Wed 04 Feb 14:00: Polar Oceans Seminar Talk - Giangiacomo Navarra 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.
Machine learning (ML) methods are increasingly transforming the analysis and modeling of ocean biogeochemistry by enabling the extraction of complex, nonlinear relationships from large and heterogeneous datasets. In this talk, I will present recent applications of ML to improve the reconstruction, prediction, and interpretation of key biogeochemical variables, specifically primary production and flux of oraganic carbon. I will highlight how data-driven approaches can complement traditional process-based models, enhance spatial and temporal coverage of observations, and provide new insights into the physical and biological drivers of ocean biogeochemical variability. Finally, I will discuss current challenges and future opportunities for integrating ML with mechanistic understanding to advance ocean biogeochemical modeling.
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: Giangiacomo Navarra - Princeton
- Wednesday 04 February 2026, 14:00-15:00
- Venue: BAS Seminar Room 1.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Katherine Turner.
Thu 12 Mar 16:00: Against the rising tide: polar climate change and comms in the misinformation era
TBD
- Speaker: Dr. Ella Gilbert
- Thursday 12 March 2026, 16:00-17:00
- Venue: Scott Polar Research Institute, main lecture theatre.
- Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: meh91.
Thu 05 Mar 16:00: Lakes on the ice - modelling Antarctica's surface hydrology
The formation of surface meltwater has been linked with the disintegration of many ice shelves in the Antarctic Peninsula over the last several decades. Despite the importance of surface meltwater production and transport to ice shelf stability, knowledge of these processes is still lacking. Understanding the surface hydrology of ice shelves is an essential first step to reliably project future sea level rise from ice sheet melt.
In order to better understand the processes driving meltwater distribution on ice shelves, we present the first comprehensive model of surface hydrology to be developed for Antarctic ice shelves, enabling us to incorporate key processes such as the lateral transport of surface meltwater. Recent observations suggest that surface hydrology processes on ice shelves are more complex than previously thought, and that processes such as lateral routing of meltwater across ice shelves, ice shelf flexure and surface debris all play a role in the location and influence of meltwater. Our model allows us to account for these and is calibrated and validated through both remote sensing and field observations.
In this talk I’ll describe our modelling results, as well as giving a brief flavour of some of the other research projects that Centre for Polar Observation and Modelling are involved in, ranging from monitoring Greenland using drones to biochemistry in the Southern Ocean.
- Speaker: Dr. Sammie Buzzard (Northumbria University)
- Thursday 05 March 2026, 16:00-17:00
- Venue: Scott Polar Research Institute, main lecture theatre.
- Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: meh91.
Thu 19 Feb 16:00: Arctic Subsurface Ocean Change under the Climate Crisis: Long-Term CPIES Observations in the Chukchi Sea
Long-term observations from arrays of current- and pressure-recording inverted echo sounders (CPIES) in the Chukchi Sea reveal pronounced variability in near-bottom thermal and dynamical processes, as well as in subsurface ocean heat content. This variability is closely linked to changes in sea-ice conditions and the associated inflow of Atlantic Water (AW). Time series of near-bottom temperatures along the Chukchi Slope exhibit quasi-seasonal to quasi-monthly variability, with warmer conditions during winter and spring corresponding to intensified AW boundary currents and a deepening of the lower AW layer. These variations are modulated by regional sea surface height gradients and wind stress curl over the Chukchi Shelf, which regulate AW transport through geostrophic adjustment. Observations of near-bottom currents further indicate that deep near-inertial motions and topographic Rossby wave activity are strongly seasonal, with substantially enhanced energy levels during summer and fall following sea-ice melt-out. Longer-term acoustic round-trip travel time measurements between the seafloor and the sea surface, together with hydrographic observations, reveal steric warming in the Northwind Abyssal Plain over the past several years, likely associated with a weakened Beaufort Gyre and increased AW inflow. These results demonstrate that the recent acceleration of Arctic sea-ice decline exerts strong control over ongoing subsurface ocean changes in the Arctic Ocean.
- Speaker: Dr. Jae-Hun Park (Inha University)
- Thursday 19 February 2026, 16:00-17:00
- Venue: Scott Polar Research Institute, main lecture theatre.
- Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: meh91.
Thu 12 Feb 16:00: Ice structure, brine infiltration, and firn saturation from field observations on three Antarctic ice shelves
Antarctic ice shelves are the floating extensions of the continental ice sheet into the ocean, buttressing the flow of inland, grounded ice from the continent’s interior. Over 50% of the Antarctic margin is fringed by such ice shelves, which are formed of alternating bands of meteoric glacier and suture zone ice. Suture zone ice is softer and fractures less easily than meteoric ice – understanding the structure and mechanical state of ice shelves is crucial to assessment of their vulnerability to thinning, rift propagation, and potential disintegration. In this talk, I will present field observations from three ice shelves around Antarctica (Larsen C, Shackleton, and McMurdo): optical televiewer imaging of the interior of hot-water drilled boreholes to infer ice structure; ground-penetrating radar surveys informing on the extent of brine infiltration; and observations of firn saturation and near-surface refrozen melt layers, concluding with implications for more widespread ice slab presence and formation.
- Speaker: Dr. Katie Miles (Lancaster University)
- Thursday 12 February 2026, 16:00-17:00
- Venue: Scott Polar Research Institute, main lecture theatre.
- Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: meh91.
Wed 04 Mar 17:30: Antarctica as a pacemaker of Pleistocene climate transitions: from the Mid-Brunhes Transition to the Mid-Pleistocene Transition
Tbc
- Speaker: Xu Zhang, British Antarctic Survey
- Wednesday 04 March 2026, 17:30-19:00
- Venue: Latimer Room, Clare College.
- Series: Quaternary Discussion Group (QDG); organiser: sr632.
Thu 19 Feb 16:00: Arctic Subsurface Ocean Change under the Climate Crisis: Long-Term CPIES Observations in the Chukchi Sea
Long-term observations from arrays of current- and pressure-recording inverted echo sounders (CPIES) in the Chukchi Sea reveal pronounced variability in near-bottom thermal and dynamical processes, as well as in subsurface ocean heat content. This variability is closely linked to changes in sea-ice conditions and the associated inflow of Atlantic Water (AW). Time series of near-bottom temperatures along the Chukchi Slope exhibit quasi-seasonal to quasi-monthly variability, with warmer conditions during winter and spring corresponding to intensified AW boundary currents and a deepening of the lower AW layer. These variations are modulated by regional sea surface height gradients and wind stress curl over the Chukchi Shelf, which regulate AW transport through geostrophic adjustment. Observations of near-bottom currents further indicate that deep near-inertial motions and topographic Rossby wave activity are strongly seasonal, with substantially enhanced energy levels during summer and fall following sea-ice melt-out. Longer-term acoustic round-trip travel time measurements between the seafloor and the sea surface, together with hydrographic observations, reveal steric warming in the Northwind Abyssal Plain over the past several years, likely associated with a weakened Beaufort Gyre and increased AW inflow. These results demonstrate that the recent acceleration of Arctic sea-ice decline exerts strong control over ongoing subsurface ocean changes in the Arctic Ocean.
- Speaker: Dr. Jae-Hun Park
- Thursday 19 February 2026, 16:00-17:00
- Venue: Scott Polar Research Institute, main lecture theatre.
- Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: meh91.
Thu 05 Mar 16:00: Lakes on the ice - modelling Antarctica's surface hydrology
The formation of surface meltwater has been linked with the disintegration of many ice shelves in the Antarctic Peninsula over the last several decades. Despite the importance of surface meltwater production and transport to ice shelf stability, knowledge of these processes is still lacking. Understanding the surface hydrology of ice shelves is an essential first step to reliably project future sea level rise from ice sheet melt.
In order to better understand the processes driving meltwater distribution on ice shelves, we present the first comprehensive model of surface hydrology to be developed for Antarctic ice shelves, enabling us to incorporate key processes such as the lateral transport of surface meltwater. Recent observations suggest that surface hydrology processes on ice shelves are more complex than previously thought, and that processes such as lateral routing of meltwater across ice shelves, ice shelf flexure and surface debris all play a role in the location and influence of meltwater. Our model allows us to account for these and is calibrated and validated through both remote sensing and field observations.
In this talk I’ll describe our modelling results, as well as giving a brief flavour of some of the other research projects that Centre for Polar Observation and Modelling are involved in, ranging from monitoring Greenland using drones to biochemistry in the Southern Ocean.
- Speaker: Dr. Sammie Buzzard
- Thursday 05 March 2026, 16:00-17:00
- Venue: Scott Polar Research Institute, main lecture theatre.
- Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: meh91.
Mon 09 Mar 14:30: Deciphering the principles of epithelial tissue organization
Delphine Delacour
Affiliation: Institut de Biologie du Développement de Marseille (Marseille Developmental Biology Institute)
Title: Deciphering the principles of epithelial tissue organization
Abstract:
Epithelia constitute the primary physical barrier against external insults while simultaneously ensuring organ function. Defects in epithelial assembly or function lead to a broad spectrum of pathological conditions, ranging from rare developmental disorders to cancer. Despite their fundamental importance, the mechanisms by which epithelial cells coordinate individual behaviors across entire tissues to ensure spatial organization, integrity, and function remain poorly understood. To date, epithelial coherence has been studied predominantly in invertebrate systems or in transformed cell lines, limiting our understanding of its regulation in physiological mammalian contexts.
The intestinal epithelium represents an exceptional model to address these questions. It is one of the most rapidly renewing tissues in mammals and is continuously exposed to challenges. Its homeostasis relies on the precise balance between cell proliferation, differentiation, migration, and death. However, the cellular and developmental principles governing intestinal tissue organization and maintenance remain largely unexplored.
The main objective of our project is to elucidate how functional domains of the intestinal epithelium are established, maintained, and coordinated in space and time. Specifically, we aim to: 1) understand the mechanisms that preserve the integrity of the proliferative compartment and determine their role in crypt morphogenesis and maintenance; and 2) uncover epithelial connectivity and collective behavior within the differentiated compartment, both under homeostatic conditions and in response to perturbations.
A major strength of this project lies in its integrative and comparative strategy, combining in vivo and in vitro murine models with human disease-relevant systems. The project brings together advanced approaches in cell and developmental biology, tissue engineering, histology, molecular biology, biophysics, and computational modeling. This multidisciplinary framework will enable the identification of adaptive mechanisms by which epithelial cells polarize, self-organize, and dynamically regulate their fate in response to their environment, with broad implications for developmental biology, regenerative medicine, and disease pathology.
Key words: Tissue morphogenesis, mouse intestine, intestinal organoids, cytoskeleton, mechanics
- Speaker: Delphine Delacour
- Monday 09 March 2026, 14:30-15:30
- Venue: Online.
- Series: Morphogenesis Seminar Series; organiser: Jia CHEN.
Mon 23 Feb 14:30: Marc Trani Bustos: Building the mammalian embryo body: tissue surface mechanics constrains proliferation-driven forces to guide axial elongation; Denis Krndija-“Cracking” the Gut Epithelium: How Goblet Cells Mechanically Disrupt the...
Name: Marc Trani Bustos
Affiliation: Max Planck Institute for Cell Biology and Genetics, Dresden, Germany
Title: Building the mammalian embryo body: tissue surface mechanics constrains proliferation-driven forces to guide axial elongation.
Abstract: Mammalian embryos undergo complex morphogenetic changes after implantation in the uterus. The elongation of the body along a head-to-tail axis is a pivotal event, as it lays the foundation of the body plan. While genetic and biochemical aspects of mammalian body elongation have been uncovered, the physical mechanism of axial morphogenesis remains unknown, largely due to the inaccessibility of the implanted embryo to physical measurements and manipulations in utero. Gastruloids, a stem-cell-based embryo model of mammalian axial morphogenesis, lift such limitations. Combining live imaging, direct mechanical measurements, and chemical and mechanical perturbations, here we show that axis elongation in mouse and human gastruloids is guided by a posterior ‘actin cap’ at the tissue surface that constrains the expansive forces of cell proliferation. Measurements of mechanical stresses using oil microdroplets, as well as inhibition of cell proliferation and myosin activity, show that the forces driving elongation arise from cell proliferation, and not from convergent extension movements. We find that isotropic tissue expansion is re-directed into posterior elongation by the formation of a supracellular actin cap at the posterior tissue surface that restricts lateral tissue expansion. Finally, we show that posterior elongation in mouse embryos displays the key features of the physical elongation mechanism reported for mouse and human gastruloids. These findings reveal that mammalian body axis elongation, including human, occurs via a different physical mechanism from other vertebrate species.
Preprint: https://doi.org/10.1101/2025.10.27.684710
Denis Krndija
Affiliation: Group Leader (ATIP-Avenir), Centre for Integrative Biology (CBI), Molecular, Cellular and Developmental Biology (MCD), France
Title: “Cracking” the Gut Epithelium: How Goblet Cells Mechanically Disrupt the Gut Barrier
Abstract: The intestinal epithelium, one of the largest epithelial surfaces, has to maintain a tight barrier against the harsh luminal environment. Barrier integrity primarily depends on cell-cell junctions formed by enterocytes, absorptive cells characterised by their polygonal and columnar morphology. In contrast, mucus-producing goblet cells, which are interspersed among enterocytes, exhibit a rounded apical cell shape and a voluminous body – raising the question of how epithelial integrity is maintained among cells with such different morphologies. Here, we show that goblet cells mechanically induce tight junction fractures between neighbouring enterocytes under homeostatic conditions in vivo, and that this effect is exacerbated during goblet cell hypertrophy, leading to increased gut permeability. Using a combination of in vivo (mouse) and organoid models, along with pharmacological, genetic and mechanical perturbations, as well as theoretical modelling, we demonstrate that these fractures arise from a force imbalance at cell interfaces: goblet cells exert compressive forces that deform adjacent enterocytes, whose junctions rupture depending on tissue rheology controlled by myosin II. Together, our findings uncover a previously unrecognised mechanical role of goblet cells in destabilising epithelial cohesion and establish cell type heterogeneity and intercellular force balance as critical determinants of junctional integrity and gut barrier function.
- Speaker: Marc Trani Bustos, Denis Krndija
- Monday 23 February 2026, 14:30-15:30
- Venue: Online.
- Series: Morphogenesis Seminar Series; organiser: Jia CHEN.
Wed 04 Mar 17:30: Tbc
Tbc
- Speaker: Xu Zhang, British Antarctic Survey
- Wednesday 04 March 2026, 17:30-19:00
- Venue: Latimer Room, Clare College.
- Series: Quaternary Discussion Group (QDG); organiser: sr632.
Wed 18 Feb 17:30: Holocene sea-ice dynamics north of Greenland – from the Arctic’s Last Ice Area to the North Water Polynya
The northern coastline of Greenland, spanning from the Lincoln Sea to northern Baffin Bay, is a unique sea-ice regime. It is part of the Last Ice Area, where the dominant surface currents in the Arctic Ocean push sea ice towards the coastlines of northern Greenland and the Canadian Arctic Archipelago. Research indicates that, under continued and future climate warming, the Last Ice Area is expected to remain the final refuge of multi-year sea ice in the Arctic, important for sea-ice dependent ecosystems. However, prolonged periods of open water observed in the Lincoln Sea and elsewhere in the Last Ice Area during recent years raise concerns about its long-term stability. From the Lincoln Sea, the Nares Strait connects the perennially sea-ice covered Last Ice Area to the Pikialasorsuaq or North Water Polynya (NOW), the Arctic’s largest and most productive polynya. The NOW is influenced by both sensible and latent heat processes, with the latter driven by strong northeasterly winds and aided by the formation of ice arches in the narrow passages of Nares Strait. Recurrent failure of ice arches in Nares Strait during recent years influence the extent, ice cover, and stratification of the NOW and with it its ecosystem.
Using sea-ice biomarkers on a transect of marine sediment cores spanning from the Lincoln Sea to northern Baffin Bay, we can investigate the stability of perennial sea ice in the Last Ice Area, understand the evolution of ice arching in Nares Strait, and explore the extent of the NOW throughout the Holocene. In the context of regional climate variability and ocean circulation, this can provide insights into the mechanisms governing sea-ice dynamics in this region and improve our understanding of their spatiotemporal links to ecosystem shifts.
- Speaker: Henrieka Detlef, Aarhus University
- Wednesday 18 February 2026, 17:30-19:00
- Venue: Latimer Room, Clare College.
- Series: Quaternary Discussion Group (QDG); organiser: sr632.