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1. The evolution of warm rain in trade-wind cumulus during EUREC4A.

Author

Lloyd, Gary, Blyth, Alan, Cui, Zhiqiang, Choularton, Thomas, Bower, Keith, Gallagher, Martin, Flynn, Michael, Marsden, Nicholas, Denby, Leif, and Gallimore, Peter

Subjects
BIOMASS burning, CONVECTIVE clouds, PRECIPITATION scavenging, AEROSOLS, MICROPHYSICS, ATMOSPHERIC methane
Abstract

In this paper measurements are presented of the observed properties of aerosols and microphysics of clouds associated with the characteristics of precipitation in convective clouds that formed off the east coast of Barbados during EUREC4A. Most data were gathered by the instrumented British Antarctic Survey Twin Otter aircraft supported by detailed in-situ aerosol measurements at the Ragged Point observatory on Barbados as well as HALO and PoldiRad radars, dropsonde and satellite data. The development of precipitation was studied in the three aerosol regimes previously reported, i.e. one low aerosol regime and two containing desert dust that had been advected across the Atlantic Ocean. The later dust event also contained evidence of biomass burning aerosol. Results showed that the maximum intensity of rain was similar for all the aerosol regimes. Clouds that developed in an environment with high aerosol loading tended to be deeper than those that developed in the clean environment. It was also found that the greatest intensities occurred in clouds that had aggregated, in agreement with previous work. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Deep Convective Microphysics Experiment (DCMEX) coordinated aircraft and ground observations: microphysics, aerosol, and dynamics during cumulonimbus development.

Author

Finney, Declan L., Blyth, Alan M., Gallagher, Martin, Wu, Huihui, Nott, Graeme J., Biggerstaff, Michael I., Sonnenfeld, Richard G., Daily, Martin, Walker, Dan, Dufton, David, Bower, Keith, Böing, Steven, Choularton, Thomas, Crosier, Jonathan, Groves, James, Field, Paul R., Coe, Hugh, Murray, Benjamin J., Lloyd, Gary, and Marsden, Nicholas A.

Subjects
MICROPHYSICS, WIND shear, CONVECTIVE clouds, ATMOSPHERIC models, AIR masses, CUMULONIMBUS
Abstract

Cloud feedbacks associated with deep convective anvils remain highly uncertain. In part, this uncertainty arises from a lack of understanding of how microphysical processes influence the cloud radiative effect. In particular, climate models have a poor representation of microphysics processes, thereby encouraging the collection and study of observation data to enable better representation of these processes in models. As such, the Deep Convective Microphysics Experiment (DCMEX) undertook an in situ aircraft and ground-based measurement campaign of New Mexico deep convective clouds during July–August 2022. The campaign coordinated a broad range of instrumentation measuring aerosol, cloud physics, radar, thermodynamics, dynamics, electric fields, and weather. This paper introduces the potential data user to DCMEX observational campaign characteristics, relevant instrument details, and references to more detailed instrument descriptions. Also included is information on the structure and important files in the dataset in order to aid the accessibility of the dataset to new users. Our overview of the campaign cases illustrates the complementary operational observations available and demonstrates the breadth of the campaign cases observed. During the campaign, a wide selection of environmental conditions occurred, ranging from dry, northerly air masses with low wind shear to moist, southerly air masses with high wind shear. This provided a wide range of different convective growth situations. Of 19 flight days, only 2 d lacked the formation of convective cloud. The dataset presented (10.5285/B1211AD185E24B488D41DD98F957506C;) will help establish a new understanding of processes on the smallest cloud- and aerosol-particle scales and, once combined with operational satellite observations and modelling, can support efforts to reduce the uncertainty of anvil cloud radiative impacts on climate scales. [ABSTRACT FROM AUTHOR]

Published
2024
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3. Supplementary material to "DCMEX coordinated aircraft and ground observations: Microphysics, aerosol and dynamics during cumulonimbus development"

Author

Finney, Declan L., primary, Blyth, Alan M., additional, Gallagher, Martin, additional, Wu, Huihui, additional, Nott, Graeme, additional, Biggerstaff, Mike, additional, Sonnenfeld, Richard G., additional, Daily, Martin, additional, Walker, Dan, additional, Dufton, David, additional, Bower, Keith, additional, Boeing, Steven, additional, Choularton, Thomas, additional, Crosier, Jonathan, additional, Groves, James, additional, Field, Paul R., additional, Coe, Hugh, additional, Murray, Benjamin J., additional, Lloyd, Gary, additional, Marsden, Nicholas A., additional, Flynn, Michael, additional, Hu, Kezhen, additional, Thamban, Naveneeth M., additional, Williams, Paul I., additional, McQuaid, James B., additional, Robinson, Joseph, additional, Carrie, Gordon, additional, Moore, Robert, additional, Aulich, Graydon, additional, Burton, Ralph R., additional, and Connolly, Paul J., additional

Published
2023
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4. DCMEX coordinated aircraft and ground observations: Microphysics, aerosol and dynamics during cumulonimbus development

Author

Finney, Declan L., primary, Blyth, Alan M., additional, Gallagher, Martin, additional, Wu, Huihui, additional, Nott, Graeme, additional, Biggerstaff, Mike, additional, Sonnenfeld, Richard G., additional, Daily, Martin, additional, Walker, Dan, additional, Dufton, David, additional, Bower, Keith, additional, Boeing, Steven, additional, Choularton, Thomas, additional, Crosier, Jonathan, additional, Groves, James, additional, Field, Paul R., additional, Coe, Hugh, additional, Murray, Benjamin J., additional, Lloyd, Gary, additional, Marsden, Nicholas A., additional, Flynn, Michael, additional, Hu, Kezhen, additional, Thamban, Naveneeth M., additional, Williams, Paul I., additional, McQuaid, James B., additional, Robinson, Joseph, additional, Carrie, Gordon, additional, Moore, Robert, additional, Aulich, Graydon, additional, Burton, Ralph R., additional, and Connolly, Paul J., additional

Published
2023
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7. Understanding the aerosol-cloud interactions in ship-dominated and cleaner environments in the Celtic Sea.

Author

Thamban, Navaneeth Meena, primary, Wu, Huihui, additional, Choularton, Thomas, additional, Coe, Hugh, additional, Bower, Keith, additional, Matthews, Emily, additional, Bannan, Thomas, additional, Marsden, Nicholas, additional, Lee, James, additional, Pasternak, Dominika, additional, Yang, Ming-Xi, additional, Batten, Stephanie, additional, Bell, Thomas, additional, Temple, Loren, additional, and Bauguitte, Stéphane, additional

Published
2023
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8. EUREC 4 A

Author

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Stevens, Bjorn, Bony, Sandrine, Farrell, David, Ament, Felix, Blyth, Alan, Fairall, Christopher, Karstensen, Johannes, Quinn, Patricia K., Speich, Sabrina, Acquistapace, Claudia, Aemisegger, Franziska, Albright, Anna Lea, Bellenger, Hugo, Bodenschatz, Eberhard, Caesar, Kathy-Ann, Chewitt-Lucas, Rebecca, de Boer, Gijs, Delanoë, Julien, Denby, Leif, Ewald, Florian, Fildier, Benjamin, Forde, Marvin, George, Geet, Gross, Silke, Hagen, Martin, Hausold, Andrea, Heywood, Karen J., Hirsch, Lutz, Jacob, Marek, Jansen, Friedhelm, Kinne, Stefan, Klocke, Daniel, Kölling, Tobias, Konow, Heike, Lothon, Marie, Mohr, Wiebke, Naumann, Ann Kristin, Nuijens, Louise, Olivier, Léa, Pincus, Robert, Pöhlker, Mira, Reverdin, Gilles, Roberts, Gregory, Schnitt, Sabrina, Schulz, Hauke, Siebesma, A. Pier, Stephan, Claudia Christine, Sullivan, Peter, Touzé-Peiffer, Ludovic, Vial, Jessica, Vogel, Raphaela, Zuidema, Paquita, Alexander, Nicola, Alves, Lyndon, Arixi, Sophian, Asmath, Hamish, Bagheri, Gholamhossein, Baier, Katharina, Bailey, Adriana, Baranowski, Dariusz, Baron, Alexandre, Barrau, Sébastien, Barrett, Paul A., Batier, Frédéric, Behrendt, Andreas, Bendinger, Arne, Beucher, Florent, Bigorre, Sebastien, Blades, Edmund, Blossey, Peter, Bock, Olivier, Böing, Steven, Bosser, Pierre, Bourras, Denis, Bouruet-Aubertot, Pascale, Bower, Keith, Branellec, Pierre, Branger, Hubert, Brennek, Michal, Brewer, Alan, Brilouet, Pierre-Etienne, Brügmann, Björn, Buehler, Stefan A., Burke, Elmo, Burton, Ralph, Calmer, Radiance, Canonici, Jean-Christophe, Carton, Xavier, Cato Jr., Gregory, Charles, Jude Andre, Chazette, Patrick, Chen, Yanxu, Chilinski, Michal T., Choularton, Thomas, Chuang, Patrick, Clarke, Shamal, Coe, Hugh, Cornet, Céline, Coutris, Pierre, Couvreux, Fleur, Crewell, Susanne, Cronin, Timothy, Cui, Zhiqiang, Cuypers, Yannis, Daley, Alton, Damerell, Gillian M., Dauhut, Thibaut, Deneke, Hartwig, Desbios, Jean-Philippe, Dörner, Steffen, Donner, Sebastian, Douet, Vincent, Drushka, Kyla, Dütsch, Marina, Ehrlich, André, Emanuel, Kerry, Emmanouilidis, Alexandros, Etienne, Jean-Claude, Etienne-Leblanc, Sheryl, Faure, Ghislain, Feingold, Graham, Ferrero, Luca, Fix, Andreas, Flamant, Cyrille, Flatau, Piotr Jacek, Foltz, Gregory R., Forster, Linda, Furtuna, Iulian, Gadian, Alan, Galewsky, Joseph, Gallagher, Martin, Gallimore, Peter, Gaston, Cassandra, Gentemann, Chelle, Geyskens, Nicolas, Giez, Andreas, Gollop, John, Gouirand, Isabelle, Gourbeyre, Christophe, de Graaf, Dörte, de Groot, Geiske E., Grosz, Robert, Güttler, Johannes, Gutleben, Manuel, Hall, Kashawn, Harris, George, Helfer, Kevin C., Henze, Dean, Herbert, Calvert, Holanda, Bruna, Ibanez-Landeta, Antonio, Intrieri, Janet, Iyer, Suneil, Julien, Fabrice, Kalesse, Heike, Kazil, Jan, Kellman, Alexander, Kidane, Abiel T., Kirchner, Ulrike, Klingebiel, Marcus, Körner, Mareike, Kremper, Leslie Ann, Kretzschmar, Jan, Krüger, Ovid, Kumala, Wojciech, Kurz, Armin, L'Hégaret, Pierre, Labaste, Matthieu, Lachlan-Cope, Tom, Laing, Arlene, Landschützer, Peter, Lang, Theresa, Lange, Diego, Lange, Ingo, Laplace, Clément, Lavik, Gauke, Laxenaire, Rémi, Le Bihan, Caroline, Leandro, Mason, Lefevre, Nathalie, Lena, Marius, Lenschow, Donald, Li, Qiang, Lloyd, Gary, Los, Sebastian, Losi, Niccolò, Lovell, Oscar, Luneau, Christopher, Makuch, Przemyslaw, Malinowski, Szymon, Manta, Gaston, Marinou, Eleni, Marsden, Nicholas, Masson, Sebastien, Maury, Nicolas, Mayer, Bernhard, Mayers-Als, Margarette, Mazel, Christophe, McGeary, Wayne, McWilliams, James C., Mech, Mario, Mehlmann, Melina, Meroni, Agostino Niyonkuru, Mieslinger, Theresa, Minikin, Andreas, Minnett, Peter, Möller, Gregor, Morfa Avalos, Yanmichel, Muller, Caroline, Musat, Ionela, Napoli, Anna, Neuberger, Almuth, Noisel, Christophe, Noone, David, Nordsiek, Freja, Nowak, Jakub L., Oswald, Lothar, Parker, Douglas J., Peck, Carolyn, Person, Renaud, Philippi, Miriam, Plueddemann, Albert, Pöhlker, Christopher, Pörtge, Veronika, Pöschl, Ulrich, Pologne, Lawrence, Posyniak, Michał, Prange, Marc, Quiñones Meléndez, Estefanía, Radtke, Jule, Ramage, Karim, Reimann, Jens, Renault, Lionel, Reus, Klaus, Reyes, Ashford, Ribbe, Joachim, Ringel, Maximilian, Ritschel, Markus, Rocha, Cesar B., Rochetin, Nicolas, Röttenbacher, Johannes, Rollo, Callum, Royer, Haley, Sadoulet, Pauline, Saffin, Leo, Sandiford, Sanola, Sandu, Irina, Schäfer, Michael, Schemann, Vera, Schirmacher, Imke, Schlenczek, Oliver, Schmidt, Jerome, Schröder, Marcel, Schwarzenboeck, Alfons, Sealy, Andrea, Senff, Christoph J., Serikov, Ilya, Shohan, Samkeyat, Siddle, Elizabeth, Smirnov, Alexander, Späth, Florian, Spooner, Branden, Stolla, M. Katharina, Szkółka, Wojciech, de Szoeke, Simon P., Tarot, Stéphane, Tetoni, Eleni, Thompson, Elizabeth, Thomson, Jim, Tomassini, Lorenzo, Totems, Julien, Ubele, Alma Anna, Villiger, Leonie, von Arx, Jan, Wagner, Thomas, Walther, Andi, Webber, Ben, Wendisch, Manfred, Whitehall, Shanice, Wiltshire, Anton, Wing, Allison A., Wirth, Martin, Wiskandt, Jonathan, Wolf, Kevin, Worbes, Ludwig, Wright, Ethan, Wulfmeyer, Volker, Young, Shanea, Zhang, Chidong, Zhang, Dongxiao, Ziemen, Florian, Zinner, Tobias, Zöger, Martin, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Stevens, Bjorn, Bony, Sandrine, Farrell, David, Ament, Felix, Blyth, Alan, Fairall, Christopher, Karstensen, Johannes, Quinn, Patricia K., Speich, Sabrina, Acquistapace, Claudia, Aemisegger, Franziska, Albright, Anna Lea, Bellenger, Hugo, Bodenschatz, Eberhard, Caesar, Kathy-Ann, Chewitt-Lucas, Rebecca, de Boer, Gijs, Delanoë, Julien, Denby, Leif, Ewald, Florian, Fildier, Benjamin, Forde, Marvin, George, Geet, Gross, Silke, Hagen, Martin, Hausold, Andrea, Heywood, Karen J., Hirsch, Lutz, Jacob, Marek, Jansen, Friedhelm, Kinne, Stefan, Klocke, Daniel, Kölling, Tobias, Konow, Heike, Lothon, Marie, Mohr, Wiebke, Naumann, Ann Kristin, Nuijens, Louise, Olivier, Léa, Pincus, Robert, Pöhlker, Mira, Reverdin, Gilles, Roberts, Gregory, Schnitt, Sabrina, Schulz, Hauke, Siebesma, A. Pier, Stephan, Claudia Christine, Sullivan, Peter, Touzé-Peiffer, Ludovic, Vial, Jessica, Vogel, Raphaela, Zuidema, Paquita, Alexander, Nicola, Alves, Lyndon, Arixi, Sophian, Asmath, Hamish, Bagheri, Gholamhossein, Baier, Katharina, Bailey, Adriana, Baranowski, Dariusz, Baron, Alexandre, Barrau, Sébastien, Barrett, Paul A., Batier, Frédéric, Behrendt, Andreas, Bendinger, Arne, Beucher, Florent, Bigorre, Sebastien, Blades, Edmund, Blossey, Peter, Bock, Olivier, Böing, Steven, Bosser, Pierre, Bourras, Denis, Bouruet-Aubertot, Pascale, Bower, Keith, Branellec, Pierre, Branger, Hubert, Brennek, Michal, Brewer, Alan, Brilouet, Pierre-Etienne, Brügmann, Björn, Buehler, Stefan A., Burke, Elmo, Burton, Ralph, Calmer, Radiance, Canonici, Jean-Christophe, Carton, Xavier, Cato Jr., Gregory, Charles, Jude Andre, Chazette, Patrick, Chen, Yanxu, Chilinski, Michal T., Choularton, Thomas, Chuang, Patrick, Clarke, Shamal, Coe, Hugh, Cornet, Céline, Coutris, Pierre, Couvreux, Fleur, Crewell, Susanne, Cronin, Timothy, Cui, Zhiqiang, Cuypers, Yannis, Daley, Alton, Damerell, Gillian M., Dauhut, Thibaut, Deneke, Hartwig, Desbios, Jean-Philippe, Dörner, Steffen, Donner, Sebastian, Douet, Vincent, Drushka, Kyla, Dütsch, Marina, Ehrlich, André, Emanuel, Kerry, Emmanouilidis, Alexandros, Etienne, Jean-Claude, Etienne-Leblanc, Sheryl, Faure, Ghislain, Feingold, Graham, Ferrero, Luca, Fix, Andreas, Flamant, Cyrille, Flatau, Piotr Jacek, Foltz, Gregory R., Forster, Linda, Furtuna, Iulian, Gadian, Alan, Galewsky, Joseph, Gallagher, Martin, Gallimore, Peter, Gaston, Cassandra, Gentemann, Chelle, Geyskens, Nicolas, Giez, Andreas, Gollop, John, Gouirand, Isabelle, Gourbeyre, Christophe, de Graaf, Dörte, de Groot, Geiske E., Grosz, Robert, Güttler, Johannes, Gutleben, Manuel, Hall, Kashawn, Harris, George, Helfer, Kevin C., Henze, Dean, Herbert, Calvert, Holanda, Bruna, Ibanez-Landeta, Antonio, Intrieri, Janet, Iyer, Suneil, Julien, Fabrice, Kalesse, Heike, Kazil, Jan, Kellman, Alexander, Kidane, Abiel T., Kirchner, Ulrike, Klingebiel, Marcus, Körner, Mareike, Kremper, Leslie Ann, Kretzschmar, Jan, Krüger, Ovid, Kumala, Wojciech, Kurz, Armin, L'Hégaret, Pierre, Labaste, Matthieu, Lachlan-Cope, Tom, Laing, Arlene, Landschützer, Peter, Lang, Theresa, Lange, Diego, Lange, Ingo, Laplace, Clément, Lavik, Gauke, Laxenaire, Rémi, Le Bihan, Caroline, Leandro, Mason, Lefevre, Nathalie, Lena, Marius, Lenschow, Donald, Li, Qiang, Lloyd, Gary, Los, Sebastian, Losi, Niccolò, Lovell, Oscar, Luneau, Christopher, Makuch, Przemyslaw, Malinowski, Szymon, Manta, Gaston, Marinou, Eleni, Marsden, Nicholas, Masson, Sebastien, Maury, Nicolas, Mayer, Bernhard, Mayers-Als, Margarette, Mazel, Christophe, McGeary, Wayne, McWilliams, James C., Mech, Mario, Mehlmann, Melina, Meroni, Agostino Niyonkuru, Mieslinger, Theresa, Minikin, Andreas, Minnett, Peter, Möller, Gregor, Morfa Avalos, Yanmichel, Muller, Caroline, Musat, Ionela, Napoli, Anna, Neuberger, Almuth, Noisel, Christophe, Noone, David, Nordsiek, Freja, Nowak, Jakub L., Oswald, Lothar, Parker, Douglas J., Peck, Carolyn, Person, Renaud, Philippi, Miriam, Plueddemann, Albert, Pöhlker, Christopher, Pörtge, Veronika, Pöschl, Ulrich, Pologne, Lawrence, Posyniak, Michał, Prange, Marc, Quiñones Meléndez, Estefanía, Radtke, Jule, Ramage, Karim, Reimann, Jens, Renault, Lionel, Reus, Klaus, Reyes, Ashford, Ribbe, Joachim, Ringel, Maximilian, Ritschel, Markus, Rocha, Cesar B., Rochetin, Nicolas, Röttenbacher, Johannes, Rollo, Callum, Royer, Haley, Sadoulet, Pauline, Saffin, Leo, Sandiford, Sanola, Sandu, Irina, Schäfer, Michael, Schemann, Vera, Schirmacher, Imke, Schlenczek, Oliver, Schmidt, Jerome, Schröder, Marcel, Schwarzenboeck, Alfons, Sealy, Andrea, Senff, Christoph J., Serikov, Ilya, Shohan, Samkeyat, Siddle, Elizabeth, Smirnov, Alexander, Späth, Florian, Spooner, Branden, Stolla, M. Katharina, Szkółka, Wojciech, de Szoeke, Simon P., Tarot, Stéphane, Tetoni, Eleni, Thompson, Elizabeth, Thomson, Jim, Tomassini, Lorenzo, Totems, Julien, Ubele, Alma Anna, Villiger, Leonie, von Arx, Jan, Wagner, Thomas, Walther, Andi, Webber, Ben, Wendisch, Manfred, Whitehall, Shanice, Wiltshire, Anton, Wing, Allison A., Wirth, Martin, Wiskandt, Jonathan, Wolf, Kevin, Worbes, Ludwig, Wright, Ethan, Wulfmeyer, Volker, Young, Shanea, Zhang, Chidong, Zhang, Dongxiao, Ziemen, Florian, Zinner, Tobias, and Zöger, Martin

Abstract

Abstract. The science guiding the EUREC4A campaign and its measurements is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC4A marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200 km) and larger (500 km) scales, roughly 400 h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10 000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC4A explored – from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation – are presented along with an overview of EUREC4A's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement.

Published
2023

9. SUPPLEMENT : THE CONVECTIVE PRECIPITATION EXPERIMENT (COPE) Investigating the Origins of Heavy Precipitation in the Southwestern United Kingdom

Author

Leon, David C., French, Jeffrey R., Lasher-Trapp, Sonia, Blyth, Alan M., Abel, Steven J., Ballard, Susan, Bennett, Lindsay J., Bower, Keith, Brooks, Barbara, Brown, Phil, Choularton, Thomas, Clark, Peter, Collier, Chris, Crosier, Jonathan, Cui, Zhiqiang, Dufton, David, Eagle, Chloe, Flynn, Michael J., Gallagher, Martin, Hanley, Kirsty, Huang, Yahui, Kitchen, Malcolm, Korolev, Alexei, Lean, Humphrey, Liu, Zixia, Marsham, John, Moser, Daniel, Nicol, John, Norton, Emily G., Plummer, David, Price, Jeremy, Ricketts, Hugo, Roberts, Nigel, Taylor, Jonathan W., and Williams, Paul I.

Published
2016

10. THE CONVECTIVE PRECIPITATION EXPERIMENT (COPE) : Investigating the Origins of Heavy Precipitation in the Southwestern United Kingdom

Author

Leon, David C., French, Jeffrey R., Lasher-Trapp, Sonia, Blyth, Alan M., Abel, Steven J., Ballard, Susan, Barrett, Andrew, Bennett, Lindsay J., Bower, Keith, Brooks, Barbara, Brown, Phil, Charlton-Perez, Cristina, Choularton, Thomas, Clark, Peter, Collier, Chris, Crosier, Jonathan, Cui, Zhiqiang, Dey, Seonaid, Dufton, David, Eagle, Chloe, Flynn, Michael J., Gallagher, Martin, Halliwell, Carol, Hanley, Kirsty, Hawkness-Smith, Lee, Huang, Yahui, Kelly, Graeme, Kitchen, Malcolm, Korolev, Alexei, Lean, Humphrey, Liu, Zixia, Marsham, John, Moser, Daniel, Nicol, John, Norton, Emily G., Plummer, David, Price, Jeremy, Ricketts, Hugo, Roberts, Nigel, Rosenberg, Phil D., Simonin, David, Taylor, Jonathan W., Warren, Robert, Williams, Paul I., and Young, Gillian

Published
2016

11. DCMEX coordinated aircraft and ground observations: Microphysics, aerosol and dynamics during cumulonimbus development.

Author

Finney, Declan L., Blyth, Alan M., Gallagher, Martin, Huihui Wu, Nott, Graeme, Biggerstaff, Mike, Sonnenfeld, Richard G., Daily, Martin, Walker, Dan, Dufton, David, Bower, Keith, Böing, Steven, Choularton, Thomas, Crosier, Jonathan, Groves, James, Field, Paul R., Coe, Hugh, Murray, Benjamin J., Lloyd, Gary, and Marsden, Nicholas A.

Subjects
CLIMATE change models, MICROPHYSICS, CLIMATE sensitivity, AEROSOLS, CLOUD physics, CUMULONIMBUS
Abstract

Sensitivity of global temperature to rising CO2 remains highly uncertain. One of the greatest sources of uncertainty arises from cloud feedbacks associated with deep convective anvils. For deep convective clouds, their growth and characteristics are substantially controlled by mixed-phase microphysical processes. However, there remain several questions about cloud microphysical processes, especially in deep, mixed-phase clouds. Meanwhile, the representation of these processes in global climate models is limited. As such, the Deep ConvectiveMicrophysics Experiment (DCMEX) has undertaken an in-situ aircraft and ground-based measurement campaign. The data, combined with operational satellite observations and modelling, will help establish new understanding from the smallest, cloud and aerosol particle scales through to the largest, cloud-system and climate scales. DCMEX is one of four projects in the UK Natural Environment Research Council, Uncertainty in climate sensitivity due to clouds, CloudSense programme. Along with other CloudSense projects, DCMEX will support progress in reducing the uncertainty in cloud feedbacks and equilibrium climate sensitivity. This paper lays out the underpinning dataset from the DCMEX summer 2022 field campaign. Its content describes the coordinated operation and technical details of the broad range of aerosol, cloud physics, radar, thermodynamics, dynamics, electric field and weather instruments deployed. In addition, an overview of the characteristics of campaign cases illustrates the complementary operational observations available, as well as demonstrating the breadth of the campaign cases observed. [ABSTRACT FROM AUTHOR]

Published
2023
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12. Observations of secondary ice formation in the Deep Convective Microphysics Experiment (DCMEX)

Author

Hu, Kezhen, Lloyd, Gary, Wu, huihui, bower, Keith, Flynn, Michael, Marsden, Nicholas, Choularton, Thomas, blyth, Alan, Coe, Hugh, Connolly, Paul, Nott, Graeme, Reed, Chris, Schledewitz, Waldemar, and Gallagher, Martin

Abstract

The radiative properties and lifetime of mixed-phase clouds are strongly influenced by ice formation, and the formation of secondary ice in clouds is one of the longest-standing problems in cloud physics. In DCMEX we conducted multiple flights over New Mexico in the Magdalena Mountain region to provide high-resolution cloud microphysical and aerosol measurements to provide information on the temporal and spatial distribution of ice phase evolution and the linkage between convective cloud thermodynamic and secondary ice processes. We used a combination of high-resolution instruments (including 3VCPI, 2DS, HVPS, and CDP) to provide measurements of the evolution of cloud particle and precipitation concentrations, sizes and morphology to identify and assess primary and secondary ice production contributions as well as where precipitation particles first form and how they develop. The initial results suggest the principal secondary ice production mechanism in these clouds was ice splinter production during riming (Hallet-Mossop) but other production mechanisms were also contributed. Our next step is to combine these data with the cloud thermodynamic background confirming the occurrence of secondary ice and identifying the conditions for the formation of secondary ice. In addition, the aerosol data including cloud particle chemical composition will be used to investigate and quantify their contribution to primary ice formation., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

14. Insights from ACRUISE (Atmospheric Composition and Radiative forcing changes due to UN International Ship Emissions regulations) from aircraft, modelling, and satellite perspectives

Author

Yang, Mingxi, primary, Bell, Thomas, additional, Bower, Keith, additional, Carslaw, Ken, additional, Choularton, Thomas, additional, Christensen, Matt, additional, Coe, Hugh, additional, Grosvenor, Daniel, additional, Lee, James, additional, Watson-Parris, Duncan, additional, Stier, Philip, additional, and Yoshioka, Masaru, additional

Published
2022
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18. EUREC 4A

Author

Choularton, Thomas, Lloyd, Gary, Bower, Keith, Coe, Hugh, Gallagher, Martin, Gallimore, Peter, and Flynn, Michael

Abstract

The science guiding the EUREC4A campaign and its measurements is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic –eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC4Amarked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso-(200km) and larger (500km) scales, roughly 400h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced groundbased cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC4A explored –from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation–are presented along with an overview of EUREC4A’s outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement.

Published
2021

19. EUREC<sup>4</sup>A

Author

Stevens, Bjorn, primary, Bony, Sandrine, additional, Farrell, David, additional, Ament, Felix, additional, Blyth, Alan, additional, Fairall, Christopher, additional, Karstensen, Johannes, additional, Quinn, Patricia K., additional, Speich, Sabrina, additional, Acquistapace, Claudia, additional, Aemisegger, Franziska, additional, Albright, Anna Lea, additional, Bellenger, Hugo, additional, Bodenschatz, Eberhard, additional, Caesar, Kathy-Ann, additional, Chewitt-Lucas, Rebecca, additional, de Boer, Gijs, additional, Delanoë, Julien, additional, Denby, Leif, additional, Ewald, Florian, additional, Fildier, Benjamin, additional, Forde, Marvin, additional, George, Geet, additional, Gross, Silke, additional, Hagen, Martin, additional, Hausold, Andrea, additional, Heywood, Karen J., additional, Hirsch, Lutz, additional, Jacob, Marek, additional, Jansen, Friedhelm, additional, Kinne, Stefan, additional, Klocke, Daniel, additional, Kölling, Tobias, additional, Konow, Heike, additional, Lothon, Marie, additional, Mohr, Wiebke, additional, Naumann, Ann Kristin, additional, Nuijens, Louise, additional, Olivier, Léa, additional, Pincus, Robert, additional, Pöhlker, Mira, additional, Reverdin, Gilles, additional, Roberts, Gregory, additional, Schnitt, Sabrina, additional, Schulz, Hauke, additional, Siebesma, A. Pier, additional, Stephan, Claudia Christine, additional, Sullivan, Peter, additional, Touzé-Peiffer, Ludovic, additional, Vial, Jessica, additional, Vogel, Raphaela, additional, Zuidema, Paquita, additional, Alexander, Nicola, additional, Alves, Lyndon, additional, Arixi, Sophian, additional, Asmath, Hamish, additional, Bagheri, Gholamhossein, additional, Baier, Katharina, additional, Bailey, Adriana, additional, Baranowski, Dariusz, additional, Baron, Alexandre, additional, Barrau, Sébastien, additional, Barrett, Paul A., additional, Batier, Frédéric, additional, Behrendt, Andreas, additional, Bendinger, Arne, additional, Beucher, Florent, additional, Bigorre, Sebastien, additional, Blades, Edmund, additional, Blossey, Peter, additional, Bock, Olivier, additional, Böing, Steven, additional, Bosser, Pierre, additional, Bourras, Denis, additional, Bouruet-Aubertot, Pascale, additional, Bower, Keith, additional, Branellec, Pierre, additional, Branger, Hubert, additional, Brennek, Michal, additional, Brewer, Alan, additional, Brilouet, Pierre-Etienne, additional, Brügmann, Björn, additional, Buehler, Stefan A., additional, Burke, Elmo, additional, Burton, Ralph, additional, Calmer, Radiance, additional, Canonici, Jean-Christophe, additional, Carton, Xavier, additional, Cato Jr., Gregory, additional, Charles, Jude Andre, additional, Chazette, Patrick, additional, Chen, Yanxu, additional, Chilinski, Michal T., additional, Choularton, Thomas, additional, Chuang, Patrick, additional, Clarke, Shamal, additional, Coe, Hugh, additional, Cornet, Céline, additional, Coutris, Pierre, additional, Couvreux, Fleur, additional, Crewell, Susanne, additional, Cronin, Timothy, additional, Cui, Zhiqiang, additional, Cuypers, Yannis, additional, Daley, Alton, additional, Damerell, Gillian M., additional, Dauhut, Thibaut, additional, Deneke, Hartwig, additional, Desbios, Jean-Philippe, additional, Dörner, Steffen, additional, Donner, Sebastian, additional, Douet, Vincent, additional, Drushka, Kyla, additional, Dütsch, Marina, additional, Ehrlich, André, additional, Emanuel, Kerry, additional, Emmanouilidis, Alexandros, additional, Etienne, Jean-Claude, additional, Etienne-Leblanc, Sheryl, additional, Faure, Ghislain, additional, Feingold, Graham, additional, Ferrero, Luca, additional, Fix, Andreas, additional, Flamant, Cyrille, additional, Flatau, Piotr Jacek, additional, Foltz, Gregory R., additional, Forster, Linda, additional, Furtuna, Iulian, additional, Gadian, Alan, additional, Galewsky, Joseph, additional, Gallagher, Martin, additional, Gallimore, Peter, additional, Gaston, Cassandra, additional, Gentemann, Chelle, additional, Geyskens, Nicolas, additional, Giez, Andreas, additional, Gollop, John, additional, Gouirand, Isabelle, additional, Gourbeyre, Christophe, additional, de Graaf, Dörte, additional, de Groot, Geiske E., additional, Grosz, Robert, additional, Güttler, Johannes, additional, Gutleben, Manuel, additional, Hall, Kashawn, additional, Harris, George, additional, Helfer, Kevin C., additional, Henze, Dean, additional, Herbert, Calvert, additional, Holanda, Bruna, additional, Ibanez-Landeta, Antonio, additional, Intrieri, Janet, additional, Iyer, Suneil, additional, Julien, Fabrice, additional, Kalesse, Heike, additional, Kazil, Jan, additional, Kellman, Alexander, additional, Kidane, Abiel T., additional, Kirchner, Ulrike, additional, Klingebiel, Marcus, additional, Körner, Mareike, additional, Kremper, Leslie Ann, additional, Kretzschmar, Jan, additional, Krüger, Ovid, additional, Kumala, Wojciech, additional, Kurz, Armin, additional, L'Hégaret, Pierre, additional, Labaste, Matthieu, additional, Lachlan-Cope, Tom, additional, Laing, Arlene, additional, Landschützer, Peter, additional, Lang, Theresa, additional, Lange, Diego, additional, Lange, Ingo, additional, Laplace, Clément, additional, Lavik, Gauke, additional, Laxenaire, Rémi, additional, Le Bihan, Caroline, additional, Leandro, Mason, additional, Lefevre, Nathalie, additional, Lena, Marius, additional, Lenschow, Donald, additional, Li, Qiang, additional, Lloyd, Gary, additional, Los, Sebastian, additional, Losi, Niccolò, additional, Lovell, Oscar, additional, Luneau, Christopher, additional, Makuch, Przemyslaw, additional, Malinowski, Szymon, additional, Manta, Gaston, additional, Marinou, Eleni, additional, Marsden, Nicholas, additional, Masson, Sebastien, additional, Maury, Nicolas, additional, Mayer, Bernhard, additional, Mayers-Als, Margarette, additional, Mazel, Christophe, additional, McGeary, Wayne, additional, McWilliams, James C., additional, Mech, Mario, additional, Mehlmann, Melina, additional, Meroni, Agostino Niyonkuru, additional, Mieslinger, Theresa, additional, Minikin, Andreas, additional, Minnett, Peter, additional, Möller, Gregor, additional, Morfa Avalos, Yanmichel, additional, Muller, Caroline, additional, Musat, Ionela, additional, Napoli, Anna, additional, Neuberger, Almuth, additional, Noisel, Christophe, additional, Noone, David, additional, Nordsiek, Freja, additional, Nowak, Jakub L., additional, Oswald, Lothar, additional, Parker, Douglas J., additional, Peck, Carolyn, additional, Person, Renaud, additional, Philippi, Miriam, additional, Plueddemann, Albert, additional, Pöhlker, Christopher, additional, Pörtge, Veronika, additional, Pöschl, Ulrich, additional, Pologne, Lawrence, additional, Posyniak, Michał, additional, Prange, Marc, additional, Quiñones Meléndez, Estefanía, additional, Radtke, Jule, additional, Ramage, Karim, additional, Reimann, Jens, additional, Renault, Lionel, additional, Reus, Klaus, additional, Reyes, Ashford, additional, Ribbe, Joachim, additional, Ringel, Maximilian, additional, Ritschel, Markus, additional, Rocha, Cesar B., additional, Rochetin, Nicolas, additional, Röttenbacher, Johannes, additional, Rollo, Callum, additional, Royer, Haley, additional, Sadoulet, Pauline, additional, Saffin, Leo, additional, Sandiford, Sanola, additional, Sandu, Irina, additional, Schäfer, Michael, additional, Schemann, Vera, additional, Schirmacher, Imke, additional, Schlenczek, Oliver, additional, Schmidt, Jerome, additional, Schröder, Marcel, additional, Schwarzenboeck, Alfons, additional, Sealy, Andrea, additional, Senff, Christoph J., additional, Serikov, Ilya, additional, Shohan, Samkeyat, additional, Siddle, Elizabeth, additional, Smirnov, Alexander, additional, Späth, Florian, additional, Spooner, Branden, additional, Stolla, M. Katharina, additional, Szkółka, Wojciech, additional, de Szoeke, Simon P., additional, Tarot, Stéphane, additional, Tetoni, Eleni, additional, Thompson, Elizabeth, additional, Thomson, Jim, additional, Tomassini, Lorenzo, additional, Totems, Julien, additional, Ubele, Alma Anna, additional, Villiger, Leonie, additional, von Arx, Jan, additional, Wagner, Thomas, additional, Walther, Andi, additional, Webber, Ben, additional, Wendisch, Manfred, additional, Whitehall, Shanice, additional, Wiltshire, Anton, additional, Wing, Allison A., additional, Wirth, Martin, additional, Wiskandt, Jonathan, additional, Wolf, Kevin, additional, Worbes, Ludwig, additional, Wright, Ethan, additional, Wulfmeyer, Volker, additional, Young, Shanea, additional, Zhang, Chidong, additional, Zhang, Dongxiao, additional, Ziemen, Florian, additional, Zinner, Tobias, additional, and Zöger, Martin, additional

Published
2021
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21. EUREC4A

Author

Stevens, Bjorn, Bony, Sandrine, Farrell, David, Ament, Felix, Blyth, Alan, Fairall, Christopher, Karstensen, Johannes, Quinn, Patricia K., Speich, Sabrina, Acquistapace, Claudia, Aemisegger, Franziska, Albright, Anna Lea, Bellenger, Hugo, Bodenschatz, Eberhard, Caesar, Kathy-ann, Chewitt-lucas, Rebecca, De Boer, Gijs, Delanoe, Julien, Denby, Leif, Ewald, Florian, Fildier, Benjamin, Forde, Marvin, George, Geet, Gross, Silke, Hagen, Martin, Hausold, Andrea, Heywood, Karen J., Hirsch, Lutz, Jacob, Marek, Jansen, Friedhelm, Kinne, Stefan, Klocke, Daniel, Kolling, Tobias, Konow, Heike, Lothon, Marie, Mohr, Wiebke, Naumann, Ann Kristin, Nuijens, Louise, Olivier, Lea, Pincus, Robert, Pohlker, Mira, Reverdin, Gilles, Roberts, Gregory, Schnitt, Sabrina, Schulz, Hauke, Siebesma, A. Pier, Stephan, Claudia Christine, Sullivan, Peter, Touze-peiffer, Ludovic, Vial, Jessica, Vogel, Raphaela, Zuidema, Paquita, Alexander, Nicola, Alves, Lyndon, Arixi, Sophian, Asmath, Hamish, Bagheri, Gholamhossein, Baier, Katharina, Bailey, Adriana, Baranowski, Dariusz, Baron, Alexandre, Barrau, Sebastien, Barrett, Paul A., Batier, Frederic, Behrendt, Andreas, Bendinger, Arne, Beucher, Florent, Bigorre, Sebastien, Blades, Edmund, Blossey, Peter, Bock, Olivier, Boing, Steven, Bosser, Pierre, Bourras, Denis, Bouruet-aubertot, Pascale, Bower, Keith, Branellec, Pierre, Branger, Hubert, Brennek, Michal, Brewer, Alan, Brilouet, Pierre Etienne, Brugmann, Bjorn, Buehler, Stefan A., Burke, Elmo, Burton, Ralph, Calmer, Radiance, Canonici, Jean-christophe, Carton, Xavier, Cato, Gregory, Jr., Charles, Jude Andre, Chazette, Patrick, Chen, Yanxu, Chilinski, Michal T., Choularton, Thomas, Chuang, Patrick, Clarke, Shamal, Coe, Hugh, Cornet, Celine, Coutris, Pierre, Couvreux, Fleur, Crewell, Susanne, Cronin, Timothy, Cui, Zhiqiang, Cuypers, Yannis, Daley, Alton, Damerell, Gillian M., Dauhut, Thibaut, Deneke, Hartwig, Desbios, Jean-philippe, Dorner, Steffen, Donner, Sebastian, Douet, Vincent, Drushka, Kyla, Dutsch, Marina, Ehrlich, Andre, Emanuel, Kerry, Emmanouilidis, Alexandros, Etienne, Jean-claude, Etienne-leblanc, Sheryl, Faure, Ghislain, Feingold, Graham, Ferrero, Luca, Fix, Andreas, Flamant, Cyrille, Flatau, Piotr Jacek, Foltz, Gregory R., Forster, Linda, Furtuna, Iulian, Gadian, Alan, Galewsky, Joseph, Gallagher, Martin, Gallimore, Peter, Gaston, Cassandra, Gentemann, Chelle, Geyskens, Nicolas, Giez, Andreas, Gollop, John, Gouirand, Isabelle, Gourbeyre, Christophe, De Graaf, Dorte, De Groot, Geiske E., Grosz, Robert, Guttler, Johannes, Gutleben, Manuel, Hall, Kashawn, Harris, George, Helfer, Kevin C., Henze, Dean, Herbert, Calvert, Holanda, Bruna, Ibanez-landeta, Antonio, Intrieri, Janet, Iyer, Suneil, Julien, Fabrice, Kalesse, Heike, Kazil, Jan, Kellman, Alexander, Kidane, Abiel T., Kirchner, Ulrike, Klingebiel, Marcus, Korner, Mareike, Kremper, Leslie Ann, Kretzschmar, Jan, Kruger, Ovid, Kumala, Wojciech, Kurz, Armin, L'Hegaret, Pierre, Labaste, Matthieu, Lachlan-cope, Tom, Laing, Arlene, Landschutzer, Peter, Lang, Theresa, Lange, Diego, Lange, Ingo, Laplace, Clement, Lavik, Gauke, Laxenaire, Remi, Le Bihan, Caroline, Leandro, Mason, Lefevre, Nathalie, Lena, Marius, Lenschow, Donald, Li, Qiang, Lloyd, Gary, Los, Sebastian, Losi, Niccolo, Lovell, Oscar, Luneau, Christopher, Makuch, Przemyslaw, Malinowski, Szymon, Manta, Gaston, Marinou, Eleni, Marsden, Nicholas, Masson, Sebastien, Maury, Nicolas, Mayer, Bernhard, Mayers-als, Margarette, Mazel, Christophe, Mcgeary, Wayne, Mcwilliams, James C., Mech, Mario, Mehlmann, Melina, Meroni, Agostino Niyonkuru, Mieslinger, Theresa, Minikin, Andreas, Minnett, Peter, Moller, Gregor, Avalos, Yanmichel Morfa, Muller, Caroline, Musat, Ionela, Napoli, Anna, Neuberger, Almuth, Noisel, Christophe, Noone, David, Nordsiek, Freja, Nowak, Jakub L., Oswald, Lothar, Parker, Douglas J., Peck, Carolyn, Person, Renaud, Philippi, Miriam, Plueddemann, Albert, Pohlker, Christopher, Portge, Veronika, Poschl, Ulrich, Pologne, Lawrence, Posyniak, Michal, Prange, Marc, Melendez, Estefania Quinones, Radtke, Jule, Ramage, Karim, Reimann, Jens, Renault, Lionel, Reus, Klaus, Reyes, Ashford, Ribbe, Joachim, Ringel, Maximilian, Ritschel, Markus, Rocha, Cesar B., Rochetin, Nicolas, Rottenbacher, Johannes, Rollo, Callum, Royer, Haley, Sadoulet, Pauline, Saffin, Leo, Sandiford, Sanola, Sandu, Irina, Schafer, Michael, Schemann, Vera, Schirmacher, Imke, Schlenczek, Oliver, Schmidt, Jerome, Schroder, Marcel, Schwarzenboeck, Alfons, Sealy, Andrea, Senff, Christoph J., Serikov, Ilya, Shohan, Samkeyat, Siddle, Elizabeth, Smirnov, Alexander, Spath, Florian, Spooner, Branden, Stolla, M. Katharina, Szkolka, Wojciech, De Szoeke, Simon P., Tarot, Stephane, Tetoni, Eleni, Thompson, Elizabeth, Thomson, Jim, Tomassini, Lorenzo, Totems, Julien, Ubele, Alma Anna, Villiger, Leonie, Von Arx, Jan, Wagner, Thomas, Walther, Andi, Webber, Ben, Wendisch, Manfred, Whitehall, Shanice, Wiltshire, Anton, Wing, Allison A., Wirth, Martin, Wiskandt, Jonathan, Wolf, Kevin, Worbes, Ludwig, Wright, Ethan, Wulfmeyer, Volker, Young, Shanea, Zhang, Chidong, Zhang, Dongxiao, Ziemen, Florian, Zinner, Tobias, Zoger, Martin, Stevens, Bjorn, Bony, Sandrine, Farrell, David, Ament, Felix, Blyth, Alan, Fairall, Christopher, Karstensen, Johannes, Quinn, Patricia K., Speich, Sabrina, Acquistapace, Claudia, Aemisegger, Franziska, Albright, Anna Lea, Bellenger, Hugo, Bodenschatz, Eberhard, Caesar, Kathy-ann, Chewitt-lucas, Rebecca, De Boer, Gijs, Delanoe, Julien, Denby, Leif, Ewald, Florian, Fildier, Benjamin, Forde, Marvin, George, Geet, Gross, Silke, Hagen, Martin, Hausold, Andrea, Heywood, Karen J., Hirsch, Lutz, Jacob, Marek, Jansen, Friedhelm, Kinne, Stefan, Klocke, Daniel, Kolling, Tobias, Konow, Heike, Lothon, Marie, Mohr, Wiebke, Naumann, Ann Kristin, Nuijens, Louise, Olivier, Lea, Pincus, Robert, Pohlker, Mira, Reverdin, Gilles, Roberts, Gregory, Schnitt, Sabrina, Schulz, Hauke, Siebesma, A. Pier, Stephan, Claudia Christine, Sullivan, Peter, Touze-peiffer, Ludovic, Vial, Jessica, Vogel, Raphaela, Zuidema, Paquita, Alexander, Nicola, Alves, Lyndon, Arixi, Sophian, Asmath, Hamish, Bagheri, Gholamhossein, Baier, Katharina, Bailey, Adriana, Baranowski, Dariusz, Baron, Alexandre, Barrau, Sebastien, Barrett, Paul A., Batier, Frederic, Behrendt, Andreas, Bendinger, Arne, Beucher, Florent, Bigorre, Sebastien, Blades, Edmund, Blossey, Peter, Bock, Olivier, Boing, Steven, Bosser, Pierre, Bourras, Denis, Bouruet-aubertot, Pascale, Bower, Keith, Branellec, Pierre, Branger, Hubert, Brennek, Michal, Brewer, Alan, Brilouet, Pierre Etienne, Brugmann, Bjorn, Buehler, Stefan A., Burke, Elmo, Burton, Ralph, Calmer, Radiance, Canonici, Jean-christophe, Carton, Xavier, Cato, Gregory, Jr., Charles, Jude Andre, Chazette, Patrick, Chen, Yanxu, Chilinski, Michal T., Choularton, Thomas, Chuang, Patrick, Clarke, Shamal, Coe, Hugh, Cornet, Celine, Coutris, Pierre, Couvreux, Fleur, Crewell, Susanne, Cronin, Timothy, Cui, Zhiqiang, Cuypers, Yannis, Daley, Alton, Damerell, Gillian M., Dauhut, Thibaut, Deneke, Hartwig, Desbios, Jean-philippe, Dorner, Steffen, Donner, Sebastian, Douet, Vincent, Drushka, Kyla, Dutsch, Marina, Ehrlich, Andre, Emanuel, Kerry, Emmanouilidis, Alexandros, Etienne, Jean-claude, Etienne-leblanc, Sheryl, Faure, Ghislain, Feingold, Graham, Ferrero, Luca, Fix, Andreas, Flamant, Cyrille, Flatau, Piotr Jacek, Foltz, Gregory R., Forster, Linda, Furtuna, Iulian, Gadian, Alan, Galewsky, Joseph, Gallagher, Martin, Gallimore, Peter, Gaston, Cassandra, Gentemann, Chelle, Geyskens, Nicolas, Giez, Andreas, Gollop, John, Gouirand, Isabelle, Gourbeyre, Christophe, De Graaf, Dorte, De Groot, Geiske E., Grosz, Robert, Guttler, Johannes, Gutleben, Manuel, Hall, Kashawn, Harris, George, Helfer, Kevin C., Henze, Dean, Herbert, Calvert, Holanda, Bruna, Ibanez-landeta, Antonio, Intrieri, Janet, Iyer, Suneil, Julien, Fabrice, Kalesse, Heike, Kazil, Jan, Kellman, Alexander, Kidane, Abiel T., Kirchner, Ulrike, Klingebiel, Marcus, Korner, Mareike, Kremper, Leslie Ann, Kretzschmar, Jan, Kruger, Ovid, Kumala, Wojciech, Kurz, Armin, L'Hegaret, Pierre, Labaste, Matthieu, Lachlan-cope, Tom, Laing, Arlene, Landschutzer, Peter, Lang, Theresa, Lange, Diego, Lange, Ingo, Laplace, Clement, Lavik, Gauke, Laxenaire, Remi, Le Bihan, Caroline, Leandro, Mason, Lefevre, Nathalie, Lena, Marius, Lenschow, Donald, Li, Qiang, Lloyd, Gary, Los, Sebastian, Losi, Niccolo, Lovell, Oscar, Luneau, Christopher, Makuch, Przemyslaw, Malinowski, Szymon, Manta, Gaston, Marinou, Eleni, Marsden, Nicholas, Masson, Sebastien, Maury, Nicolas, Mayer, Bernhard, Mayers-als, Margarette, Mazel, Christophe, Mcgeary, Wayne, Mcwilliams, James C., Mech, Mario, Mehlmann, Melina, Meroni, Agostino Niyonkuru, Mieslinger, Theresa, Minikin, Andreas, Minnett, Peter, Moller, Gregor, Avalos, Yanmichel Morfa, Muller, Caroline, Musat, Ionela, Napoli, Anna, Neuberger, Almuth, Noisel, Christophe, Noone, David, Nordsiek, Freja, Nowak, Jakub L., Oswald, Lothar, Parker, Douglas J., Peck, Carolyn, Person, Renaud, Philippi, Miriam, Plueddemann, Albert, Pohlker, Christopher, Portge, Veronika, Poschl, Ulrich, Pologne, Lawrence, Posyniak, Michal, Prange, Marc, Melendez, Estefania Quinones, Radtke, Jule, Ramage, Karim, Reimann, Jens, Renault, Lionel, Reus, Klaus, Reyes, Ashford, Ribbe, Joachim, Ringel, Maximilian, Ritschel, Markus, Rocha, Cesar B., Rochetin, Nicolas, Rottenbacher, Johannes, Rollo, Callum, Royer, Haley, Sadoulet, Pauline, Saffin, Leo, Sandiford, Sanola, Sandu, Irina, Schafer, Michael, Schemann, Vera, Schirmacher, Imke, Schlenczek, Oliver, Schmidt, Jerome, Schroder, Marcel, Schwarzenboeck, Alfons, Sealy, Andrea, Senff, Christoph J., Serikov, Ilya, Shohan, Samkeyat, Siddle, Elizabeth, Smirnov, Alexander, Spath, Florian, Spooner, Branden, Stolla, M. Katharina, Szkolka, Wojciech, De Szoeke, Simon P., Tarot, Stephane, Tetoni, Eleni, Thompson, Elizabeth, Thomson, Jim, Tomassini, Lorenzo, Totems, Julien, Ubele, Alma Anna, Villiger, Leonie, Von Arx, Jan, Wagner, Thomas, Walther, Andi, Webber, Ben, Wendisch, Manfred, Whitehall, Shanice, Wiltshire, Anton, Wing, Allison A., Wirth, Martin, Wiskandt, Jonathan, Wolf, Kevin, Worbes, Ludwig, Wright, Ethan, Wulfmeyer, Volker, Young, Shanea, Zhang, Chidong, Zhang, Dongxiao, Ziemen, Florian, Zinner, Tobias, and Zoger, Martin

Abstract

The science guiding the \EURECA campaign and its measurements are presented. \EURECA comprised roughly five weeks of measurements in the downstream winter trades of the North Atlantic — eastward and south-eastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, \EURECA marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or, or the life-cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso (200 km) and larger (500 km) scales, roughly four hundred hours of flight time by four heavily instrumented research aircraft, four global-ocean class research vessels, an advanced ground-based cloud observatory, a flotilla of autonomous or tethered measurement devices operating in the upper ocean (nearly 10000 profiles), lower atmosphere (continuous profiling), and along the air-sea interface, a network of water stable isotopologue measurements, complemented by special programmes of satellite remote sensing and modeling with a new generation of weather/climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that \EURECA explored — from Brazil Ring Current Eddies to turbulence induced clustering of cloud droplets and its influence on warm-rain formation — are presented along with an overview \EURECA’s outreach activities, environmental impact, and guidelines for scientific practice.

Published
2021
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24. Measurements of ice crystal fluxes from the surface at a mountain top site.

Author

Schledewitch, Waldemar, Lloyd, Gary, Bower, Keith, Choularton, Thomas, Flynn, Michael, and Gallagher, Martin

Abstract

New observations of anomalously high cloud ice crystal concentrations at the Jungfraujoch research station (Switzerland, 3.5 km a.s.l.) are presented. High-resolution measurements of these ice crystals using a high-speed 2D imaging cloud particle spectrometer confirm that the concentrations far exceed those expected from any known primary ice production mechanisms and are at temperatures well below those for known secondary ice production processes to contribute. A detailed analysis of the cloud ice crystal sizes and habits with respect to wind speed and growth regimes confirms, as hypothesised in previous studies, that their origin is not due to blowing snow or related wind speed influences. As first hypothesised by Vali et al. (Vali et al., 2012) using remote sensing and by Lloyd et al., (2015) with in situ measurements, the most likely explanation is due to a strong surface source generated by the interaction of turbulent deposition of supercooled droplets to fragile ice-covered snow surfaces. This process enhances the detachment of crystal fragments wherein the smaller size mode is turbulently re-suspended even at low wind speeds below expected blowing snow thresholds. These then continue to grow, adding significantly to the ice crystal number concentrations whose size and habit is determined by the transport time between the ice crystal source and measurement location and liquid water profile within the cloud. We confirm, using eddy covariance measurements of ice particle number fluxes, that the likely source is significantly far upwind to preclude flow distortion effects such that the source plume has homogenised by the time they are measured at the mountain top summit. [ABSTRACT FROM AUTHOR]

Published
2022
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25. Small ice particles at slightly supercooled temperatures in tropical maritime convection

Author

Lloyd, Gary, primary, Choularton, Thomas, additional, Bower, Keith, additional, Crosier, Jonathan, additional, Gallagher, Martin, additional, Flynn, Michael, additional, Dorsey, James, additional, Liu, Dantong, additional, Taylor, Jonathan W., additional, Schlenczek, Oliver, additional, Fugal, Jacob, additional, Borrmann, Stephan, additional, Cotton, Richard, additional, Field, Paul, additional, and Blyth, Alan, additional

Published
2020
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27. Multi-thermals and high concentrations of secondary ice: A modelling study of convective clouds during the ICE-D campaign.

Author

Cui, Zhiqiang, Blyth, Alan, Lloyd, Gary, Choularton, Thomas, Bower, Keith, Field, Paul, Hawker, Rachel, and Bennett, Lindsay

Abstract

This paper examines the mechanisms responsible for the production of ice in convective clouds influenced by mineral dust. Observations were made in the Ice in Clouds Experiment - Dust (ICE-D) field campaign which took place in the vicinity of Cape Verde during August 2015. Measurements made with instruments on the FAAM aircraft through the clouds on 21 August showed that ice particles were observed in high concentrations at temperatures greater than about -8 °C. Sensitivity studies were performed using existing parametrisation schemes in a cloud model to explore the impact of the freezing onset temperature, the efficiency of freezing, mineral dust as efficient ice nuclei, and multi-thermals on secondary ice production by the rime-splintering process. The simulation with the default Morrison microphysics scheme (Morrison et al., 2005) that involved a single thermal produced a concentration of secondary ice that was much lower than the observed value of total ice number concentration. Relaxing the onset temperature to a higher value, enhancing the freezing efficiency, or combinations of these, increased the secondary ice particle concentration, but not by a sufficient amount. Simulations that involved only dust particles as ice nucleating particles produced a lower concentration of secondary ice particles, since the freezing onset temperature is low. The simulations implicate that a higher concentration of ice nucleating particles with a higher freezing onset temperature may explain some of the observed high concentrations of secondary ice. However, a simulation with two thermals that used the original Morrison scheme without enhancement or relaxation produced the greatest concentration of secondary ice particles. It did so because of the increased time that graupel particles were exposed to significant cloud liquid water content in the Hallett-Mossop temperature zone. The forward-facing camera and measurements of the vertical wind in repeated passes of the same cloud suggested that these tropical clouds contained multiple thermals. Hence, in a similar way to other convective clouds observed elsewhere in the world, it is likely that multi-thermals play an important role in producing very high concentrations of secondary ice particles in some tropical clouds. [ABSTRACT FROM AUTHOR]

Published
2021
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28. Atmospheric Ice-Nucleating Particles in the Dusty Tropical Atlantic

Author

Price, Hannah, Bower, Keith, Choularton, Thomas, Gallagher, Martin, and Taylor, J. W.

Subjects
Atmospheric Science, FAAM, Soil Science, Aquatic Science, Oceanography, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Water Science and Technology, Earth-Surface Processes, Ecology, Palaeontology, tropical, Forestry, ice-nucleating particle, filters, Geophysics, Space and Planetary Science, Atlantic, dust
Abstract

Desert dust is one of the most important atmospheric ice-nucleating aerosol species around the globe. However, there have been very few measurements of ice-nucleating particle (INP) concentrations in dusty air close to desert sources. In this study we report the concentration of INPs in dust laden air over the tropical Atlantic within a few days' transport of one of the world's most important atmospheric sources of desert dust, the Sahara. These measurements were performed as part of the Ice in Clouds Experiment-Dust campaign based in Cape Verde, during August 2015. INP concentrations active in the immersion mode, determined using a droplet-on-filter technique, ranged from around 102 m−3 at −12°C to around 105 m−3 at −23°C. There is about 2 orders of magnitude variability in INP concentration for a particular temperature, which is determined largely by the variability in atmospheric dust loading. These measurements were made at altitudes from 30 to 3,500 m in air containing a range of dust loadings. The ice active site density (ns) for desert dust dominated aerosol derived from our measurements agrees with several laboratory-based parameterizations for ice nucleation by desert dust within 1 to 2 orders of magnitude. The small variability in ns values determined from our measurements (within about 1 order of magnitude) is striking given that the back trajectory analysis suggests that the sources of dust were geographically diverse. This is consistent with previous work, which indicates that desert dust's ice-nucleating activity is only weakly dependent on source.

Published
2018

29. Relating large-scale subsidence to convection development in Arctic mixed-phase marine stratocumulus:Atmos. Chem. Phys., 18, 1475-1494, 2018 https://doi.org/10.5194/acp-18-1475-2018

Author

Young, Gillian, Connolly, Paul, Dearden, Christopher, and Choularton, Thomas

Abstract

Large-scale subsidence, associated with high-pressure systems, is often imposed in large-eddy simulation (LES) models to maintain the height of boundary layer (BL) clouds. Previous studies have considered the influence of subsidence on warm liquid clouds in subtropical regions; however, the relationship between subsidence and mixed-phase cloud microphysics has not specifically been studied. For the first time, we investigate how widespread subsidence associated with synoptic-scale meteorological features can affect the microphysics of Arctic mixed-phase marine stratocumulus (Sc) clouds. Modelled with LES, four idealised scenarios – a stable Sc, varied droplet (Ndrop) or ice (Nice) number concentrations, and a warming surface (representing motion southwards) – were subjected to different levels of subsidence to investigate the cloud microphysical response. We find strong sensitivities to large-scale subsidence, indicating that high-pressure systems in the ocean-exposed Arctic regions have the potential to generate turbulence and changes in cloud microphysics in any resident BL mixed-phase clouds.Increased cloud convection is modelled with increased subsidence, driven by longwave radiative cooling at cloud top and rain evaporative cooling and latent heating from snow growth below cloud. Subsidence strengthens the BL temperature inversion, thus reducing entrainment and allowing the liquid- and ice-water paths (LWPs, IWPs) to increase. Through increased cloud-top radiative cooling and subsequent convective overturning, precipitation production is enhanced: rain particle number concentrations (Nrain), in-cloud rain mass production rates, and below-cloud evaporation rates increase with increased subsidence.Ice number concentrations (Nice) play an important role, as greater concentrations suppress the liquid phase; therefore, Nice acts to mediate the strength of turbulent overturning promoted by increased subsidence. With a warming surface, a lack of – or low – subsidence allows for rapid BL turbulent kinetic energy (TKE) coupling, leading to a heterogeneous cloud layer, cloud-top ascent, and cumuli formation below the Sc cloud. In these scenarios, higher levels of subsidence act to stabilise the Sc layer, where the combination of these two forcings counteract one another to produce a stable, yet dynamic, cloud layer.

Published
2018

31. Coarse mode mineral dust size distributions, composition and optical properties from AER-D aircraft measurements over the Tropical Eastern Atlantic

Author

Ryder, Claire L., Marenco, F., Brooke, Jennifer K., Estelles, V., Cotton, Richard, Formenti, P, McQuaid, James B., Price, Hannah, Liu, Dantong, Rosenberg, Phil, Taylor, J. W., Choularton, Thomas, Bower, Keith, Coe, Hugh, Gallagher, Martin, Crosier, Jonathan, Lloyd, Gary, and Highwood, Eleanor

Abstract

Mineral dust is an important component of the climate system, affecting the radiation balance, cloud properties, biogeochemical cycles, regional circulation and precipitation, as well as having negative effects on aviation, solar energy generation and human health. Dust size and composition has an impact on all these processes. However, changes in dust size distribution and composition during transport, particularly for coarse particles, are poorly understood and poorly represented in climate models. Here we present new in-situ airborne observations of dust in the Saharan Air Layer (SAL) and the Marine Boundary Layer (MBL) during the beginning of its trans-Atlantic transport pathway, from the AER-D fieldwork in August 2015, within the peak season of North African dust export. This study focuses on coarse mode dust properties, including size distribution, mass loading, shape, composition, refractive indices and optical properties. Size distributions from 0.1 to 100µm diameter (d) are presented, fully incorporating the coarse and giant modes of dust. Within the SAL, particles larger than 20µm diameter were always present up to 5km altitude, in concentrations over 10−5cm−3, constituting up to 40% of dust mass. Mean effective diameter and volume median diameter were 4.0µm and 5.5µm respectively. Larger particles were detected in the SAL than can be explained by sedimentation theory alone. Coarse mode composition was dominated by quartz and alumino-silicates; the accumulation mode showed a strong contribution from sulfate-rich and sea salt particles. In the SAL, measured single scattering albedos (SSAs) at 550nm representing d

Published
2018

32. Small Ice Particles at Slightly Supercooled Temperatures in Tropical Maritime Convection

Author

Lloyd, Gary, primary, Choularton, Thomas, additional, Bower, Keith, additional, Crosier, Jonathan, additional, Gallagher, Martin, additional, Flynn, Michael, additional, Dorsey, James, additional, Liu, Dantong, additional, Taylor, Jonathan W., additional, Schlenczek, Oliver, additional, Fugal, Jacob, additional, Borrmann, Stephan, additional, Cotton, Richard, additional, Field, Paul, additional, and Blyth, Alan, additional

Published
2019
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33. Real-time detection of airborne fluorescent bioparticles in Antarctica

Author

Crawford, Ian, Gallagher, Martin, Bower, Keith, Choularton, Thomas, Flynn, Michael, Ruske, Simon, Listowski, Constantino, Brough, Neil, Lachlan-Cope, Thomas, Fleming, Zoë, Foot, Virginia, Stanley, Warren, School of Earth and Environmental Sciences [Manchester] (SEES), University of Manchester [Manchester], British Antarctic Survey (BAS), Natural Environment Research Council (NERC), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry [Leicester], University of Leicester, Defence Science and Technology Laboratory (Dstl), Ministry of Defence (UK) (MOD), Science and Technology Research Institute [Hatfield] (STRI), and University of Hertfordshire [Hatfield] (UH)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], ComputingMilieux_MISCELLANEOUS
Abstract

We demonstrate, for the first time, continuous real-time observations of airborne bio-fluorescent aerosols recorded at the British Antarctic Survey's Halley VI Research Station, located on the Brunt Ice Shelf close to the Weddell Sea coast (lat 75°34′59′′ S, long 26°10′0′′ W) during Antarctic summer, 2015. As part of the NERC MAC (Microphysics of Antarctic Clouds) aircraft aerosol cloud interaction project, observations with a real-time ultraviolet-light-induced fluorescence (UV-LIF) spectrometer were conducted to quantify airborne biological containing particle concentrations along with dust particles as a function of wind speed and direction over a 3-week period. Significant, intermittent enhancements of both non- and bio-fluorescent particles were observed to varying degrees in very specific wind directions and during strong wind events. Analysis of the particle UV-induced emission spectra, particle sizes and shapes recorded during these events suggest the majority of particles were likely a subset of dust with weak fluorescence emission responses. A minor fraction, however, were likely primary biological particles that were very strongly fluorescent, with a subset identified as likely being pollen based on comparison with laboratory data obtained using the same instrument. A strong correlation of bio-fluorescent particles with wind speed was observed in some, but not all, periods. Interestingly, the fraction of fluorescent particles to total particle concentration also increased significantly with wind speed during these events. The enhancement in concentrations of these particles could be interpreted as due to resuspension from the local ice surface but more likely due to emissions from distal sources within Antarctica as well as intercontinental transport. Likely distal sources identified by back trajectory analyses and dispersion modelling were the coastal ice margin zones in Halley Bay consisting of bird colonies with likely associated high bacterial activity together with contributions from exposed ice margin bacterial colonies but also long-range transport from the southern coasts of Argentina and Chile. Dispersion modelling also demonstrated emissions from shipping lanes, and therefore marine anthropogenic sources cannot be ruled out. Average total concentrations of total fluorescent aerosols were found to be 1.9 ± 2.6 L−1 over a 3-week period crossing over from November into December, but peak concentrations during intermittent enhancement events could be up to several tens per litre. While this short pilot study is not intended to be generally representative of Antarctic aerosol, it demonstrates the usefulness of the UV-LIF measurement technique for quantification of airborne bioaerosol concentrations and to understand their dispersion. The potential importance for microbial colonisation of Antarctica is highlighted.

Published
2017

34. In situ measurements of cloud microphysical and aerosol properties during the break-up of stratocumulus cloud layers in cold air outbreaks over the North Atlantic

Author

Lloyd, Gary, primary, Choularton, Thomas W., additional, Bower, Keith N., additional, Gallagher, Martin W., additional, Crosier, Jonathan, additional, O'Shea, Sebastian, additional, Abel, Steven J., additional, Fox, Stuart, additional, Cotton, Richard, additional, and Boutle, Ian A., additional

Published
2018
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35. Ice-Lollies: An ice particle generated in supercooled conveyor belts

Author

Keppas, Stavros, Crosier, Jonathan, Choularton, Thomas, and Bower, Keith

Abstract

On 21st January 2009, a maturing low pressure weather system approached the UK along with several associated frontal systems. As a part of the APPRAISE-Clouds project, an observational research flight took place in southern England, sampling the leading warm front of this system. During the flight, a distinctive hydrometeor type was repeatedly observed which has not been widely reported in previous studies. We refer to the hydrometeors as “drizzle-rimed columnar ice”, or “ice-lollies” for short due to their characteristic shape. We discuss the processes that led to their formation using in-situ and remote sensing data.

Published
2017

38. In situ measurements of cloud microphysics and aerosol over coastal Antarctica during the MAC campaign

Author

O 'Shea, Sebastian, Choularton, Thomas W., Flynn, Michael, Bower, Keith N., Gallagher, Martin, Crosier, Jonathan, Williams, Paul, Crawford, Ian, Fleming, Zoë L., Listowski, Constantino, Kirchgaessner, Amélie, Ladkin, Russell S., Lachlan-Cope, Thomas, School of Earth and Environmental Sciences [Manchester] (SEES), University of Manchester [Manchester], National Centre for Atmospheric Science [Manchester] (NCAS), National Centre for Atmospheric Science [Leicester] (NCAS), University of Leicester, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), British Antarctic Survey (BAS), and Natural Environment Research Council (NERC)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], 010504 meteorology & atmospheric sciences, 13. Climate action, 14. Life underwater, 010501 environmental sciences, 01 natural sciences, 0105 earth and related environmental sciences
Abstract

International audience; During austral summer 2015, the Microphysics of Antarctic Clouds (MAC) field campaign collected unique and detailed airborne and ground-based in situ measurements of cloud and aerosol properties over coastal Antarctica and the Weddell Sea. This paper presents the first results from the experiment and discusses the key processes important in this region, which is critical to predicting future climate change. The sampling was predominantly of stratus clouds, at temperatures between −20 and 0°C. These clouds were dominated by supercooled liquid water droplets, which had a median concentration of 113 cm −3 and an interquartile range of 86 cm −3. Both cloud liquid water content and effective radius increased closer to cloud top. The cloud droplet effective radius increased from 4 ± 2 µm near cloud base to 8 ± 3 µm near cloud top. Cloud ice particle concentrations were highly variable with the ice tending to occur in small, isolated patches. Below approximately 1000 m, glaciated cloud regions were more common at higher temperatures; however, the clouds were still predominantly liquid throughout. When ice was present at temperatures higher than −10°C, secondary ice production most likely through the Hallett–Mossop mechanism led to ice concentrations 1 to 3 orders of magnitude higher than the number predicted by commonly used primary ice nucleation parameterisations. The drivers of the ice crystal variability are investigated. No clear dependence on the droplet size distribution was found. The source of first ice in the clouds remains uncertain but may include contributions from biogenic particles, blowing snow or other surface ice production mechanisms. The concentration of large aerosols (diameters 0.5 to 1.6 µm) decreased with altitude and were depleted in air masses that originated over the Antarctic continent compared to those more heavily influenced by the Southern Ocean and sea ice regions. The dominant aerosol in the region was hygroscopic in nature, with the hygroscopicity parameter κ having a median value for the campaign of 0.66 (interquar-tile range of 0.38). This is consistent with other remote marine locations that are dominated by sea salt/sulfate.

Published
2017

39. Real Time Detection of Airborne Bioparticles in Antarctica

Author

Crawford, Ian A., Gallagher, Martin W., Bower, Keith N., Choularton, Thomas W., Flynn, Michael J., Ruske, Simon, Listowski, Constantino, Brough, Neil, Lachlan-Cope, Thomas, Flemming, Zoë L., Foot, Virginia E., Stanley, Warren R., Centre for Atmospheric Science [Manchester] (CAS), School of Earth and Environmental Sciences [Manchester] (SEES), University of Manchester [Manchester]-University of Manchester [Manchester], British Antarctic Survey (BAS), Natural Environment Research Council (NERC), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry [Leicester], University of Leicester, Defence Science and Technology Laboratory (Dstl), Ministry of Defence (UK) (MOD), Science and Technology Research Institute [Hatfield] (STRI), and University of Hertfordshire [Hatfield] (UH)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; We demonstrate for the first time, continuous real-time observations of airborne bio-fluorescent aerosols recorded at the British Antarctic Survey's Halley VI Research Station, located on the Brunt ice shelf close to the Weddell Sea coast (Lat. 75°34'59"S, Long. 26°10'0"W) during Antarctic Summer, 2015. As part of the NERC MAC (Microphysics of Antarctic Clouds) aircraft aerosol cloud interaction project, observations with a real-time Ultraviolet Light Induced Fluorescence (UV-LIF) spectrometer were conducted to quantify airborne biological containing particle concentrations along with dust particles as a function of wind speed and direction over a three week period. Significant, intermittent enhancements of both non- and bio-fluorescent particles were observed to varying degrees in very specific wind directions and during strong wind events. Analysis of the particle UV induced emission spectra, particle sizes and shapes recorded during these events suggest the majority of particles were likely a subset of dust with weak fluorescence emission responses. A minor fraction, however, were clearly primary biological particles that were very strongly fluorescent, with a subset identified as likely being pollen based on comparison with laboratory data obtained using the same instrument. A strong correlation of biofluorescent particles with wind speed was observed in some, but not all, periods. Interestingly the fraction of fluorescent particles to total particle concentration also increased significantly with wind speed during these events. The enhancement in concentrations of these particles could be interpreted as due to re-suspension from the local ice surface but more likely due to emissions from distal sources within Antarctica as well as intercontinental transport. Likely distal sources identified by back trajectory analyses and dispersion modelling were the coastal ice margin zones in Halley Bay consisting of bird colonies with likely associated high bacterial activity together with contributions from exposed ice margin bacterial colonies but also long range transport from the southern coasts of Argentina and Chile. Average total concentrations of total fluorescent aerosols were found to be 1.9 ± 2.6 L-1 over a 3 week period crossing over from November into December, but peak concentrations during intermittent enhancement events could be up to several 10's L-1. The usefulness of the measurement technique for quantification of airborne bioaerosol concentrations, and to understand their dispersion and potential importance for microbial colonisation of Antarctica is highlighted.

Published
2017

40. In-Situ Measurements of Cloud Microphysical and Aerosol Properties during the Breakup of Stratocumulus Cloud Layers in Cold Air Outbreaks over the North Atlantic

Author

Lloyd, Gary, primary, Choularton, Thomas W., additional, Bower, Keith N., additional, Gallagher, Martin W., additional, Crosier, Jonathan, additional, O'Shea, Sebastian, additional, Abel, Steven J., additional, Fox, Stuart, additional, Cotton, Richard, additional, and Boutle, Ian A., additional

Published
2018
Full Text
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42. Summertime Arctic Aircraft Measurements during ACCACIA

Author

Jones, Hazel M., primary, Young, Gillian, additional, Choularton, Thomas W., additional, Bower, Keith N., additional, Lachlan-Cope, Thomas, additional, O'Shea, Sebastian, additional, Dorsey, James, additional, Ladkin, Russell, additional, Kirchgaessner, Amelié, additional, and Weiss, Alexandra, additional

Published
2018
Full Text
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44. In situ measurements of cloud microphysics and aerosol over coastal Antarctica during the MAC campaign

Author

O'Shea, Sebastian J., primary, Choularton, Thomas W., additional, Flynn, Michael, additional, Bower, Keith N., additional, Gallagher, Martin, additional, Crosier, Jonathan, additional, Williams, Paul, additional, Crawford, Ian, additional, Fleming, Zoë L., additional, Listowski, Constantino, additional, Kirchgaessner, Amélie, additional, Ladkin, Russell S., additional, and Lachlan-Cope, Thomas, additional

Published
2017
Full Text
View/download PDF

45. In situ measurements of cloud microphysics and aerosol over coastal Antarctica during the MAC campaign

Author

O'Shea, Sebastian J., Choularton, Thomas W., Flynn, Michael, Bower, Keith N., Gallagher, Martin, Crosier, Jonathan, Williams, Paul, Crawford, Ian, Fleming, Zoë L., Listowski, Constantino, Kirchgaessner, Amelie, Ladkin, Russell S., Lachlan-Cope, Thomas, O'Shea, Sebastian J., Choularton, Thomas W., Flynn, Michael, Bower, Keith N., Gallagher, Martin, Crosier, Jonathan, Williams, Paul, Crawford, Ian, Fleming, Zoë L., Listowski, Constantino, Kirchgaessner, Amelie, Ladkin, Russell S., and Lachlan-Cope, Thomas

Abstract

During austral summer 2015, the Microphysics of Antarctic Clouds (MAC) field campaign collected unique and detailed airborne and ground-based in situ measurements of cloud and aerosol properties over coastal Antarctica and the Weddell Sea. This paper presents the first results from the experiment and discusses the key processes important in this region, which is critical to predicting future climate change. The sampling was predominantly of stratus clouds, at temperatures between −20 and 0 °C. These clouds were dominated by supercooled liquid water droplets, which had a median concentration of 113 cm−3 and an interquartile range of 86 cm−3. Both cloud liquid water content and effective radius increased closer to cloud top. The cloud droplet effective radius increased from 4 ± 2 µm near cloud base to 8 ± 3 µm near cloud top. Cloud ice particle concentrations were highly variable with the ice tending to occur in small, isolated patches. Below approximately 1000 m, glaciated cloud regions were more common at higher temperatures; however, the clouds were still predominantly liquid throughout. When ice was present at temperatures higher than −10 °C, secondary ice production most likely through the Hallett–Mossop mechanism led to ice concentrations 1 to 3 orders of magnitude higher than the number predicted by commonly used primary ice nucleation parameterisations. The drivers of the ice crystal variability are investigated. No clear dependence on the droplet size distribution was found. The source of first ice in the clouds remains uncertain but may include contributions from biogenic particles, blowing snow or other surface ice production mechanisms. The concentration of large aerosols (diameters 0.5 to 1.6 µm) decreased with altitude and were depleted in air masses that originated over the Antarctic continent compared to those more heavily influenced by the Southern Ocean and sea ice regions. The dominant aerosol in the region was hygroscopic in nature, with the hygros

Published
2017

46. Real time detection of airborne fluorescent bioparticles in Antarctica

Author

Crawford, I., Gallagher, Martin W., Bower, Keith N., Choularton, Thomas W., Flynn, Michael J., Ruske, Simon, Listowski, Constantino, Brough, Neil, Lachlan-Cope, Thomas, Fleming, Zoe L., Foot, Virginia E., Stanley, Warren R., Crawford, I., Gallagher, Martin W., Bower, Keith N., Choularton, Thomas W., Flynn, Michael J., Ruske, Simon, Listowski, Constantino, Brough, Neil, Lachlan-Cope, Thomas, Fleming, Zoe L., Foot, Virginia E., and Stanley, Warren R.

Abstract

We demonstrate, for the first time, continuous real-time observations of airborne bio-fluorescent aerosols recorded at the British Antarctic Survey's Halley VI Research Station, located on the Brunt Ice Shelf close to the Weddell Sea coast (lat 75°34′59′′ S, long 26°10′0′′ W) during Antarctic summer, 2015. As part of the NERC MAC (Microphysics of Antarctic Clouds) aircraft aerosol cloud interaction project, observations with a real-time ultraviolet-light-induced fluorescence (UV-LIF) spectrometer were conducted to quantify airborne biological containing particle concentrations along with dust particles as a function of wind speed and direction over a 3-week period. Significant, intermittent enhancements of both non- and bio-fluorescent particles were observed to varying degrees in very specific wind directions and during strong wind events. Analysis of the particle UV-induced emission spectra, particle sizes and shapes recorded during these events suggest the majority of particles were likely a subset of dust with weak fluorescence emission responses. A minor fraction, however, were likely primary biological particles that were very strongly fluorescent, with a subset identified as likely being pollen based on comparison with laboratory data obtained using the same instrument. A strong correlation of bio-fluorescent particles with wind speed was observed in some, but not all, periods. Interestingly, the fraction of fluorescent particles to total particle concentration also increased significantly with wind speed during these events. The enhancement in concentrations of these particles could be interpreted as due to resuspension from the local ice surface but more likely due to emissions from distal sources within Antarctica as well as intercontinental transport. Likely distal sources identified by back trajectory analyses and dispersion modelling were the coastal ice margin zones in Halley Bay consisting of bird colonies with likely associated high bacterial activit

Published
2017

47. Airborne observations of the microphysical structure of two contrasting cirrus clouds

Author

O'Shea, Sebastian, Choularton, Thomas, Lloyd, G, Crosier, Jonathan, Bower, Keith, Gallagher, Martin, Abel, S. J., Cotton, R. J., Brown, P. R. A., P. Fugal, J., Schlenczek, O, Borrmann, S, C Pickering, J., and Natural Environment Research Council (NERC)

Subjects
PARAMETERIZATION, Science & Technology, PREDICTION, CLIMATE MODELS, SENSITIVITY-ANALYSIS, LAND-SURFACE, VALIDATION, EVAPORATION, SOIL HYDROLOGY, LAYER, Physical Sciences, Meteorology & Atmospheric Sciences, MESOSCALE ETA-MODEL, Physics::Atmospheric and Oceanic Physics
Abstract

We present detailed airborne in situ measurements of cloud microphysics in two midlatitude cirrus clouds, collected as part of the Cirrus Coupled Cloud-Radiation Experiment (CIRCCREX). A new habit recognition algorithm for sorting cloud particle images using a neural network is introduced. Both flights observed clouds that were related to frontal systems, but one was actively developing whilst the other dissipated as it was sampled. The two clouds showed distinct differences in particle number, habit and size. However a number of common features were observed in the 2DS dataset, including a distinct bimodal size distribution within the higher temperature regions of the clouds. This may result from a combination of local heterogeneous nucleation and large particles sedimenting from aloft. Both clouds had small ice crystals (

Published
2016

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