Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [ca. 1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ca. 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Small Lecture Theatre, Department of Geography, Downing Site.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 01 May 15:00: Ocean, ice, and the spherical cow
“Consider a spherical cow in the vacuum…” – that’s how most physics problems start. A very simplified version of the real world that we can wrap our heads around and find answers using pencil and paper. Numerical models that simulate the components of the climate system are no different: we start simple and build it up as scientific knowledge of the system advances and technology allows us to explore smaller-scale processes. My research focuses on understanding ice-ocean interactions, focusing on the behaviour of icebergs and their impacts in the polar oceans, using said models. Join me as I explain my journey towards drawing a cow that looks less like a balloon and more like a quadruped.
- Speaker: Juliana Marson, University of Manitoba
- Wednesday 01 May 2024, 15:00-16:00
- Venue: BAS Seminar Room 1; https://bas-ac-uk.zoom.us/j/92407581181.
- Series: British Antarctic Survey - Polar Oceans seminar series; organiser: Dr Birgit Rogalla.
Tue 04 Jun 11:30: Aerosols and clouds in the UKCA across time and space Join Zoom Meeting https://us02web.zoom.us/j/89998723970?pwd=ekw0Q3RqaUVFU3NaT3J1djlHTytiQT09
In this talk I will present work that I have done on aerosols and clouds in UKCA -based models: the UK Earth System climate model and the regional high resolution UKCA model. The work spans a large range of time and spatial scales ranging from historical climate modelling of the 1850-2014 period to a case study of volcanic event at 4km resolution.
In the historical study we determined what caused the long-term trends in the upwelling short-wave (SW) top-of-the-atmosphere (TOA) fluxes over the North Atlantic region. The UKESM showed a positive trend between 1850 and 1970 (increasing SW reflection) and a negative trend between 1970 and 2014. We found that the 1850–1970 positive trend is mainly driven by an increase in cloud droplet number concentration due to increases in aerosol, while the 1970–2014 trend was mainly driven by a decrease in cloud fraction, which we attributed mainly to cloud feedbacks caused by greenhouse gas-induced warming.
In the high resolution modelling work we use an eruption of sulphur dioxide from the Kilauea volcano in Hawaii as a natural laboratory to evaluate aerosol-cloud interaction processes against satellite observations. The model produces an increase in aerosol optical depth due to the volcano that is too large compared to observations, but the increase in cloud droplet number concentration compares well. The cloud liquid water path (a measure of cloud thickness) and cloud fraction responses are in the opposite direction what is observed, although with a large observational uncertainty. This suggests some issues with the model, but also underscores the difficulty in observing aerosol-cloud interactions.
I’m now working in the UKESM development team at the Met Office. Therefore I will also look forwards towards the next iterations of the UKESM model with respect to aerosols and clouds, where we hope to bring together the things learnt from the research across various time and spatial scales that has been performed by scientists across the UK.
Join Zoom Meeting https://us02web.zoom.us/j/89998723970?pwd=ekw0Q3RqaUVFU3NaT3J1djlHTytiQT09
- Speaker: Daniel Grosvenor, Institute for Climate and Atmospheric Science (ICAS), University of Leeds,
- Tuesday 04 June 2024, 11:30-12:30
- Venue: Chemistry Dept, Unilever Lecture Theatre and Zoom.
- Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Vichawan (Print) Sakulsupich.
Tue 21 May 15:00: Epistemic Exclusion in Climate Science: Why We Grow the Wrong Trees in the Wrong Places Join Zoom Meeting https://us02web.zoom.us/j/88161587298?pwd=U0I2ejRHTXROQmhiNHo2OTF6NE1kZz09
Why do we grow the wrong trees in the wrong places? This paper investigates this through the REDD + initiatives under the UNFCCC that advocated for planting trees in developing countries to cool down our global temperature. The intuition behind this initiative, that growing trees in the tropics are good for fighting climate change, was naturalized by mainstream climate science in the Global North. Yet, as biologists point out, trees especially in the tropics emit gases known as BVO Cs that can further exacerbate global warming. In other words, planting an enormous number of inappropriate species of trees in the tropics can even hurt rather than help the earth. This is surprising: why, given the espoused scientific commitment to pluralism as well as the interdisciplinary and global nature of climate change, are some scientific perspectives, especially biologists from the Global South, not well integrated into mainstream climate science? I show that rendering the climate as a singular legible entity from a god’s eye view also erects structural barriers to more heterogenous scientific studies of local ecologies from being integrated. Moreover, because models of the climate are based on environmental assumptions and tools of the Global North, they struggle to incorporate knowledge where these assumptions do not hold – especially in the Global South, where trees are more likely to emit gases that can exacerbate climate change – leading to international policies that ironically harms, rather than helps, the planet. I illustrate these challenges to integrating knowledge on BVO Cs into mainstream climate models based on 48 interviews with climate scientists in both the Global North and Global South, as well as fieldwork based in climate science labs in the U.S. and Thailand.
——————————————————————————————
Topic: CAS Seminar: Jittip Mongkolnchaiarunya Time: May 21, 2024 03:00 PM London
Join Zoom Meeting https://us02web.zoom.us/j/88161587298?pwd=U0I2ejRHTXROQmhiNHo2OTF6NE1kZz09
Meeting ID: 881 6158 7298 Passcode: 174484
Join Zoom Meeting https://us02web.zoom.us/j/88161587298?pwd=U0I2ejRHTXROQmhiNHo2OTF6NE1kZz09
- Speaker: Jittip Mongkolnchaiarunya, The George Washington University
- Tuesday 21 May 2024, 15:00-16:00
- Venue: Chemistry Dept, Unilever Lecture Theatre and Zoom.
- Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: Vichawan (Print) Sakulsupich.
Mon 13 May 19:30: CSAR lecture: Creating brain organoids to uncover what makes us human.
Using in vitro models to study human brain evolution and disease. The human brain is amazingly complex, and it’s this complexity that enables our remarkable cognitive power but also makes us susceptible to a range of neurological and mental health conditions. How this complexity arises specifically in humans is one of the most important questions in biology. Because it is a question that can’t be answered in standard animal models, we need a human model. We are exploring this by using stem cell derived models called organoids, small tissues that self-organise and build themselves in a petri dish. By making organoids that mimic the early stages of brain development, we can compare these tissues made from human cells with those made from our closest living relatives, the other great apes, to discover what sets us apart. We have discovered that the cells that produce neurons develop more slowly in human, and that this delay enables them to expand more before making neurons, and thus enables greater neuron number production in the end, hence a larger more complex brain. We are now exploring how this happens, and what goes wrong in disorders like autism and schizophrenia. By using a human model, we are finally revealing the key processes that set us apart as a species.
Open to all. More details, and a link for booking, here
- Speaker: Dr. Madeline Lancaster, MRC Laboratory of Molecular Biology
- Monday 13 May 2024, 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.
Mon 13 May 19:30: CSAR lecture: Creating brain organoids to uncover what makes us human.
Using in vitro models to study human brain evolution and disease. The human brain is amazingly complex, and it’s this complexity that enables our remarkable cognitive power but also makes us susceptible to a range of neurological and mental health conditions. How this complexity arises specifically in humans is one of the most important questions in biology. Because it is a question that can’t be answered in standard animal models, we need a human model. We are exploring this by using stem cell derived models called organoids, small tissues that self-organise and build themselves in a petri dish. By making organoids that mimic the early stages of brain development, we can compare these tissues made from human cells with those made from our closest living relatives, the other great apes, to discover what sets us apart. We have discovered that the cells that produce neurons develop more slowly in human, and that this delay enables them to expand more before making neurons, and thus enables greater neuron number production in the end, hence a larger more complex brain. We are now exploring how this happens, and what goes wrong in disorders like autism and schizophrenia. By using a human model, we are finally revealing the key processes that set us apart as a species.
- Speaker: Dr. Madeline Lancaster, MRC Laboratory of Molecular Biology
- Monday 13 May 2024, 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.
Mon 29 Apr 12:30: Large-scale flow structures in turbulent Rayleigh-Bénard convection: Dynamical origin, formation, and role in material transport
The interplay of gravity with mass density inhomogeneities introduces natural (thermal) convection and represents the essential mechanism by which heat is transported in natural flows. Simultaneously, natural flows are often far more extended in the horizontal direction than in the vertical one. Motivated by these two observations and the various geo- and astrophysical applications (e.g. the solar convection zone), 3-dimensional Rayleigh-Bénard convection as the paradigm of thermal convection has been studied. This talk will cover some recent results from studying the impact of thermal (and mechanical) boundary conditions on large-scale flow structures in Rayleigh-Bénard convection by means of direct numerical simulations. It will be shown that thermal boundary conditions are crucial to the formation of long-living large-scale (turbulent) flow structures. In particular, a slow transient aggregation process — that only stops once the horizontal extent of the domain is reached — can be found once the fluid layer is subjected to Neumann-type constant heat flux boundary conditions. As a result, the temperature field in the domain is separated into one extended hot and another extended cold region. We trace this mechanism of self-organisation of flow structures back to secondary instabilities as well as an inverse cascade in spectral space. The talk will finish with a brief overview of our work on the identification of those large-scale flow structures by the use of unsupervised machine learning based on Lagrangian particle data.
- Speaker: Philipp Vieweg
- Monday 29 April 2024, 12:30-13:30
- Venue: MR5, CMS.
- Series: Geophysical and Environmental Processes; organiser: Prof. John R. Taylor.
Large-scale chemoproteomics expedites ligand discovery and predicts ligand behavior in cells | Science
Genomic factors shape carbon and nitrogen metabolic niche breadth across Saccharomycotina yeasts | Science
Sequence basis of transcription initiation in the human genome | Science
Ciliopathy patient variants reveal organelle-specific functions for TUBB4B in axonemal microtubules | Science
A gene mutation turned these fish into intrepid explorers
News at a glance: Plants’ tree of life, conserving U.S. federal lands, and entertaining invertebrate sentience
Can science find ways to ease loneliness?
Tue 07 May 11:30: The role of methane for chemistry-climate interactions: rapid radiative adjustments and climate feedbacks Zoom link: https://us02web.zoom.us/j/89826306833?pwd=cnNHSG9OWHRjVngzMGVMc2F0NnA4dz09
Methane (CH4), the second most important greenhouse gas directly emitted by human activity, is removed from the atmosphere via chemical degradation. The chemical sink of CH4 is influenced by temperature and the chemical composition of the atmosphere. It is further an important source of water vapour in the stratosphere and affects the ozone concentration in the troposphere and the stratosphere via secondary feedbacks.
The talk will focus on the role of these chemistry-climate interactions in numerical simulations with the chemistry-climate model EMAC perturbed by either CO2 or CH4 increase. For both forcing agents, CO2 and CH4 , so called rapid radiative adjustments are assessed in simulations with prescribed sea surface temperatures, as well as climate feedbacks in respective simulations using an interactive oceanic mixed layer.
The simulation set-up uses CH4 emission fluxes instead of prescribed CH4 concentrations at the lower boundary so that changes of the chemical sink can feed back on the atmospheric CH4 concentration without constraints.
The results show a shortening of the CH4 lifetime and, accordingly, a reduction of the CH4 mixing ratios in a warming and moistening troposphere. This decrease in CH4 also affects the response of tropospheric ozone.
Furthermore, recently an additional radiation scheme was implemented into the EMAC model, which represents the direct radiative effect of CH4 better and also accounts for the absorption by CH4 in the solar shortwave spectrum. With the new radiation scheme the effective radiative forcing for the same perturbation of CH4 emissions is larger, and individual rapid radiative adjustments, e.g. of clouds, are changed.
Zoom link: https://us02web.zoom.us/j/89826306833?pwd=cnNHSG9OWHRjVngzMGVMc2F0NnA4dz09
- Speaker: Laura Stecher, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre (Engl: German Aerospace Center, Institute of Atmospheric Physics)
- Tuesday 07 May 2024, 11:30-12:30
- Venue: Chemistry Dept, Unilever Lecture Theatre and Zoom.
- Series: Centre for Atmospheric Science seminars, Chemistry Dept.; organiser: .