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4. Overview: Quasi-Lagrangian observations of Arctic air mass transformations – Introduction and initial results of the HALO–(AC)3 aircraft campaign

Author

Wendisch, Manfred, primary, Crewell, Susanne, additional, Ehrlich, André, additional, Herber, Andreas, additional, Kirbus, Benjamin, additional, Lüpkes, Christof, additional, Mech, Mario, additional, Abel, Steven J., additional, Akansu, Elisa F., additional, Ament, Felix, additional, Aubry, Clémantyne, additional, Becker, Sebastian, additional, Borrmann, Stephan, additional, Bozem, Heiko, additional, Brückner, Marlen, additional, Clemen, Hans-Christian, additional, Dahlke, Sandro, additional, Dekoutsidis, Georgios, additional, Delanoë, Julien, additional, De La Torre Castro, Elena, additional, Dorff, Henning, additional, Dupuy, Regis, additional, Eppers, Oliver, additional, Ewald, Florian, additional, George, Geet, additional, Gorodetskaya, Irina V., additional, Grawe, Sarah, additional, Groß, Silke, additional, Hartmann, Jörg, additional, Henning, Silvia, additional, Hirsch, Lutz, additional, Jäkel, Evelyn, additional, Joppe, Philipp, additional, Jourdan, Olivier, additional, Jurányi, Zsofia, additional, Karalis, Michail, additional, Kellermann, Mona, additional, Klingebiel, Marcus, additional, Lonardi, Michael, additional, Lucke, Johannes, additional, Luebke, Anna, additional, Maahn, Maximilian, additional, Maherndl, Nina, additional, Maturilli, Marion, additional, Mayer, Bernhard, additional, Mayer, Johanna, additional, Mertes, Stephan, additional, Michaelis, Janosch, additional, Michalkov, Michel, additional, Mioche, Guillaume, additional, Moser, Manuel, additional, Müller, Hanno, additional, Neggers, Roel, additional, Ori, Davide, additional, Paul, Daria, additional, Paulus, Fiona, additional, Pilz, Christian, additional, Pithan, Felix, additional, Pöhlker, Mira, additional, Pörtge, Veronika, additional, Ringel, Maximilian, additional, Risse, Nils, additional, Roberts, Gregory C., additional, Rosenburg, Sophie, additional, Röttenbacher, Johannes, additional, Rückert, Janna, additional, Schäfer, Michael, additional, Schäfer, Jonas, additional, Schemannn, Vera, additional, Schirmacher, Imke, additional, Schmidt, Jörg, additional, Schmidt, Sebastian, additional, Schneider, Johannes, additional, Schnitt, Sabrina, additional, Schwarz, Anja, additional, Siebert, Holger, additional, Sodemann, Harald, additional, Sperzel, Tim, additional, Spreen, Gunnar, additional, Stevens, Bjorn, additional, Stratmann, Frank, additional, Svensson, Gunilla, additional, Tatzelt, Christian, additional, Tuch, Thomas, additional, Vihma, Timo, additional, Voigt, Christiane, additional, Volkmer, Lea, additional, Walbröl, Andreas, additional, Weber, Anna, additional, Wehner, Birgit, additional, Wetzel, Bruno, additional, Wirth, Martin, additional, and Zinner, Tobias, additional

Published
2024
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6. Tethered balloon-borne observations of thermal-infrared irradiance and cooling rate profiles in the Arctic atmospheric boundary layer.

Author

Lonardi, Michael, Akansu, Elisa F., Ehrlich, André, Mazzola, Mauro, Pilz, Christian, Shupe, Matthew D., Siebert, Holger, and Wendisch, Manfred

Subjects
ATMOSPHERIC boundary layer, RADIATION, MICROPHYSICS, ICE clouds, RADIATIVE transfer, ARCTIC climate, CLOUD droplets
Abstract

Clouds play an important role in controlling the radiative energy budget of the Arctic atmospheric boundary layer. To quantify the impact of clouds on the radiative heating or cooling of the lower atmosphere and of the surface, vertical profile observations of thermal-infrared irradiances were collected using a radiation measurement system carried by a tethered balloon. We present 70 profiles of thermal-infrared radiative quantities measured in summer 2020 during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition and in autumn 2021 and spring 2022 in Ny-Ålesund, Svalbard. Measurements are classified into four groups: cloudless, low-level liquid-bearing cloud, elevated liquid-bearing cloud, and elevated ice cloud. Cloudless cases display an average radiative cooling rate of about - 2 K d -1 throughout the atmospheric boundary layer. Instead, low-level liquid-bearing clouds are characterized by a radiative cooling up to - 80 K d -1 within a shallow layer at cloud top, while no temperature tendencies are identified underneath the cloud layer. Radiative transfer simulations are performed to quantify the sensitivity of radiative cooling rates to cloud microphysical properties. In particular, cloud top cooling is strongly driven by the liquid water path, especially in optically thin clouds, while for optically thick clouds the cloud droplet number concentration has an increased influence. Additional radiative transfer simulations are used to demonstrate the enhanced radiative importance of the liquid relative to ice clouds. To analyze the temporal evolution of thermal-infrared radiation profiles during the transitions from a cloudy to a cloudless atmosphere, a respective case study is investigated. [ABSTRACT FROM AUTHOR]

Published
2024
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9. Estimating turbulent energy flux vertical profiles from uncrewed aircraft system measurements: exemplary results for the MOSAiC campaign

Author

Egerer, Ulrike, primary, Cassano, John J., additional, Shupe, Matthew D., additional, de Boer, Gijs, additional, Lawrence, Dale, additional, Doddi, Abhiram, additional, Siebert, Holger, additional, Jozef, Gina, additional, Calmer, Radiance, additional, Hamilton, Jonathan, additional, Pilz, Christian, additional, and Lonardi, Michael, additional

Published
2023
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12. Tethered balloon-borne observations of thermal-infrared irradiance and cooling rate profiles in the Arctic atmospheric boundary layer.

Author

Lonardi, Michael, Akansu, Elisa F., Ehrlich, André, Mazzola, Mauro, Pilz, Christian, Shupe, Matthew D., Siebert, Holger, and Wendisch, Manfred

Subjects
ATMOSPHERIC boundary layer, RADIATION, CLOUDINESS, ARCTIC climate, RADIATIVE transfer, STRATOCUMULUS clouds, ICE clouds
Abstract

Clouds play an important role in controlling the radiative energy budget of the Arctic atmospheric boundary layer. To quantify their impact on diabatic heating or cooling of the atmosphere and of the surface, vertical profile observations of thermal-infrared irradiances were collected using a tethered balloon. We present 70 profiles of thermal-infrared radiative quantities measured in summer 2020 at the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, and in autumn 2021 and spring 2022 in Ny-Ålesund, Svalbard. Measurements are classified into four groups: cloudless, low-level liquid-bearing cloud, elevated liquid-bearing cloud, and elevated ice cloud. Cloudless cases display a radiative cooling rate of about -2 K day-1. Observed low-level liquid-bearing clouds are characterized by a radiative cooling up to -80 K day-1 in a shallow layer at cloud top. Radiative transfer simulations are performed to quantify the sensitivity of radiative cooling rates to cloud microphysical properties. In particular, cloud top cooling has a strong response to variation of the liquid water path, especially in optically thin clouds, while for optically thick clouds the cloud droplet number concentration has an increased relative importance. Two case studies with a changing cloud cover are presented to investigate the temporal evolution of radiation profiles during the transitions between (a) cloudy to cloudless and (b) low-level to elevated clouds. Additional radiative transfer simulations are used to reproduce the observed scenarios and to showcase the radiative impacts of elevated liquid and ice clouds, demonstrating the increased radiative significance of the liquid clouds. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Overview of the MOSAiC expedition - Atmosphere

Author

Shupe, Matthew D., Rex, Markus, Blomquist, Byron, Persson, P. Ola G., Schmale, Julia, Uttal, Taneil, Althausen, Dietrich, Angot, Hélène, Archer, Stephen, Bariteau, Ludovic, Beck, Ivo, Bilberry, John, Bucci, Silvia, Buck, Clifton, Boyer, Matt, Brasseur, Zoé, Brooks, Ian M., Calmer, Radiance, Cassano, John, Castro, Vagner, Chu, David, Costa, David, Cox, Christopher J., Creamean, Jessie, Crewell, Susanne, Dahlke, Sandro, Damm, Ellen, de Boer, Gijs, Deckelmann, Holger, Dethloff, Klaus, Dütsch, Marina, Ebell, Kerstin, Ehrlich, André, Ellis, Jody, Engelmann, Ronny, Fong, Allison A., Frey, Markus M., Gallagher, Michael R., Ganzeveld, Laurens, Gradinger, Rolf, Graeser, Jürgen, Greenamyer, Vernon, Griesche, Hannes, Griffiths, Steele, Hamilton, Jonathan, Heinemann, Günther, Helmig, Detlev, Herber, Andreas, Heuzé, Céline, Hofer, Julian, Houchens, Todd, Howard, Dean, Inoue, Jun, Jacobi, Hans-Werner, Jaiser, Ralf, Jokinen, Tuija, Jourdan, Olivier, Jozef, Gina, King, Wessley, Kirchgaessner, Amelie, Klingebiel, Marcus, Krassovski, Misha, Krumpen, Thomas, Lampert, Astrid, Landing, William, Laurila, Tiia, Lawrence, Dale, Lonardi, Michael, Loose, Brice, Lüpkes, Christof, Maahn, Maximilian, Macke, Andreas, Maslowski, Wieslaw, Marsay, Christopher, Maturilli, Marion, Mech, Mario, Morris, Sara, Moser, Manuel, Nicolaus, Marcel, Ortega, Paul, Osborn, Jackson, Pätzold, Falk, Perovich, Donald K., Petäjä, Tuukka, Pilz, Christian, Pirazzini, Roberta, Posman, Kevin, Powers, Heath, Pratt, Kerri A., Preußer, Andreas, Quéléver, Lauriane, Radenz, Martin, Rabe, Benjamin, Rinke, Annette, Sachs, Torsten, Schulz, Alexander, Siebert, Holger, Silva, Tercio, Solomon, Amy, Sommerfeld, Anja, Spreen, Gunnar, Stephens, Mark, Stohl, Andreas, Svensson, Gunilla, Uin, Janek, Viegas, Juarez, Voigt, Christiane, von der Gathen, Peter, Wehner, Birgit, Welker, Jeffrey M., Wendisch, Manfred, Werner, Martin, Xie, ZhouQing, Yue, Fange, Shupe, Matthew D., Rex, Markus, Blomquist, Byron, Persson, P. Ola G., Schmale, Julia, Uttal, Taneil, Althausen, Dietrich, Angot, Hélène, Archer, Stephen, Bariteau, Ludovic, Beck, Ivo, Bilberry, John, Bucci, Silvia, Buck, Clifton, Boyer, Matt, Brasseur, Zoé, Brooks, Ian M., Calmer, Radiance, Cassano, John, Castro, Vagner, Chu, David, Costa, David, Cox, Christopher J., Creamean, Jessie, Crewell, Susanne, Dahlke, Sandro, Damm, Ellen, de Boer, Gijs, Deckelmann, Holger, Dethloff, Klaus, Dütsch, Marina, Ebell, Kerstin, Ehrlich, André, Ellis, Jody, Engelmann, Ronny, Fong, Allison A., Frey, Markus M., Gallagher, Michael R., Ganzeveld, Laurens, Gradinger, Rolf, Graeser, Jürgen, Greenamyer, Vernon, Griesche, Hannes, Griffiths, Steele, Hamilton, Jonathan, Heinemann, Günther, Helmig, Detlev, Herber, Andreas, Heuzé, Céline, Hofer, Julian, Houchens, Todd, Howard, Dean, Inoue, Jun, Jacobi, Hans-Werner, Jaiser, Ralf, Jokinen, Tuija, Jourdan, Olivier, Jozef, Gina, King, Wessley, Kirchgaessner, Amelie, Klingebiel, Marcus, Krassovski, Misha, Krumpen, Thomas, Lampert, Astrid, Landing, William, Laurila, Tiia, Lawrence, Dale, Lonardi, Michael, Loose, Brice, Lüpkes, Christof, Maahn, Maximilian, Macke, Andreas, Maslowski, Wieslaw, Marsay, Christopher, Maturilli, Marion, Mech, Mario, Morris, Sara, Moser, Manuel, Nicolaus, Marcel, Ortega, Paul, Osborn, Jackson, Pätzold, Falk, Perovich, Donald K., Petäjä, Tuukka, Pilz, Christian, Pirazzini, Roberta, Posman, Kevin, Powers, Heath, Pratt, Kerri A., Preußer, Andreas, Quéléver, Lauriane, Radenz, Martin, Rabe, Benjamin, Rinke, Annette, Sachs, Torsten, Schulz, Alexander, Siebert, Holger, Silva, Tercio, Solomon, Amy, Sommerfeld, Anja, Spreen, Gunnar, Stephens, Mark, Stohl, Andreas, Svensson, Gunilla, Uin, Janek, Viegas, Juarez, Voigt, Christiane, von der Gathen, Peter, Wehner, Birgit, Welker, Jeffrey M., Wendisch, Manfred, Werner, Martin, Xie, ZhouQing, and Yue, Fange

Abstract

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system

Published
2022

15. Tethered balloon-borne profile measurements of atmospheric properties in the cloudy atmospheric boundary layer over the Arctic sea ice during MOSAiC: Overview and first results

Author

Lonardi, Michael, Pilz, Christian, Akansu, Elisa F., Dahlke, Sandro, Egerer, Ulrike, Ehrlich, André, Griesche, Hannes, Heymsfield, Andrew J., Kirbus, Benjamin, Schmitt, Carl G., Shupe, Matthew D., Siebert, Holger, Wehner, Birgit, Wendisch, Manfred, Lonardi, Michael, Pilz, Christian, Akansu, Elisa F., Dahlke, Sandro, Egerer, Ulrike, Ehrlich, André, Griesche, Hannes, Heymsfield, Andrew J., Kirbus, Benjamin, Schmitt, Carl G., Shupe, Matthew D., Siebert, Holger, Wehner, Birgit, and Wendisch, Manfred

Abstract

The tethered balloon-borne measurement system BELUGA (Balloon-bornE moduLar Utility for profilinG the lower Atmosphere) was deployed over the Arctic sea ice for 4 weeks in summer 2020 as part of the Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition. Using BELUGA, vertical profiles of dynamic, thermodynamic, aerosol particle, cloud, radiation, and turbulence properties were measured from the ground up to a height of 1,500 m. BELUGA was operated during an anomalously warm period with frequent liquid water clouds and variable sea ice conditions. Three case studies of liquid water phase, single-layer clouds observed on 3 days (July 13, 23, and 24, 2020) are discussed to show the potential of the collected data set to comprehensively investigate cloud properties determining cloud evolution in the inner Arctic over sea ice. Simulated back-trajectories show that the observed clouds have evolved within 3 different air masses (“aged Arctic,” “advected over sea ice,” and “advected over open ocean”), which left distinct fingerprints in the cloud properties. Strong cloud top radiative cooling rates agree with simulated results of previous studies. The weak warming at cloud base is mostly driven by the vertical temperature profile between the surface and cloud base. In-cloud turbulence induced by the cloud top cooling was similar in strength compared to former studies. From the extent of the mixing layer, it is speculated that the overall cloud cooling is stronger and thus faster in the warm oceanic air mass. Larger aerosol particle number concentrations and larger sizes were observed in the air mass advected over the sea ice and in the air mass advected over the open ocean.

Published
2022

16. Overview of the MOSAiC expedition-Atmosphere INTRODUCTION

Author

Shupe, Matthew D., Rex, Markus, Blomquist, Byron, Persson, P. Ola G., Schmale, Julia, Uttal, Taneil, Althausen, Dietrich, Angot, Helene, Archer, Stephen, Bariteau, Ludovic, Beck, Ivo, Bilberry, John, Bucci, Silvia, Buck, Clifton, Boyer, Matt, Brasseur, Zoe, Brooks, Ian M., Calmer, Radiance, Cassano, John, Castro, Vagner, Chu, David, Costa, David, Cox, Christopher J., Creamean, Jessie, Crewell, Susanne, Dahlke, Sandro, Damm, Ellen, de Boer, Gijs, Deckelmann, Holger, Dethloff, Klaus, Duetsch, Marina, Ebell, Kerstin, Ehrlich, Andre, Ellis, Jody, Engelmann, Ronny, Fong, Allison A., Frey, Markus M., Gallagher, Michael R., Ganzeveld, Laurens, Gradinger, Rolf, Graeser, Juergen, Greenamyer, Vernon, Griesche, Hannes, Griffiths, Steele, Hamilton, Jonathan, Heinemann, Guenther, Helmig, Detlev, Herber, Andreas, Heuze, Celine, Hofer, Julian, Houchens, Todd, Howard, Dean, Inoue, Jun, Jacobi, Hans-Werner, Jaiser, Ralf, Jokinen, Tuija, Jourdan, Olivier, Jozef, Gina, King, Wessley, Kirchgaessner, Amelie, Klingebiel, Marcus, Krassovski, Misha, Krumpen, Thomas, Lampert, Astrid, Landing, William, Laurila, Tiia, Lawrence, Dale, Lonardi, Michael, Loose, Brice, Luepkes, Christof, Maahn, Maximilian, Macke, Andreas, Maslowski, Wieslaw, Marsay, Christopher, Maturilli, Marion, Mech, Mario, Morris, Sara, Moser, Manuel, Nicolaus, Marcel, Ortega, Paul, Osborn, Jackson, Paetzold, Falk, Perovich, Donald K., Petaja, Tuukka, Pilz, Christian, Pirazzini, Roberta, Posman, Kevin, Powers, Heath, Pratt, Kerri A., Preusser, Andreas, Quelever, Lauriane, Radenz, Martin, Rabe, Benjamin, Rinke, Annette, Sachs, Torsten, Schulz, Alexander, Siebert, Holger, Silva, Tercio, Solomon, Amy, Sommerfeld, Anja, Spreen, Gunnar, Stephens, Mark, Stohl, Andreas, Svensson, Gunilla, Uin, Janek, Viegas, Juarez, Voigt, Christiane, von der Gathen, Peter, Wehner, Birgit, Welker, Jeffrey M., Wendisch, Manfred, Werner, Martin, Xie, ZhouQing, Yue, Fange, Shupe, Matthew D., Rex, Markus, Blomquist, Byron, Persson, P. Ola G., Schmale, Julia, Uttal, Taneil, Althausen, Dietrich, Angot, Helene, Archer, Stephen, Bariteau, Ludovic, Beck, Ivo, Bilberry, John, Bucci, Silvia, Buck, Clifton, Boyer, Matt, Brasseur, Zoe, Brooks, Ian M., Calmer, Radiance, Cassano, John, Castro, Vagner, Chu, David, Costa, David, Cox, Christopher J., Creamean, Jessie, Crewell, Susanne, Dahlke, Sandro, Damm, Ellen, de Boer, Gijs, Deckelmann, Holger, Dethloff, Klaus, Duetsch, Marina, Ebell, Kerstin, Ehrlich, Andre, Ellis, Jody, Engelmann, Ronny, Fong, Allison A., Frey, Markus M., Gallagher, Michael R., Ganzeveld, Laurens, Gradinger, Rolf, Graeser, Juergen, Greenamyer, Vernon, Griesche, Hannes, Griffiths, Steele, Hamilton, Jonathan, Heinemann, Guenther, Helmig, Detlev, Herber, Andreas, Heuze, Celine, Hofer, Julian, Houchens, Todd, Howard, Dean, Inoue, Jun, Jacobi, Hans-Werner, Jaiser, Ralf, Jokinen, Tuija, Jourdan, Olivier, Jozef, Gina, King, Wessley, Kirchgaessner, Amelie, Klingebiel, Marcus, Krassovski, Misha, Krumpen, Thomas, Lampert, Astrid, Landing, William, Laurila, Tiia, Lawrence, Dale, Lonardi, Michael, Loose, Brice, Luepkes, Christof, Maahn, Maximilian, Macke, Andreas, Maslowski, Wieslaw, Marsay, Christopher, Maturilli, Marion, Mech, Mario, Morris, Sara, Moser, Manuel, Nicolaus, Marcel, Ortega, Paul, Osborn, Jackson, Paetzold, Falk, Perovich, Donald K., Petaja, Tuukka, Pilz, Christian, Pirazzini, Roberta, Posman, Kevin, Powers, Heath, Pratt, Kerri A., Preusser, Andreas, Quelever, Lauriane, Radenz, Martin, Rabe, Benjamin, Rinke, Annette, Sachs, Torsten, Schulz, Alexander, Siebert, Holger, Silva, Tercio, Solomon, Amy, Sommerfeld, Anja, Spreen, Gunnar, Stephens, Mark, Stohl, Andreas, Svensson, Gunilla, Uin, Janek, Viegas, Juarez, Voigt, Christiane, von der Gathen, Peter, Wehner, Birgit, Welker, Jeffrey M., Wendisch, Manfred, Werner, Martin, Xie, ZhouQing, and Yue, Fange

Abstract

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore crosscutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system s

Published
2022

17. Overview of the MOSAiC expedition: Atmosphere

Author

Shupe, Matthew, Rex, Markus, Blomquist, Byron, Ola, P, Persson, G, Schmale, Julia, Uttal, Taneil, Althausen, Dietrich, Lè Ne Angot, Hé, Archer, Stephen, Bariteau, Ludovic, Beck, Ivo, Bilberry, John, Bucci, Silvia, Buck, Clifton, Boyer, Matt, Brasseur, Zoé, Brooks, Ian, Cassano, John, Castro, Vagner, Chu, David, Costa, David, Cox, Christopher, Creamean, Jessie, Crewell, Susanne, Dahlke, Sandro, Damm, Ellen, de Boer, Gijs, Deckelmann, Holger, Dethloff, Klaus, Dütsch, Marina, Ebell, Kerstin, Ehrlich, André, Ellis, Jody, Engelmann, Ronny, Fong, Allison, Frey, Markus, Gallagher, Michael, Ganzeveld, Laurens, Gradinger, Rolf, Graeser, Jürgen, Greenamyer, Vernon, Griesche, Hannes, Griffiths, Steele, Hamilton, Jonathan, Heinemann, Günther, Helmig, Detlev, Herber, Andreas, Line Heuzé, Cé, Hofer, Julian, Houchens, Todd, Inoue, Jun, Jacobi, Hans-Werner, Jaiser, Ralf, Jokinen, Tuija, Jourdan, Olivier, King, Wessley, Kirchgaessner, Amelie, Klingebiel, Marcus, Krassovski, Misha, Krumpen, Thomas, Lampert, Astrid, Landing, William, Laurila, Tiia, Lawrence, Dale, Lonardi, Michael, Loose, Brice, Lüpkes, Christof, Maahn, Maximilian, Macke, Andreas, Maslowski, Wieslaw, Marsay, Christopher, Maturilli, Marion, Mech, Mario, Morris, Sara, Moser, Manuel, Nicolaus, Marcel, Ortega, Paul, Osborn, Jackson, Pätzold, Falk, Perovich, Donald, Petäjä, Tuukka, Pilz, Christian, Pirazzini, Roberta, Posman, Kevin, Powers, Heath, Pratt, Kerri, Preusser, Andreas, Qué Lé Ver, Lauriane, Radenz, Martin, Rabe, Benjamin, Rinke, Annette, Sachs, Torsten, Schulz, Alexander, Siebert, Holger, Silva, Tercio, Solomon, Amy, Sommerfeld, Anja, Spreen, Gunnar, Stephens, Mark, Stohl, Andreas, Svensson, Gunilla, Uin, Janek, Viegas, Juarez, Voigt, Christiane, von Der Gathen, Peter, Wehner, Birgit, Welker, Jeffrey, Wendisch, Manfred, Werner, Martin, Xie, Zhouqing, Yue, Fange, Jourdan, Olivier, Laboratoire de Météorologie Physique (LaMP), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Arctic, Field campaign, Atmosphere, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

International audience; With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore crosscutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge.The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic.

Published
2022

18. Tethered balloon-borne profile measurements of atmospheric properties in the cloudy atmospheric boundary layer over the Arctic sea ice during MOSAiC: Overview and first results

Author

Lonardi, Michael, primary, Pilz, Christian, additional, Akansu, Elisa F., additional, Dahlke, Sandro, additional, Egerer, Ulrike, additional, Ehrlich, André, additional, Griesche, Hannes, additional, Heymsfield, Andrew J., additional, Kirbus, Benjamin, additional, Schmitt, Carl G., additional, Shupe, Matthew D., additional, Siebert, Holger, additional, Wehner, Birgit, additional, and Wendisch, Manfred, additional

Published
2022
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19. CAMP: a balloon-borne platform for aerosol particle studies in the lower atmosphere.

Author

Pilz, Christian, Düsing, Sebastian, Wehner, Birgit, Müller, Thomas, Siebert, Holger, Voigtländer, Jens, and Lonardi, Michael

Subjects
ATMOSPHERIC boundary layer, AEROSOLS, TEMPERATURE inversions, VOLUME (Cubic content), TROPOSPHERIC aerosols, EARTH stations, MICROBIOLOGICAL aerosols
Abstract

Airborne observations of vertical aerosol particle distributions are crucial for detailed process studies and model improvements. Tethered balloon systems represent a less expensive alternative to aircraft to capture shallow atmospheric boundary layers (ABL). This study presents the newly developed cubic aerosol measurement platform (CAMP) for balloon-borne observations of aerosol particle microphysical properties. With an edge length of 30 cm and a weight of 9 kg, the cube is an environmentally robust instrument platform intended for measurements at low temperatures, with a particular focus on applications in cloudy Arctic ABLs. The aerosol instrumentation onboard CAMP comprises two condensation particle counters with different lower detection limits, one optical particle size spectrometer, and a miniaturized absorption photometer. Comprehensive calibrations and characterizations of the instruments were performed in laboratory experiments. The first field study with a tethered balloon system took place at the TROPOS research station in Melpitz, Germany, in the winter of 2019. At ambient temperatures between -10 and 15°C, the platform was operated up to 1.5 km height on 14 flights under a clear sky and cloudy conditions. The continuous aerosol observations at the ground station served as a reference for evaluating the CAMP measurements. During two subsequent balloon flights on the late morning of 15 February, descending layers with increased concentrations of nucleation mode particles were observed above a shallow well-mixed surface layer separated by a weakening temperature inversion. A subsequent increase in nucleation mode particles on the ground after the balloon flights suggests a downward mixing of the particles. Based on the laboratory instrument characterizations and the observations during the field campaign, CAMP demonstrated the capability to provide comprehensive aerosol particle measurements in cold and cloudy ABL. [ABSTRACT FROM AUTHOR]

Published
2022
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21. Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC)

Author

Brückner, Marlen, Lonardi, Michael, Ehrlich, André, Wendisch, Manfred, Jäkel, Evelyn, Schäfer, Michael, Quaas, Johannes, and Kalesse, Heike

Subjects
geomagnetischer Sturm, Ionosphäre, O/N2 Verhältnis, CTIPe Modell, ddc:551, geomagnetic storm, ionosphere, O/N2 ratio, CTIPe model
Abstract

The thermosphere-ionosphere regions are mainly controlled by the solar, but also by geomagnetic activity. In this case study, the Earth’s ionospheric response to the 25-26 August 2018 intense geomagnetic storm is investigated using the International GNSS System (IGS) Total Electron Content (TEC) observations. During this major storm, the minimum disturbance storm time (Dst) index reached -174 nT. We use observations and model simulations to analyse the ionospheric response during the initial phase and the main phase of the magnetic storm. A significant difference between storm day and quiet day TEC is observed. The O/N2 ratio observed from the GUVI instrument onboard the TIMED satellite is used to analyse the storm effect. The result shows a clear depletion of the O/N2 ratio in the high latitude region, and an enhancement in the low latitude region during the main phase of the storm. Furthermore, the Coupled Thermosphere Ionosphere Plasmasphere electrodynamics (CTIPe) model simulations were used. The results suggest that the CTIPe model can capture the ionospheric variations during storms. Die Regionen der Ionosphären und Thermosphäre werden hauptsächlich von der Sonne sowie auch von geomagnetische Aktivität beeinflusst. In dieser Fallstudie wurde die ionosphärische Reaktion der Erde auf den starken geomagnetischen Sturm vom 25./26. August 2018 unter Verwendung der Gesamtelektronengehaltsdaten (Total Electron Content, TEC) vom Internationalen GNSS Service untersucht. Während dieses großen Sturms wurde ein ”Disturbance Storm Time Index” Dst von -174 nT erreicht. Beobachtungen und Modellsimulationen wurden verwendet, um die ionosphärische Reaktion während der Anfangsphase und der Hauptphase des magnetischen Sturms zu untersuchen. Ein signifikanter Unterschied zwischen TEC während eines Sturmtages und eines ruhigen Tages wurde beobachtet. Das vom GUVI-Instrument an Bord des TIMED-Satelliten beobachtete O/N2 -Verhältnis wurde verwendet, um den Sturmeffekt weiter zu untersuchen. Das Ergebnis zeigt eine deutliche Abnahme/Zunahme des O/N2 Verhältnis in hohen/niedrigen Breiten während der Hauptphase des Sturms. Darüber hinaus wurde das Coupled Thermosphere Ionosphere Plasmasphere ectrodynamics (CTIPe) Modell verwendet. Die Ergebnisse legen nahe, dass das CTIPe-Modell die ionosphärischen Schwankungen während eines Sturms erfassen kann.

Published
2020

22. Characterization of Wind Channeling Around Longyearbyen, Svalbard

Author

Lonardi, Michael

Subjects
snow transport, Meteorology and Atmospheric Sciences, wind channeling, Meteorologi och atmosfärforskning, Longyeardalen
Abstract

Due to climate change and arctic amplification, the avalanche activity is expected to increase at higher latitudes (Hall et al., 1994). The arctic settlement of Longyearbyen, Svalbard, situated inside the valley Longyeardalen, is yearly threatened by avalanche activity (Eckerstorfer & Christiansen, 2011a). The surrounding slopes are known to produce avalanche, and during the last century they have proven to be able to cause substantial damages and even fatalities (Hallerstig, 2010). Previous studies investigated magnitude and forcing of the avalanches, including a meteorological perspective (Eckerstorfer & Christiansen, 2011b). This allowed for the usage of forecasts from the weather model AROME-Arctic in order to have an avalanche bulletin.The forecast for the area of Longyearbyen suffers from the location and the insufficient resolution of its source data. The data are obtained from an AWS located at the local airport, at the mouth of a relatively wide NW/SE oriented valley. Conversely, Longyeardalen is oriented NE/SW and is narrower. Because of the topography, channeling of winds is expected to produce difference weather conditions at the two sites, generating two distinct local weather conditions (Whiteman, 2000). If these different weather conditions are not taken into account, the weather model may provide forecasts that are not reliable for the area of Longyeardalen, hence resulting in biased avalanche bulletins.In this work I compare the data from the airport, from Longyeardalen and from the plateau above in order to assess if relevant differences exist in some important meteorological parameters (temperature, wind speed and direction, precipitation) between these sites. The weather station at the airport is an official AWS while the data from the other two sites were obtained using portable weather stations deployed during a field campaign between March 1st and April 11th 2018. During this time, snow data from the slopes surrounding Longyeardalen were also obtained. These data have been used to look for correlations among the wind conditions in the valley and the depth of the snow, as it is known that snow transport is a major factor determining snow accumulation in the area (Jaedicke and Sandvik, 2002; Hestnes, 2000).Temperature and precipitation have been found to be consistent among the two investigated valleys, while wind parameters differed significantly. Wind speed in Longyeardalen is on average overestimated by 3 m/s if only the data from the airport are used while the direction data are uncorrelated. This is due to the different circulations that occur at the two sites. Adventdalen is mostly influenced by southeasterly winds that are forcedly channeled or induced by the synoptic circulation, while in the smaller Longyeardalen southerly winds prevail due a thermal circulation induced by the presence of two glaciers on the top part of the valley. Snow depth is altered by the wind transport but it was not possible to find any correlation due to the low resolution of the snow depth data.

Published
2018

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