Research activities in the Atmospheric Chemistry and Climate of the Anthropocene research group. Our broad research interests are: Detection and attribution of climate change Understanding past and future climate variability and change Remote sensing of composition in the troposphere and stratosphere Land-atmosphere interactions Global and regional modelling of climate and atmospheric composition Long-range transport of air pollution Climate change and air pollution impacts on human health Air pollution at the indoor-outdoor interface: energy efficiency and clean air policies Current projects Causes of climate change and implications for the future We are part of the GloSAT consortium reconstructing climate since the industrial revolution and a EUCP project aiming at European seamless predictions, among others. We also collaborate with ecologists on a project focusing on the future of the dry tropics. Our European Advanced Grant “Transition into the Anthropocene” (TITAN) determined the causes of climate variations and change from the Industrial Revolution to the present time. It found that the cold conditions in the early 19th century were largely caused by volcanic eruptions. The 1816 “year without a summer” in Europe was greatly influenced by the eruption of Mount Tambora. Climate rebounded from this active volcanic period to warmer conditions over the 19th century, by the end of which greenhouse warming can be detected in long-term trends. Researchers found that exceptionally cold conditions in the South Atlantic during the beginning of the 20th century, which spread northward, enhanced the slope of the warming trend into the early 20th century. That warming culminated in an unusually warm North Atlantic in the 1940s, to which they discovered was involved in setting the stage for dry springs and record hot summers in the Great Plains of the US. Climate models do not reproduce these record heat waves under “standard” climate boundary conditions but can simulate similar heatwaves if accounting for the removal of vegetation associated with the dust bowl droughts and agricultural crisis. Visit the GloSat consortium website More information on the EUCP project Visit the SECO project website For more on Professor Gabi Hegerl’s work visit her blog Publications * Affiliated authors are highlighted in bold (2018) The early 20th-century warming: Anomalies, causes, and consequences. WIREs Climate Change, 9. *Authors: Hegerl, G., Brönnimann, S., Schurer, A., Cowan, T. View publication (2020) Present-day greenhouse gases could cause more frequent and longer Dust Bowl heatwaves. Nature Climate Change, 10, 505–510. *Authors: Cowan, T., Undorf, S., Hegerl, G.C., Harrington, L. J., Otto, F.E.L. View publication (2020) Ocean and land forcing of the record-breaking Dust Bowl heatwaves across central United States. Nature Communications, 11, 2870. *Authors: Cowan, T., Hegerl, G.C., Schurer, A, Tett, S.F.B, Vautard, R., Yiou, P., Jézéquel, A., Otto, F.E.L., Harrington, L.J., Ng, B. View publication (2019) Disentangling the causes of the 1816 European year without a summer. Environmental Research Letters, 14. *Authors: Schurer, A., Hegerl, G., Luterbacher, J., Brönnimann, S., Cowan, T., Tett, S., Zanchettin, D., Timmreck, C. View publication Changing risks and attribution of extreme weather events Evaluating Extreme Rainfall In Eastern China (EERCH) is a Newton Fund project exploring the role of human forcings in changing extreme precipitation events in Eastern China. This project builds on a previous set of Newton funded projects examining extreme events in China. Key to the work is understanding the mechanisms that drive extreme events in reality and testing if models are capable of reproducing them. From that, we can see how much human influences have changed the risk of events and how they might change in the future. This project is collaborative with the University of Oxford and the National Centre for Atmospheric Science. As part of a set of Newton Fund projects, we have led workshops teaching event attribution to early-career scientists. These workshops last a week and participants learn by doing, with support from tutors. The goal is for groups of participants to have a draft paper studying a specific event and estimating how much its risk has changed due to human influences relative to a natural “counterfactual” world. Nine papers have been produced and published from the workshops to date. Find out more on this project on *ERE * Edinburgh Research Explorer (ERE) is the University's research information system and is managed by Library and University Collections. Publications *Affiliated authors are highlighted in bold (2018) Storylines: An alternative approach to representing uncertainty in physical aspects of climate change. Climatic Change, 151, 555-571. *Authors: Shepherd, T. G., Boyd, E., Calel, R. A., Chapman, S. C., Dessai, S., Dima-West, I. M., Fowler, H. J., James, R., Maraun, D., Martius, O., Senior, C. A., Sobel, A. H., Stainforth, D. A., Tett, S., Trenberth, K. E., Van den Hurk, B. J. K. M., Watkins, N. W., Wilby, R. L., Zenghelis, D. A. View publication (2020) Anthropogenically-driven increases in the risks of summertime compound hot extremes. Nature Communications, 11, 528. *Authors: Wang, J., Tett, S., Yan, Z., Zhai, P., Feng, J. & Xia, J. View publication (2017) Summer heat waves over Eastern China: Dynamical processes and trend attribution. Environmental Research Letters. 12, 024015. *Authors: Freychet, N., Tett, S., Wang, J., Hegerl, G. View publication Drivers and mechanisms of regional climate change Our research addresses major questions regarding the drivers and underpinning physical mechanisms of regional climate variability and change across a range of spatial and temporal scales, using observations and a range of atmospheric/climate models of various complexity. We focus on improving understanding and reducing uncertainties associated with the regional-to-global impact of anthropogenic aerosols, the dominant contributor to the uncertainty in total anthropogenic forcing over the industrial era. This work has led to novel findings on the modulation of the monsoon system and the wider tropical circulation by aerosols, both in the past and in the future, on the potential to generate hemispheric-wide responses and teleconnections across the globe, on the key contribution of aerosols to past climate decadal variability over Europe and the Atlantic, and on their key role in driving past and future changes in precipitation and temperature extremes. Motivated by an interest in understanding regional climate variability from a broader holistic perspective of identifying drivers and mechanisms, we have also shed new light on modes of variability and atmospheric teleconnections, the role of internal climate variability via changes in the atmospheric circulation and ensuing large-scale teleconnections, fundamental coupled land-atmosphere-ocean processes in the climate system, the forcing by dust aerosols, and changes in the monsoon system on paleoclimate time scales. The above work has received support from NERC and the Newton Fund. Publications *Affiliated authors are highlighted in bold (2020) Accelerated increases in global and Asian summer monsoon precipitation from future aerosol reductions. Atmospheric Chemistry and Physics Discussions *Authors: Wilcox, L. J., Liu, Z., Samset, B.H., Hawkins, E., Lund, M.T., Nordling, K., Undorf. S., Bollasina, M., Ekman, A.M.L., Krishnan, S.,Merikanto, J., Turner, A.G. View publication (2019) Strong influence of aerosol reductions on future heatwaves. Geophysical Research Letters, 46, 4913– 4923. *Authors: Zhao, A., Bollasina, M.A., Stevenson, D.S. View publication (2019) A model investigation of aerosol‐induced changes in the East Asian winter monsoon. Geophysical Research Letters, 46, 9362-9369. *Authors: Liu, Z., Ming, Y., Wang, L., Bollasina , M., Luo, M., Lau, N-C., Hung‐Lam Yim, S. View publication Impacts of CO2 removal on climate Metrics for Emissions Removal LImits for Nature (MERLIN) is a NERC funded project exploring the potential impact of overshoot and negative emissions using a low-resolution Earth System model driven by pulses of CO2 emission and removal. This shows that surface temperature changes are roughly proportional to total emitted carbon while sea-level change is roughly proportional to the emitted carbon times the time since the positive pulse. Drawdown leads to anomalously cool temperatures and a return to zero temperature change. However, sea level takes centuries to return to normal. In terms of the policy, it is not possible to overshoot and then return to the original temperature and sea-level climate without overshoot, even with the same net carbon emission. Find out more on this project on *ERE * Edinburgh Research Explorer (ERE) is the University's research information system and is managed by Library and University Collections. Atmospheric composition We are a group of research staff and students led by Professor Paul Palmer that study Earth's atmosphere and other planets using data, models, and theory. This group forms part of the Centre for Exoplanet Science. Visit the Centre for Exoplanet Science Visit the ACMG website for details of our work on studying the atmospheres of the Earth and other planets using data, models and theory Information relating to atmospheric composition publications Remote sensing of the atmosphere We collaborate with the following: Microwave Limb Sounder (MLS) at NASA JPL - the study of the causes of the Ozone hole, effects of water vapour on the Earth's climate and the dispersion of pollutants (e.g. volcanic SO2 and CO from wildfires) in the upper troposphere and lower stratosphere. Orbital Micro Systems (OMS) and Weatherstream - OMS use novel microwave radiometers on small satellites to improve near-real-time weather data delivery and forecasting. Visit the Microwave Limb Sounder website for more details Visit the Orbital Micro Systems website More information about Weatherstream In situ atmospheric composition monitoring We study what changes in atmospheric composition are happening now and the changes that have occurred over the last few decades. We are particularly interested in understanding observations of greenhouse gases. Source and sink magnitudes of greenhouse gases can be quantified from high precision ambient air measurements using atmospheric transport models and statistical techniques. Our School has a strong collaboration with the National Physical Laboratory, the UK’s National Measurement Institute, and we work on the analysis techniques and protocols and interpretation of data towards our mutual aim to improve quality and innovation in atmospheric measurement. This research has an important impact on climate change policy through the ability to verify officially reported ‘bottom-up’ estimates (that are calculated from activity data and emission factors) and with the potential to see the true impact of policy changes quickly. Listed below is some active work in this area: Detection and Attribution of Regional greenhouse gas Emissions in the UK (DARE-UK): this project focuses on the next generation of measurement and modelling to understand UK emissions and how they are changing. UK Deriving Emissions linked to Climate Change Network (UK DECC Network): we contribute to the UK Deriving Emissions linked to Climate Change Network (University of Bristol) through measurements made at the Heathfield tall tower observatory together with the National Physical Laboratory (NPL). Tall tower atmospheric observatory in Scotland: together with the James Hutton Institute and NPL this is a project that started in 2021 to deliver a new atmospheric monitoring facility for Scotland together with our collaborators. Isotopic atmospheric measurements and modelling We are creating new atmospheric monitoring methods for methane through the development of high-precision in situ isotope ratio measurements and delving into understanding the atmospheric distribution of rare ‘multiply-substituted’, or ‘clumped’ isotopologues. This is a collaboration with the National Physical Laboratory and other universities across the UK. The ratios of the stable isotopic variants of CH4 molecules (10 in total; the major isotopologues being 12CH4, 13CH4, 12CH3D, 13CH3D and 12CH2D2), serve as quantitative tracers of various processes involving CH4 in the environment. The different formation, transport, and removal processes of CH4 often impart distinctive isotopic fractionations. As a result, the stable isotopes of CH4 can be used to reconstruct and quantify those processes. Listed below is some active work in this area: POLYGRAM (POLYisotopologues of GReenhouse gases: Analysis and Modelling) POLYGRAM is an Edinburgh led project involving multiple UK-based co-investigators and international partners. POLYGRAM will push the frontiers for both CO2 and CH4 polyisotopologue measurement capability using the latest advances in laser spectroscopic analysis and very high-resolution isotope ratio mass spectrometry. In addition to these challenging technological developments, we will establish a small global atmospheric sampling network to examine latitudinal and longitudinal variations in polyisotopologues, which will help us to constrain overall global budgets of CO2 and CH4. Researchers will carry out field campaigns to determine polyisotopologue source signatures, for example, of CH4 from wetlands, cattle and landfills, and of CO2 from plant photosynthesis and respiration, and from fossil fuel burning. We will conduct laboratory experiments to estimate the reaction rates for CH4 isotopologues when they are oxidised and destroyed in the atmosphere. Finally, we will examine atmospheric transport modelling for both gases to better interpret and understand the measurements. Visit the POLYGRAM website Air pollution and impacts on human health Professor Ruth Doherty’s research interests lie in global, regional and urban modelling of air pollution and its impacts on human health. She uses chemistry-climate models to study: climate-chemistry interactions, regional and urban air quality, climate change and air quality, and performs interdisciplinary research on the health impacts of air pollution. Ruth is a member of the UNECE Task Force on Hemispheric Transport of Air Pollution (TF HTAP) and a nominated member of the International Commission on Atmospheric Chemistry and Global Pollution (iCACGP: 2019-2023). Visit the TF HTAP website More information on iCACGP Listed below is some active work in this area: HEICCAM: (Health and equity impacts of climate change mitigation measures on indoor and outdoor air pollution exposure ( PI Doherty) - funded by NERC under the SPF Clean Air Programme - The transition to a low carbon economy and policies to improve air quality have important implications for exposure to air pollutants in the connected indoor and outdoor environments. The HEICCAM network aims to develop an interdisciplinary, multi-sectoral network aimed at improving research evidence, policy and regulatory advice on optimising the health impacts of changes to indoor and outdoor air pollution levels. We have a particular focus on the transition to a low carbon economy, home energy efficiency and the associated implications for health equity and vulnerable groups. It brings together eighteen investigators from nine different UK Universities and one Public Sector Research Establishment (PSRE) and twenty-two project partners providing expertise with that span: atmospheric pollution measurements and modelling, building physics, sustainable architecture, low carbon, public health epidemiology, environmental health and health inequalities, education economics and health psychology and behavioural science. Our twenty-two project partners encompass stakeholders across the public sector, business/industry and the third sector. CleanAir4V (Air Pollution Solutions for Vulnerable Groups (Co-I Doherty) funded by NERC under the SPF Clean Air Programme The aim of CleanAir4V is to develop innovative and cost-effective behaviour and technology interventions to reduce further air pollution exposure and improve the health of vulnerable groups and implement these interventions through policy advice, planning and business innovation. MAQS-Health (Multi-Model Air Quality System for Health Research (Co-I Doherty) This project will provide a high-resolution prediction capability to support personal exposure for health impacts. The system will comprise a coupled air quality modelling system spanning national to urban street scales and accounting for physical and chemical processes occurring at all relevant spatial and temporal scales. Information on CleanAir4V Wave 1 Information on CleanAir4V Wave 2 Ixchel (Building understanding of the physical, cultural and socio-economic drivers of risk for strengthening resilience in the Guatemalan cordillera, Co-I Doherty) funded by NERC under the Global Challenges Research Fund Ixchel adopts a holistic approach to risk, by providing new approaches for improved hazard and risk assessment, which places close attention on the geographies at play in Guatemala. Ruth's contribution to this large interdisciplinary project is to understand the processes that link rainfall associated with tropical cyclones to lahar flow for hazard assessment. Chemistry-climate interactions We focus on global and regional modelling of atmospheric composition, to diagnose how composition influences climate (e.g. via Short-Lived Climate Forcers, such as ozone, aerosols, and methane), and also how climate influences composition (e.g. process-based emissions and chemistry-climate feedbacks). Publications *Affiliated authors are highlighted in bold (2021) A climate-dependent global model of ammonia emissions from chicken farming. Biogeosciences, 18, 135-158. *Authors: Jiang, J., Stevenson, D. S., Uwizeye, A., Tempio, G. and Sutton, M. A. View publication (2020) Trends in global tropospheric hydroxyl radical and methane lifetime since 1850 from AerChemMIP. Atmospheric Chemistry and Physics, 12905-12920. *Authors: Stevenson, D. S., Zhao, A., Naik, V., O'Connor, F. M., Tilmes, S., Zeng, G., Murray, L. T., Collins, W. J., Griffiths, P. T., Shim, S., Horowitz, L. W., Sentman, L. T., and Emmons, L. View publication (2019) Strong influence of aerosol reductions on future heatwaves. Geophysical Research Letters, 46, 4913-4923. *Authors: Zhao, A., Bollasina, M. A., Stevenson, D. S. View publication Snow-climate interactions Our seasonal snow cover research combines field studies at Arctic and Alpine sites, remote sensing and modelling. We work on scales from landscapes (where snow influences the activities of people, animals and plants living in cold regions), to mountain ranges (where snow stores and releases essential water resources), to continents (where snow-atmosphere interactions shape the climate). Activities under the NERC-funded Reducing Snow-Climate Uncertainty in Earth System modelling (ReSCUES) project that we lead include: evaluation of Earth system model snow schemes at highly instrumented reference sites Download the model forcing data development of a flexible snow model for exploring sources of uncertainty in snow modelling Download the snow models We are contributing to the European Space Agency (ESA) Snow project to generate a long-term series of daily snow extent and mass maps from remote sensing and to develop Earth Observation products for operational needs in the Alps. Visit the Snow project website Visit the AlpSnow website for information on products Publications *Affiliated authors are highlighted in bold (2020) Snow cover duration trends observed at sites and predicted by multiple models. The Cryosphere, 14, 4687–4698. *Authors: Essery, R., Kim, H., Wang, L., Bartlett, P., Boone, A., Brutel-Vuilmet, C., Burke, E., Cuntz, M., Decharme, B., Dutra, E., Fang, X., Gusev, Y., Hagemann, S., Haverd, V., Kontu, A., Krinner, G., Lafaysse, M., Lejeune, Y., Marke, T., Marks, D., Marty, C., Menard, C.B., Nasonova, O., Nitta, T., Pomeroy, J., Schädler, G., Semenov, V., Smirnova, T., Swenson, S., Turkov, D., Wever, N., Yuan, H. View publication (2020) Process‐level evaluation of a hyper‐resolution forest snow model using distributed multisensor observations. Water Resources Research, 56, e2020WR027572. *Authors: Mazzotti, G., Essery, R., Webster, C., Malle, J., Jonas, T. View publication (2020) Historical Northern Hemisphere snow cover trends and projected changes in the CMIP6 multi-model ensemble. The Cryosphere, 14, 2495–2514. *Authors: Mudryk, L., Santolaria-Otín, M., Krinner, G., Ménégoz, M., Derksen, C., Brutel-Vuilmet, C., Brady, M., Essery, R. View publication This article was published on 2024-07-01