Articles | Volume 24, issue 3
https://doi.org/10.5194/acp-24-1919-2024
© Author(s) 2024. 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-24-1919-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
13 Feb 2024
Research article |
| 13 Feb 2024
| 13 Feb 2024
Effects of intermittent aerosol forcing on the stratocumulus-to-cumulus transition
Prasanth Prabhakaran
CORRESPONDING AUTHOR
Cooperative Institute for Research In Environmental Sciences (CIRES), University of Colorado, Boulder, CO, USA
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
Fabian Hoffmann
Meteorologisches Institut, Ludwig-Maximilians-Universität München, Munich, Germany
Graham Feingold
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
Related authors
Prasanth Prabhakaran, Timothy A. Myers, Fabian Hoffmann, and Graham Feingold
Atmos. Chem. Phys., 26, 5151–5167, https://doi.org/10.5194/acp-26-5151-2026, https://doi.org/10.5194/acp-26-5151-2026, 2026
Short summary
Short summary
We explore how climate change and aerosol affect the evolution of marine low-clouds. Using high-resolution simulations, we find that warming has a stronger impact on these clouds, but aerosol becomes more important after the clouds form precipitation. Our results suggest that attempts to brighten these clouds using aerosol may become less effective in a warmer future due to the decrease in cloud cover.
Yao-Sheng Chen, Prasanth Prabhakaran, Fabian Hoffmann, Jan Kazil, Takanobu Yamaguchi, and Graham Feingold
Atmos. Chem. Phys., 25, 6141–6159, https://doi.org/10.5194/acp-25-6141-2025, https://doi.org/10.5194/acp-25-6141-2025, 2025
Short summary
Short summary
Injecting sea salt aerosols into marine stratiform clouds can distribute the cloud water over more droplets in smaller sizes. This process is expected to make the clouds brighter, allowing them to reflect more sunlight back to space. However, it may also cause the clouds to lose water over time, reducing their ability to reflect sunlight. We use a computer model to show that the loss of cloud water occurs relatively quickly and does not completely offset the initial brightening.
Benjamin Ascher and Fabian Hoffmann
Atmos. Chem. Phys., 26, 11747–11770, https://doi.org/10.5194/acp-26-11747-2026, https://doi.org/10.5194/acp-26-11747-2026, 2026
Short summary
Short summary
Arctic clouds with liquid and ice have important effects on climate. To investigate how ice crystals and liquid droplets grow in shallow Arctic clouds, we conducted high-resolution simulations. We find that drier air above the cloud leads to a greater sublimation rate of ice beneath the cloud and recycling of particles necessary for ice formation within the cloud. We also find that the amount of sublimation and recycling is affected by the rate of temperature change with height above the cloud.
Johannes Kainz, Daniel P. Harrison, and Fabian Hoffmann
Atmos. Chem. Phys., 26, 9443–9451, https://doi.org/10.5194/acp-26-9443-2026, https://doi.org/10.5194/acp-26-9443-2026, 2026
Short summary
Short summary
Marine Cloud Brightening (MCB) aims to counter global warming. It suggests to increase cloud reflectance by spraying aerosols from which additional cloud droplets can form. We demonstrate that MCB can be applied to cumulus clouds. The impact of aerosol particles released by a single aerosol sprayer using simulations is analyzed. The study draws conclusions on the optimal placement height of the sprayer to optimize aerosol transport, the ability to form new cloud droplets, and the area affected.
Benjamin Hernandez, Martin S. Singh, Takanobu Yamaguchi, Graham Feingold, and Franziska Glassmeier
Atmos. Chem. Phys., 26, 9337–9356, https://doi.org/10.5194/acp-26-9337-2026, https://doi.org/10.5194/acp-26-9337-2026, 2026
Short summary
Short summary
Using detailed numerical simulations, we quantify how stratocumulus cloud decks dissipate energy and produce entropy. We find that entropy production is dominated by irreversible moist processes and is much smaller than in deeper convective clouds. As a result, stratocumulus are remarkably inefficient at converting available energy into atmospheric motions.
Netta Yeheskel, Matthew W. Christensen, Fabian Hoffmann, Graham Feingold, and Guy Dagan
Atmos. Chem. Phys., 26, 8765–8781, https://doi.org/10.5194/acp-26-8765-2026, https://doi.org/10.5194/acp-26-8765-2026, 2026
Short summary
Short summary
Aerosols influence cloud formation, structure, and radiative effects. As air masses move from the subtropics to the tropics, clouds transition from shallow to deeper systems. Using five years of satellite observations and numerical simulations, we find a robust aerosol impact on this Lagrangian cloud evolution: higher aerosol levels produce thicker, more reflective clouds, enhancing cooling and modifying energy and moisture transport toward the tropics.
Rebecca Gjini, Matthias Morzfeld, Franziska Glassmeier, and Graham Feingold
EGUsphere, https://doi.org/10.5194/egusphere-2026-2871, https://doi.org/10.5194/egusphere-2026-2871, 2026
Short summary
Short summary
We connect two very different types of precipitating stratocumulus cloud models. The first model is a high-resolution simulation that can realistically represent clouds. The second model is a simple, 1D equation that interprets clouds as prey and rain as the predator of clouds. We evaluate the extent to which a simplified cloud model can represent selected aspects of a realistic cloud simulation under different meteorological conditions, highlighting both successes and limitations.
Anna Weber, Fabian Hoffmann, and Bernhard Mayer
Atmos. Chem. Phys., 26, 8001–8020, https://doi.org/10.5194/acp-26-8001-2026, https://doi.org/10.5194/acp-26-8001-2026, 2026
Short summary
Short summary
The vertical evolution of microphysical cloud properties in low-level mixed-phase clouds during a marine cold air outbreak in the Arctic is analyzed based on measurements collected during the HALO–(𝒜𝒞)3 campaign. In particular, pseudo-vertical profiles of cloud thermodynamic phase and the cloud droplet size are constructed. The measured vertical profiles are compared to predictions from an entraining parcel model to investigate the influence of ice processes on supercooled liquid water droplets.
Tom Goren, Goutam Choudhury, and Graham Feingold
Atmos. Chem. Phys., 26, 7193–7206, https://doi.org/10.5194/acp-26-7193-2026, https://doi.org/10.5194/acp-26-7193-2026, 2026
Short summary
Short summary
We introduce a new way to describe marine low cloud morphologies as a continuous range rather than discrete types. Using this approach, we show that cloud brightness responses to changes in droplet concentrations vary strongly across cloud morphologies, but the overall effect is small. This suggests that marine cloud brightening may rely more on increasing cloud cover than on making existing clouds brighter.
Jianhao Zhang, David Painemal, Tom Dror, Jung-Sub Lim, Armin Sorooshian, and Graham Feingold
Atmos. Chem. Phys., 26, 6015–6034, https://doi.org/10.5194/acp-26-6015-2026, https://doi.org/10.5194/acp-26-6015-2026, 2026
Short summary
Short summary
Clouds transitioning from overcast to broken fields play an important role in regulating the amount of sunlight reaching Earth’s surface. Using satellite imagery and a novel space-time exchange approach, we examine these transitions during marine cold-air outbreaks. Our analysis reveals characteristic signatures (or fingerprints) of liquid- and ice-phase processes, demonstrating how space-borne observations can provide new physical insight into cloud evolution.
Jung-Sub Lim and Fabian Hoffmann
Atmos. Chem. Phys., 26, 5427–5446, https://doi.org/10.5194/acp-26-5427-2026, https://doi.org/10.5194/acp-26-5427-2026, 2026
Short summary
Short summary
We used high-resolution simulations to track individual cloud droplets within marine clouds. We discovered that while droplets grow similarly, they evaporate differently depending on their specific history of exposure to dry air. This helps resolve ambiguities in interpreting field observations, where droplet history is often unknown. We also propose a simple formula to capture this variability, offering a more accurate tool for representing cloud evolution in models.
Prasanth Prabhakaran, Timothy A. Myers, Fabian Hoffmann, and Graham Feingold
Atmos. Chem. Phys., 26, 5151–5167, https://doi.org/10.5194/acp-26-5151-2026, https://doi.org/10.5194/acp-26-5151-2026, 2026
Short summary
Short summary
We explore how climate change and aerosol affect the evolution of marine low-clouds. Using high-resolution simulations, we find that warming has a stronger impact on these clouds, but aerosol becomes more important after the clouds form precipitation. Our results suggest that attempts to brighten these clouds using aerosol may become less effective in a warmer future due to the decrease in cloud cover.
Richard Maier, Fabian Jakub, Fabian Hoffmann, and Bernhard Mayer
EGUsphere, https://doi.org/10.5194/egusphere-2026-1417, https://doi.org/10.5194/egusphere-2026-1417, 2026
Short summary
Short summary
Most atmospheric models only use 1D radiation, neglecting any 3D radiative effects. Here, we show that the dynamic TenStream solver provides a computationally efficient way to represent these effects. Like full 3D radiation, it causes daytime clouds to organize into streets, grow larger, and contain more liquid water. We show that this occurs because 3D radiation does not shade cloud updrafts and modifies the surface energy balance, resulting in an increased latent heat flux into the atmosphere.
Levin Rug, Willi Schimmel, Fabian Hoffmann, and Oswald Knoth
Geosci. Model Dev., 18, 9039–9059, https://doi.org/10.5194/gmd-18-9039-2025, https://doi.org/10.5194/gmd-18-9039-2025, 2025
Short summary
Short summary
We present the Chemical Mechanism Integrator (Cminor) v1.0, a tool to predict concentrations of chemical compounds undergoing arbitrary reactions. Cminor is an advanced, open-source solver to model either combustion chemistry, or atmospheric chemistry and its direct influence on condensation of cloud droplets and the subsequent processing of aerosol. It uses the superdroplet idea, making it particularly feasible for coupling with such models, which is part of future work.
Isabel L. McCoy, Sunil Baidar, Paquita Zuidema, Jan Kazil, W. Alan Brewer, Wayne M. Angevine, and Graham Feingold
Atmos. Chem. Phys., 25, 16233–16261, https://doi.org/10.5194/acp-25-16233-2025, https://doi.org/10.5194/acp-25-16233-2025, 2025
Short summary
Short summary
We use ship observations to investigate the dynamics of small clouds over the tropical oceans. When these cumulus clouds cluster together, they more efficiently move moisture into the cloud layer due to strengthened updrafts. This encourages further clustering, increases local cloud development success, and may help sustain clouds against diurnal variations in their environment. These results have implications for cumulus feedback on the climate, a significant uncertainty in future projections.
Graham Feingold, Franziska Glassmeier, Jianhao Zhang, and Fabian Hoffmann
Atmos. Chem. Phys., 25, 10869–10885, https://doi.org/10.5194/acp-25-10869-2025, https://doi.org/10.5194/acp-25-10869-2025, 2025
Short summary
Short summary
Scientists usually use snapshots of atmospheric data to glean understanding of time-evolving atmospheric processes. We examine how much can be learned about processes from snapshots using examples from cloud and atmospheric physics. We couch the analysis in terms of the theory of ergodic systems, space-time-exchange, and the Deborah number – concepts that are commonly applied in other branches of physics. We discuss the reasons for the varying degrees of success.
Fabian Hoffmann, Yao-Sheng Chen, and Graham Feingold
Atmos. Chem. Phys., 25, 8657–8670, https://doi.org/10.5194/acp-25-8657-2025, https://doi.org/10.5194/acp-25-8657-2025, 2025
Short summary
Short summary
Clouds reflect a substantial portion of the incoming solar radiation back into space. This capacity is determined by the number of cloud droplets, which in turn is influenced by the number of aerosol particles, forming the basis for aerosol–cloud–climate interactions. In this study, we use a simple entrainment parameterization to understand the effect of aerosol on cloud water in weakly and non-precipitating stratocumulus.
Yao-Sheng Chen, Prasanth Prabhakaran, Fabian Hoffmann, Jan Kazil, Takanobu Yamaguchi, and Graham Feingold
Atmos. Chem. Phys., 25, 6141–6159, https://doi.org/10.5194/acp-25-6141-2025, https://doi.org/10.5194/acp-25-6141-2025, 2025
Short summary
Short summary
Injecting sea salt aerosols into marine stratiform clouds can distribute the cloud water over more droplets in smaller sizes. This process is expected to make the clouds brighter, allowing them to reflect more sunlight back to space. However, it may also cause the clouds to lose water over time, reducing their ability to reflect sunlight. We use a computer model to show that the loss of cloud water occurs relatively quickly and does not completely offset the initial brightening.
Jung-Sub Lim, Yign Noh, Hyunho Lee, and Fabian Hoffmann
Atmos. Chem. Phys., 25, 5313–5329, https://doi.org/10.5194/acp-25-5313-2025, https://doi.org/10.5194/acp-25-5313-2025, 2025
Short summary
Short summary
Rain formation in warm clouds begins when small droplets collide, but this process can be slow without larger droplets. We used simulations to explore the role of bigger droplets, known as precipitation embryos, in triggering rain. We found that they speed up rain only when their size and number exceed a critical threshold. This threshold becomes larger when collisions are naturally efficient, such as in clouds with broad droplet size distributions or strong turbulence.
Fan Yang, Hamed Fahandezh Sadi, Raymond A. Shaw, Fabian Hoffmann, Pei Hou, Aaron Wang, and Mikhail Ovchinnikov
Atmos. Chem. Phys., 25, 3785–3806, https://doi.org/10.5194/acp-25-3785-2025, https://doi.org/10.5194/acp-25-3785-2025, 2025
Short summary
Short summary
Large-eddy simulations of a convection cloud chamber show two new microphysics regimes, cloud oscillation and cloud collapse, due to haze–cloud interactions. Our results suggest that haze particles and their interactions with cloud droplets should be considered especially in polluted conditions. To properly simulate haze–cloud interactions, we need to resolve droplet activation and deactivation processes, instead of using Twomey-type activation parameterization.
Fabian Hoffmann, Franziska Glassmeier, and Graham Feingold
Atmos. Chem. Phys., 24, 13403–13412, https://doi.org/10.5194/acp-24-13403-2024, https://doi.org/10.5194/acp-24-13403-2024, 2024
Short summary
Short summary
Clouds constitute a major cooling influence on Earth's climate system by reflecting a large fraction of the incident solar radiation back to space. This ability is controlled by the number of cloud droplets, which is governed by the number of aerosol particles in the atmosphere, laying the foundation for so-called aerosol–cloud–climate interactions. In this study, a simple model to understand the effect of aerosol on cloud water is developed and applied.
Yao-Sheng Chen, Jianhao Zhang, Fabian Hoffmann, Takanobu Yamaguchi, Franziska Glassmeier, Xiaoli Zhou, and Graham Feingold
Atmos. Chem. Phys., 24, 12661–12685, https://doi.org/10.5194/acp-24-12661-2024, https://doi.org/10.5194/acp-24-12661-2024, 2024
Short summary
Short summary
Marine stratocumulus cloud is a type of shallow cloud that covers the vast areas of Earth's surface. It plays an important role in Earth's energy balance by reflecting solar radiation back to space. We used numerical models to simulate a large number of marine stratocumuli with different characteristics. We found that how the clouds develop throughout the day is affected by the level of humidity in the air above the clouds and how closely the clouds connect to the ocean surface.
Jianhao Zhang, Yao-Sheng Chen, Takanobu Yamaguchi, and Graham Feingold
Atmos. Chem. Phys., 24, 10425–10440, https://doi.org/10.5194/acp-24-10425-2024, https://doi.org/10.5194/acp-24-10425-2024, 2024
Short summary
Short summary
Quantifying cloud response to aerosol perturbations presents a major challenge in understanding the human impact on climate. Using a large number of process-resolving simulations of marine stratocumulus, we show that solar heating drives a negative feedback mechanism that buffers the persistent negative trend in cloud water adjustment after sunrise. This finding has implications for the dependence of the cloud cooling effect on the timing of deliberate aerosol perturbations.
Hong Chen, K. Sebastian Schmidt, Steven T. Massie, Vikas Nataraja, Matthew S. Norgren, Jake J. Gristey, Graham Feingold, Robert E. Holz, and Hironobu Iwabuchi
Atmos. Meas. Tech., 16, 1971–2000, https://doi.org/10.5194/amt-16-1971-2023, https://doi.org/10.5194/amt-16-1971-2023, 2023
Short summary
Short summary
We introduce the Education and Research 3D Radiative Transfer Toolbox (EaR3T) and propose a radiance self-consistency approach for quantifying and mitigating 3D bias in legacy airborne and spaceborne imagery retrievals due to spatially inhomogeneous clouds and surfaces.
Jianhao Zhang and Graham Feingold
Atmos. Chem. Phys., 23, 1073–1090, https://doi.org/10.5194/acp-23-1073-2023, https://doi.org/10.5194/acp-23-1073-2023, 2023
Short summary
Short summary
Using observations from space, we show maps of potential brightness changes in marine warm clouds in response to increases in cloud droplet concentrations. The environmental and aerosol conditions in which these clouds reside covary differently in each ocean basin, leading to distinct evolutions of cloud brightness changes. This work stresses the central importance of the covariability between meteorology and aerosol for scaling up the radiative response of cloud brightness changes.
Michael S. Diamond, Pablo E. Saide, Paquita Zuidema, Andrew S. Ackerman, Sarah J. Doherty, Ann M. Fridlind, Hamish Gordon, Calvin Howes, Jan Kazil, Takanobu Yamaguchi, Jianhao Zhang, Graham Feingold, and Robert Wood
Atmos. Chem. Phys., 22, 12113–12151, https://doi.org/10.5194/acp-22-12113-2022, https://doi.org/10.5194/acp-22-12113-2022, 2022
Short summary
Short summary
Smoke from southern Africa blankets the southeast Atlantic from June-October, overlying a major transition region between overcast and scattered clouds. The smoke affects Earth's radiation budget by absorbing sunlight and changing cloud properties. We investigate these effects in regional climate and large eddy simulation models based on international field campaigns. We find that large-scale circulation changes more strongly affect cloud transitions than smoke microphysical effects in our case.
Vikas Nataraja, Sebastian Schmidt, Hong Chen, Takanobu Yamaguchi, Jan Kazil, Graham Feingold, Kevin Wolf, and Hironobu Iwabuchi
Atmos. Meas. Tech., 15, 5181–5205, https://doi.org/10.5194/amt-15-5181-2022, https://doi.org/10.5194/amt-15-5181-2022, 2022
Short summary
Short summary
A convolutional neural network (CNN) is introduced to retrieve cloud optical thickness (COT) from passive cloud imagery. The CNN, trained on large eddy simulations from the Sulu Sea, learns from spatial information at multiple scales to reduce cloud inhomogeneity effects. By considering the spatial context of a pixel, the CNN outperforms the traditional independent pixel approximation (IPA) across several cloud morphology metrics.
Edward Gryspeerdt, Franziska Glassmeier, Graham Feingold, Fabian Hoffmann, and Rebecca J. Murray-Watson
Atmos. Chem. Phys., 22, 11727–11738, https://doi.org/10.5194/acp-22-11727-2022, https://doi.org/10.5194/acp-22-11727-2022, 2022
Short summary
Short summary
The response of clouds to changes in aerosol remains a large uncertainty in our understanding of the climate. Studies typically look at aerosol and cloud processes in snapshot images, measuring all properties at the same time. Here we use multiple images to characterise how cloud temporal development responds to aerosol. We find a reduction in liquid water path with increasing aerosol, party due to feedbacks. This suggests the aerosol impact on cloud water may be weaker than in previous studies.
Graham Feingold, Tom Goren, and Takanobu Yamaguchi
Atmos. Chem. Phys., 22, 3303–3319, https://doi.org/10.5194/acp-22-3303-2022, https://doi.org/10.5194/acp-22-3303-2022, 2022
Short summary
Short summary
The evaluation of radiative forcing associated with aerosol–cloud interactions remains a significant source of uncertainty in future climate projections. Using high-resolution numerical model output, we mimic typical satellite retrieval methodologies to show that data aggregation can introduce significant error (hundreds of percent) in the cloud albedo susceptibility metric. Spatial aggregation errors tend to be countered by temporal aggregation errors.
Jianhao Zhang, Xiaoli Zhou, Tom Goren, and Graham Feingold
Atmos. Chem. Phys., 22, 861–880, https://doi.org/10.5194/acp-22-861-2022, https://doi.org/10.5194/acp-22-861-2022, 2022
Short summary
Short summary
Oceanic liquid-form clouds are effective sunlight reflectors. Their brightness is highly sensitive to changes in the amount of aerosol particles in the atmosphere and the state of the atmosphere they reside in. This study quantifies this sensitivity using long-term satellite observations and finds an overall cloud brightening (a cooling effect) potential and an essential role of the covarying meteorological conditions in governing this sensitivity for northeastern Pacific stratocumulus.
Matthew W. Christensen, Andrew Gettelman, Jan Cermak, Guy Dagan, Michael Diamond, Alyson Douglas, Graham Feingold, Franziska Glassmeier, Tom Goren, Daniel P. Grosvenor, Edward Gryspeerdt, Ralph Kahn, Zhanqing Li, Po-Lun Ma, Florent Malavelle, Isabel L. McCoy, Daniel T. McCoy, Greg McFarquhar, Johannes Mülmenstädt, Sandip Pal, Anna Possner, Adam Povey, Johannes Quaas, Daniel Rosenfeld, Anja Schmidt, Roland Schrödner, Armin Sorooshian, Philip Stier, Velle Toll, Duncan Watson-Parris, Robert Wood, Mingxi Yang, and Tianle Yuan
Atmos. Chem. Phys., 22, 641–674, https://doi.org/10.5194/acp-22-641-2022, https://doi.org/10.5194/acp-22-641-2022, 2022
Short summary
Short summary
Trace gases and aerosols (tiny airborne particles) are released from a variety of point sources around the globe. Examples include volcanoes, industrial chimneys, forest fires, and ship stacks. These sources provide opportunistic experiments with which to quantify the role of aerosols in modifying cloud properties. We review the current state of understanding on the influence of aerosol on climate built from the wide range of natural and anthropogenic laboratories investigated in recent decades.
Cited articles
Ackerman, A. S., Stevens, B., Savic-Jovcic, V., Bretherton, C. S., Chlond, A., Golaz, J. C., Jiang, H., Khairoutdinov, M., Krueger, S. K., Lewellen, D. C., and Lock, A.: Large-eddy simulations of a drizzling, stratocumulus-topped marine boundary layer, Mon. Weather Rev., 137, 1083–1110, 2009. a
Ahlm, L., Jones, A., Stjern, C. W., Muri, H., Kravitz, B., and Kristjánsson, J. E.: Marine cloud brightening – as effective without clouds, Atmos. Chem. Phys., 17, 13071–13087, https://doi.org/10.5194/acp-17-13071-2017, 2017. a
Albrecht, B. A.: Aerosols, cloud microphysics, and fractional cloudiness, Science, 245, 1227–1230, 1989. a
Baker, M. B. and Charlson, R. J.: Bistability of CCN concentrations and thermodynamics in the cloud-topped boundary layer, Nature, 345, 142–145, 1990. a
Bretherton, C.: A conceptual model of the stratocumulus-trade-cumulus transition in the subtropical oceans, in: Proceedings of the 11th International Conference on Clouds and Precipitation, 17–21 August 1992, Montreal, PQ, Canada, International Commission on Clouds and Precipitation, vol. 1, 374–377, https://www.google.com/url?sa=t&rct=j&q=&esrc=s &source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjY9but3 aeEAxULxTgGHRhDBzEQFnoECA8QAQ&url=https%3A %2F%2Fwww.iamas.org%2Ficcp%2Fwp-content%2F uploads%2Fsites%2F3%2F2021%2F01%2F11th-Internation-Conference-on-Clouds-and-Precipitation-Proceedings-Vol-I.pdf&usg=AOvVaw0dh-5QnZxuc1yfjDzwZoXl&opi=89978449 (last access: 12 February 2024), 1992. a, b
Bretherton, C., Blossey, P. N., and Uchida, J.: Cloud droplet sedimentation, entrainment efficiency, and subtropical stratocumulus albedo, Geophys. Res. Lett., 34, L03813, https://doi.org/10.1029/2006GL027648, 2007. a, b
Bretherton, C. S. and Blossey, P. N.: Low cloud reduction in a greenhouse-warmed climate: Results from Lagrangian LES of a subtropical marine cloudiness transition, J. Adv. Model. Earth Syst., 6, 91–114, 2014. a
Bretherton, C. S. and Pincus, R.: Cloudiness and marine boundary layer dynamics in the ASTEX Lagrangian experiments. Part I: Synoptic setting and vertical structure, J. Atmos. Sci., 52, 2707–2723, 1995. a
Bretherton, C. S., McCoy, I. L., Mohrmann, J., Wood, R., Ghate, V., Gettelman, A., Bardeen, C. G., Albrecht, B. A., and Zuidema, P.: Cloud, aerosol, and boundary layer structure across the Northeast Pacific stratocumulus–cumulus transition as observed during CSET, Mon. Weather Rev., 147, 2083–2103, 2019. a
Chun, J.-Y., Wood, R., Blossey, P. N., and Doherty, S. J.: The impact of aerosol injections and adjustments in large-scale subsidence on stratocumulus-to-cumulus transition, in: AGU Fall Meeting Abstracts, 12–16 December 2022, Chicago, USA, vol. 2022, A12G-07, 2022. a
Chun, J.-Y., Wood, R., Blossey, P., and Doherty, S. J.: Microphysical, macrophysical, and radiative responses of subtropical marine clouds to aerosol injections, Atmos. Chem. Phys., 23, 1345–1368, https://doi.org/10.5194/acp-23-1345-2023, 2023. a, b, c, d
Clark, T. L.: Numerical modeling of the dynamics and microphysics of warm cumulus convection, J. Atmos. Sci., 30, 857–878, 1973. a
Diamond, M. S.: Detection of large-scale cloud microphysical changes within a major shipping corridor after implementation of the International Maritime Organization 2020 fuel sulfur regulations, Atmos. Chem. Phys., 23, 8259–8269, https://doi.org/10.5194/acp-23-8259-2023, 2023. a
Diamond, M. S., Director, H. M., Eastman, R., Possner, A., and Wood, R.: Substantial cloud brightening from shipping in subtropical low clouds, AGU Advances, 1, e2019AV000111, https://doi.org/10.1029/2019AV000111, 2020. a
Eastman, R. and Wood, R.: Factors controlling low-cloud evolution over the eastern subtropical oceans: A Lagrangian perspective using the A-Train satellites, J. Atmos. Sci., 73, 331–351, 2016. a
Eastman, R., McCoy, I. L., and Wood, R.: Environmental and internal controls on Lagrangian transitions from closed cell mesoscale cellular convection over subtropical oceans, J. Atmos. Sci., 78, 2367–2383, 2021. a
Erfani, E., Blossey, P., Wood, R., Mohrmann, J., Doherty, S. J., Wyant, M., and O, K.-T.: Simulating Aerosol Lifecycle Impacts on the Subtropical Stratocumulus-to-Cumulus Transition Using Large-Eddy Simulations, J. Geophys. Res.-Atmos., 127, e2022JD037258, https://doi.org/10.1029/2022JD037258, 2022. a, b
Feingold, G., Koren, I., Yamaguchi, T., and Kazil, J.: On the reversibility of transitions between closed and open cellular convection, Atmos. Chem. Phys., 15, 7351–7367, https://doi.org/10.5194/acp-15-7351-2015, 2015. a, b
Feingold, G., Goren, T., and Yamaguchi, T.: Quantifying albedo susceptibility biases in shallow clouds, Atmos. Chem. Phys., 22, 3303–3319, https://doi.org/10.5194/acp-22-3303-2022, 2022. a
Goren, T. and Rosenfeld, D.: Decomposing aerosol cloud radiative effects into cloud cover, liquid water path and Twomey components in marine stratocumulus, Atmos. Res., 138, 378–393, 2014. a
Goren, T., Kazil, J., Hoffmann, F., Yamaguchi, T., and Feingold, G.: Anthropogenic air pollution delays marine stratocumulus breakup to open cells, Geophys. Res. Lett., 46, 14135–14144, 2019. a
Goren, T., Feingold, G., Gryspeerdt, E., Kazil, J., Kretzschmar, J., Jia, H., and Quaas, J.: Projecting stratocumulus transitions on the albedo–cloud fraction relationship reveals linearity of albedo to droplet concentrations, Geophys. Res. Lett., 49, e2022GL101169, https://doi.org/10.1029/2022GL101169, 2022. a, b, c, d
Hartmann, D. L. and Short, D. A.: On the use of earth radiation budget statistics for studies of clouds and climate, J. Atmos. Sci., 37, 1233–1250, 1980. a
Haywood, J. M., Jones, A., Jones, A. C., and Rasch, P. J.: Climate Intervention using marine cloud brightening (MCB) compared with stratospheric aerosol injection (SAI) in the UKESM1 climate model, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-1611, 2023. a
Hoffmann, F. and Feingold, G.: Cloud microphysical implications for marine cloud brightening: The importance of the seeded particle size distribution, J. Atmos. Sci., 78, 3247–3262, 2021. a
Hoffmann, F. and Feingold, G.: A Note on Aerosol Processing by Droplet Collision-Coalescence, Geophys. Res. Lett., 50, e2023GL103716, https://doi.org/10.1029/2023GL103716, 2023. a
Jenkins, A. K. L., Forster, P. M., and Jackson, L. S.: The effects of timing and rate of marine cloud brightening aerosol injection on albedo changes during the diurnal cycle of marine stratocumulus clouds, Atmos. Chem. Phys., 13, 1659–1673, https://doi.org/10.5194/acp-13-1659-2013, 2013. a, b
Kazil, J., Wang, H., Feingold, G., Clarke, A. D., Snider, J. R., and Bandy, A. R.: Modeling chemical and aerosol processes in the transition from closed to open cells during VOCALS-REx, Atmos. Chem. Phys., 11, 7491–7514, https://doi.org/10.5194/acp-11-7491-2011, 2011. a
Kessler, E.: On the distribution and continuity of water substance in atmospheric circulations, in: On the distribution and continuity of water substance in atmospheric circulations, Springer, 1–84, https://doi.org/10.1007/978-1-935704-36-2_1, 1969. a
Khairoutdinov, M.: SAM, Harvard repository [code], https://wiki.harvard.edu/confluence/display/climatemodeling/SAM, last access: 11 February 2024. a
Khairoutdinov, M. and Kogan, Y.: A new cloud physics parameterization in a large-eddy simulation model of marine stratocumulus, Mon. Weather Rev., 128, 229–243, 2000. a
Klein, S. A. and Hartmann, D. L.: The seasonal cycle of low stratiform clouds, J. Climate, 6, 1587–1606, 1993. a
Latham, J. and Smith, M.: Effect on global warming of wind-dependent aerosol generation at the ocean surface, Nature, 347, 372–373, 1990. a
Mlawer, E. J., Taubman, S. J., Brown, P. D., Iacono, M. J., and Clough, S. A.: Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave, J. Geophys. Res.-Atmos., 102, 16663–16682, 1997. a
Paluch, I. and Lenschow, D.: Stratiform cloud formation in the marine boundary layer, J. Atmos. Sci., 48, 2141–2158, 1991. a
Possner, A., Wang, H., Wood, R., Caldeira, K., and Ackerman, T. P.: The efficacy of aerosol–cloud radiative perturbations from near-surface emissions in deep open-cell stratocumuli, Atmos. Chem. Phys., 18, 17475–17488, https://doi.org/10.5194/acp-18-17475-2018, 2018. a
Prabhakaran, P.: Index of/groups/csl9/datasets/data/cloud_phys/2023-Prabhakaran-etal, NOAA Chemical Sciences Laboratory (CSL) [data set], https://csl.noaa.gov/groups/csl9/datasets/data/cloud_phys/2023-Prabhakaran-etal/, last access: 21 July 2023. a
Rasch, P. J., Latham, J., and Chen, C.-C. J.: Geoengineering by cloud seeding: influence on sea ice and climate system, Environ. Res. Lett., 4, 045112, https://doi.org/10.1088/1748-9326/4/4/045112, 2009. a
Sandu, I., Brenguier, J.-L., Geoffroy, O., Thouron, O., and Masson, V.: Aerosol impacts on the diurnal cycle of marine stratocumulus, J. Atmos. Sci., 65, 2705–2718, 2008. a
Sandu, I., Stevens, B., and Pincus, R.: On the transitions in marine boundary layer cloudiness, Atmos. Chem. Phys., 10, 2377–2391, https://doi.org/10.5194/acp-10-2377-2010, 2010. a, b, c, d
Sarkar, M., Zuidema, P., Albrecht, B., Ghate, V., Jensen, J., Mohrmann, J., and Wood, R.: Observations pertaining to precipitation within the northeast Pacific stratocumulus-to-cumulus transition, Mon. Weather Rev., 148, 1251–1273, 2020. a
Stevens, B. and Feingold, G.: Untangling aerosol effects on clouds and precipitation in a buffered system, Nature, 461, 607–613, 2009. a
Stjern, C. W., Muri, H., Ahlm, L., Boucher, O., Cole, J. N. S., Ji, D., Jones, A., Haywood, J., Kravitz, B., Lenton, A., Moore, J. C., Niemeier, U., Phipps, S. J., Schmidt, H., Watanabe, S., and Kristjánsson, J. E.: Response to marine cloud brightening in a multi-model ensemble, Atmos. Chem. Phys., 18, 621–634, https://doi.org/10.5194/acp-18-621-2018, 2018. a
Turton, J. and Nicholls, S.: A study of the diurnal variation of stratocumulus using a multiple mixed layer model, Q. J. Roy. Meteor. Soc., 113, 969–1009, 1987. a
Twomey, S.: Pollution and the planetary albedo, Atmos. Environ., 8, 1251–1256, 1974. a
Twomey, S.: The influence of pollution on the shortwave albedo of clouds, J. Atmos. Sci., 34, 1149–1152, 1977. a
Wang, H., Rasch, P. J., and Feingold, G.: Manipulating marine stratocumulus cloud amount and albedo: a process-modelling study of aerosol-cloud-precipitation interactions in response to injection of cloud condensation nuclei, Atmos. Chem. Phys., 11, 4237–4249, https://doi.org/10.5194/acp-11-4237-2011, 2011. a, b, c
Watson-Parris, D., Sutherland, S., Christensen, M., Eastman, R., and Stier, P.: A large-scale analysis of pockets of open cells and their radiative impact, Geophys. Res. Lett., 48, e2020GL092213, https://doi.org/10.1029/2020GL092213, 2021. a
Westervelt, D. M., Horowitz, L. W., Naik, V., Golaz, J.-C., and Mauzerall, D. L.: Radiative forcing and climate response to projected 21st century aerosol decreases, Atmos. Chem. Phys., 15, 12681–12703, https://doi.org/10.5194/acp-15-12681-2015, 2015. a
Wood, R.: Stratocumulus clouds, Mon. Weather Rev., 140, 2373–2423, 2012. a
Wood, R.: Assessing the potential efficacy of marine cloud brightening for cooling Earth using a simple heuristic model, Atmos. Chem. Phys., 21, 14507–14533, https://doi.org/10.5194/acp-21-14507-2021, 2021. a, b
Zhou, X., Ackerman, A. S., Fridlind, A. M., Wood, R., and Kollias, P.: Impacts of solar-absorbing aerosol layers on the transition of stratocumulus to trade cumulus clouds, Atmos. Chem. Phys., 17, 12725–12742, https://doi.org/10.5194/acp-17-12725-2017, 2017. a, b
Short summary
In this study, we explore the impact of deliberate aerosol perturbation in the northeast Pacific region using large-eddy simulations. Our results show that cloud reflectivity is sensitive to the aerosol sprayer arrangement in the pristine system, whereas in the polluted system it is largely proportional to the total number of aerosol particles injected. These insights would aid in assessing the efficiency of various aerosol injection strategies for climate intervention applications.
In this study, we explore the impact of deliberate aerosol perturbation in the northeast Pacific...
Altmetrics
Final-revised paper
Preprint