Articles | Volume 22, issue 9
https://doi.org/10.5194/acp-22-6135-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-22-6135-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
10 May 2022
Research article | Highlight paper |
| 10 May 2022
| 10 May 2022
Assessing the consequences of including aerosol absorption in potential stratospheric aerosol injection climate intervention strategies
College of Engineering, Mathematics and Physical Science, University
of Exeter, Exeter, EX4 4QE, UK
Met Office Hadley Centre, Exeter, EX1 3PB, UK
Andy Jones
Met Office Hadley Centre, Exeter, EX1 3PB, UK
Ben T. Johnson
Met Office Hadley Centre, Exeter, EX1 3PB, UK
William McFarlane Smith
College of Engineering, Mathematics and Physical Science, University
of Exeter, Exeter, EX4 4QE, UK
now at: Downing College, Cambridge, CB2 1DQ, UK
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George Jordan, Florent Malavelle, Ying Chen, Amy Peace, Eliza Duncan, Daniel G. Partridge, Paul Kim, Duncan Watson-Parris, Toshihiko Takemura, David Neubauer, Gunnar Myhre, Ragnhild Skeie, Anton Laakso, and James Haywood
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Jim M. Haywood, Andy Jones, Anthony C. Jones, Paul Halloran, and Philip J. Rasch
Atmos. Chem. Phys., 23, 15305–15324, https://doi.org/10.5194/acp-23-15305-2023, https://doi.org/10.5194/acp-23-15305-2023, 2023
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The difficulties in ameliorating global warming and the associated climate change via conventional mitigation are well documented, with all climate model scenarios exceeding 1.5 °C above the preindustrial level in the near future. There is therefore a growing interest in geoengineering to reflect a greater proportion of sunlight back to space and offset some of the global warming. We use a state-of-the-art Earth-system model to investigate two of the most prominent geoengineering strategies.
Calvin Howes, Pablo E. Saide, Hugh Coe, Amie Dobracki, Steffen Freitag, Jim M. Haywood, Steven G. Howell, Siddhant Gupta, Janek Uin, Mary Kacarab, Chongai Kuang, L. Ruby Leung, Athanasios Nenes, Greg M. McFarquhar, James Podolske, Jens Redemann, Arthur J. Sedlacek, Kenneth L. Thornhill, Jenny P. S. Wong, Robert Wood, Huihui Wu, Yang Zhang, Jianhao Zhang, and Paquita Zuidema
Atmos. Chem. Phys., 23, 13911–13940, https://doi.org/10.5194/acp-23-13911-2023, https://doi.org/10.5194/acp-23-13911-2023, 2023
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To better understand smoke properties and its interactions with clouds, we compare the WRF-CAM5 model with observations from ORACLES, CLARIFY, and LASIC field campaigns in the southeastern Atlantic in August 2017. The model transports and mixes smoke well but does not fully capture some important processes. These include smoke chemical and physical aging over 4–12 days, smoke removal by rain, sulfate particle formation, aerosol activation into cloud droplets, and boundary layer turbulence.
Matthew Henry, Jim Haywood, Andy Jones, Mohit Dalvi, Alice Wells, Daniele Visioni, Ewa M. Bednarz, Douglas G. MacMartin, Walker Lee, and Mari R. Tye
Atmos. Chem. Phys., 23, 13369–13385, https://doi.org/10.5194/acp-23-13369-2023, https://doi.org/10.5194/acp-23-13369-2023, 2023
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Solar climate interventions, such as injecting sulfur in the stratosphere, may be used to offset some of the adverse impacts of global warming. We use two independently developed Earth system models to assess the uncertainties around stratospheric sulfur injections. The injection locations and amounts are optimized to maintain the same pattern of surface temperature. While both models show reduced warming, the change in rainfall patterns (even without sulfur injections) is uncertain.
Chenwei Fang, Jim M. Haywood, Ju Liang, Ben T. Johnson, Ying Chen, and Bin Zhu
Atmos. Chem. Phys., 23, 8341–8368, https://doi.org/10.5194/acp-23-8341-2023, https://doi.org/10.5194/acp-23-8341-2023, 2023
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Daniele Visioni, Ben Kravitz, Alan Robock, Simone Tilmes, Jim Haywood, Olivier Boucher, Mark Lawrence, Peter Irvine, Ulrike Niemeier, Lili Xia, Gabriel Chiodo, Chris Lennard, Shingo Watanabe, John C. Moore, and Helene Muri
Atmos. Chem. Phys., 23, 5149–5176, https://doi.org/10.5194/acp-23-5149-2023, https://doi.org/10.5194/acp-23-5149-2023, 2023
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Geoengineering indicates methods aiming to reduce the temperature of the planet by means of reflecting back a part of the incoming radiation before it reaches the surface or allowing more of the planetary radiation to escape into space. It aims to produce modelling experiments that are easy to reproduce and compare with different climate models, in order to understand the potential impacts of these techniques. Here we assess its past successes and failures and talk about its future.
Alice F. Wells, Andy Jones, Martin Osborne, Lilly Damany-Pearce, Daniel G. Partridge, and James M. Haywood
Atmos. Chem. Phys., 23, 3985–4007, https://doi.org/10.5194/acp-23-3985-2023, https://doi.org/10.5194/acp-23-3985-2023, 2023
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In 2019 the Raikoke volcano erupted explosively, emitting the largest injection of SO2 into the stratosphere since 2011. Observations indicated that a large amount of volcanic ash was also injected. Previous studies have identified that volcanic ash can prolong the lifetime of stratospheric aerosol optical depth, which we explore in UKESM1. Comparisons to observations suggest that including ash in model emission schemes can improve the representation of volcanic plumes in global climate models.
Ju Liang and Jim Haywood
Atmos. Chem. Phys., 23, 1687–1703, https://doi.org/10.5194/acp-23-1687-2023, https://doi.org/10.5194/acp-23-1687-2023, 2023
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The recent record-breaking flood events in China during the summer of 2021 highlight the importance of mitigating the risks from future changes in high-impact weather systems under global warming. Based on a state-of-the-art Earth system model, we demonstrate a pilot study on the responses of atmospheric rivers and extreme precipitation over East Asia to anthropogenically induced climate warming and an unconventional mitigation strategy – stratospheric aerosol injection.
Ewa M. Bednarz, Daniele Visioni, Ben Kravitz, Andy Jones, James M. Haywood, Jadwiga Richter, Douglas G. MacMartin, and Peter Braesicke
Atmos. Chem. Phys., 23, 687–709, https://doi.org/10.5194/acp-23-687-2023, https://doi.org/10.5194/acp-23-687-2023, 2023
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Building on Part 1 of this two-part study, we demonstrate the role of biases in climatological circulation and specific aspects of model microphysics in driving the differences in simulated sulfate distributions amongst three Earth system models. We then characterize the simulated changes in stratospheric and free-tropospheric temperatures, ozone, water vapor, and large-scale circulation, elucidating the role of the above aspects in the surface responses discussed in Part 1.
Daniele Visioni, Ewa M. Bednarz, Walker R. Lee, Ben Kravitz, Andy Jones, Jim M. Haywood, and Douglas G. MacMartin
Atmos. Chem. Phys., 23, 663–685, https://doi.org/10.5194/acp-23-663-2023, https://doi.org/10.5194/acp-23-663-2023, 2023
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The paper constitutes Part 1 of a study performing a first systematic inter-model comparison of the atmospheric responses to stratospheric sulfate aerosol injections (SAIs) at various latitudes as simulated by three state-of-the-art Earth system models. We identify similarities and differences in the modeled aerosol burden, investigate the differences in the aerosol approaches between the models, and ultimately show the differences produced in surface climate, temperature and precipitation.
Paul A. Barrett, Steven J. Abel, Hugh Coe, Ian Crawford, Amie Dobracki, James Haywood, Steve Howell, Anthony Jones, Justin Langridge, Greg M. McFarquhar, Graeme J. Nott, Hannah Price, Jens Redemann, Yohei Shinozuka, Kate Szpek, Jonathan W. Taylor, Robert Wood, Huihui Wu, Paquita Zuidema, Stéphane Bauguitte, Ryan Bennett, Keith Bower, Hong Chen, Sabrina Cochrane, Michael Cotterell, Nicholas Davies, David Delene, Connor Flynn, Andrew Freedman, Steffen Freitag, Siddhant Gupta, David Noone, Timothy B. Onasch, James Podolske, Michael R. Poellot, Sebastian Schmidt, Stephen Springston, Arthur J. Sedlacek III, Jamie Trembath, Alan Vance, Maria A. Zawadowicz, and Jianhao Zhang
Atmos. Meas. Tech., 15, 6329–6371, https://doi.org/10.5194/amt-15-6329-2022, https://doi.org/10.5194/amt-15-6329-2022, 2022
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To better understand weather and climate, it is vital to go into the field and collect observations. Often measurements take place in isolation, but here we compared data from two aircraft and one ground-based site. This was done in order to understand how well measurements made on one platform compared to those made on another. Whilst this is easy to do in a controlled laboratory setting, it is more challenging in the real world, and so these comparisons are as valuable as they are rare.
Flossie Brown, Gerd A. Folberth, Stephen Sitch, Susanne Bauer, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Makoto Deushi, Inês Dos Santos Vieira, Corinne Galy-Lacaux, James Haywood, James Keeble, Lina M. Mercado, Fiona M. O'Connor, Naga Oshima, Kostas Tsigaridis, and Hans Verbeeck
Atmos. Chem. Phys., 22, 12331–12352, https://doi.org/10.5194/acp-22-12331-2022, https://doi.org/10.5194/acp-22-12331-2022, 2022
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Surface ozone can decrease plant productivity and impair human health. In this study, we evaluate the change in surface ozone due to climate change over South America and Africa using Earth system models. We find that if the climate were to change according to the worst-case scenario used here, models predict that forested areas in biomass burning locations and urban populations will be at increasing risk of ozone exposure, but other areas will experience a climate benefit.
Simone Tilmes, Daniele Visioni, Andy Jones, James Haywood, Roland Séférian, Pierre Nabat, Olivier Boucher, Ewa Monica Bednarz, and Ulrike Niemeier
Atmos. Chem. Phys., 22, 4557–4579, https://doi.org/10.5194/acp-22-4557-2022, https://doi.org/10.5194/acp-22-4557-2022, 2022
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This study assesses the impacts of climate interventions, using stratospheric sulfate aerosol and solar dimming on stratospheric ozone, based on three Earth system models with interactive stratospheric chemistry. The climate interventions have been applied to a high emission (baseline) scenario in order to reach global surface temperatures of a medium emission scenario. We find significant increases and decreases in total column ozone, depending on regions and seasons.
Andy Jones, Jim M. Haywood, Adam A. Scaife, Olivier Boucher, Matthew Henry, Ben Kravitz, Thibaut Lurton, Pierre Nabat, Ulrike Niemeier, Roland Séférian, Simone Tilmes, and Daniele Visioni
Atmos. Chem. Phys., 22, 2999–3016, https://doi.org/10.5194/acp-22-2999-2022, https://doi.org/10.5194/acp-22-2999-2022, 2022
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Simulations by six Earth-system models of geoengineering by introducing sulfuric acid aerosols into the tropical stratosphere are compared. A robust impact on the northern wintertime North Atlantic Oscillation is found, exacerbating precipitation reduction over parts of southern Europe. In contrast, the models show no consistency with regard to impacts on the Quasi-Biennial Oscillation, although results do indicate a risk that the oscillation could become locked into a permanent westerly phase.
Zixia Liu, Martin Osborne, Karen Anderson, Jamie D. Shutler, Andy Wilson, Justin Langridge, Steve H. L. Yim, Hugh Coe, Suresh Babu, Sreedharan K. Satheesh, Paquita Zuidema, Tao Huang, Jack C. H. Cheng, and James Haywood
Atmos. Meas. Tech., 14, 6101–6118, https://doi.org/10.5194/amt-14-6101-2021, https://doi.org/10.5194/amt-14-6101-2021, 2021
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This paper first validates the performance of an advanced aerosol observation instrument POPS against a reference instrument and examines any biases introduced by operating it on a quadcopter drone. The results show the POPS performs relatively well on the ground. The impact of the UAV rotors on the POPS is small at low wind speeds, but when operating under higher wind speeds, larger discrepancies occur. It appears that the POPS measures sub-micron aerosol particles more accurately on the UAV.
Daniele Visioni, Alan Robock, Alistair Duffey, Matthew Henry, Haruki Hirasawa, Walker Raymond Lee, Cindy Wang, Kelsey Roberts, Shingo Watanabe, Michelle Simões Reboita, Masahiro Sugiyama, Ben Kravitz, Jim Haywood, Simone Tilmes, Frédéric K. Bonou, Jack Chen, Timofei Sukhodolov, Sandro Vattioni, Andrin Jörimann, Diego Villanueva, Ryan Vella, Paul Farron, Ewa Bednarz, Ulrike Niemeier, Colleen Golja, and Juan A. Añel
Geosci. Model Dev., 19, 8469–8499, https://doi.org/10.5194/gmd-19-8469-2026, https://doi.org/10.5194/gmd-19-8469-2026, 2026
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The Geoengineering Model Intercomparison Project is a coordinated international model intercomparison effort aiming to provide robust experimental protocols for simulations of various Solar Radiation Modification (SRM) methods. In this manuscript, we describe a list of novel experiments decided by the community, to be run by climate models to better understand sources of uncertainty in SRM. We also show and discuss some preliminary results from a few climate models.
Ewa M. Bednarz, Amy H. Butler, James M. Haywood, Matthew Henry, Andy Jones, Ben Kravitz, Walker R. Lee, Douglas G. MacMartin, Amanda C. Maycock, Takashi Sekiya, Shingo Watanabe, and Daniele Visioni
Atmos. Chem. Phys., 26, 12751–12770, https://doi.org/10.5194/acp-26-12751-2026, https://doi.org/10.5194/acp-26-12751-2026, 2026
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An assessment of the potential impacts of Stratospheric Aerosol Injection, a proposed method to offset global warming, on stratospheric ozone projections over the 21st century using the new multi-model GeoMIP (Geoengineering Model Intercomparison Project) G6-1.5K-SAI (Stratospheric Aerosol Injection) experiment. We discuss drivers of the responses, identify areas of model agreement and disagreement and sources of uncertainty. Our results highlight the need to assess any projected SAI impacts in wider strategy and scenario dimension using a multi-model framework.
Alex M. Mason, Matthew Henry, Haruki Hirasawa, Fiona M. O'Connor, and James Haywood
Atmos. Chem. Phys., 26, 10861–10879, https://doi.org/10.5194/acp-26-10861-2026, https://doi.org/10.5194/acp-26-10861-2026, 2026
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Marine Cloud Brightening (MCB) proposes the spraying of sea salt particles into marine clouds to cool the planet. MCB in midlatitude regions in models gave a relatively even climate response. We use 42 simulations of MCB to target several climate responses. Two optimised combinations are compared to a midlatitude MCB simulation, which improved sea ice restoration and the temperature response pattern, highlighting the importance of high latitude MCB for MCB optimisation in this model.
Anthony C. Jones, James M. Haywood, Matthew Henry, and Alistair Duffey
Atmos. Chem. Phys., 26, 7589–7605, https://doi.org/10.5194/acp-26-7589-2026, https://doi.org/10.5194/acp-26-7589-2026, 2026
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Injecting aerosol into the stratosphere has been suggested to rapidly cool the planet and counter climate change. Rival actors who oppose deployment may seek to counter stratospheric aerosol injection. Using a climate model, we investigate whether stratospheric aerosol removal could be hastened by injecting coarse aerosol which promote aerosol growth and gravitational settling. We find that this could be effective, reducing aerosol impacts by 30 % in simulations, and warrants further research.
Walker Raymond Lee, Daniele Visioni, Benjamin Moore Wagman, Christopher Robert Wentland, Ben Kravitz, Shingo Watanabe, Takashi Sekiya, Andy Jones, Jim Haywood, Matthew Henry, and Ewa Monika Bednarz
Atmos. Chem. Phys., 26, 7463–7483, https://doi.org/10.5194/acp-26-7463-2026, https://doi.org/10.5194/acp-26-7463-2026, 2026
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Stratospheric aerosol injection (SAI) is a proposed method of cooling the planet by introducing reflective particles called aerosols into the middle atmosphere to reflect sunlight back into space. We consider recent simulations of SAI from four different climate models. SAI cools the planet effectively in all four models; we examine the impacts on temperature and precipitation in each model and compare to previous experiments. Our simulations will help inform future research and policy.
Martin R. Willett, Melissa E. Brooks, Andrew Bushell, Paul Earnshaw, Charline Marzin, Samantha Smith, Lorenzo Tomassini, Nathan Luke Abraham, Martin Best, John M. Edwards, Kalli Furtado, Catherine Hardacre, Alan J. Hewitt, Ben Johnson, Adrian Lock, Jane P. Mulcahy, James Manners, Alistair Sellar, Peter Sheridan, Warren Tennant, Kwinten Van Weverberg, Vidya Varma, and Michael Whitall
EGUsphere, https://doi.org/10.5194/egusphere-2026-2425, https://doi.org/10.5194/egusphere-2026-2425, 2026
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Global Atmosphere and Land (GAL) configurations of the Unified Model (UM) and JULES are developed for use in any global atmospheric modelling application. We describe the latest version, GAL9. We compare GAL9 with its predecessor and show that it gives improved forecasts of weather and climate. GAL9 has been used for weather forecasts in the UK from early 2026 and it will be used to study the Earth's climate.
Daniel A. Williams, Cyril J. Morcrette, and James M. Haywood
EGUsphere, https://doi.org/10.5194/egusphere-2026-2490, https://doi.org/10.5194/egusphere-2026-2490, 2026
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Contrails (condensation trails) are ice clouds that form behind aircraft in a region of cold and moist atmosphere. If contrails persist for many hours or into the night, they warm the climate. A minority of flights produce persistent contrails, so the climate impact of aviation could be decreased if we can predict and avoid where contrails form in advance. Using statistics on climate model and satellite data, we developed a model to predict contrails and tested it against historical data.
Josh Smith, Matthew Henry, Masaru Yoshioka, Ben Johnson, and Jim Haywood
EGUsphere, https://doi.org/10.5194/egusphere-2026-2654, https://doi.org/10.5194/egusphere-2026-2654, 2026
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In 2020, new international rules cut sulphur in shipping fuels by roughly eighty percent, removing particles that had been brightening clouds over the oceans and reflecting sunlight. Using a climate model, we tested how this loss of cooling has been calculated and found that recent studies have
likely underestimated the resulting warming by a factor of two to four. This means cleaner shipping fuels may be contributing more to recent global warming than previously recognised.
likely underestimated the resulting warming by a factor of two to four. This means cleaner shipping fuels may be contributing more to recent global warming than previously recognised.
Man Mei Chim, Nathan Luke Abraham, Thomas J. Aubry, Ben Johnson, Hella Garny, Susan Solomon, and Anja Schmidt
Atmos. Chem. Phys., 26, 6781–6797, https://doi.org/10.5194/acp-26-6781-2026, https://doi.org/10.5194/acp-26-6781-2026, 2026
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Sulfate aerosols from explosive eruptions can provide surfaces for chemical reactions destroying ozone. Assessing the effects of volcanic sulfate aerosols is crucial for understanding future ozone recovery. We find sporadic eruptions can induce a small delay in stratospheric ozone recovery by a few years over Antarctica and Southern Hemisphere mid-latitudes. Our results highlight the importance to continuously monitor atmospheric composition and processes to understand changes in ozone recovery.
Elizabeth Quaye, Ben T. Johnson, James M. Haywood, Guido R. van der Werf, Roland Vernooij, Stephen A. Sitch, and Tom Eames
Atmos. Chem. Phys., 26, 6629–6654, https://doi.org/10.5194/acp-26-6629-2026, https://doi.org/10.5194/acp-26-6629-2026, 2026
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We find aerosol optical depths in a global climate model are overestimated during extreme wildfire events if emissions are scaled up by a factor of two, typically applied to improve simulated aerosol on seasonal–annual timescales. We propose a technique where a variable scaling factor is determined by fuel consumption, improving correlation in five fire-affected areas. We explore the impact of this change on aerosol radiative effects, during extreme events and on broader space and time scales.
Eliza K. Duncan, George Jordan, Paul Kim, James M. Haywood, Duncan Watson-Parris, Ben Johnson, Alistair Sellar, Zak Kipling, João Teixeira, Florent Malavelle, and Daniel G. Partridge
EGUsphere, https://doi.org/10.5194/egusphere-2026-1043, https://doi.org/10.5194/egusphere-2026-1043, 2026
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The 2014–15 Holuhraun eruption offers a natural experiment to assess how well climate models can capture the changes in aerosol associated with the plume. We investigate the aerosol lifecycle during transport to identify key differences in climate models' representation of aerosol processes, which could affect the models’ ability to capture changes in cloud properties. Our study highlights the importance of the representation of boundary layer nucleation processes in climate models.
Thomas J. Aubry, Matthew Toohey, Sujan Khanal, Man Mei Chim, Magali Verkerk, Ben Johnson, Anja Schmidt, Mahesh Kovilakam, Michael Sigl, Zebedee Nicholls, Larry Thomason, Vaishali Naik, Landon Rieger, Dominik Stiller, Elisa Ziegler, Paul Durack, and Isabel H. Smith
Geosci. Model Dev., 19, 3725–3756, https://doi.org/10.5194/gmd-19-3725-2026, https://doi.org/10.5194/gmd-19-3725-2026, 2026
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Climate forcings, such as solar radiation or anthropogenic greenhouse gases, are required to run global climate model simulations. Stratospheric aerosols, which mostly originate from large volcanic eruptions, are a key natural forcing. In this paper, we document the stratospheric aerosol forcing dataset that will feed the next generation (CMIP7) of climate models. Our dataset is very different from its predecessor (CMIP6), which might affect simulations of the 1850–2021 climate.
Haruki Hirasawa, Matthew Henry, Philip J. Rasch, Robert Wood, Sarah J. Doherty, James Haywood, Alex Wong, Jean-Francois Lamarque, Ezra Brody, and Hailong Wang
Geosci. Model Dev., 19, 3257–3283, https://doi.org/10.5194/gmd-19-3257-2026, https://doi.org/10.5194/gmd-19-3257-2026, 2026
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Marine cloud brightening (MCB) is a proposal to emit sea salt aerosols to make clouds more reflective and cool the climate. Here, we use three climate models to study a hypothetical future where MCB is used to maintain temperatures near 2020–2039 conditions. The simulation results indicate that using MCB in midlatitude ocean regions can keep the climate close to present day conditions. This reduces many of the negative impacts shown in previous studies, informing future modeling efforts.
Isobel M. Parry, Paul D. L. Ritchie, Olivier Boucher, Peter M. Cox, James M. Haywood, Ulrike Niemeier, Roland Séférian, Simone Tilmes, and Daniele Visioni
Earth Syst. Dynam., 17, 387–414, https://doi.org/10.5194/esd-17-387-2026, https://doi.org/10.5194/esd-17-387-2026, 2026
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Contrary to some expectations, results from the latest Earth System Models suggest that Solar Radiation Geoengineering could protect the Amazon rainforest from climate-driven dieback. Under Stratospheric Aerosol Injection, carbon storage in Amazonia was projected to increase by a mean of 10.8 % relative to a high CO2 emissions scenario, and even by 8.6% compared to a more conventional medium CO2 emissions scenario.
Masaru Yoshioka, Daniel P. Grosvenor, Amy H. Peace, Jim M. Haywood, Ying Chen, and Paul R. Field
Atmos. Chem. Phys., 26, 4341–4358, https://doi.org/10.5194/acp-26-4341-2026, https://doi.org/10.5194/acp-26-4341-2026, 2026
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We used advanced computer simulations to study how aerosol particles from a volcanic eruption in Iceland affected clouds. The eruption plume increased small droplets, but changes in cloud water and horizontal extent were not clear. Satellite comparisons between plume and non-plume regions can miss volcanic effects due to spatial variability in weather and aerosol, but simulations can isolate the impact by comparing cases with and without the eruption.
Martin Willett, Melissa Brooks, Andrew Bushell, Paul Earnshaw, Samantha Smith, Lorenzo Tomassini, Martin Best, Ian Boutle, Jennifer Brooke, John M. Edwards, Andrew D. Elvidge, Kalli Furtado, Catherine Hardacre, Andrew J. Hartley, Alan J. Hewitt, Ben Johnson, Adrian Lock, Andy Malcolm, Jane Mulcahy, Eike Müller, Ian A. Renfrew, Heather Rumbold, Gabriel G. Rooney, Alistair Sellar, Masashi Ujiie, Annelize van Niekerk, Andy Wiltshire, and Michael Whitall
Geosci. Model Dev., 19, 1473–1517, https://doi.org/10.5194/gmd-19-1473-2026, https://doi.org/10.5194/gmd-19-1473-2026, 2026
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Global Atmosphere (GA) configurations of the Unified Model (UM) and Global Land (GL) configurations of Joint UK Land Environment Simulator (JULES) are developed for use in any global atmospheric modelling application. We describe a recent iteration of these configurations, GA8GL9, which includes improvements to the representation of convection and other physical processes. GA8GL9 is used for operational weather prediction in the UK and forms the basis for the next GA and GL configuration.
Huihui Wu, Fanny Peers, Jonathan W. Taylor, Chenjie Yu, Steven J. Abel, Paul A. Barrett, Jamie Trembath, Keith Bower, Jim M. Haywood, and Hugh Coe
Atmos. Chem. Phys., 25, 16589–16609, https://doi.org/10.5194/acp-25-16589-2025, https://doi.org/10.5194/acp-25-16589-2025, 2025
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This study investigates the transport history of African Biomass-Burning aerosols (BBAs) over the Southeast Atlantic (SEA) and their impacts on cloud properties. Using in situ airborne measurements around Ascension Island, this work provides critical parameterizations of aerosol–cloud interactions to improve the assessment of radiative forcing in the SEA region. It also identifies key entrainment regions for understanding the vertical transport process of African BBAs.
Eliza K. Duncan, Jonathan E. Fieldsend, Alistair Sellar, Emanuele Tovazzi, Paul Kim, James M. Haywood, and Daniel G. Partridge
EGUsphere, https://doi.org/10.5194/egusphere-2025-4298, https://doi.org/10.5194/egusphere-2025-4298, 2025
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Atmospheric aerosol particles are a major confounding factor in accurately representing climate change. We build a novel generic framework to untangle the role of complex processes focusing on a remote site in Antarctica as a case study in near-pristine conditions. Our machine-learning model predicts aerosol concentrations from an airmass history, considering the meteorology and potential sources and removal processes, enabling improved representation in climate models.
Natalie G. Ratcliffe, Claire L. Ryder, Nicolas Bellouin, Anthony Jones, Ben Johnson, Stephanie Woodward, Lisa-Maria Wieland, Josef Gasteiger, and Bernadett Weinzierl
EGUsphere, https://doi.org/10.5194/egusphere-2025-5143, https://doi.org/10.5194/egusphere-2025-5143, 2025
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Observations show large dust particles travel much further than expected, which is not replicated in weather and climate models. We use a climate model to understand which processes dominantly impact large particle transport, and find that modelled large particle transport agrees with observations best after reducing the particle gravitational settling by ~ 80 %. We prove the presence of processes not represented accurately or at all in the model which act on large particles in the real-world.
George Jordan, Florent Malavelle, Jim Haywood, Ying Chen, Ben Johnson, Daniel Partridge, Amy Peace, Eliza Duncan, Duncan Watson-Parris, David Neubauer, Anton Laakso, Martine Michou, and Pierre Nabat
Atmos. Chem. Phys., 25, 13393–13428, https://doi.org/10.5194/acp-25-13393-2025, https://doi.org/10.5194/acp-25-13393-2025, 2025
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The 2014–15 Holuhraun eruption created a vast aerosol plume that acted as a natural experiment to assess how well climate models capture changes in cloud properties due to increased aerosol. We find that climate models represent the observed shift to smaller, more numerous cloud droplets well. However, climate models diverge in their aerosol-induced changes to large-scale cloud properties, particularly cloud liquid water content. Our study shows that Holuhraun had a cooling effect on the Earth.
Yunqian Zhu, Hideharu Akiyoshi, Valentina Aquila, Elizabeth Asher, Ewa M. Bednarz, Slimane Bekki, Christoph Brühl, Amy H. Butler, Parker Case, Simon Chabrillat, Gabriel Chiodo, Margot Clyne, Peter R. Colarco, Sandip Dhomse, Lola Falletti, Eric Fleming, Ben Johnson, Andrin Jörimann, Mahesh Kovilakam, Gerbrand Koren, Ales Kuchar, Nicolas Lebas, Qing Liang, Cheng-Cheng Liu, Graham Mann, Michael Manyin, Marion Marchand, Olaf Morgenstern, Paul Newman, Luke D. Oman, Freja F. Østerstrøm, Yifeng Peng, David Plummer, Ilaria Quaglia, William Randel, Samuel Rémy, Takashi Sekiya, Stephen Steenrod, Timofei Sukhodolov, Simone Tilmes, Kostas Tsigaridis, Rei Ueyama, Daniele Visioni, Xinyue Wang, Shingo Watanabe, Yousuke Yamashita, Pengfei Yu, Wandi Yu, Jun Zhang, and Zhihong Zhuo
Geosci. Model Dev., 18, 5487–5512, https://doi.org/10.5194/gmd-18-5487-2025, https://doi.org/10.5194/gmd-18-5487-2025, 2025
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To understand the climate impact of the 2022 Hunga volcanic eruption, we developed a climate model–observation comparison project. The paper describes the protocols and models that participate in the experiments. We designed several experiments to achieve our goals of this activity: (1) to evaluate the climate model performance and (2) to understand the Earth system responses to this eruption.
Mariya Petrenko, Ralph Kahn, Mian Chin, Susanne E. Bauer, Tommi Bergman, Huisheng Bian, Gabriele Curci, Ben Johnson, Johannes W. Kaiser, Zak Kipling, Harri Kokkola, Xiaohong Liu, Keren Mezuman, Tero Mielonen, Gunnar Myhre, Xiaohua Pan, Anna Protonotariou, Samuel Remy, Ragnhild Bieltvedt Skeie, Philip Stier, Toshihiko Takemura, Kostas Tsigaridis, Hailong Wang, Duncan Watson-Parris, and Kai Zhang
Atmos. Chem. Phys., 25, 1545–1567, https://doi.org/10.5194/acp-25-1545-2025, https://doi.org/10.5194/acp-25-1545-2025, 2025
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We compared smoke plume simulations from 11 global models to each other and to satellite smoke amount observations aimed at constraining smoke source strength. In regions where plumes are thick and background aerosol is low, models and satellites compare well. However, the input emission inventory tends to underestimate in many places, and particle property and loss rate assumptions vary enormously among models, causing uncertainties that require systematic in situ measurements to resolve.
Lauren R. Marshall, Anja Schmidt, Andrew P. Schurer, Nathan Luke Abraham, Lucie J. Lücke, Rob Wilson, Kevin J. Anchukaitis, Gabriele C. Hegerl, Ben Johnson, Bette L. Otto-Bliesner, Esther C. Brady, Myriam Khodri, and Kohei Yoshida
Clim. Past, 21, 161–184, https://doi.org/10.5194/cp-21-161-2025, https://doi.org/10.5194/cp-21-161-2025, 2025
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Large volcanic eruptions have caused temperature deviations over the past 1000 years; however, climate model results and reconstructions of surface cooling using tree rings do not match. We explore this mismatch using the latest models and find a better match to tree-ring reconstructions for some eruptions. Our results show that the way in which eruptions are simulated in models matters for the comparison to tree-rings, particularly regarding the spatial spread of volcanic aerosol.
Matthew Henry, Ewa M. Bednarz, and Jim Haywood
Atmos. Chem. Phys., 24, 13253–13268, https://doi.org/10.5194/acp-24-13253-2024, https://doi.org/10.5194/acp-24-13253-2024, 2024
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Stratospheric aerosol injection (SAI) refers to a climate intervention by which aerosols are intentionally added to the high atmosphere to increase the amount of reflected sunlight and reduce Earth's temperature. The climate outcomes of SAI depend on the latitude of injection. While injecting aerosols at the Equator has undesirable side effects, injecting away from the Equator has different effects on temperature, rainfall, ozone, and atmospheric circulation, which are analysed in this work.
Philip J. Rasch, Haruki Hirasawa, Mingxuan Wu, Sarah J. Doherty, Robert Wood, Hailong Wang, Andy Jones, James Haywood, and Hansi Singh
Geosci. Model Dev., 17, 7963–7994, https://doi.org/10.5194/gmd-17-7963-2024, https://doi.org/10.5194/gmd-17-7963-2024, 2024
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We introduce a protocol to compare computer climate simulations to better understand a proposed strategy intended to counter warming and climate impacts from greenhouse gas increases. This slightly changes clouds in six ocean regions to reflect more sunlight and cool the Earth. Example changes in clouds and climate are shown for three climate models. Cloud changes differ between the models, but precipitation and surface temperature changes are similar when their cooling effects are made similar.
Ou Wang, Ju Liang, Yuchen Gu, Jim M. Haywood, Ying Chen, Chenwei Fang, and Qin'geng Wang
Atmos. Chem. Phys., 24, 12355–12373, https://doi.org/10.5194/acp-24-12355-2024, https://doi.org/10.5194/acp-24-12355-2024, 2024
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As extreme precipitation events increase in China, this study explores the potential of stratospheric aerosol injection (SAI) to mitigate these effects by the end of the 21st century using the UKESM1 model. Results show that SAI reduces extreme precipitation in eastern China. However, caution is advised due to potential side effects in high-latitude regions, and further optimization is required for future SAI deployment.
Natalie G. Ratcliffe, Claire L. Ryder, Nicolas Bellouin, Stephanie Woodward, Anthony Jones, Ben Johnson, Lisa-Maria Wieland, Maximilian Dollner, Josef Gasteiger, and Bernadett Weinzierl
Atmos. Chem. Phys., 24, 12161–12181, https://doi.org/10.5194/acp-24-12161-2024, https://doi.org/10.5194/acp-24-12161-2024, 2024
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Large mineral dust particles are more abundant in the atmosphere than expected and have different impacts on the environment than small particles, which are better represented in climate models. We use aircraft measurements to assess a climate model representation of large-dust transport. We find that the model underestimates the amount of large dust at all stages of transport and that fast removal of the large particles increases this underestimation with distance from the Sahara.
Amy H. Peace, Ying Chen, George Jordan, Daniel G. Partridge, Florent Malavelle, Eliza Duncan, and Jim M. Haywood
Atmos. Chem. Phys., 24, 9533–9553, https://doi.org/10.5194/acp-24-9533-2024, https://doi.org/10.5194/acp-24-9533-2024, 2024
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Natural aerosols from volcanic eruptions can help us understand how anthropogenic aerosols modify climate. We use observations and model simulations of the 2014–2015 Holuhraun eruption plume to examine aerosol–cloud interactions in September 2014. We find a shift to clouds with smaller, more numerous cloud droplets in the first 2 weeks of the eruption. In the third week, the background meteorology and previous conditions experienced by air masses modulate the aerosol perturbation to clouds.
Daniele Visioni, Alan Robock, Jim Haywood, Matthew Henry, Simone Tilmes, Douglas G. MacMartin, Ben Kravitz, Sarah J. Doherty, John Moore, Chris Lennard, Shingo Watanabe, Helene Muri, Ulrike Niemeier, Olivier Boucher, Abu Syed, Temitope S. Egbebiyi, Roland Séférian, and Ilaria Quaglia
Geosci. Model Dev., 17, 2583–2596, https://doi.org/10.5194/gmd-17-2583-2024, https://doi.org/10.5194/gmd-17-2583-2024, 2024
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This paper describes a new experimental protocol for the Geoengineering Model Intercomparison Project (GeoMIP). In it, we describe the details of a new simulation of sunlight reflection using the stratospheric aerosols that climate models are supposed to run, and we explain the reasons behind each choice we made when defining the protocol.
George Jordan, Florent Malavelle, Ying Chen, Amy Peace, Eliza Duncan, Daniel G. Partridge, Paul Kim, Duncan Watson-Parris, Toshihiko Takemura, David Neubauer, Gunnar Myhre, Ragnhild Skeie, Anton Laakso, and James Haywood
Atmos. Chem. Phys., 24, 1939–1960, https://doi.org/10.5194/acp-24-1939-2024, https://doi.org/10.5194/acp-24-1939-2024, 2024
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The 2014–15 Holuhraun eruption caused a huge aerosol plume in an otherwise unpolluted region, providing a chance to study how aerosol alters cloud properties. This two-part study uses observations and models to quantify this relationship’s impact on the Earth’s energy budget. Part 1 suggests the models capture the observed spatial and chemical evolution of the plume, yet no model plume is exact. Understanding these differences is key for Part 2, where changes to cloud properties are explored.
Jim M. Haywood, Andy Jones, Anthony C. Jones, Paul Halloran, and Philip J. Rasch
Atmos. Chem. Phys., 23, 15305–15324, https://doi.org/10.5194/acp-23-15305-2023, https://doi.org/10.5194/acp-23-15305-2023, 2023
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The difficulties in ameliorating global warming and the associated climate change via conventional mitigation are well documented, with all climate model scenarios exceeding 1.5 °C above the preindustrial level in the near future. There is therefore a growing interest in geoengineering to reflect a greater proportion of sunlight back to space and offset some of the global warming. We use a state-of-the-art Earth-system model to investigate two of the most prominent geoengineering strategies.
Calvin Howes, Pablo E. Saide, Hugh Coe, Amie Dobracki, Steffen Freitag, Jim M. Haywood, Steven G. Howell, Siddhant Gupta, Janek Uin, Mary Kacarab, Chongai Kuang, L. Ruby Leung, Athanasios Nenes, Greg M. McFarquhar, James Podolske, Jens Redemann, Arthur J. Sedlacek, Kenneth L. Thornhill, Jenny P. S. Wong, Robert Wood, Huihui Wu, Yang Zhang, Jianhao Zhang, and Paquita Zuidema
Atmos. Chem. Phys., 23, 13911–13940, https://doi.org/10.5194/acp-23-13911-2023, https://doi.org/10.5194/acp-23-13911-2023, 2023
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To better understand smoke properties and its interactions with clouds, we compare the WRF-CAM5 model with observations from ORACLES, CLARIFY, and LASIC field campaigns in the southeastern Atlantic in August 2017. The model transports and mixes smoke well but does not fully capture some important processes. These include smoke chemical and physical aging over 4–12 days, smoke removal by rain, sulfate particle formation, aerosol activation into cloud droplets, and boundary layer turbulence.
Matthew Henry, Jim Haywood, Andy Jones, Mohit Dalvi, Alice Wells, Daniele Visioni, Ewa M. Bednarz, Douglas G. MacMartin, Walker Lee, and Mari R. Tye
Atmos. Chem. Phys., 23, 13369–13385, https://doi.org/10.5194/acp-23-13369-2023, https://doi.org/10.5194/acp-23-13369-2023, 2023
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Solar climate interventions, such as injecting sulfur in the stratosphere, may be used to offset some of the adverse impacts of global warming. We use two independently developed Earth system models to assess the uncertainties around stratospheric sulfur injections. The injection locations and amounts are optimized to maintain the same pattern of surface temperature. While both models show reduced warming, the change in rainfall patterns (even without sulfur injections) is uncertain.
Chenwei Fang, Jim M. Haywood, Ju Liang, Ben T. Johnson, Ying Chen, and Bin Zhu
Atmos. Chem. Phys., 23, 8341–8368, https://doi.org/10.5194/acp-23-8341-2023, https://doi.org/10.5194/acp-23-8341-2023, 2023
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The responses of Asian summer monsoon duration and intensity to air pollution mitigation are identified given the net-zero future. We show that reducing scattering aerosols makes the rainy season longer and stronger across South Asia and East Asia but that absorbing aerosol reduction has the opposite effect. Our results hint at distinct monsoon responses to emission controls that target different aerosols.
Daniele Visioni, Ben Kravitz, Alan Robock, Simone Tilmes, Jim Haywood, Olivier Boucher, Mark Lawrence, Peter Irvine, Ulrike Niemeier, Lili Xia, Gabriel Chiodo, Chris Lennard, Shingo Watanabe, John C. Moore, and Helene Muri
Atmos. Chem. Phys., 23, 5149–5176, https://doi.org/10.5194/acp-23-5149-2023, https://doi.org/10.5194/acp-23-5149-2023, 2023
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Geoengineering indicates methods aiming to reduce the temperature of the planet by means of reflecting back a part of the incoming radiation before it reaches the surface or allowing more of the planetary radiation to escape into space. It aims to produce modelling experiments that are easy to reproduce and compare with different climate models, in order to understand the potential impacts of these techniques. Here we assess its past successes and failures and talk about its future.
Alice F. Wells, Andy Jones, Martin Osborne, Lilly Damany-Pearce, Daniel G. Partridge, and James M. Haywood
Atmos. Chem. Phys., 23, 3985–4007, https://doi.org/10.5194/acp-23-3985-2023, https://doi.org/10.5194/acp-23-3985-2023, 2023
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In 2019 the Raikoke volcano erupted explosively, emitting the largest injection of SO2 into the stratosphere since 2011. Observations indicated that a large amount of volcanic ash was also injected. Previous studies have identified that volcanic ash can prolong the lifetime of stratospheric aerosol optical depth, which we explore in UKESM1. Comparisons to observations suggest that including ash in model emission schemes can improve the representation of volcanic plumes in global climate models.
Ju Liang and Jim Haywood
Atmos. Chem. Phys., 23, 1687–1703, https://doi.org/10.5194/acp-23-1687-2023, https://doi.org/10.5194/acp-23-1687-2023, 2023
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The recent record-breaking flood events in China during the summer of 2021 highlight the importance of mitigating the risks from future changes in high-impact weather systems under global warming. Based on a state-of-the-art Earth system model, we demonstrate a pilot study on the responses of atmospheric rivers and extreme precipitation over East Asia to anthropogenically induced climate warming and an unconventional mitigation strategy – stratospheric aerosol injection.
Yangxin Chen, Duoying Ji, Qian Zhang, John C. Moore, Olivier Boucher, Andy Jones, Thibaut Lurton, Michael J. Mills, Ulrike Niemeier, Roland Séférian, and Simone Tilmes
Earth Syst. Dynam., 14, 55–79, https://doi.org/10.5194/esd-14-55-2023, https://doi.org/10.5194/esd-14-55-2023, 2023
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Solar geoengineering has been proposed as a way of counteracting the warming effects of increasing greenhouse gases by reflecting solar radiation. This work shows that solar geoengineering can slow down the northern-high-latitude permafrost degradation but cannot preserve the permafrost ecosystem as that under a climate of the same warming level without solar geoengineering.
Ewa M. Bednarz, Daniele Visioni, Ben Kravitz, Andy Jones, James M. Haywood, Jadwiga Richter, Douglas G. MacMartin, and Peter Braesicke
Atmos. Chem. Phys., 23, 687–709, https://doi.org/10.5194/acp-23-687-2023, https://doi.org/10.5194/acp-23-687-2023, 2023
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Building on Part 1 of this two-part study, we demonstrate the role of biases in climatological circulation and specific aspects of model microphysics in driving the differences in simulated sulfate distributions amongst three Earth system models. We then characterize the simulated changes in stratospheric and free-tropospheric temperatures, ozone, water vapor, and large-scale circulation, elucidating the role of the above aspects in the surface responses discussed in Part 1.
Daniele Visioni, Ewa M. Bednarz, Walker R. Lee, Ben Kravitz, Andy Jones, Jim M. Haywood, and Douglas G. MacMartin
Atmos. Chem. Phys., 23, 663–685, https://doi.org/10.5194/acp-23-663-2023, https://doi.org/10.5194/acp-23-663-2023, 2023
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The paper constitutes Part 1 of a study performing a first systematic inter-model comparison of the atmospheric responses to stratospheric sulfate aerosol injections (SAIs) at various latitudes as simulated by three state-of-the-art Earth system models. We identify similarities and differences in the modeled aerosol burden, investigate the differences in the aerosol approaches between the models, and ultimately show the differences produced in surface climate, temperature and precipitation.
Paul A. Barrett, Steven J. Abel, Hugh Coe, Ian Crawford, Amie Dobracki, James Haywood, Steve Howell, Anthony Jones, Justin Langridge, Greg M. McFarquhar, Graeme J. Nott, Hannah Price, Jens Redemann, Yohei Shinozuka, Kate Szpek, Jonathan W. Taylor, Robert Wood, Huihui Wu, Paquita Zuidema, Stéphane Bauguitte, Ryan Bennett, Keith Bower, Hong Chen, Sabrina Cochrane, Michael Cotterell, Nicholas Davies, David Delene, Connor Flynn, Andrew Freedman, Steffen Freitag, Siddhant Gupta, David Noone, Timothy B. Onasch, James Podolske, Michael R. Poellot, Sebastian Schmidt, Stephen Springston, Arthur J. Sedlacek III, Jamie Trembath, Alan Vance, Maria A. Zawadowicz, and Jianhao Zhang
Atmos. Meas. Tech., 15, 6329–6371, https://doi.org/10.5194/amt-15-6329-2022, https://doi.org/10.5194/amt-15-6329-2022, 2022
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To better understand weather and climate, it is vital to go into the field and collect observations. Often measurements take place in isolation, but here we compared data from two aircraft and one ground-based site. This was done in order to understand how well measurements made on one platform compared to those made on another. Whilst this is easy to do in a controlled laboratory setting, it is more challenging in the real world, and so these comparisons are as valuable as they are rare.
Flossie Brown, Gerd A. Folberth, Stephen Sitch, Susanne Bauer, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Makoto Deushi, Inês Dos Santos Vieira, Corinne Galy-Lacaux, James Haywood, James Keeble, Lina M. Mercado, Fiona M. O'Connor, Naga Oshima, Kostas Tsigaridis, and Hans Verbeeck
Atmos. Chem. Phys., 22, 12331–12352, https://doi.org/10.5194/acp-22-12331-2022, https://doi.org/10.5194/acp-22-12331-2022, 2022
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Surface ozone can decrease plant productivity and impair human health. In this study, we evaluate the change in surface ozone due to climate change over South America and Africa using Earth system models. We find that if the climate were to change according to the worst-case scenario used here, models predict that forested areas in biomass burning locations and urban populations will be at increasing risk of ozone exposure, but other areas will experience a climate benefit.
Qirui Zhong, Nick Schutgens, Guido van der Werf, Twan van Noije, Kostas Tsigaridis, Susanne E. Bauer, Tero Mielonen, Alf Kirkevåg, Øyvind Seland, Harri Kokkola, Ramiro Checa-Garcia, David Neubauer, Zak Kipling, Hitoshi Matsui, Paul Ginoux, Toshihiko Takemura, Philippe Le Sager, Samuel Rémy, Huisheng Bian, Mian Chin, Kai Zhang, Jialei Zhu, Svetlana G. Tsyro, Gabriele Curci, Anna Protonotariou, Ben Johnson, Joyce E. Penner, Nicolas Bellouin, Ragnhild B. Skeie, and Gunnar Myhre
Atmos. Chem. Phys., 22, 11009–11032, https://doi.org/10.5194/acp-22-11009-2022, https://doi.org/10.5194/acp-22-11009-2022, 2022
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Aerosol optical depth (AOD) errors for biomass burning aerosol (BBA) are evaluated in 18 global models against satellite datasets. Notwithstanding biases in satellite products, they allow model evaluations. We observe large and diverse model biases due to errors in BBA. Further interpretations of AOD diversities suggest large biases exist in key processes for BBA which require better constraining. These results can contribute to further model improvement and development.
Simone Tilmes, Daniele Visioni, Andy Jones, James Haywood, Roland Séférian, Pierre Nabat, Olivier Boucher, Ewa Monica Bednarz, and Ulrike Niemeier
Atmos. Chem. Phys., 22, 4557–4579, https://doi.org/10.5194/acp-22-4557-2022, https://doi.org/10.5194/acp-22-4557-2022, 2022
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This study assesses the impacts of climate interventions, using stratospheric sulfate aerosol and solar dimming on stratospheric ozone, based on three Earth system models with interactive stratospheric chemistry. The climate interventions have been applied to a high emission (baseline) scenario in order to reach global surface temperatures of a medium emission scenario. We find significant increases and decreases in total column ozone, depending on regions and seasons.
Davide Zanchettin, Claudia Timmreck, Myriam Khodri, Anja Schmidt, Matthew Toohey, Manabu Abe, Slimane Bekki, Jason Cole, Shih-Wei Fang, Wuhu Feng, Gabriele Hegerl, Ben Johnson, Nicolas Lebas, Allegra N. LeGrande, Graham W. Mann, Lauren Marshall, Landon Rieger, Alan Robock, Sara Rubinetti, Kostas Tsigaridis, and Helen Weierbach
Geosci. Model Dev., 15, 2265–2292, https://doi.org/10.5194/gmd-15-2265-2022, https://doi.org/10.5194/gmd-15-2265-2022, 2022
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This paper provides metadata and first analyses of the volc-pinatubo-full experiment of CMIP6-VolMIP. Results from six Earth system models reveal significant differences in radiative flux anomalies that trace back to different implementations of volcanic forcing. Surface responses are in contrast overall consistent across models, reflecting the large spread due to internal variability. A second phase of VolMIP shall consider both aspects toward improved protocol for volc-pinatubo-full.
Andy Jones, Jim M. Haywood, Adam A. Scaife, Olivier Boucher, Matthew Henry, Ben Kravitz, Thibaut Lurton, Pierre Nabat, Ulrike Niemeier, Roland Séférian, Simone Tilmes, and Daniele Visioni
Atmos. Chem. Phys., 22, 2999–3016, https://doi.org/10.5194/acp-22-2999-2022, https://doi.org/10.5194/acp-22-2999-2022, 2022
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Simulations by six Earth-system models of geoengineering by introducing sulfuric acid aerosols into the tropical stratosphere are compared. A robust impact on the northern wintertime North Atlantic Oscillation is found, exacerbating precipitation reduction over parts of southern Europe. In contrast, the models show no consistency with regard to impacts on the Quasi-Biennial Oscillation, although results do indicate a risk that the oscillation could become locked into a permanent westerly phase.
Anthony C. Jones, Adrian Hill, Samuel Remy, N. Luke Abraham, Mohit Dalvi, Catherine Hardacre, Alan J. Hewitt, Ben Johnson, Jane P. Mulcahy, and Steven T. Turnock
Atmos. Chem. Phys., 21, 15901–15927, https://doi.org/10.5194/acp-21-15901-2021, https://doi.org/10.5194/acp-21-15901-2021, 2021
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Ammonium nitrate is hard to model because it forms and evaporates rapidly. One approach is to relate its equilibrium concentration to temperature, humidity, and the amount of nitric acid and ammonia gases. Using this approach, we limit the rate at which equilibrium is reached using various condensation rates in a climate model. We show that ammonium nitrate concentrations are highly sensitive to the condensation rate. Our results will help improve the representation of nitrate in climate models.
Zixia Liu, Martin Osborne, Karen Anderson, Jamie D. Shutler, Andy Wilson, Justin Langridge, Steve H. L. Yim, Hugh Coe, Suresh Babu, Sreedharan K. Satheesh, Paquita Zuidema, Tao Huang, Jack C. H. Cheng, and James Haywood
Atmos. Meas. Tech., 14, 6101–6118, https://doi.org/10.5194/amt-14-6101-2021, https://doi.org/10.5194/amt-14-6101-2021, 2021
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This paper first validates the performance of an advanced aerosol observation instrument POPS against a reference instrument and examines any biases introduced by operating it on a quadcopter drone. The results show the POPS performs relatively well on the ground. The impact of the UAV rotors on the POPS is small at low wind speeds, but when operating under higher wind speeds, larger discrepancies occur. It appears that the POPS measures sub-micron aerosol particles more accurately on the UAV.
Cited articles
Aquila, V., Garfinkel, C. I., Newman, P. A., Oman, L. D., and Waugh, D. W.:
Modifications of the quasi-biennial oscillation
by a geoengineering perturbation of the stratospheric aerosol layer,
Geophys. Res. Lett., 41, 1738–1744,
https://doi.org/10.1002/2013GL058818, 2014.
Archibald, A. T., O'Connor, F. M., Abraham, N. L., Archer-Nicholls, S., Chipperfield, M. P., Dalvi, M., Folberth, G. A., Dennison, F., Dhomse, S. S., Griffiths, P. T., Hardacre, C., Hewitt, A. J., Hill, R. S., Johnson, C. E., Keeble, J., Köhler, M. O., Morgenstern, O., Mulcahy, J. P., Ordóñez, C., Pope, R. J., Rumbold, S. T., Russo, M. R., Savage, N. H., Sellar, A., Stringer, M., Turnock, S. T., Wild, O., and Zeng, G.: Description and evaluation of the UKCA stratosphere–troposphere chemistry scheme (StratTrop vn 1.0) implemented in UKESM1, Geosci. Model Dev., 13, 1223–1266, https://doi.org/10.5194/gmd-13-1223-2020, 2020.
Baker, L. H., Shaffrey, L. C., Sutton, R. T., Weisheimer, A., and Scaife, A.
A.: An intercomparison of skill and overconfidence/underconfidence of the
wintertime North Atlantic Oscillation in multimodel seasonal forecasts,
Geophys. Res. Lett., 45, 7808–7817, https://doi.org/10.1029/2018GL078838, 2018.
Bala, G., Duffy, P. B., and Taylor, K. E.: Impact of geoengineering schemes on
the global hydrological cycle, P. Natl. Acad. Sci. USA, 105, 7664–7669, 2008.
Banerjee, A., Butler, A. H., Polvani, L. M., Robock, A., Simpson, I. R., and Sun, L.: Robust winter warming over Eurasia under stratospheric sulfate geoengineering – the role of stratospheric dynamics, Atmos. Chem. Phys., 21, 6985–6997, https://doi.org/10.5194/acp-21-6985-2021, 2021.
Best, M. J., Pryor, M., Clark, D. B., Rooney, G. G., Essery, R. L. H., Ménard, C. B., Edwards, J. M., Hendry, M. A., Porson, A., Gedney, N., Mercado, L. M., Sitch, S., Blyth, E., Boucher, O., Cox, P. M., Grimmond, C. S. B., and Harding, R. J.: The Joint UK Land Environment Simulator (JULES), model description – Part 1: Energy and water fluxes, Geosci. Model Dev., 4, 677–699, https://doi.org/10.5194/gmd-4-677-2011, 2011.
Brenna, H., Kutterolf, S., Mills, M. J., Niemeier, U., Timmreck, C., and
Krüger, K.: Decadal disruption of the QBO by tropical volcanic
supereruptions, Geophys. Res. Lett., 48, 1–13,
https://doi.org/10.1029/2020GL089687, 2021.
Christian, K., Wang, J., Ge, C., Peterson, D., Hyer, E., Yorks, J., and McGill, M.: Radiative forcing and stratospheric warming of pyrocumulonimbus
smoke aerosols: First modeling results with multisensor (EPIC, CALIPSO, and
CATS) views from space, Geophys. Res. Lett., 46,
10061–10071, 2019.
Coupe, J., Bardeen, C. G., Robock, A., and Toon, O. B.: Nuclear winter
responses to nuclear war between the United States and Russia in the whole
atmosphere community climate model version 4 and the Goddard Institute for
Space Studies ModelE, J. Geophys. Res.-Atmos., 124,
8522–8543, 2019.
Davidson, P., Burgoyne, C., Hunt, H., and Causier, M.: Lifting options for
stratospheric aerosol geoengineering: advantages of tethered balloon
systems, Philos. T. Roy. Soc. A, 370, 4263–4300, 2012.
Dykema, J. D., Keith, D. W., and Keutch, F. N.: Improved aerosol radiative
properties as a foundation for solar geoengineering risk assessment,
Geophys. Res. Lett., 43, 7758–7766, https://doi.org/10.1002/2016GL069258, 2016.
Eyring, V., Bony, S., Meehl, G. A., Senior, C. A., Stevens, B., Stouffer, R. J., and Taylor, K. E.: Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization, Geosci. Model Dev., 9, 1937–1958, https://doi.org/10.5194/gmd-9-1937-2016, 2016.
Fromm, M., Alfred, J., Hoppel, K., Hornstein, J., Bevilacqua, R., Shettle,
E., and Stocks, B.: Observations of boreal forest fire smoke in the
stratosphere by POAM III, SAGE II, and lidar in 1998, Geophys. Res.
Lett., 27, 1407–1410. https://doi.org/10.1029/1999GL011200, 2000.
Fromm, M., Bevilacqua, R., Servranckx, R., Rosen, J., Thayer, J. P., Herman,
J., and Larko, D.: Pyro-cumulonimbus injection of smoke to the
stratosphere: Observations and impact of a super blowup in northwestern
Canada on 34 August 1998, J. Geophys. Res., 110, D08205,
https://doi.org/10.1029/2004JD005350, 2005.
Gao, R. S., Rosenlof, K. H., Kärcher, B., Tilmes, S., Toon, O. B., Maloney,
C., and Yu, P.: Toward practical stratospheric aerosol albedo modification:
Solar-powered lofting, Sci. Adv., 7, eabe3416, https://doi.org/10.1126/sciadv.abe3416, 2021.
Holland, M. M. and Bitz, C. M.: Polar amplification of climate change in
coupled models, Clim. Dynam., 21, 221–232, 2003.
Holton, J. R., Haynes, P. H., McIntyre, M. E., Douglass, A. R., Rood, R. B., and
Pfister, L.: Stratosphere-troposphere exchange, Rev.
Geophys., 33, 403–439, 1995.
Hurrell, J. W.: Decadal trends in the North Atlantic Oscillation: regional
temperatures and precipitation, Science, 269, 676–679,
https://doi.org/10.1126/science.269.5224.676, 1995.
IPCC: Global warming of 1.5 ∘C. An IPCC Special Report on the
impacts of global warming of 1.5 ∘C above pre-industrial levels
and related global greenhouse gas emission pathways, in the context of
strengthening the global response to the threat of climate change,
sustainable development, and efforts to eradicate poverty, edited by:
Masson-Delmotte, V., Zhai, P., Pörtner, H. O., Roberts, D., Skea, J.,
Shukla, P. R., Pirani, A., Moufouma-Okia, W., Péan, C., Pidcock, R., Connors, S., Matthews, J.
B. R., Chen, Y., Zhou, X., Gomis, M. I., Lonnoy, E., Maycock, T.,
Tignor, M., and Waterfield, T., 2018.
IPCC: Climate Change 2021: The Physical Science Basis. Contribution of
Working Group I to the Sixth Assessment Report of the Intergovernmental
Panel on Climate Change, edited by: Masson-Delmotte, V., Zhai, P., Pirani, A.,
Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I.,
Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K.,
Waterfield, T., Yelekçi, O., Yu, R., and Zhou, B., Cambridge University
Press, 2021.
Johnson, B. T., Haywood, J. M., and Hawcroft, M. K.: Are changes in
atmospheric circulation important for black carbon aerosol impacts on
clouds, precipitation, and radiation?, J. Geophys. Res.-Atmos, 124, 7930–7950, https://doi.org/10.1029/2019JD030568, 2019.
Jones, A., Haywood, J. M., Alterskjær, K., Boucher, O., Cole, J. N.,
Curry, C. L., Irvine, P. J., Ji, D., Kravitz, B., Kristjánsson, J. E., and
Moore, J. C.: The impact of abrupt suspension of solar radiation management
(termination effect) in experiment G2 of the Geoengineering Model
Intercomparison Project (GeoMIP), J. Geophys. Res.-Atmos., 118, 9743–9752, 2013.
Jones, A. C., Haywood, J. M., Dunstone, N., Emanuel, K., Hawcroft, M. K.,
Hodges, K. I., and Jones, A.: Impacts of hemispheric solar geoengineering on
tropical cyclone frequency, Nat. Commun., 8, 1–10, 2017.
Jones, A., Haywood, J. M., Jones, A. C., Tilmes, S., Kravitz, B., and Robock, A.: North Atlantic Oscillation response in GeoMIP experiments G6solar and G6sulfur: why detailed modelling is needed for understanding regional implications of solar radiation management, Atmos. Chem. Phys., 21, 1287–1304, https://doi.org/10.5194/acp-21-1287-2021, 2021.
Jones, A., Haywood, J. M., Scaife, A. A., Boucher, O., Henry, M., Kravitz, B., Lurton, T., Nabat, P., Niemeier, U., Séférian, R., Tilmes, S., and Visioni, D.: The impact of stratospheric aerosol intervention on the North Atlantic and Quasi-Biennial Oscillations in the Geoengineering Model Intercomparison Project (GeoMIP) G6sulfur experiment, Atmos. Chem. Phys., 22, 2999–3016, https://doi.org/10.5194/acp-22-2999-2022, 2022.
Jones, A. C., Haywood, J. M., and Jones, A.: Climatic impacts of stratospheric geoengineering with sulfate, black carbon and titania injection, Atmos. Chem. Phys., 16, 2843–2862, https://doi.org/10.5194/acp-16-2843-2016, 2016.
Khaykin, S., Legras, B., Bucci, S., Sellitto, P., Isaksen, L., Tence, F.,
Bekki, S., Bourassa, A., Rieger, L., Zawada, D., and Jumelet, J.: The 2019/20
Australian wildfires generated a persistent smoke-charged vortex rising up
to 35 km altitude, Commun. Earth Environ., 1, 1–12, 2020.
Kloss, C., Berthet, G., Sellitto, P., Ploeger, F., Taha, G., Tidiga, M., Eremenko, M., Bossolasco, A., Jégou, F., Renard, J.-B., and Legras, B.: Stratospheric aerosol layer perturbation caused by the 2019 Raikoke and Ulawun eruptions and their radiative forcing, Atmos. Chem. Phys., 21, 535–560, https://doi.org/10.5194/acp-21-535-2021, 2021.
Kravitz, B., Robock, A., Boucher, O., Schmidt, H., Taylor, K. E., Stenchikov,
G., and Schulz, M.: The geoengineering model intercomparison project
(GeoMIP), Atmos. Sci. Lett., 12, 162–167, 2011.
Kravitz, B., Robock, A., Shindell, D. T., and Miller, M. A.: Sensitivity of
stratospheric geoengineering with black carbon to aerosol size and altitude
of injection, J. Geophys. Res., 117, D09203, https://doi.org/10.1029/2011JD017341, 2012.
Kravitz, B., Caldeira, K., Boucher, O., Robock, A., Rasch, P. J.,
Alterskjær, K., Karam, D. B., Cole, J. N., Curry, C. L., Haywood, J. M., and
Irvine, P. J.: Climate model response from the geoengineering model
intercomparison project (GeoMIP), J. Geophys. Res.-Atmos., 118, 8320–8332, 2013.
Kravitz, B., Robock, A., Tilmes, S., Boucher, O., English, J. M., Irvine, P. J., Jones, A., Lawrence, M. G., MacCracken, M., Muri, H., Moore, J. C., Niemeier, U., Phipps, S. J., Sillmann, J., Storelvmo, T., Wang, H., and Watanabe, S.: The Geoengineering Model Intercomparison Project Phase 6 (GeoMIP6): simulation design and preliminary results, Geosci. Model Dev., 8, 3379–3392, https://doi.org/10.5194/gmd-8-3379-2015, 2015.
Kravitz, B., MacMartin, D. G., Wang, H., and Rasch, P. J.: Geoengineering as a design problem, Earth Syst. Dynam., 7, 469–497, https://doi.org/10.5194/esd-7-469-2016, 2016.
Kravitz, B., MacMartin, D. G., Tilmes, S., Richter, J. H., Mills, M. J., Cheng,
W., Dagon, K., Glanville, A. S., Lamarque, J. F., Simpson, I. R., and Tribbia,
J.: Comparing surface and stratospheric impacts of geoengineering with
different SO2 injection strategies, J. Geophys. Res.-Atmos., 124, 7900–7918, 2019.
Lawrence, M. G., Schäfer, S., Muri, H., Scott, V., Oschlies, A., Vaughan,
N. E., Boucher, O., Schmidt, H., Haywood, J., and Scheffran, J.: Evaluating
climate geoengineering proposals in the context of the Paris Agreement
temperature goals, Nat. Commun., 9, 1–19, 2018.
Lee, W. R., MacMartin, D. G., Visioni, D., and Kravitz, B.: High-Latitude
Stratospheric Aerosol Geoengineering Can Be More Effective if Injection Is
Limited to Spring, Geophys. Res. Lett., 48, e2021GL092696, https://doi.org/10.1029/2021GL092696, 2021.
Le Texier, H., Solomon, S., and Garcia, R. R.: The role of molecular hydrogen
and methane oxidation in the water vapour budget of the
stratosphere, Q. J. Roy. Meteor. Soc., 114, 281–295, 1988.
López-Moreno, J. I. and Vicente-Serrano, S. M.: Positive and negative
phases of the wintertime North Atlantic Oscillation and drought occurrence
over Europe: a multitemporal-scale approach, J. Climate, 21, 1220–1243,
https://doi.org/10.1175/2007JCLI1739.1, 2008.
Mann, G. W., Carslaw, K. S., Spracklen, D. V., Ridley, D. A., Manktelow, P. T., Chipperfield, M. P., Pickering, S. J., and Johnson, C. E.: Description and evaluation of GLOMAP-mode: a modal global aerosol microphysics model for the UKCA composition-climate model, Geosci. Model Dev., 3, 519–551, https://doi.org/10.5194/gmd-3-519-2010, 2010.
McClellan, J., Keith, D. W., and Apt, J.: Cost analysis of stratospheric albedo
modification delivery systems, Environ. Res. Lett., 7, 034019, https://doi.org/10.1088/1748-9326/7/3/034019, 2012.
Millar, R. J., Fuglestvedt, J. S., Friedlingstein, P., Rogelj, J., Grubb,
M. J., Matthews, H. D., Skeie, R. B., Forster, P. M., Frame, D. J., and Allen,
M. R.: Emission budgets and pathways consistent with limiting warming to 1.5∘C, Nat. Geosci., 10, 741–747, 2017.
Mills, M. J., Toon, O. B., Lee-Taylor, J., and Robock, A.: Multidecadal
global cooling and unprecedented ozone loss following a regional nuclear
conflict, Earth's
Future, 2, 161–176, https://doi.org/10.1002/2013EF000205, 2014.
Mulcahy, J. P., Jones, C., Sellar, A., Johnson, B., Boutle, I. A., Jones,
A., Andrews, T., Rumbold, S. T., Mollard, J., Bellouin, N., Johnson, C. E.,
Williams, K. D., Grosvenor, D. P., and Mc-Coy, D. T.: Improved Aerosol
Processes and Effective Radiative Forcing in HadGEM3 and UKESM1, J. Adv.
Model. Earth Sy., 10, 2786–2805, https://doi.org/10.1029/2018MS001464,
2018.
NAS (National Academies of Sciences), Engineering, and Medicine: Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance,
Washington, DC, The National Academies Press https://doi.org/10.17226/25762, 2021.
Niemeier, U., Schmidt, H., Alterskjær, K., and Kristjánsson, J. E.: Solar irradiance reduction via climate engineering: Impact of different techniques on the energy balance and the hydrological cycle, J. Geophys. Res.-Atmos., 118, 11–905, 2013.
O'Neill, B. C., Kriegler, E., Riahi, K., Ebi, K. L., Hallegatte, S., Carter,
T. R., Mathur, R., and van Vuuren, D.P.: A new scenario framework for climate
change research: the concept of shared socioeconomic pathways, Climatic Change, 122,
387–400, 2014.
Osborne, M. J., de Leeuw, J., Witham, C., Schmidt, A., Beckett, F., Kristiansen, N., Buxmann, J., Saint, C., Welton, E. J., Fochesatto, J., Gomes, A. R., Bundke, U., Petzold, A., Marenco, F., and Haywood, J.: The 2019 Raikoke volcanic eruption – Part 2: Particle-phase dispersion and concurrent wildfire smoke emissions, Atmos. Chem. Phys., 22, 2975–2997, https://doi.org/10.5194/acp-22-2975-2022, 2022.
Peterson, D. A., Campbell, J. R., Hyer, E. J., Fromm, M. D., Kablick, G. P.,
Cossuth, J. H., and DeLand, M. T.: Wildfire-driven thunderstorms cause a
volcano-like stratospheric injection of smoke, NPJ Clim. Atmos. Sci., 1, 1–8, 2018.
Richter, J. H., Tilmes, S., Mills, M. J., Tribbia, J. J., Kravitz, B.,
MacMartin, D. G., Vitt, F., and Lamarque, J.-F.: Stratospheric Dynamical
Response and Ozone Feedbacks in the Presence of SO2 Injections, J. Geophys.
Res.-Atmos., 122, 12557–12573, https://doi.org/10.1002/2017JD026912, 2017.
Richter, J. H., Tilmes, S., Glanville, A., Kravitz, B., MacMartin, D. G.,
Mills, M. J., Simpson, I. R., Vitt, F., Tribbia, J. J., and Lamarque, J. F.:
Stratospheric response in the first geoengineering simulation meeting
multiple surface climate objectives, J. Geophys. Res.-Atmos., 123, 5762–5782, 2018.
Richter, J. H., Anstey, J. A., Butchart, N., Kawatani, Y., Meehl, G. A.,
Osprey, S., and Simpson, I. R.: Progress in simulating the quasi-biennial
oscillation in CMIP models, J. Geophys. Res.-Atmos., 125, e2019JD032362, https://doi.org/10.1029/2019JD032362, 2020.
Ridley, J. K., Blockley, E. W., Keen, A. B., Rae, J. G. L., West, A. E., and Schroeder, D.: The sea ice model component of HadGEM3-GC3.1, Geosci. Model Dev., 11, 713–723, https://doi.org/10.5194/gmd-11-713-2018, 2018.
Robock, A., Marquardt, A., Kravitz, B., and Stenchikov, G.: Benefits, risks,
and costs of stratospheric geoengineering, Geophys. Res. Lett., 36, L19703, https://doi.org/10.1029/2009GL039209, 2009.
Rogelj, J., Den Elzen, M., Höhne, N., Fransen, T., Fekete, H., Winkler,
H., Schaeffer, R., Sha, F., Riahi, K., and Meinshausen, M.: Paris Agreement
climate proposals need a boost to keep warming well below 2 ∘C, Nature,
534, 631–639, 2016.
Samset, B. H., Stjern, C. W., Andrews, E., Kahn, R., Myhre, G., Schulz, M.,
and Schuster, G.: Aerosol absorption: Progress towards global and regional
constraints, Current Climate Change Reports, 4, 65–83,
https://doi.org/10.1007/s40641-018-0091-4, 2018.
Schmidt, H., Alterskjær, K., Bou Karam, D., Boucher, O., Jones, A., Kristjánsson, J. E., Niemeier, U., Schulz, M., Aaheim, A., Benduhn, F., Lawrence, M., and Timmreck, C.: Solar irradiance reduction to counteract radiative forcing from a quadrupling of CO2: climate responses simulated by four earth system models, Earth Syst. Dynam., 3, 63–78, https://doi.org/10.5194/esd-3-63-2012, 2012.
Sellar, A., Jones, C. G., Mulcahy, J. P., Tang, Y., Yool, A., Wiltshire, A.,
O'Connor, F. M., Stringer, M., Hill, R., Palmieri, J., Woodward, S., de
Mora, L., Kuhlbrodt, T., Rumbold, S., Kelley, D. I., Ellis, R., Johnson, C.
E., Walton, J., Abraham, N. L., Andrews, M. B., Andrews, T., Archibald, A.
T., Berthou, S., Burke, E., Blockley, E., Carslaw, K., Dalvi, M., Edwards,
J., Folberth, G. A., Gedney, N., Griffiths, P. T., Harper, A. B., Hendry, M.
A., Hewitt, A. J., Johnson, B., Jones, A., Jones, C. D., Keeble, J.,
Liddicoat, S., Morgenstern, O., Parker, R. J., Predoi, V., Robertson, E.,
Siahaan, A., Smith, R. S., Swaminathan, R., Woodhouse, M., Zeng, G., and
Zerroukat, M.: UKESM1: Description and evaluation of the UK Earth System
Model, J. Adv. Model. Earth Sy., 11, 4513–4558,
https://doi.org/10.1029/2019MS001739, 2019.
Shepherd, J. G.: Geoengineering the climate: science, governance and uncertainty, Royal Society, RS Policy document 10/09, ISBN: 978-0-85403-773-5, 2009.
Sherwood, S. C. and Dessler, A. E.: A model for transport across the tropical
tropopause, J. Atmos. Sci., 58, 765–779, 2001.
Shindell, D. T., Schmidt, G. A., Mann, M. E., and Faluvegi, G.: Dynamic winter
climate response to large tropical volcanic eruptions since 1600, J. Geophys. Res.-Atmos., 109, D05104, https://doi.org/10.1029/2003JD004151,
2004.
Simpson, I. R., Tilmes, S., Richter, J. H., Kravitz, B., MacMartin, D. G.,
Mills, M. J., Fasullo, J. T., and Pendergrass, A. G.: The regional hydroclimate
response to stratospheric sulfate geoengineering and the role of
stratospheric heating, J. Geophys. Res.-Atmos.,
124, 12587–12616, 2019.
Smith, W.: The cost of stratospheric aerosol injection through
2100, Environ. Res. Lett., 15, 114004, https://doi.org/10.1088/1748-9326/aba7e7, 2020.
Smith, C. J., Kramer, R. J., Myhre, G., Forster, P. M., Soden, B. J., Andrews,
T., Boucher, O., Faluvegi, G., Fläschner, D., Hodnebrog, Ø., and
Kasoar, M.: Understanding rapid adjustments to diverse forcing
agents, Geophys. Res. Lett., 45, 12–23, 2018.
Solomon, S.: Stratospheric ozone depletion: A review of concepts and
history, Rev. Geophys., 37, 275–316, 1999.
Stephenson, D. B., Pavan, V., Collins, M., Junge, M. M., and Quadrelli, R.:
North Atlantic Oscillation response to transient greenhouse gas forcing and
the impact on European winter climate: a CMIP2 multi-model
assessment, Clim. Dynam., 27, 401–420, 2006.
Storkey, D., Blaker, A. T., Mathiot, P., Megann, A., Aksenov, Y., Blockley, E. W., Calvert, D., Graham, T., Hewitt, H. T., Hyder, P., Kuhlbrodt, T., Rae, J. G. L., and Sinha, B.: UK Global Ocean GO6 and GO7: a traceable hierarchy of model resolutions, Geosci. Model Dev., 11, 3187–3213, https://doi.org/10.5194/gmd-11-3187-2018, 2018.
Tilmes, S., Fasullo, J., Lamarque, J. F., Marsh, D. R., Mills, M.,
Alterskjær, K., Muri, H., Kristjánsson, J. E., Boucher, O., Schulz,
M., and Cole, J. N.: The hydrological impact of geoengineering in the
Geoengineering Model Intercomparison Project (GeoMIP), J. Geophys. Res.-Atmos., 118, 11–36,
2013.
Tilmes, S., Richter, J. H., Mills, M. J., Kravitz, B., MacMartin, D. G., Vitt,
F., Tribbia, J. J., and Lamarque, J. F.: Sensitivity of aerosol distribution
and climate response to stratospheric SO2 injection locations, J. Geophys. Res.-Atmos., 122,
12–591, 2017.
Tilmes, S., Visioni, D., Jones, A., Haywood, J., Séférian, R., Nabat, P., Boucher, O., Bednarz, E. M., and Niemeier, U.: Stratospheric ozone response to sulfate aerosol and solar dimming climate interventions based on the G6 Geoengineering Model Intercomparison Project (GeoMIP) simulations, Atmos. Chem. Phys., 22, 4557–4579, https://doi.org/10.5194/acp-22-4557-2022, 2022.
Tollefson, J.: IPCC says limiting global warming to 1.5∘C will require
drastic action, Nature, 562, 172–173, 2018.
Trigo, R. M., Pozo-Vázquez, D., Osborn, T. J., Castro-Díez, Y.,
Gámiz-Fortis, S., and Esteban-Parra, M. J.: North Atlantic Oscillation
influence on precipitation, river flow and water resources in the Iberian
Peninsula, Int. J. Climatol., 24, 925–944, https://doi.org/10.1002/joc.1048, 2004.
Visioni, D., MacMartin, D. G., Kravitz, B., Richter, J. H., Tilmes, S., and
Mills, M. J.: Seasonally modulated stratospheric aerosol geoengineering
alters the climate outcomes, Geophys. Res. Lett., 47, e2020GL088337, https://doi.org/10.1029/2020GL088337, 2020.
Visioni, D., MacMartin, D. G., Kravitz, B., Boucher, O., Jones, A., Lurton, T., Martine, M., Mills, M. J., Nabat, P., Niemeier, U., Séférian, R., and Tilmes, S.: Identifying the sources of uncertainty in climate model simulations of solar radiation modification with the G6sulfur and G6solar Geoengineering Model Intercomparison Project (GeoMIP) simulations, Atmos. Chem. Phys., 21, 10039–10063, https://doi.org/10.5194/acp-21-10039-2021, 2021.
Walters, D., Baran, A. J., Boutle, I., Brooks, M., Earnshaw, P., Edwards, J., Furtado, K., Hill, P., Lock, A., Manners, J., Morcrette, C., Mulcahy, J., Sanchez, C., Smith, C., Stratton, R., Tennant, W., Tomassini, L., Van Weverberg, K., Vosper, S., Willett, M., Browse, J., Bushell, A., Carslaw, K., Dalvi, M., Essery, R., Gedney, N., Hardiman, S., Johnson, B., Johnson, C., Jones, A., Jones, C., Mann, G., Milton, S., Rumbold, H., Sellar, A., Ujiie, M., Whitall, M., Williams, K., and Zerroukat, M.: The Met Office Unified Model Global Atmosphere 7.0/7.1 and JULES Global Land 7.0 configurations, Geosci. Model Dev., 12, 1909–1963, https://doi.org/10.5194/gmd-12-1909-2019, 2019.
World Climate Research Programme (WCRP): WCRP Coupled Model Intercomparison Project (Phase 6),
https://esgf-node.llnl.gov/projects/cmip6 (last access: 2 February
2022), 2021.
Yool, A., Popova, E. E., and Anderson, T. R.: MEDUSA-2.0: an intermediate complexity biogeochemical model of the marine carbon cycle for climate change and ocean acidification studies, Geosci. Model Dev., 6, 1767–1811, https://doi.org/10.5194/gmd-6-1767-2013, 2013
Yu, P., Toon, O. B., Bardeen, C. G., Zhu, Y., Rosenlof, K. H., Portmann, R. W.,
Thornberry, T. D., Gao, R. S., Davis, S. M., Wolf, E. T., and de Gouw, J.: Black
carbon lofts wildfire smoke high into the stratosphere to form a persistent
plume, Science, 365, 587–590, 2019.
Zanardo, S., Nicotina, L., Hilberts, A. G. J., and Jewson, S. P.: Modulation
of economic losses from European floods by the North Atlantic Oscillation,
Geophys. Res. Lett., 46, 2563–2572, https://doi.org/10.1029/2019GL081956, 2019.
Short summary
Simulations are presented investigating the influence of moderately absorbing aerosol in the stratosphere to combat the impacts of climate change. A number of detrimental impacts are noted compared to sulfate aerosol, including (i) reduced cooling efficiency, (ii) increased deficits in global precipitation, (iii) delays in the recovery of the stratospheric ozone hole, and (iv) disruption of the stratospheric circulation and the wintertime storm tracks that impact European precipitation.
Simulations are presented investigating the influence of moderately absorbing aerosol in the...
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