the Labrador Sea exhibits a delayed response to surface wind stress and buoyancy forcing outside the convective interior of the Labrador Sea at important locations in the North Atlantic Ocean. In particular, patterns of wind and surface density anomalies can act as a “traffic controller” and regulate the North Atlantic Current’s (NAC’s) transport of warm and saline subtropical water masses that are precursors for the formation of LSW . This propensity for a delayed response of LSW to remote forcing allows us to predict a limited yet substantial and significant fraction of LSW variability at least 1 year into the future. Our analysis also enables us to attribute LSW variability to different boundary conditions and to gain insight into the major mechanisms that contribute to volume anomalies in this deep water mass. We point out the important role of key processes that promote the formation of LSW in both the Irminger and Labrador seas: buoyancy loss and preconditioning along the NAC pathway and in the Iceland Basin, the Irminger Sea, and the Nordic Seas.
If you are external to BAS and would like to attend please reach out to the organisers before the talk and arrive at reception 10 minutes before so we can let you in.
- Speaker: Yavor Kostov
- Wednesday 01 April 2026, 14:00-15:00
- Venue: BAS Seminar Room 1.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Katherine Turner.
Fri 12 Mar 17:30: Cooperation for Nature
Abstract not available
- Speaker: Dr Mike Rands, Cambridge Conservation Initiative
- Friday 12 March 2027, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.
Fri 26 Feb 17:30: Security Cooperation within Government and between Governments
Abstract not available
- Speaker: Ms Suzanne Raine, Selwyn College Cambridge
- Friday 26 February 2027, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.
Fri 05 Mar 17:30: Together Now: Cooperation and Collaboration in Social Art Practice
Abstract not available
- Speaker: Mr Harold Offeh, Royal College of Art
- Friday 05 March 2027, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.
Fri 19 Feb 17:30: The Magic of Magnetism
Abstract not available
- Speaker: Professor Russell Cowburn, University of Cambridge
- Friday 19 February 2027, 17:30-18:30
- Venue: Lady Mitchell Hall, Sidgwick Avenue.
- Series: Darwin College Lecture Series; organiser: Janet Gibson.