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A historian interrogates the mythical creatures we create to dehumanize and devalue others

Large genome rearrangements in mammalian cells can be generated at scale

Before the hippocampus goes down memory lane, it takes a detour

Structural snapshots of an enzyme complex reveal missing pieces of a biological process

Enhanced antibacterial skin inflammation is an adaptation of the itch-scratch cycle

A reappraisal of the constitutional position of science in American democracy is needed

To many in the scientific community, the 1975 Asilomar Conference on Recombinant DNA stands as a singular achievement. This experiment in governance seemed to demonstrate that citizens could trust scientists to anticipate their fields’ risks and propose ...

The Greenland Inland Ice Sheet and its watery margins: sediments and freshwater fluxes

Abstract not available

• Speaker: Prof. Nanna Karlsson, Geological Survey of Denmark and Greenland
• Thursday 13 February 2025, 16:00-17:00
• Venue: Scott Polar Research Institute, main lecture theatre.
• Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: rld46.

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Antarctic Atmospheric Rivers in the Present and Future Climates

Abstract not available

• Speaker: Dr. Michelle Maclennan, British Antarctic Survey
• Thursday 27 February 2025, 16:00-17:00
• Venue: Scott Polar Research Institute, main lecture theatre.
• Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: rld46.

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West Antarctic Ice Sheet readvance in the Holocene

Sea-level rise is accelerating, predominantly due to the ice sheets shrinking. There is significant uncertainty as to how this will continue. Understanding how ice sheets have changed in the past can improve our predictions of future change by highlighting important processes and helping to test and tune ice-sheet models. This talk is about how West Antarctica changed during the Holocene. Until recently, it was assumed that the West Antarctic Ice Sheet shrank monotonically from an expanded state at the Last Glacial Maximum (LGM), to its current state, which it then maintained through most of the Holocene. In this talk I will describe a decade of work by myself and many others suggesting that after the LGM the ice sheet instead shrank to a size significantly smaller than today, then regrew to its current size in the Weddell and Ross sea sectors. In places, the grounding line may have reached more than 200 km inland of its current position.

The cause of the retreat and readvance is debated. Potential causes include glacial isostatic adjustment (GIA) and climate fluctuations. Which proves the best explanation has implications for our understanding of these sectors’ sensitivity to future climate-driven changes.

I will discuss a wide range of evidence for retreat and readvance. This includes englacial structure mapped with ice-penetrating radar, englacial temperatures measured in boreholes, radiocarbon in subglacial water and sediments, and indicators of relative sea-level change. I will also discuss what these observations tell us about the timing of retreat and readvance and several modelling studies aimed at determining the cause of these changes. Finally, I will discuss future work that could improve our understanding of these sectors of the ice sheet and their climate sensitivity.

• Speaker: Dr. Jonathan Kingslake, Lamont-Doherty Earth Observatory (LDEO), Columbia Climate School
• Thursday 06 March 2025, 17:00-18:00
• Venue: Scott Polar Research Institute, main lecture theatre.
• Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: rld46.

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Just Ice For All: Global Ice-Thickness Inversions and Committed Ice Loss to 2050

Abstract not available

• Speaker: Dr. Samuel Cook, Friedrich-Alexander-University
• Thursday 20 March 2025, 16:00-17:00
• Venue: Scott Polar Research Institute, main lecture theatre.
• Series: Scott Polar Research Institute - Polar Physical Sciences Seminar; organiser: rld46.

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Nation has been trying to phase out smoky traditional stoves that burn wood and dung

Breakdown of collaboration with CERN forcing many physicists to reorient work

The loss of genetic variation means species may be less resilient to climate change and other stressors

Modelling sea ice dynamics using brittle dynamics: impact in pack ice and marginal ice zones

Sea ice dynamics are highly complex and generally poorly resolved by sea ice models. This is problematic, as they modulate the amount of momentum exchanged between the atmosphere and the ocean in polar regions, as well as play a key role in heat and light fluxes through the opening/closing of sea ice leads. A solution to improve simulated sea ice dynamics is to use a brittle rheology to represent the mechanical behaviour of sea ice. Such rheology is included in the sea ice model neXtSIM, and we demonstrated its ability to capture the observed characteristics and complexity of fine-scale sea ice deformations.Here, we present two cases where we coupled this sea ice model to better understand the role of ice dynamics in ice-ocean interactions.

In the first case, we set up a 12km resolution ocean—sea-ice coupled model, using OPA , the ocean component of NEMO . We investigate the sea ice mass balance of the model for the period 2000-2018. We estimate the contribution of leads and polynyas to winter ice production. We find this contribution to add up from 25% to 35% of the total ice growth in pack ice in winter, showing a significant increase over the 18 years covered by the model simulation.

In the second case, we focus on the marginal ice zone (MIZ) and couple neXtSIM with the wave model WAVEWATCH III . We investigate how wave-induced breakup impacts sea ice dynamics in the MIZ . We show how, using the “damage” quantity that is at the core of the brittle rheology framework, we can represent the loss of ice strength associated with wave-induced breakup, and how breakup can increase the mobility of the thickest ice in the MIZ after storms. For both cases, we will also discuss briefly how using a brittle sea ice model could impact the modelling of Antarctic sea ice using preliminary results from a new configuration.

• Speaker: Guillaume Boutin (Nansen Environmental and Remote Sensing Center)
• Wednesday 29 January 2025, 14:00-15:00
• Venue: BAS Seminar Room 1; https://ukri.zoom.us/j/97264211524.
• Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.

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“You’re completely erasing nonbinary, gender-diverse people,” one researcher says

Short-term, high-resolution sea ice forecasting with diffusion model ensembles

Sea ice plays a key role in Earth’s climate system and exhibits significant seasonal variability as it advances and retreats across the Arctic and Antarctic every year. The production of sea ice forecasts provides great scientific and practical value to stakeholders across the polar regions, informing shipping, conservation, logistics, and the daily lives of inhabitants of local communities. Machine learning offers a promising means by which to develop such forecasts, capturing the nonlinear dynamics and subtle spatiotemporal patterns at play as effectively—if not more effectively—than conventional physics-based models. In particular, the ability of deep generative models to produce probabilistic forecasts which acknowledge the inherent stochasticity of sea ice processes and represent uncertainty by design make them a sensible choice for the task of sea ice forecasting. Diffusion models, a class of deep generative models, present a strong option given their state-of-the-art performance on computer vision tasks and their strong track record when adapted to spatiotemporal modelling tasks in weather and climate domains. In this talk, I will present preliminary results from a IceNet-like [1] diffusion model trained to autoregressively forecast daily, 6.25 km resolution sea ice concentration in the Bellingshausen Sea along the Antarctic Peninsula. I will also touch on the downstream applications for these forecasts, from conservation to marine route planning, which are under development at the British Antarctic Survey (BAS). I welcome ideas and suggestions for improvement and look forward to discussing opportunities for collaboration within and beyond BAS .

[1] Andersson, Tom R., et al. “Seasonal Arctic sea ice forecasting with probabilistic deep learning.” Nature communications 12.1 (2021): 5124. https://www.nature.com/articles/s41467-021-25257-4

• Speaker: Andrew McDonald, University of Cambridge and British Antarctic Survey
• Wednesday 12 February 2025, 14:00-15:00
• Venue: BAS Seminar Room 2.
• Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.

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High-Resolution PM2.5 Mapping Across Malaysia Using Multi-Satellite Data and Machine Learning Techniques

Air pollution assessment in urban and rural areas is really challenging due to high spatio-temporal variability of aerosols and pollutants and the uncertainties in measurements and modelling estimates. Nevertheless, accurate determination of the pollution sources and distribution of PM2 .5 concentrations is especially important for source apportionment and mitigation strategies. This study provides estimates of PM2 .5 concentrations across Malaysia in high spatial resolution, based on multi-satellite data and machine learning (ML) models, namely Random Forest (RF), Support Vector Regression (SVR) and extreme Gradient Boosting (XGBoost), also covering remote areas without measurement networks. The study aims to develop ML models that are simpler than previous works and demonstrate computational efficiency. Six sub-models were developed to represent different locations and seasons in Malaysia. Model 1 includes all data from 65 air-quality stations, Models 2 and 3 characterize urban/industrial and suburban sites, respectively, while Models 4 to 6 correspond to dry, wet, and inter-monsoon seasons, respectively. The RF technique exhibited slightly better performance compared to the XGBoost and SVR approaches. More specifically, for model 1, it exhibited a high correlation with a coefficient of determination (R2) of 0.64 and RMSE of 12.17 μg m−3, while similar results were obtained for models 3, model 4 and model 5. The lower performance (R2 = 0.16-0.94) observed in the wet and inter-monsoon seasons is due to fewer numbers of data used in model calibration. Integration of two Aerosol Optical Depth products from the Advanced Himawari Imager and Visible Infrared Imaging Radiometer Suite (VIIRS) sensors together with gases pollutants from Sentinel 5P enabled seamless seasonal PM2 .5 mapping over Malaysia, even for a short period of time. However, usage of data with insufficient information during the model training procedure, and lack of satellite data due to cloud contamination, can limit the PM2 .5 prediction accuracy.

https://teams.microsoft.com/l/meetup-join/19%3ameeting_MTQ5N2Q5ZDYtODRmYi00MzJhLTg0ZjctNjc2NGVlZDUzYmUx%40thread.v2/0?context=%7b%22Tid%22%3a%2249a50445-bdfa-4b79-ade3-547b4f3986e9%22%2c%22Oid%22%3a%228b208bd5-8570-491b-abae-83a85a1ca025%22%7d

• Speaker: Kasturi Kanniah, Centre for Environmental Sustainability and Water Security (IPASA), Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia
• Tuesday 04 March 2025, 11:00-12:00
• Venue: Chemistry Dept, Unilever Lecture Theatre and Zoom.
• Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Dr Megan Brown.

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Could stratospheric aerosol injection produce meaningful global cooling without novel aircraft?

Stratospheric aerosol injection (SAI) is a proposed method of cooling the planet and reducing the impacts of climate change by adding a layer of small particles to the high atmosphere where they would reflect a fraction of incoming sunlight. While it is likely that SAI could reduce global temperature, it has many serious risks and would not perfectly offset climate change. For SAI to be effective, injection would need to take place in the stratosphere. The height of the transition to the stratosphere decreases with latitude, from around 17km near the equator to 8km near the poles. The required injection height would therefore also decrease for higher latitude injection. In this talk, I will present simulations of SAI in an earth system model, UKESM , which quantify how impacts would vary with the injection location and timing, focusing on low-altitude high-latitude injection strategies. Our results suggest that SAI could meaningfully cool the planet even if limited to using existing large jets and injecting at around 13km altitude, if this injection is in the high latitudes during spring and summer. However, relative to a more optimal deployment with novel aircraft at 20km, this strategy requires three times more sulphur dioxide injection and so would strongly increase some side-effects.

https://teams.microsoft.com/l/meetup-join/19%3ameeting_ZjVmYTU2YmItNmMyZC00NGYzLTllZmMtNGU5OWJiMjlhNDAy%40thread.v2/0?context=%7b%22Tid%22%3a%2249a50445-bdfa-4b79-ade3-547b4f3986e9%22%2c%22Oid%22%3a%228b208bd5-8570-491b-abae-83a85a1ca025%22%7d

• Speaker: Alistair Duffey, PhD Student at University College London, Earth Sciences
• Tuesday 04 February 2025, 11:00-12:00
• Venue: Chemistry Dept, Unilever Lecture Theatre and Teams.
• Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Yao Ge.

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Little powerhouses might someday replace billion-dollar, kilometer-long behemoths at major x-ray facilities