Articles | Volume 26, issue 21
https://doi.org/10.5194/acp-26-15895-2026
© Author(s) 2026. 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-26-15895-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
11 Nov 2026
Research article |
| 11 Nov 2026
| 11 Nov 2026
Sensitivity of marine cloud brightening over the Great Barrier Reef to spatial variability in aerosol forcing: a case study using a convection-permitting model
School of Geography, Earth and Atmospheric Science, The University of Melbourne, Melbourne, VIC, Australia
School of Geography, Earth and Atmospheric Science, The University of Melbourne, Melbourne, VIC, Australia
Australian Research Council (ARC) Centre of Excellence for 21st Century Weather, Melbourne, VIC, Australia
Steven Siems
Australian Research Council (ARC) Centre of Excellence for 21st Century Weather, Melbourne, VIC, Australia
School of Earth, Atmosphere and Environment, Monash University, Melbourne, VIC, Australia
Daniel Harrison
National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW, Australia
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This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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Daniel Robbins, Caroline Poulsen, Steven Siems, and Simon Proud
Atmos. Meas. Tech., 15, 3031–3051, https://doi.org/10.5194/amt-15-3031-2022, https://doi.org/10.5194/amt-15-3031-2022, 2022
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A neural network (NN)-based cloud mask for a geostationary satellite instrument, AHI, is developed using collocated data and is better at not classifying thick aerosols as clouds versus the Japanese Meteorological Association and the Bureau of Meteorology masks, identifying 1.13 and 1.29 times as many non-cloud pixels than each mask, respectively. The improvement during the day likely comes from including the shortest wavelength bands from AHI in the NN mask, which the other masks do not use.
Francisco Lang, Luis Ackermann, Yi Huang, Son C. H. Truong, Steven T. Siems, and Michael J. Manton
Atmos. Chem. Phys., 22, 2135–2152, https://doi.org/10.5194/acp-22-2135-2022, https://doi.org/10.5194/acp-22-2135-2022, 2022
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Marine low-level clouds cover vast areas of the Southern Ocean, and they are essential to the Earth system energy balance. We use 3 years of satellite observations to group low-level clouds by their spatial structure using a pattern-recognizing program. We studied two primary cloud type patterns, i.e. open and closed clouds. Open clouds are uniformly distributed over the storm track, while closed clouds are most predominant in the southeastern Indian Ocean. Closed clouds exhibit a daily cycle.
Cited articles
Ackerman, A. S., Kirkpatrick, M. P., Stevens, D. E., and Toon, O. B.: The impact of humidity above stratiform clouds on indirect aerosol climate forcing, Nature, 432, 1014–1017, 2004.
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.
Albrecht, B. A.: Aerosols, cloud microphysics, and fractional cloudiness, Science, 245, 1227–1230, https://doi.org/10.1126/science.245.4923.1227, 1989.
Arbizu-Barrena, C., Pozo-Vázquez, D., Ruiz-Arias, J. A., and Tovar-Pescador, J.: Macroscopic: cloud properties in the WRF NWP model: An assessment using sky camera and ceilometer data, J. Geophys. Res.-Atmos., 120, 10–297, 2015.
Australian Institute of Marine Science (AIMS): Coral Bleaching Events, https://www.aims.gov.au/research-topics/environmental-issues/coral-bleaching/coral-bleaching-events (last access: 2 February 2026), 2026.
Bao, S., Letu, H., Zhao, J., Lei, Y., Zhao, C., Li, J., Tana, G., Liu, C., Guo, E., Zhang, J., He, J., and Bao, Y.: Spatiotemporal distributions of cloud radiative forcing and response to cloud parameters over the Mongolian Plateau during 2003–2017, Int. J. Climatol., 40, 4082–4101, https://doi.org/10.1002/joc.6444, 2020.
Baresi, U., Baum, C. M., Fischer, T. B., Lockie, S., Piggott-McKellar, A., Graham, V., Bohensky, E., Fritz, L. B., Shumway, N., Harrison, D. P., Foster, R., Sovacool, B. K., Vella, K., and Ristovski, Z.: A call for strategic assessments of regional applications of solar radiation management: Exploring the challenges and opportunities from marine cloud brightening and albedo surface modification, Environ. Impact Assess., 110, 107701, https://doi.org/10.1016/j.eiar.2024.107701, 2025.
Bennartz, R.: Global assessment of marine boundary layer cloud droplet number concentration from satellite, J. Geophys. Res., 112, D02201, https://doi.org/10.1029/2006JD007547, 2007.
Bennartz, R. and Rausch, J.: Global and regional estimates of warm cloud droplet number concentration based on 13 years of AQUA-MODIS observations, Atmos. Chem. Phys., 17, 9815–9836, https://doi.org/10.5194/acp-17-9815-2017, 2017.
Braga, R. C., Rosenfeld, D., Hernandez, D., Medcraft, C., Efraim, A., Moser, M., Lucke J., Doss A., and Harrison, D.: Cloud processing dominates the vertical profiles of aerosols in marine air masses over the Great Barrier Reef, Atmos. Res., 315, 107928, https://doi.org/10.1016/j.atmosres.2025.107928, 2025.
Bretherton, C. S., 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.
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.
Bureau of Meteorology: Bureau of Meteorology Satellite Observations (Collection), NCI Australia [data set], https://doi.org/10.25914/61A609F9E7FFA, 2021.
Bureau of Meteorology: Bureau of Meteorology Satellite Derived Products (Collection), NCI Australia [data set], https://doi.org/10.25914/5QRS-QB54, 2022.
Chen, F. and Dudhia, J.: Coupling an advanced landsurface/hydrology model with the Penn State/NCAR MM5 modeling system. Part I: Model description and implementation, Mon. Weather Rev., 129, 569–585, https://doi.org/10.1175/1520-0493(2001)129<0569:CAALSH>2.0.CO;2, 2001.
Chen, Y., Haywood, J., Wang, Y., Malavelle, F., Jordan, G., Peace, A., Partridge, D. G., Cho, N., Oreopoulos, L., Grosvenor, D., Field, P., Allan, R. P., and Lohmann, U.: Substantial cooling effect from aerosol-induced increase in tropical marine cloud cover, Nat. Geosci., 17, 404–410, https://doi.org/10.1038/s41561-024-01427-z, 2024.
Colarco, P., da Silva, A., Chin, M., and Diehl, T.: Online simulations of global aerosol distributions in the NASA GEOS-4 model and comparisons to satellite and ground-based aerosol optical depth, J. Geophys. Res., 115, D14207, https://doi.org/10.1029/2009JD012820, 2010.
Condie, S. A., Anthony, K., Babcock, R. C., Baird, M. E., Beeden, R., Fletcher, C. S., Gorton, R., Harrison, D., Hobday, A. J., Plagányi, É. E., and Westcott, D. A.: Large-scale interventions may delay decline of the Great Barrier Reef, Royal Society Open Science, 8, 201296, https://doi.org/10.1098/rsos.201296, 2021.
Dagan, G., Koren, I., Altaratz, O., and Heiblum, R. H.: Aerosol effect on the evolution of the thermodynamic properties of warm convective cloud fields, Sci. Rep., 6, 38769, https://doi.org/10.1038/srep38769, 2016.
Feingold, G., Koren, I., Wang, H., Xue, H., and Brewer, W. A.: Precipitation-generated oscillations in open cellular cloud fields, Nature, 466, 849–852, 2010.
Feingold, G., Ghate, V. P., Russell, L. M., Blossey, P., Cantrell, W., Christensen, M. W., Diamond, M. S., Gettelman, A., Glassmeier, F., Gryspeerdt, E., Haywood, J., Hoffmann, F., Kaul, C. M., Lebsock, M., McComiskey, A. C., McCoy, D. T., Ming, Y., Mülmenstädt, J., Possner, A., Prabhakaran, P., Quinn, P. K., Schmidt, K. S., Shaw, R. A., Singer, C. E., Sorooshian, A., Toll, V., Wan, J. S., Wood, R., Yang, F., Zhang, J., and Zheng, X.: Physical science research needed to evaluate the viability and risks of marine cloud brightening, Sci. Adv., 10, eadi8594, https://doi.org/10.1126/sciadv.adi8594, 2024.
Gryspeerdt, E., Goren, T., Sourdeval, O., Quaas, J., Mülmenstädt, J., Dipu, S., Unglaub, C., Gettelman, A., and Christensen, M.: Constraining the aerosol influence on cloud liquid water path, Atmos. Chem. Phys., 19, 5331–5347, https://doi.org/10.5194/acp-19-5331-2019, 2019.
Harrison, D. P.: Could “marine cloud brightening” reduce coral bleaching on the Great Barrier Reef?, The Conversation, https://theconversation.com/could-marine-cloud-brightening-reduce-coral-bleaching-on-the-great-barrier-reef-214308 (last access: 10 November 2026), 2023.
Harrison, D. P.: An overview of environmental engineering methods for reducing coral bleaching stress, Oceanographic Processes of Coral Reefs, 403–418, 2024.
Harrison, D. P., Harrison, L., Baird, M., Utembe, S., Schofield, R., Escobar Correa, R., Mongin, M., and Rizwi, F.: T14: Environmental Modelling of Large Scale Solar Radiation Management. A report provided to the Australian Government from the Reef Restoration and Adaptation Program, RRAP, https://gbrrestoration.org/resources/reports/ (last access: 4 November 2026), 2019.
Harrison, L. P., Medcraft, C., and Harrison, D.: Effervescent nozzle design to enable outdoor marine cloud brightening experimentation, Environ. Sci.: Atmospheres, 5, 1071–1080, https://doi.org/10.1039/D5EA00073D, 2025.
Heidinger, A. K. and Straka, W.: NOAA Enterprise Cloud Mask: Algorithm Theoretical Basis Document, Version 1.2, NOAA/NESDIS Center for Satellite Applications and Research, https://www.star.nesdis.noaa.gov/goesr/documents/ATBDs/Enterprise/ATBD_Enterprise_Cloud_Mask_v1.2_2020_10_01.pdf (last access: 10 November 2026), 2020.
Hernandez-Jaramillo, D. C., Medcraft, C., Braga, R. C., Butcherine, P., Doss, A., Kelaher, B., Rosenfeld, D., and Harrison, D. P.: New airborne research facility observes sensitivity of cumulus cloud microphysical properties to aerosol regime over the great barrier reef, Environ. Sci.: Atmospheres, 4, 861–871, 2024.
Hernandez-Jaramillo, D. C., Harrison, L., Gunner, G., McGrath, A., Junkermann, W., Lieff, W., Hacker, J., Rosenfeld, D., Kelaher, B., and Harrison, D. P.: First generation outdoor marine cloud brightening trial increases aerosol concentration at cloud base height, Environ. Res. Lett., 20, 054065, https://doi.org/10.1088/1748-9326/adccd7, 2025.
Hersbach, H., de Rosnay, P., Bell, B., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Alonso-Balmaseda, M., Balsamo, G., Bechtold, P., and Berrisfold, P.: Operational global reanalysis: Progress, future directions and synergies with NWP, ECMWF ERA Report Series, 27, 65, https://doi.org/10.21957/tkic6g3wm, 2018.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., and Simmons, A.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020.
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J.-N.: ERA5 hourly data on pressure levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.bd0915c6 (last access: 4 November 2026), 2023.
Hong, S.-Y., Noh, Y., and Dudhia, J.: A new vertical diffusion package with an explicit treatment of entrainment processes, Mon. Weather Rev., 134, 2318–2341, https://doi.org/10.1175/MWR3199.1, 2006.
Huang, Y., Siems, S. T., Manton, M. J., Rosenfeld, D., Marchand, R., McFarquhar, G. M., and Protat, A.: What is the Role of Sea Surface Temperature in Modulating Cloud and Precipitation Properties over the Southern Ocean?, J. Climate, 29, 7453–7476, https://doi.org/10.1175/JCLI-D-15-0768.1, 2016.
Hughes, T. P., Kerry, J. T., Álvarez-Noriega, M., Álvarez-Romero, J. G., Anderson, K. D., Baird, A. H., Babcock, R. C., Beger, M., Bellwood, D. R., Berkelmans, R., Bridge, T. C., Butler, I. R., Byrne, M., Cantin, N. E., Comeau, S., Connolly, S. R., Cumming, G. S., Dalton, S. J., Diaz-Pulido, G., Eakin, C. M., Figueira, W. F., Gilmour, J. P., Harrison, H. B., Heron, S. F., Hoey, A. S., Hobbs, J.-P. A., Hoogenboom, M. O., Kennedy, E. V., Kuo, C.-Y., Lough, J. M., Lowe, R. J., Liu, G., McCulloch, M. T., Malcolm, H. A., McWilliam, M. J., Pandolfi, J. M., Pears, R. J., Pratchett, M. S., Schoepf, V., Simpson, T., Skirving, W. J., Sommer, B., Torda, G., Wachenfeld, D. R., Willis, B. L., and Wilson, S. K.: Global warming and recurrent mass bleaching of corals, Nature, 543, 373–377, https://doi.org/10.1038/nature21707, 2017.
Janjić, Z. I.: Comments on “Development and evaluation of a convection scheme for use in climate models”, J. Atmos. Sci., 57, 3686–3686, https://doi.org/10.1175/1520-0469(2000)057<3686:CODAEO>2.0.CO;2, 2000,
Latham, J.: Control of global warming, Nature, 347, 339–340, https://doi.org/10.1038/347339b0, 1990.
Latham, J.: Amelioration of global warming by controlled enhancement of the albedo and longevity of low-level maritime clouds, Atmos. Sci. Lett., 3, 52–58, 2002.
Latham, J., Rasch, P., Chen, C.-C., Kettles, L., Gadian, A., Gettelman, A., Morrison, H., Bower, K., and Choularton, T.: Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds, Philos. T. R. Soc. A, 366, 3969–3987, https://doi.org/10.1098/rsta.2008.0137, 2008.
Latham, J., Kleypas, J., Hauser, R., Parkes, B., and Gadian, A.: Can marine cloud brightening reduce coral bleaching?, Atmos. Sci. Lett., 14, 214–219, 2013.
Mauger, G. S. and Norris, J. R.: Assessing the impact of meteorological history on subtropical cloud fraction, J. Climate, 23, 2926–2940, 2010.
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, https://doi.org/10.1029/97JD00237, 1997.
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.
Richards, L. S., Siems, S. T., Huang, Y., Zhao, W., Harrison, D. P., Manton, M. J., and Reeder, M. J.: The meteorological drivers of mass coral bleaching on the central Great Barrier Reef during the 2022 La Niña, Sci. Rep., 14, 1–17, 2024.
Rosenfeld, D., Zhu, Y., Wang, M., Zheng, Y., Goren, T., and Yu, S.: Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds, Science, 363, eaav0566, https://doi.org/10.1126/science.aav0566, 2019.
Saffin, L., Lock, A., Tomassini, L., Blyth, A., Böing, S., Denby, L., and Marsham, J.: Kilometer-scale simulations of trade-wind cumulus capture processes of mesoscale organization, J. Adv. Model. Earth Sy., 15, e2022MS003295, https://doi.org/10.1029/2022MS003295, 2023.
Seifert, A. and Heus, T.: Large-eddy simulation of organized precipitating trade wind cumulus clouds, Atmos. Chem. Phys., 13, 5631–5645, https://doi.org/10.5194/acp-13-5631-2013, 2013.
Seifert, A., Heus, T., Pincus, R., and Stevens, B.: Large-eddy simulation of the transient and near-equilibrium behavior of precipitating shallow convection, J. Adv. Model. Earth Sy., 7, 1918–1937, 2015.
Stevens, B. and Feingold, G.: Untangling aerosol effects on clouds and precipitation in a buffered system, Nature, 461, 607–613, 2009.
Thompson, G. and Eidhammer, T.: A study of aerosol impacts on clouds and precipitation development in a large winter cyclone, J. Atmos. Sci., 71, 3636–3658, https://doi.org/10.1175/JAS-D-13-0305.1, 2014.
Tollefson, J.: Can artificially altered clouds save the Great Barrier Reef?, Nature, 596, 476–478, https://doi.org/10.1038/d41586-021-02290-3, 2021.
Twomey, S.: The influence of pollution on the shortwave albedo of clouds, J. Atmos. Sci., 34, 1149–1152, 1977.
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.
Wang, X., Zhang, L., and Moran, M. D.: Uncertainty assessment of current size-resolved parameterizations for below-cloud particle scavenging by rain, Atmos. Chem. Phys., 10, 5685–5705, https://doi.org/10.5194/acp-10-5685-2010, 2010.
Weston, M. J., Piketh, S. J., Burnet, F., Broccardo, S., Denjean, C., Bourrianne, T., and Formenti, P.: Sensitivity analysis of an aerosol-aware microphysics scheme in Weather Research and Forecasting (WRF) during case studies of fog in Namibia, Atmos. Chem. Phys., 22, 10221–10245, https://doi.org/10.5194/acp-22-10221-2022, 2022.
Wood, R.: Stratocumulus clouds, Mon. Weather Rev., 140, 2373–2423, 2012.
Wood, R. and Ackerman, T. P.: Defining success and limits of field experiments to test geoengineering by marine cloud brightening, Clim. Change, 121, 459–472, 2013.
Wood, R. and Bretherton, C. S.: On the relationship between stratiform low cloud cover and lower-tropospheric stability, J. Climate, 19, 6425–6432, 2006.
Zhang, Y., Stevens, B., and Ghil, M.: On the diurnal cycle and susceptibility to aerosol concentration in a stratocumulus-topped mixed layer, Q. J. Roy. Meteor. Soc., 131, 1567–1583, 2005.
Zhao, W., Huang, Y., Siems, S., and Manton, M.: The role of clouds in coral bleaching events over the Great Barrier Reef, Geophys. Res. Lett., 48, e2021GL093936, https://doi.org/10.1029/2021GL093936, 2021.
Zhao, W., Huang, Y., Siems, S., Manton, M., and Harrison, D.: Interactions between trade wind clouds and local forcings over the Great Barrier Reef: a case study using convection-permitting simulations, Atmos. Chem. Phys., 24, 5713–5736, https://doi.org/10.5194/acp-24-5713-2024, 2024.
Zhao, W., Huang, Y., Siems, S. T., and Harrison D.: WRF outputs of CTRL simulation, University of Melbourne [data set], https://doi.org/10.26188/30071935, 2026a.
Zhao, W., Huang, Y., Siems, S. T., and Harrison D.: WRF outputs of EXP20 simulation, University of Melbourne [data set], https://doi.org/10.26188/32592879, 2026b.
Zhao, W., Huang, Y., Siems, S. T., and Harrison D.: WRF outputs of EXP40 simulation, University of Melbourne [data set], https://doi.org/10.26188/32593914, 2026c.
Zhao, W., Huang, Y., Siems, S. T., and Harrison D.: WRF outputs of EXP100 simulation, University of Melbourne [data set], https://doi.org/10.26188/32593482, 2026d.
Short summary
Using convection-permitting Weather Research and Forecasting (WRF) simulations, this study examines how marine cloud brightening over the Great Barrier Reef (GBR) depends on aerosol emission strength and spatial distribution. Densely spaced sources generate more uniform aerosol enhancements and stronger cloud microphysical responses than sparsely distributed sources, despite identical emissions. Cloud droplet number concentration (CDNC) and optical depth increase strongly, indicating a dominant Twomey effect, while cloud water and coverage respond weakly.
Using convection-permitting Weather Research and Forecasting (WRF) simulations, this study...
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