Articles | Volume 16, issue 14
Atmos. Chem. Phys., 16, 8849–8872, 2016
https://doi.org/10.5194/acp-16-8849-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue: The Boundary-Layer Late Afternoon and Sunset Turbulence (BLLAST)...
Atmos. Chem. Phys., 16, 8849–8872, 2016
https://doi.org/10.5194/acp-16-8849-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article 19 Jul 2016
Research article | 19 Jul 2016
Turbulence kinetic energy budget during the afternoon transition – Part 1: Observed surface TKE budget and boundary layer description for 10 intensive observation period days
Erik Nilsson et al.
Related authors
Anna Rutgersson, Erik Kjellström, Jari Haapala, Martin Stendel, Irina Danilovich, Martin Drews, Kirsti Jylhä, Pentti Kujala, Xiaoli Guo Larsén, Kirsten Halsnæs, Ilari Lehtonen, Anna Luomaranta, Erik Nilsson, Taru Olsson, Jani Särkkä, Laura Tuomi, and Norbert Wasmund
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2021-13, https://doi.org/10.5194/esd-2021-13, 2021
Revised manuscript accepted for ESD
Short summary
Short summary
A natural hazard is a naturally occurring extreme event with a negative effect on people, society or environment. Events considered are major events in the region including wind storms, extreme waves, high and low sea level, ice ridging, heavy precipitation, sea-effect snowfall, river floods, heat waves, ice seasons, and drought. Increase is expected for sea-level, extreme precipitation, heat waves and phytoplankton blooms and a decrease for cold spells and severe ice winters.
Jesús Yus-Díez, Mireia Udina, Maria Rosa Soler, Marie Lothon, Erik Nilsson, Joan Bech, and Jielun Sun
Atmos. Chem. Phys., 19, 9495–9514, https://doi.org/10.5194/acp-19-9495-2019, https://doi.org/10.5194/acp-19-9495-2019, 2019
Short summary
Short summary
This study helps improve the understanding of the turbulence description and the interactions occurring in the lower part of the boundary layer. It is carried out at an orographically influenced site close to the Pyrenees to explore the hockey-stick transition (HOST) theory. HOST is seen to be strongly dependent on both the meteorological conditions and the orographic features. Examples of intermittent turbulence events that lead to transitions between the turbulence regimes are also identified.
Fleur Couvreux, Eric Bazile, Guylaine Canut, Yann Seity, Marie Lothon, Fabienne Lohou, Françoise Guichard, and Erik Nilsson
Atmos. Chem. Phys., 16, 8983–9002, https://doi.org/10.5194/acp-16-8983-2016, https://doi.org/10.5194/acp-16-8983-2016, 2016
Short summary
Short summary
This study evaluates the ability of operational models to predict the boundary-layer turbulent processes and mesoscale variability observed during the Boundary Layer Late-Afternoon and Sunset Turbulence field campaign. The models succeed in reproducing the variability from one day to another in terms of cloud cover, temperature and boundary-layer depth. However, they exhibit some systematic biases. The high-resolution model reproduces the vertical structures better.
Erik Nilsson, Marie Lothon, Fabienne Lohou, Eric Pardyjak, Oscar Hartogensis, and Clara Darbieu
Atmos. Chem. Phys., 16, 8873–8898, https://doi.org/10.5194/acp-16-8873-2016, https://doi.org/10.5194/acp-16-8873-2016, 2016
Short summary
Short summary
A new simple model for turbulence kinetic energy (TKE) and its budget is presented for the sheared convective atmospheric boundary layer. It is used to study effects of buoyancy and shear on TKE evolution during the afternoon transition, especially near the surface. We also find a region of weak turbulence during unstable afternoon conditions below the inversion top, which we refer to as a "pre-residual layer".
Dhiraj K. Singh, Spencer Donovan, Eric R. Pardyjak, and Timothy J. Garrett
Atmos. Meas. Tech., 14, 6973–6990, https://doi.org/10.5194/amt-14-6973-2021, https://doi.org/10.5194/amt-14-6973-2021, 2021
Short summary
Short summary
This paper describes a new instrument for quantifying the physical characteristics of hydrometeors such as snow and rain. The device can measure the mass, size, density and type of individual hydrometeors as well as their bulk properties. The instrument is called the Differential Emissivity Imaging Disdrometer (DEID) and is composed of a thermal camera and hotplate. The DEID measures hydrometeors at sampling frequencies up to 1 Hz with masses and effective diameters greater than 1 µg and 200 µm.
Bjorn Stevens, Sandrine Bony, David Farrell, Felix Ament, Alan Blyth, Christopher Fairall, Johannes Karstensen, Patricia K. Quinn, Sabrina Speich, Claudia Acquistapace, Franziska Aemisegger, Anna Lea Albright, Hugo Bellenger, Eberhard Bodenschatz, Kathy-Ann Caesar, Rebecca Chewitt-Lucas, Gijs de Boer, Julien Delanoë, Leif Denby, Florian Ewald, Benjamin Fildier, Marvin Forde, Geet George, Silke Gross, Martin Hagen, Andrea Hausold, Karen J. Heywood, Lutz Hirsch, Marek Jacob, Friedhelm Jansen, Stefan Kinne, Daniel Klocke, Tobias Kölling, Heike Konow, Marie Lothon, Wiebke Mohr, Ann Kristin Naumann, Louise Nuijens, Léa Olivier, Robert Pincus, Mira Pöhlker, Gilles Reverdin, Gregory Roberts, Sabrina Schnitt, Hauke Schulz, A. Pier Siebesma, Claudia Christine Stephan, Peter Sullivan, Ludovic Touzé-Peiffer, Jessica Vial, Raphaela Vogel, Paquita Zuidema, Nicola Alexander, Lyndon Alves, Sophian Arixi, Hamish Asmath, Gholamhossein Bagheri, Katharina Baier, Adriana Bailey, Dariusz Baranowski, Alexandre Baron, Sébastien Barrau, Paul A. Barrett, Frédéric Batier, Andreas Behrendt, Arne Bendinger, Florent Beucher, Sebastien Bigorre, Edmund Blades, Peter Blossey, Olivier Bock, Steven Böing, Pierre Bosser, Denis Bourras, Pascale Bouruet-Aubertot, Keith Bower, Pierre Branellec, Hubert Branger, Michal Brennek, Alan Brewer, Pierre-Etienne Brilouet, Björn Brügmann, Stefan A. Buehler, Elmo Burke, Ralph Burton, Radiance Calmer, Jean-Christophe Canonici, Xavier Carton, Gregory Cato Jr., Jude Andre Charles, Patrick Chazette, Yanxu Chen, Michal T. Chilinski, Thomas Choularton, Patrick Chuang, Shamal Clarke, Hugh Coe, Céline Cornet, Pierre Coutris, Fleur Couvreux, Susanne Crewell, Timothy Cronin, Zhiqiang Cui, Yannis Cuypers, Alton Daley, Gillian M. Damerell, Thibaut Dauhut, Hartwig Deneke, Jean-Philippe Desbios, Steffen Dörner, Sebastian Donner, Vincent Douet, Kyla Drushka, Marina Dütsch, André Ehrlich, Kerry Emanuel, Alexandros Emmanouilidis, Jean-Claude Etienne, Sheryl Etienne-Leblanc, Ghislain Faure, Graham Feingold, Luca Ferrero, Andreas Fix, Cyrille Flamant, Piotr Jacek Flatau, Gregory R. Foltz, Linda Forster, Iulian Furtuna, Alan Gadian, Joseph Galewsky, Martin Gallagher, Peter Gallimore, Cassandra Gaston, Chelle Gentemann, Nicolas Geyskens, Andreas Giez, John Gollop, Isabelle Gouirand, Christophe Gourbeyre, Dörte de Graaf, Geiske E. de Groot, Robert Grosz, Johannes Güttler, Manuel Gutleben, Kashawn Hall, George Harris, Kevin C. Helfer, Dean Henze, Calvert Herbert, Bruna Holanda, Antonio Ibanez-Landeta, Janet Intrieri, Suneil Iyer, Fabrice Julien, Heike Kalesse, Jan Kazil, Alexander Kellman, Abiel T. Kidane, Ulrike Kirchner, Marcus Klingebiel, Mareike Körner, Leslie Ann Kremper, Jan Kretzschmar, Ovid Krüger, Wojciech Kumala, Armin Kurz, Pierre L'Hégaret, Matthieu Labaste, Tom Lachlan-Cope, Arlene Laing, Peter Landschützer, Theresa Lang, Diego Lange, Ingo Lange, Clément Laplace, Gauke Lavik, Rémi Laxenaire, Caroline Le Bihan, Mason Leandro, Nathalie Lefevre, Marius Lena, Donald Lenschow, Qiang Li, Gary Lloyd, Sebastian Los, Niccolò Losi, Oscar Lovell, Christopher Luneau, Przemyslaw Makuch, Szymon Malinowski, Gaston Manta, Eleni Marinou, Nicholas Marsden, Sebastien Masson, Nicolas Maury, Bernhard Mayer, Margarette Mayers-Als, Christophe Mazel, Wayne McGeary, James C. McWilliams, Mario Mech, Melina Mehlmann, Agostino Niyonkuru Meroni, Theresa Mieslinger, Andreas Minikin, Peter Minnett, Gregor Möller, Yanmichel Morfa Avalos, Caroline Muller, Ionela Musat, Anna Napoli, Almuth Neuberger, Christophe Noisel, David Noone, Freja Nordsiek, Jakub L. Nowak, Lothar Oswald, Douglas J. Parker, Carolyn Peck, Renaud Person, Miriam Philippi, Albert Plueddemann, Christopher Pöhlker, Veronika Pörtge, Ulrich Pöschl, Lawrence Pologne, Michał Posyniak, Marc Prange, Estefanía Quiñones Meléndez, Jule Radtke, Karim Ramage, Jens Reimann, Lionel Renault, Klaus Reus, Ashford Reyes, Joachim Ribbe, Maximilian Ringel, Markus Ritschel, Cesar B. Rocha, Nicolas Rochetin, Johannes Röttenbacher, Callum Rollo, Haley Royer, Pauline Sadoulet, Leo Saffin, Sanola Sandiford, Irina Sandu, Michael Schäfer, Vera Schemann, Imke Schirmacher, Oliver Schlenczek, Jerome Schmidt, Marcel Schröder, Alfons Schwarzenboeck, Andrea Sealy, Christoph J. Senff, Ilya Serikov, Samkeyat Shohan, Elizabeth Siddle, Alexander Smirnov, Florian Späth, Branden Spooner, M. Katharina Stolla, Wojciech Szkółka, Simon P. de Szoeke, Stéphane Tarot, Eleni Tetoni, Elizabeth Thompson, Jim Thomson, Lorenzo Tomassini, Julien Totems, Alma Anna Ubele, Leonie Villiger, Jan von Arx, Thomas Wagner, Andi Walther, Ben Webber, Manfred Wendisch, Shanice Whitehall, Anton Wiltshire, Allison A. Wing, Martin Wirth, Jonathan Wiskandt, Kevin Wolf, Ludwig Worbes, Ethan Wright, Volker Wulfmeyer, Shanea Young, Chidong Zhang, Dongxiao Zhang, Florian Ziemen, Tobias Zinner, and Martin Zöger
Earth Syst. Sci. Data, 13, 4067–4119, https://doi.org/10.5194/essd-13-4067-2021, https://doi.org/10.5194/essd-13-4067-2021, 2021
Short summary
Short summary
The EUREC4A field campaign, designed to test hypothesized mechanisms by which clouds respond to warming and benchmark next-generation Earth-system models, is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. It was the first campaign that attempted to characterize the full range of processes and scales influencing trade wind clouds.
Pierre-Etienne Brilouet, Marie Lothon, Jean-Claude Etienne, Pascal Richard, Sandrine Bony, Julien Lernoult, Hubert Bellec, Gilles Vergez, Thierry Perrin, Julien Delanoë, Tetyana Jiang, Frédéric Pouvesle, Claude Lainard, Michel Cluzeau, Laurent Guiraud, Patrice Medina, and Theotime Charoy
Earth Syst. Sci. Data, 13, 3379–3398, https://doi.org/10.5194/essd-13-3379-2021, https://doi.org/10.5194/essd-13-3379-2021, 2021
Short summary
Short summary
During the EUREC4A field experiment that took place over the tropical Atlantic Ocean east of Barbados, the French ATR 42 environment research aircraft of SAFIRE aimed to characterize the shallow cloud properties near cloud base and the turbulent structure of the subcloud layer. The high-frequency measurements of wind, temperature and humidity as well as their translation in terms of turbulent fluctuations, turbulent moments and characteristic length scales of turbulence are presented.
Carlos Román-Cascón, Marie Lothon, Fabienne Lohou, Oscar Hartogensis, Jordi Vila-Guerau de Arellano, David Pino, Carlos Yagüe, and Eric R. Pardyjak
Geosci. Model Dev., 14, 3939–3967, https://doi.org/10.5194/gmd-14-3939-2021, https://doi.org/10.5194/gmd-14-3939-2021, 2021
Short summary
Short summary
The type of vegetation (or land cover) and its status influence the heat and water transfers between the surface and the air, affecting the processes that develop in the atmosphere at different (but connected) spatiotemporal scales. In this work, we investigate how these transfers are affected by the way the surface is represented in a widely used weather model. The results encourage including realistic high-resolution and updated land cover databases in models to improve their predictions.
Adrien Deroubaix, Laurent Menut, Cyrille Flamant, Peter Knippertz, Andreas Fink, Anneke Batenburg, Joel Brito, Cyrielle Denjean, Cheikh Dione, Régis Dupuy, Valerian Hahn, Norbert Kalthoff, Fabienne Lohou, Alfons Schwarzenboeck, Guillaume Siour, Paolo Tuccella, and Christiane Voigt
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1306, https://doi.org/10.5194/acp-2020-1306, 2021
Revised manuscript under review for ACP
Short summary
Short summary
During the summer monsoon in West Africa, pollutants emitted in urbanized areas modify cloud cover and precipitation patterns. We analyze these patterns with the WRF-CHIMERE model integrating the effects of aerosols on meteorology, based on the numerous observations provided by the Dynamics-Aerosol-Climate-Interactions campaign. This study adds evidence to recent findings that increased pollution levels in West Africa delay the breakup time of low-level clouds and reduce precipitation.
Anna Rutgersson, Erik Kjellström, Jari Haapala, Martin Stendel, Irina Danilovich, Martin Drews, Kirsti Jylhä, Pentti Kujala, Xiaoli Guo Larsén, Kirsten Halsnæs, Ilari Lehtonen, Anna Luomaranta, Erik Nilsson, Taru Olsson, Jani Särkkä, Laura Tuomi, and Norbert Wasmund
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2021-13, https://doi.org/10.5194/esd-2021-13, 2021
Revised manuscript accepted for ESD
Short summary
Short summary
A natural hazard is a naturally occurring extreme event with a negative effect on people, society or environment. Events considered are major events in the region including wind storms, extreme waves, high and low sea level, ice ridging, heavy precipitation, sea-effect snowfall, river floods, heat waves, ice seasons, and drought. Increase is expected for sea-level, extreme precipitation, heat waves and phytoplankton blooms and a decrease for cold spells and severe ice winters.
Maurin Zouzoua, Fabienne Lohou, Paul Assamoi, Marie Lothon, Véronique Yoboue, Cheikh Dione, Norbert Kalthoff, Bianca Adler, Karmen Babić, Xabier Pedruzo-Bagazgoitia, and Solène Derrien
Atmos. Chem. Phys., 21, 2027–2051, https://doi.org/10.5194/acp-21-2027-2021, https://doi.org/10.5194/acp-21-2027-2021, 2021
Short summary
Short summary
Based on a field experiment conducted in June and July 2016, we analyzed the daytime breakup of continental low-level stratiform clouds over southern West Africa in order to provide complementary guidance for model evaluation during the monsoon season. Those clouds exhibit weaker temperature and moisture jumps at the top compared to marine stratiform clouds. Their lifetime and the transition towards shallow convective clouds during daytime hours depend on their coupling with the surface.
Barbara Altstädter, Konrad Deetz, Bernhard Vogel, Karmen Babić, Cheikh Dione, Federica Pacifico, Corinne Jambert, Friederike Ebus, Konrad Bärfuss, Falk Pätzold, Astrid Lampert, Bianca Adler, Norbert Kalthoff, and Fabienne Lohou
Atmos. Chem. Phys., 20, 7911–7928, https://doi.org/10.5194/acp-20-7911-2020, https://doi.org/10.5194/acp-20-7911-2020, 2020
Short summary
Short summary
We present the high vertical variability of the black carbon (BC) mass concentration measured with the unmanned aerial system ALADINA during the field experiment of DACCIWA. The COSMO-ART model output was applied for the campaign period and is compared with the observational BC data during a case study on 14–15 July 2016. Enhanced BC concentrations were related to transport processes to the measurement site by maritime inflow and not to local emissions as initially expected.
Xabier Pedruzo-Bagazgoitia, Stephan R. de Roode, Bianca Adler, Karmen Babić, Cheikh Dione, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 20, 2735–2754, https://doi.org/10.5194/acp-20-2735-2020, https://doi.org/10.5194/acp-20-2735-2020, 2020
Short summary
Short summary
Using a high-resolution model we simulate the transition from night to day clouds on southern West Africa using observations from the DACCIWA project. We find that the radiative effects of clouds help mantain a thick cloud layer in the night, while the mixing of cloud air with air above during the day, aided by moisture and heat fluxes at the surface, thins this layer and promotes its transition to other clouds. The effect of changing wind with height accelerates the transition.
Fabienne Lohou, Norbert Kalthoff, Bianca Adler, Karmen Babić, Cheikh Dione, Marie Lothon, Xabier Pedruzo-Bagazgoitia, and Maurin Zouzoua
Atmos. Chem. Phys., 20, 2263–2275, https://doi.org/10.5194/acp-20-2263-2020, https://doi.org/10.5194/acp-20-2263-2020, 2020
Short summary
Short summary
A conceptual model of the low-level stratiform clouds (LLSCs), which develop almost every night in southern West Africa, is built with the dataset acquired during the DACCIWA (Dynamics Aerosol Chemistry Cloud Interactions in West Africa) ground-based field experiment. Several processes occur during the four phases composing this diurnal cycle: the cooling of the air until saturation (stable and jet phases), LLSC and low-level jet interactions (stratus phase), and LLSC breakup (convective phase).
Karmen Babić, Norbert Kalthoff, Bianca Adler, Julian F. Quinting, Fabienne Lohou, Cheikh Dione, and Marie Lothon
Atmos. Chem. Phys., 19, 13489–13506, https://doi.org/10.5194/acp-19-13489-2019, https://doi.org/10.5194/acp-19-13489-2019, 2019
Short summary
Short summary
This study investigates differences in atmospheric conditions between nights with and without low-level stratus clouds (LLCs) over southern West Africa. We use high-quality observations collected during 2016 summer monsoon season and the ERA5 reanalysis data set. Our results show that the formation of LLCs depends on the interplay between the onset time and strength of the nocturnal low-level jet, horizontal cold-air advection, and the overall moisture level in the whole region.
Marie Lothon, Paul Barnéoud, Omar Gabella, Fabienne Lohou, Solène Derrien, Sylvain Rondi, Marjolaine Chiriaco, Sophie Bastin, Jean-Charles Dupont, Martial Haeffelin, Jordi Badosa, Nicolas Pascal, and Nadège Montoux
Atmos. Meas. Tech., 12, 5519–5534, https://doi.org/10.5194/amt-12-5519-2019, https://doi.org/10.5194/amt-12-5519-2019, 2019
Short summary
Short summary
In the context of an atmospheric network of instrumented sites equipped with sky cameras for cloud monitoring, we present an algorithm named ELIFAN, which aims to estimate the cloud cover amount from full-sky visible daytime images. ELIFAN is based on red-to-blue ratio thresholding applied on the image pixels and on the use of a blue-sky library. We present its principle and its performance and highlight the interest of combining several complementary instruments.
Jesús Yus-Díez, Mireia Udina, Maria Rosa Soler, Marie Lothon, Erik Nilsson, Joan Bech, and Jielun Sun
Atmos. Chem. Phys., 19, 9495–9514, https://doi.org/10.5194/acp-19-9495-2019, https://doi.org/10.5194/acp-19-9495-2019, 2019
Short summary
Short summary
This study helps improve the understanding of the turbulence description and the interactions occurring in the lower part of the boundary layer. It is carried out at an orographically influenced site close to the Pyrenees to explore the hockey-stick transition (HOST) theory. HOST is seen to be strongly dependent on both the meteorological conditions and the orographic features. Examples of intermittent turbulence events that lead to transitions between the turbulence regimes are also identified.
Cheikh Dione, Fabienne Lohou, Marie Lothon, Bianca Adler, Karmen Babić, Norbert Kalthoff, Xabier Pedruzo-Bagazgoitia, Yannick Bezombes, and Omar Gabella
Atmos. Chem. Phys., 19, 8979–8997, https://doi.org/10.5194/acp-19-8979-2019, https://doi.org/10.5194/acp-19-8979-2019, 2019
Short summary
Short summary
Low atmospheric dynamics and low-level cloud (LLC) macrophysical properties are analyzed using in situ and remote sensing data collected from 20 June to 30 July at Savè, Benin, during the DACCIWA field campaign in 2016. We find that the low-level jet (LLJ), LLCs, monsoon flow, and maritime inflow reveal a day-to-day variability. LLCs form at the same level as the jet core height. The cloud base height is stationary at night and remains below the jet. The cloud top height is found above the jet.
Federica Pacifico, Claire Delon, Corinne Jambert, Pierre Durand, Eleanor Morris, Mat J. Evans, Fabienne Lohou, Solène Derrien, Venance H. E. Donnou, Arnaud V. Houeto, Irene Reinares Martínez, and Pierre-Etienne Brilouet
Atmos. Chem. Phys., 19, 2299–2325, https://doi.org/10.5194/acp-19-2299-2019, https://doi.org/10.5194/acp-19-2299-2019, 2019
Short summary
Short summary
Biogenic fluxes from soil at a local and regional scale are crucial to study air pollution and climate. Here we present field measurements of soil fluxes of nitric oxide (NO) and ammonia (NH3) observed over four different land cover types, i.e. bare soil, grassland, maize field, and forest, at an inland rural site in Benin, West Africa, during the DACCIWA field campaign in
June and July 2016.
Sophie L. Haslett, Jonathan W. Taylor, Konrad Deetz, Bernhard Vogel, Karmen Babić, Norbert Kalthoff, Andreas Wieser, Cheikh Dione, Fabienne Lohou, Joel Brito, Régis Dupuy, Alfons Schwarzenboeck, Paul Zieger, and Hugh Coe
Atmos. Chem. Phys., 19, 1505–1520, https://doi.org/10.5194/acp-19-1505-2019, https://doi.org/10.5194/acp-19-1505-2019, 2019
Short summary
Short summary
As the population in West Africa grows and air pollution increases, it is becoming ever more important to understand the effects of this pollution on the climate and on health. Aerosol particles can grow by absorbing water from the air around them. This paper shows that during the monsoon season, aerosol particles in the region are likely to grow significantly because of the high moisture in the air. This means that climate effects from increasing pollution will be enhanced.
Karmen Babić, Bianca Adler, Norbert Kalthoff, Hendrik Andersen, Cheikh Dione, Fabienne Lohou, Marie Lothon, and Xabier Pedruzo-Bagazgoitia
Atmos. Chem. Phys., 19, 1281–1299, https://doi.org/10.5194/acp-19-1281-2019, https://doi.org/10.5194/acp-19-1281-2019, 2019
Short summary
Short summary
The first detailed observational analysis of the complete diurnal cycle of low-level clouds (LLC) and associated atmospheric processes over southern West Africa is performed using the data gathered within the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud-Interactions in West Africa) ground-based campaign. We find cooling related to the horizontal advection, which occurs in connection with the inflow of cool maritime air mass and a prominent low-level jet, to have the dominant role in LLC formation.
Bianca Adler, Karmen Babić, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, Cheikh Dione, Xabier Pedruzo-Bagazgoitia, and Hendrik Andersen
Atmos. Chem. Phys., 19, 663–681, https://doi.org/10.5194/acp-19-663-2019, https://doi.org/10.5194/acp-19-663-2019, 2019
Short summary
Short summary
This study deals with nocturnal stratiform low-level clouds that frequently form in the atmospheric boundary layer over southern West Africa. We use observational data from 11 nights to characterize the clouds and intranight variability of boundary layer conditions as well as to assess the physical processes relevant for cloud formation. We find that cooling is crucial to reach saturation and a large part of the cooling is related to horizontal advection of cool air from the Gulf of Guinea.
Hervé Petetin, Bastien Sauvage, Herman G. J. Smit, François Gheusi, Fabienne Lohou, Romain Blot, Hannah Clark, Gilles Athier, Damien Boulanger, Jean-Marc Cousin, Philippe Nedelec, Patrick Neis, Susanne Rohs, and Valérie Thouret
Atmos. Chem. Phys., 18, 9561–9581, https://doi.org/10.5194/acp-18-9561-2018, https://doi.org/10.5194/acp-18-9561-2018, 2018
Short summary
Short summary
Based on the numerous profiles available since 1994, this paper investigates the vertical stratification of ozone, carbon monoxide and relative humidity in the lower part of the troposphere (planetary boundary layer, lower free troposphere). Such a characterization of the vertical distribution of pollution is notably important for better understanding vertical exchanges and evaluating models on the vertical dimension.
Norbert Kalthoff, Fabienne Lohou, Barbara Brooks, Gbenga Jegede, Bianca Adler, Karmen Babić, Cheikh Dione, Adewale Ajao, Leonard K. Amekudzi, Jeffrey N. A. Aryee, Muritala Ayoola, Geoffrey Bessardon, Sylvester K. Danuor, Jan Handwerker, Martin Kohler, Marie Lothon, Xabier Pedruzo-Bagazgoitia, Victoria Smith, Lukman Sunmonu, Andreas Wieser, Andreas H. Fink, and Peter Knippertz
Atmos. Chem. Phys., 18, 2913–2928, https://doi.org/10.5194/acp-18-2913-2018, https://doi.org/10.5194/acp-18-2913-2018, 2018
Short summary
Short summary
Extended low-level stratus clouds (LLC) form frequently in southern West Africa during the night-time and persist long into the next day. They affect the radiation budget, atmospheric boundary-layer (BL) evolution and regional climate. The relevant processes governing their formation and dissolution are not fully understood. Thus, a field campaign was conducted in summer 2016, which provided a comprehensive data set for process studies, specifically of interactions between LLC and BL conditions.
Line Båserud, Joachim Reuder, Marius O. Jonassen, Stephan T. Kral, Mostafa B. Paskyabi, and Marie Lothon
Atmos. Meas. Tech., 9, 4901–4913, https://doi.org/10.5194/amt-9-4901-2016, https://doi.org/10.5194/amt-9-4901-2016, 2016
Short summary
Short summary
The micro-RPAS SUMO (Small Unmanned Meteorological Observer) equipped with a five-hole-probe (5HP) system for turbulent flow measurements was operated in 49 flight missions during the BLLAST (Boundary-Layer Late Afternoon and Sunset Turbulence) field campaign in 2011. Based on data sets from these flights, we investigate the potential and limitations of airborne velocity variance and TKE (turbulent kinetic energy) estimations by an RPAS with a take-off weight below 1 kg.
Guylaine Canut, Fleur Couvreux, Marie Lothon, Dominique Legain, Bruno Piguet, Astrid Lampert, William Maurel, and Eric Moulin
Atmos. Meas. Tech., 9, 4375–4386, https://doi.org/10.5194/amt-9-4375-2016, https://doi.org/10.5194/amt-9-4375-2016, 2016
Short summary
Short summary
Turbulent processes of the atmospheric boundary layer contribute the most to transfers between the surface and the atmosphere. Typically, turbulent boundary layer parameters are measured by sonic anemometers on masts and by research aircraft. This is to measure in situ turbulent parameters in the planetary boundary layer (PBL) at altitudes above 50 m. For this purpose, our team have developed a system under a tethered balloon which has been in use since 2010.
Joan Cuxart, Burkhard Wrenger, Daniel Martínez-Villagrasa, Joachim Reuder, Marius O. Jonassen, Maria A. Jiménez, Marie Lothon, Fabienne Lohou, Oscar Hartogensis, Jens Dünnermann, Laura Conangla, and Anirban Garai
Atmos. Chem. Phys., 16, 9489–9504, https://doi.org/10.5194/acp-16-9489-2016, https://doi.org/10.5194/acp-16-9489-2016, 2016
Short summary
Short summary
Estimations of the effect of thermal advection in the surface energy budget are provided. Data from the experimental campaign BLLAST, held in Southern France in summer 2011, are used, including airborne data by drones and surface-based instrumentation. Model data outputs and satellite information are also inspected. Surface heterogeneities of the order of the kilometer or larger seem to have little effect on the budget, whereas hectometer-scale structures may contribute significantly to it.
Fleur Couvreux, Eric Bazile, Guylaine Canut, Yann Seity, Marie Lothon, Fabienne Lohou, Françoise Guichard, and Erik Nilsson
Atmos. Chem. Phys., 16, 8983–9002, https://doi.org/10.5194/acp-16-8983-2016, https://doi.org/10.5194/acp-16-8983-2016, 2016
Short summary
Short summary
This study evaluates the ability of operational models to predict the boundary-layer turbulent processes and mesoscale variability observed during the Boundary Layer Late-Afternoon and Sunset Turbulence field campaign. The models succeed in reproducing the variability from one day to another in terms of cloud cover, temperature and boundary-layer depth. However, they exhibit some systematic biases. The high-resolution model reproduces the vertical structures better.
Erik Nilsson, Marie Lothon, Fabienne Lohou, Eric Pardyjak, Oscar Hartogensis, and Clara Darbieu
Atmos. Chem. Phys., 16, 8873–8898, https://doi.org/10.5194/acp-16-8873-2016, https://doi.org/10.5194/acp-16-8873-2016, 2016
Short summary
Short summary
A new simple model for turbulence kinetic energy (TKE) and its budget is presented for the sheared convective atmospheric boundary layer. It is used to study effects of buoyancy and shear on TKE evolution during the afternoon transition, especially near the surface. We also find a region of weak turbulence during unstable afternoon conditions below the inversion top, which we refer to as a "pre-residual layer".
C. Darbieu, F. Lohou, M. Lothon, J. Vilà-Guerau de Arellano, F. Couvreux, P. Durand, D. Pino, E. G. Patton, E. Nilsson, E. Blay-Carreras, and B. Gioli
Atmos. Chem. Phys., 15, 10071–10086, https://doi.org/10.5194/acp-15-10071-2015, https://doi.org/10.5194/acp-15-10071-2015, 2015
Short summary
Short summary
A case study of the BLLAST experiment is considered to explore the decay of turbulence that occurs in the convective boundary layer over land during the afternoon. Based on observations and on a large-eddy simulation, the analysis reveals two phases in the afternoon: a first quasi-stationary phase when the turbulent kinetic energy slowly decays without significant change in the turbulence structure and a second phase of more rapid decay with a change in spectral turbulence characteristics.
C. Román-Cascón, C. Yagüe, L. Mahrt, M. Sastre, G.-J. Steeneveld, E. Pardyjak, A. van de Boer, and O. Hartogensis
Atmos. Chem. Phys., 15, 9031–9047, https://doi.org/10.5194/acp-15-9031-2015, https://doi.org/10.5194/acp-15-9031-2015, 2015
Short summary
Short summary
Stable-boundary-layer processes have been analysed using BLLAST data. Shallow drainage flows were formed at some locations after the near calm stage of the late afternoon. This stage ended with the arrival of a deeper wind associated with the mountain-plain circulation. At the same time, gravity waves were detected with an array of microbarometers. The interaction of these processes with turbulence was studied through multi-resolution flux decomposition at different sites and heights.
H. P. Pietersen, J. Vilà-Guerau de Arellano, P. Augustin, A. van de Boer, O. de Coster, H. Delbarre, P. Durand, M. Fourmentin, B. Gioli, O. Hartogensis, F. Lohou, M. Lothon, H. G. Ouwersloot, D. Pino, and J. Reuder
Atmos. Chem. Phys., 15, 4241–4257, https://doi.org/10.5194/acp-15-4241-2015, https://doi.org/10.5194/acp-15-4241-2015, 2015
M. Lothon, F. Lohou, D. Pino, F. Couvreux, E. R. Pardyjak, J. Reuder, J. Vilà-Guerau de Arellano, P Durand, O. Hartogensis, D. Legain, P. Augustin, B. Gioli, D. H. Lenschow, I. Faloona, C. Yagüe, D. C. Alexander, W. M. Angevine, E Bargain, J. Barrié, E. Bazile, Y. Bezombes, E. Blay-Carreras, A. van de Boer, J. L. Boichard, A. Bourdon, A. Butet, B. Campistron, O. de Coster, J. Cuxart, A. Dabas, C. Darbieu, K. Deboudt, H. Delbarre, S. Derrien, P. Flament, M. Fourmentin, A. Garai, F. Gibert, A. Graf, J. Groebner, F. Guichard, M. A. Jiménez, M. Jonassen, A. van den Kroonenberg, V. Magliulo, S. Martin, D. Martinez, L. Mastrorillo, A. F. Moene, F. Molinos, E. Moulin, H. P. Pietersen, B. Piguet, E. Pique, C. Román-Cascón, C. Rufin-Soler, F. Saïd, M. Sastre-Marugán, Y. Seity, G. J. Steeneveld, P. Toscano, O. Traullé, D. Tzanos, S. Wacker, N. Wildmann, and A. Zaldei
Atmos. Chem. Phys., 14, 10931–10960, https://doi.org/10.5194/acp-14-10931-2014, https://doi.org/10.5194/acp-14-10931-2014, 2014
E. Blay-Carreras, E. R. Pardyjak, D. Pino, D. C. Alexander, F. Lohou, and M. Lothon
Atmos. Chem. Phys., 14, 9077–9085, https://doi.org/10.5194/acp-14-9077-2014, https://doi.org/10.5194/acp-14-9077-2014, 2014
E. Blay-Carreras, D. Pino, J. Vilà-Guerau de Arellano, A. van de Boer, O. De Coster, C. Darbieu, O. Hartogensis, F. Lohou, M. Lothon, and H. Pietersen
Atmos. Chem. Phys., 14, 4515–4530, https://doi.org/10.5194/acp-14-4515-2014, https://doi.org/10.5194/acp-14-4515-2014, 2014
F. Lohou, L. Kergoat, F. Guichard, A. Boone, B. Cappelaere, J.-M. Cohard, J. Demarty, S. Galle, M. Grippa, C. Peugeot, D. Ramier, C. M. Taylor, and F. Timouk
Atmos. Chem. Phys., 14, 3883–3898, https://doi.org/10.5194/acp-14-3883-2014, https://doi.org/10.5194/acp-14-3883-2014, 2014
Related subject area
Subject: Dynamics | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event
Exploring the elevated water vapor signal associated with the free tropospheric biomass burning plume over the southeast Atlantic Ocean
Opinion: Gigacity – a source of problems or the new way to sustainable development
The thermodynamic structures of the planetary boundary layer dominated by synoptic circulations and the regular effect on air pollution in Beijing
Turbulent and boundary layer characteristics during VOCALS-REx
A foehn-induced haze front in Beijing: observations and implications
Airborne measurements and large-eddy simulations of small-scale gravity waves at the tropopause inversion layer over Scandinavia
Observational analysis of the daily cycle of the planetary boundary layer in the central Amazon during a non-El Niño year and El Niño year (GoAmazon project 2014/5)
Planetary boundary layer evolution over the Amazon rainforest in episodes of deep moist convection at the Amazon Tall Tower Observatory
Dominant patterns of summer ozone pollution in eastern China and associated atmospheric circulations
What controls the formation of nocturnal low-level stratus clouds over southern West Africa during the monsoon season?
Recent trends in climate variability at the local scale using 40 years of observations: the case of the Paris region of France
Nocturnal boundary layer turbulence regimes analysis during the BLLAST campaign
Low-level stratiform clouds and dynamical features observed within the southern West African monsoon
Residual layer ozone, mixing, and the nocturnal jet in California's San Joaquin Valley
From weak to intense downslope winds: origin, interaction with boundary-layer turbulence and impact on CO2 variability
On the fine vertical structure of the low troposphere over the coastal margins of East Antarctica
Spatial and temporal variability of turbulence dissipation rate in complex terrain
Characterizing wind gusts in complex terrain
Long-term trends of instability and associated parameters over the Indian region obtained using a radiosonde network
Implication of tropical lower stratospheric cooling in recent trends in tropical circulation and deep convective activity
The observed diurnal cycle of low-level stratus clouds over southern West Africa: a case study
Nocturnal low-level clouds in the atmospheric boundary layer over southern West Africa: an observation-based analysis of conditions and processes
Characteristics and evolution of diurnal foehn events in the Dead Sea valley
High tropospheric ozone in Lhasa within the Asian summer monsoon anticyclone in 2013: influence of convective transport and stratospheric intrusions
Anthropogenic and natural drivers of a strong winter urban heat island in a typical Arctic city
A comparison of plume rise algorithms to stack plume measurements in the Athabasca oil sands
Upscaling surface energy fluxes over the North Slope of Alaska using airborne eddy-covariance measurements and environmental response functions
Climatological study of the Boundary-layer air Stagnation Index for China and its relationship with air pollution
Self-organized classification of boundary layer meteorology and associated characteristics of air quality in Beijing
The strengthening relationship between Eurasian snow cover and December haze days in central North China after the mid-1990s
Observational analyses of dramatic developments of a severe air pollution event in the Beijing area
The meteorology and chemistry of high nitrogen oxide concentrations in the stable boundary layer at the South Pole
Mountain waves modulate the water vapor distribution in the UTLS
Retrieving characteristics of inertia gravity wave parameters with least uncertainties using the hodograph method
In situ temperature measurements in the upper troposphere and lowermost stratosphere from 2 decades of IAGOS long-term routine observation
A meteorological and chemical overview of the DACCIWA field campaign in West Africa in June–July 2016
Investigation of the mixing layer height derived from ceilometer measurements in the Kathmandu Valley and implications for local air quality
Air stagnation in China (1985–2014): climatological mean features and trends
Modes of vertical thermodynamic and wind variability over the Maritime Continent
Diurnal variability of the atmospheric boundary layer height over a tropical station in the Indian monsoon region
The open-ocean sensible heat flux and its significance for Arctic boundary layer mixing during early fall
Controlled meteorological (CMET) free balloon profiling of the Arctic atmospheric boundary layer around Spitsbergen compared to ERA-Interim and Arctic System Reanalyses
Boundary layer evolution over the central Himalayas from radio wind profiler and model simulations
Estimation of the advection effects induced by surface heterogeneities in the surface energy budget
How stratospheric are deep stratospheric intrusions? LUAMI 2008
Why did the storm ex-Gaston (2010) fail to redevelop during the PREDICT experiment?
A study of local turbulence and anisotropy during the afternoon and evening transition with an unmanned aerial system and mesoscale simulation
Vertical wind retrieved by airborne lidar and analysis of island induced gravity waves in combination with numerical models and in situ particle measurements
Observations of surface momentum exchange over the marginal ice zone and recommendations for its parametrisation
Markus Geldenhuys, Peter Preusse, Isabell Krisch, Christoph Zülicke, Jörn Ungermann, Manfred Ern, Felix Friedl-Vallon, and Martin Riese
Atmos. Chem. Phys., 21, 10393–10412, https://doi.org/10.5194/acp-21-10393-2021, https://doi.org/10.5194/acp-21-10393-2021, 2021
Short summary
Short summary
A large-scale gravity wave (GW) was observed spanning the whole of Greenland. The GWs proposed in this paper come from a new jet–topography mechanism. The topography compresses the flow and triggers a change in u- and
v-wind components. The jet becomes out of geostrophic balance and sheds energy in the form of GWs to restore the balance. This topography–jet interaction was not previously considered by the community, rendering the impact of the gravity waves largely unaccounted for.
Kristina Pistone, Paquita Zuidema, Robert Wood, Michael Diamond, Arlindo M. da Silva, Gonzalo Ferrada, Pablo E. Saide, Rei Ueyama, Ju-Mee Ryoo, Leonhard Pfister, James Podolske, David Noone, Ryan Bennett, Eric Stith, Gregory Carmichael, Jens Redemann, Connor Flynn, Samuel LeBlanc, Michal Segal-Rozenhaimer, and Yohei Shinozuka
Atmos. Chem. Phys., 21, 9643–9668, https://doi.org/10.5194/acp-21-9643-2021, https://doi.org/10.5194/acp-21-9643-2021, 2021
Short summary
Short summary
Using aircraft-based measurements off the Atlantic coast of Africa, we found the springtime smoke plume was strongly correlated with the amount of water vapor in the atmosphere (more smoke indicated more humidity). We see the same general feature in satellite-assimilated and free-running models. Our analysis suggests this relationship is not caused by the burning but originates due to coincident continental meteorology plus fires. This air is transported over the ocean without further mixing.
Markku Kulmala, Tom V. Kokkonen, Juha Pekkanen, Sami Paatero, Tuukka Petäjä, Veli-Matti Kerminen, and Aijun Ding
Atmos. Chem. Phys., 21, 8313–8322, https://doi.org/10.5194/acp-21-8313-2021, https://doi.org/10.5194/acp-21-8313-2021, 2021
Short summary
Short summary
The eastern part of China as a whole is practically a gigacity with 650 million inhabitants. The gigacity, with its emissions, processes in the pollution cocktail and numerous feedbacks and interactions, has a crucial and big impact on regional air quality and on global climate. A large-scale research and innovation program is needed to meet the interlinked grand challenges in this gigacity and to serve as a platform for finding pathways for sustainable development of the globe.
Yunyan Jiang, Jinyuan Xin, Ying Wang, Guiqian Tang, Yuxin Zhao, Danjie Jia, Dandan Zhao, Meng Wang, Lindong Dai, Lili Wang, Tianxue Wen, and Fangkun Wu
Atmos. Chem. Phys., 21, 6111–6128, https://doi.org/10.5194/acp-21-6111-2021, https://doi.org/10.5194/acp-21-6111-2021, 2021
Short summary
Short summary
Multiscale-circulation coupling affects pollution by changing the planetary boundary layer (PBL) structure. The multilayer PBL under cyclonic circulation has no diurnal variation; the temperature inversion and zero-speed zone can reach 600–900 m with strong mountain winds. The monolayer PBL under southwestern circulation can reach 2000 m; the inversion is lower than nocturnal PBL (400 m) with strong ambient winds. The zonal winds' vertical shear produces the inversion under western circulation.
Dillon S. Dodson and Jennifer D. Small Griswold
Atmos. Chem. Phys., 21, 1937–1961, https://doi.org/10.5194/acp-21-1937-2021, https://doi.org/10.5194/acp-21-1937-2021, 2021
Short summary
Short summary
The results here reinforce findings from previous in situ studies of the marine boundary layer. It is found that turbulence is maximized in the middle of the stratocumulus layer from latent heating effects. Precipitation acts to increase turbulence in the sub-cloud layer, while acting to stabilize the entire boundary layer after the evaporation of precipitation in the sub-cloud has stopped. A negative correlation is present between the boundary layer height and turbulence.
Ju Li, Zhaobin Sun, Donald H. Lenschow, Mingyu Zhou, Youjun Dou, Zhigang Cheng, Yaoting Wang, and Qingchun Li
Atmos. Chem. Phys., 20, 15793–15809, https://doi.org/10.5194/acp-20-15793-2020, https://doi.org/10.5194/acp-20-15793-2020, 2020
Short summary
Short summary
We analyzed a haze front event involving warm–dry downslope flow in December 2015 in Beijing, China. The haze front was formed by the collision between a clean warm–dry air mass flowing from a nearby mountainous region and a polluted cold–wet air mass over an urban area. We found that the polluted air advanced toward the clean air, resulting in a severe air pollution event. Our study highlights the need to further investigate the warm–dry downslope and its impacts on air pollution.
Sonja Gisinger, Johannes Wagner, and Benjamin Witschas
Atmos. Chem. Phys., 20, 10091–10109, https://doi.org/10.5194/acp-20-10091-2020, https://doi.org/10.5194/acp-20-10091-2020, 2020
Short summary
Short summary
Gravity waves are an important coupling mechanism in the atmosphere. Measurements by two research aircraft during a mountain wave event over Scandinavia in 2016 revealed changes of the horizontal scales in the vertical velocity field and of momentum fluxes in the vicinity of the tropopause inversion. Idealized simulations revealed the presence of interfacial waves. They are found downstream of the mountain peaks, meaning that they horizontally transport momentum/energy away from their source.
Rayonil G. Carneiro and Gilberto Fisch
Atmos. Chem. Phys., 20, 5547–5558, https://doi.org/10.5194/acp-20-5547-2020, https://doi.org/10.5194/acp-20-5547-2020, 2020
Short summary
Short summary
The objective of this study was to conduct observational evaluations of the daily cycle of the height of the planetary boundary layer from data that were measured and/or estimated using instruments such as a radiosonde, sodar, ceilometer, wind profiler, lidar and microwave radiometer installed in the central Amazon during 2014 (considered a typical year) and 2015 during which an intense El Niño–Southern Oscillation (ENSO) event predominated during the GoAmazon experiment.
Maurício I. Oliveira, Otávio C. Acevedo, Matthias Sörgel, Ernani L. Nascimento, Antonio O. Manzi, Pablo E. S. Oliveira, Daiane V. Brondani, Anywhere Tsokankunku, and Meinrat O. Andreae
Atmos. Chem. Phys., 20, 15–27, https://doi.org/10.5194/acp-20-15-2020, https://doi.org/10.5194/acp-20-15-2020, 2020
Short summary
Short summary
In this study, data collected during four deep convection events at the 80 m tower from the Amazon Tall Tower Observatory are analyzed. It provides a unique view on how such events affect the local boundary layer and how it recovers after their passage. Quantities analyzed include mean wind speed, virtual potential temperature, turbulent kinetic energy, sensible, and latent heat fluxes. A conceptual model for boundary layer structure along the passage of deep convection events is proposed.
Zhicong Yin, Bufan Cao, and Huijun Wang
Atmos. Chem. Phys., 19, 13933–13943, https://doi.org/10.5194/acp-19-13933-2019, https://doi.org/10.5194/acp-19-13933-2019, 2019
Short summary
Short summary
Ozone occurs both in the stratosphere and at ground level. Surface ozone is a man-made air pollutant and has harmful effects on people and the environment. Two dominant patterns of summer ozone pollution were determined. The most dominant pattern in 2017 and 2018 was different from that in previous years. The findings of this study help us to understand the features of surface ozone pollution in eastern China and their relationships with large-scale atmospheric circulations.
Karmen Babić, Norbert Kalthoff, Bianca Adler, Julian F. Quinting, Fabienne Lohou, Cheikh Dione, and Marie Lothon
Atmos. Chem. Phys., 19, 13489–13506, https://doi.org/10.5194/acp-19-13489-2019, https://doi.org/10.5194/acp-19-13489-2019, 2019
Short summary
Short summary
This study investigates differences in atmospheric conditions between nights with and without low-level stratus clouds (LLCs) over southern West Africa. We use high-quality observations collected during 2016 summer monsoon season and the ERA5 reanalysis data set. Our results show that the formation of LLCs depends on the interplay between the onset time and strength of the nocturnal low-level jet, horizontal cold-air advection, and the overall moisture level in the whole region.
Justine Ringard, Marjolaine Chiriaco, Sophie Bastin, and Florence Habets
Atmos. Chem. Phys., 19, 13129–13155, https://doi.org/10.5194/acp-19-13129-2019, https://doi.org/10.5194/acp-19-13129-2019, 2019
Short summary
Short summary
This study characterizes the changes observed at Paris urban scale and attempts to identify the surface–atmosphere feedbacks likely to explain the trends observed as a function of the different configurations of large-scale dynamics. This article is interested in several atmospheric parameters and their possible retroactions. Finally, to study urban environments, the analysis at the local scale is essential because it is very poorly represented in the model.
Jesús Yus-Díez, Mireia Udina, Maria Rosa Soler, Marie Lothon, Erik Nilsson, Joan Bech, and Jielun Sun
Atmos. Chem. Phys., 19, 9495–9514, https://doi.org/10.5194/acp-19-9495-2019, https://doi.org/10.5194/acp-19-9495-2019, 2019
Short summary
Short summary
This study helps improve the understanding of the turbulence description and the interactions occurring in the lower part of the boundary layer. It is carried out at an orographically influenced site close to the Pyrenees to explore the hockey-stick transition (HOST) theory. HOST is seen to be strongly dependent on both the meteorological conditions and the orographic features. Examples of intermittent turbulence events that lead to transitions between the turbulence regimes are also identified.
Cheikh Dione, Fabienne Lohou, Marie Lothon, Bianca Adler, Karmen Babić, Norbert Kalthoff, Xabier Pedruzo-Bagazgoitia, Yannick Bezombes, and Omar Gabella
Atmos. Chem. Phys., 19, 8979–8997, https://doi.org/10.5194/acp-19-8979-2019, https://doi.org/10.5194/acp-19-8979-2019, 2019
Short summary
Short summary
Low atmospheric dynamics and low-level cloud (LLC) macrophysical properties are analyzed using in situ and remote sensing data collected from 20 June to 30 July at Savè, Benin, during the DACCIWA field campaign in 2016. We find that the low-level jet (LLJ), LLCs, monsoon flow, and maritime inflow reveal a day-to-day variability. LLCs form at the same level as the jet core height. The cloud base height is stationary at night and remains below the jet. The cloud top height is found above the jet.
Dani J. Caputi, Ian Faloona, Justin Trousdell, Jeanelle Smoot, Nicholas Falk, and Stephen Conley
Atmos. Chem. Phys., 19, 4721–4740, https://doi.org/10.5194/acp-19-4721-2019, https://doi.org/10.5194/acp-19-4721-2019, 2019
Short summary
Short summary
This paper covers the importance of understanding ozone pollution in California’s southern San Joaquin Valley from the perspective of meteorological conditions that occur overnight. Our main finding is that stronger winds aloft allow ozone to be depleted overnight, leading to less ozone the following day. This finding has the potential to greatly improve ozone forecasts in the San Joaquin Valley. This study is primarily conducted with aircraft observations.
Jon Ander Arrillaga, Carlos Yagüe, Carlos Román-Cascón, Mariano Sastre, Maria Antonia Jiménez, Gregorio Maqueda, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 19, 4615–4635, https://doi.org/10.5194/acp-19-4615-2019, https://doi.org/10.5194/acp-19-4615-2019, 2019
Short summary
Short summary
Thermally driven downslope winds develop in mountainous areas under a weak large-scale forcing and clear skies. In this work, we find that their onset time and intensity are closely connected with both the large-scale wind and soil moisture. We also show how the distinct downslope intensities shape the turbulent and thermal features of the nocturnal atmosphere. The analysis concludes that the downslope–turbulence interaction and the horizontal transport explain the important CO2 variability.
Étienne Vignon, Olivier Traullé, and Alexis Berne
Atmos. Chem. Phys., 19, 4659–4683, https://doi.org/10.5194/acp-19-4659-2019, https://doi.org/10.5194/acp-19-4659-2019, 2019
Short summary
Short summary
The future sea-level rise will depend on how much the Antarctic ice sheet gain – via precipitation – or loose mass. The simulation of precipitation by numerical models used for projections depends on the representation of the atmospheric circulation over and around Antarctica. Using daily measurements from balloon soundings at nine Antarctic stations, this study characterizes the structure of the atmosphere over the Antarctic coast and its representation in atmospheric simulations.
Nicola Bodini, Julie K. Lundquist, Raghavendra Krishnamurthy, Mikhail Pekour, Larry K. Berg, and Aditya Choukulkar
Atmos. Chem. Phys., 19, 4367–4382, https://doi.org/10.5194/acp-19-4367-2019, https://doi.org/10.5194/acp-19-4367-2019, 2019
Short summary
Short summary
To improve the parameterization of the turbulence dissipation rate (ε) in numerical weather prediction models, we have assessed its temporal and spatial variability at various scales in the Columbia River Gorge during the WFIP2 field experiment. The turbulence dissipation rate shows large spatial variability, even at the microscale, with larger values in sites located downwind of complex orographic structures or in wind farm wakes. Distinct diurnal and seasonal cycles in ε have also been found.
Frederick Letson, Rebecca J. Barthelmie, Weifei Hu, and Sara C. Pryor
Atmos. Chem. Phys., 19, 3797–3819, https://doi.org/10.5194/acp-19-3797-2019, https://doi.org/10.5194/acp-19-3797-2019, 2019
Short summary
Short summary
Wind gusts are a key driver of aerodynamic loading, and common approximations used to describe wind gust behavior may not be appropriate in complex terrain at heights relevant to wind turbines and other structures. High-resolution observations from sonic anemometers and vertically pointing Doppler lidars collected in the Perdigão experiment are analyzed to provide a foundation for improved wind gust characterization in complex terrain.
Rohit Chakraborty, Madineni Venkat Ratnam, and Shaik Ghouse Basha
Atmos. Chem. Phys., 19, 3687–3705, https://doi.org/10.5194/acp-19-3687-2019, https://doi.org/10.5194/acp-19-3687-2019, 2019
Short summary
Short summary
Intense convective phenomena are a common climatic feature in the Indian tropical region which occur during the pre-monsoon to post-monsoon seasons (April–October) and are generally accompanied by intense thunderstorms, lightning, and wind gusts with heavy rainfall. Here we show long-term trends of the parameters related to convection and instability obtained from 27 radiosonde stations across six subdivisions over the Indian region during the period 1980–2016.
Kunihiko Kodera, Nawo Eguchi, Rei Ueyama, Yuhji Kuroda, Chiaki Kobayashi, Beatriz M. Funatsu, and Chantal Claud
Atmos. Chem. Phys., 19, 2655–2669, https://doi.org/10.5194/acp-19-2655-2019, https://doi.org/10.5194/acp-19-2655-2019, 2019
Short summary
Short summary
The recent cooling of the equatorial eastern Pacific Ocean occurred in conjunction with enhanced cross-equatorial southerlies associated with a strengthening of the boreal summer Hadley circulation. A combination of land surface warming and reduced static stability in the tropical tropopause layer due to stratospheric cooling is suggested to have caused the increase in the deep ascending branch of the Hadley circulation and related recent decadal change in the tropical troposphere and ocean.
Karmen Babić, Bianca Adler, Norbert Kalthoff, Hendrik Andersen, Cheikh Dione, Fabienne Lohou, Marie Lothon, and Xabier Pedruzo-Bagazgoitia
Atmos. Chem. Phys., 19, 1281–1299, https://doi.org/10.5194/acp-19-1281-2019, https://doi.org/10.5194/acp-19-1281-2019, 2019
Short summary
Short summary
The first detailed observational analysis of the complete diurnal cycle of low-level clouds (LLC) and associated atmospheric processes over southern West Africa is performed using the data gathered within the DACCIWA (Dynamics-Aerosol-Chemistry-Cloud-Interactions in West Africa) ground-based campaign. We find cooling related to the horizontal advection, which occurs in connection with the inflow of cool maritime air mass and a prominent low-level jet, to have the dominant role in LLC formation.
Bianca Adler, Karmen Babić, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, Cheikh Dione, Xabier Pedruzo-Bagazgoitia, and Hendrik Andersen
Atmos. Chem. Phys., 19, 663–681, https://doi.org/10.5194/acp-19-663-2019, https://doi.org/10.5194/acp-19-663-2019, 2019
Short summary
Short summary
This study deals with nocturnal stratiform low-level clouds that frequently form in the atmospheric boundary layer over southern West Africa. We use observational data from 11 nights to characterize the clouds and intranight variability of boundary layer conditions as well as to assess the physical processes relevant for cloud formation. We find that cooling is crucial to reach saturation and a large part of the cooling is related to horizontal advection of cool air from the Gulf of Guinea.
Jutta Vüllers, Georg J. Mayr, Ulrich Corsmeier, and Christoph Kottmeier
Atmos. Chem. Phys., 18, 18169–18186, https://doi.org/10.5194/acp-18-18169-2018, https://doi.org/10.5194/acp-18-18169-2018, 2018
Short summary
Short summary
This paper investigates frequently occurring foehn at the Dead Sea, which strongly impacts the local climatic conditions, in particular temperature and humidity, as well as evaporation from the Dead Sea, the aerosol load, and visibility. A statistical classification exposes two types of foehn and first-time, high-resolution measurements reveal trigger mechanisms and relevant characteristics, such as wind velocities, affected air layers, and resulting phenomena such as hydraulic jumps and rotors.
Dan Li, Bärbel Vogel, Rolf Müller, Jianchun Bian, Gebhard Günther, Qian Li, Jinqiang Zhang, Zhixuan Bai, Holger Vömel, and Martin Riese
Atmos. Chem. Phys., 18, 17979–17994, https://doi.org/10.5194/acp-18-17979-2018, https://doi.org/10.5194/acp-18-17979-2018, 2018
Short summary
Short summary
Balloon-borne measurements performed over Lhasa in August 2013 are investigated using CLaMS trajectory calculations. Here, we focus on high ozone mixing ratios in the free troposphere. Our findings demonstrate that both stratospheric intrusions and convective transport of air pollution play a major role in enhancing middle and upper tropospheric ozone.
Mikhail Varentsov, Pavel Konstantinov, Alexander Baklanov, Igor Esau, Victoria Miles, and Richard Davy
Atmos. Chem. Phys., 18, 17573–17587, https://doi.org/10.5194/acp-18-17573-2018, https://doi.org/10.5194/acp-18-17573-2018, 2018
Short summary
Short summary
This study reports on the urban heat island (UHI) in a typical Arctic city in winter. Using in situ observations, remote sensing data and modeling, we show that the urban temperature anomaly reaches up to 11 K with a mean value of 1.9 K. At least 50 % of this anomaly is caused by the UHI effect, driven mostly by heating. The rest is created by natural microclimatic variability over the hilly terrain. This is a strong argument in support of energy efficiency measures in the Arctic cities.
Mark Gordon, Paul A. Makar, Ralf M. Staebler, Junhua Zhang, Ayodeji Akingunola, Wanmin Gong, and Shao-Meng Li
Atmos. Chem. Phys., 18, 14695–14714, https://doi.org/10.5194/acp-18-14695-2018, https://doi.org/10.5194/acp-18-14695-2018, 2018
Short summary
Short summary
This work uses aircraft-based measurements of smokestack plumes carried out in northern Alberta in 2013. These measurements are used to test equations used to predict how high in the air smokestack plumes rise. It is important to predict plume rise height accurately as it tells us how far downwind pollutants are carried and what air quality can be expected at the surface. We found that the equations that are typically used significantly underestimate the plume rise at this location.
Andrei Serafimovich, Stefan Metzger, Jörg Hartmann, Katrin Kohnert, Donatella Zona, and Torsten Sachs
Atmos. Chem. Phys., 18, 10007–10023, https://doi.org/10.5194/acp-18-10007-2018, https://doi.org/10.5194/acp-18-10007-2018, 2018
Short summary
Short summary
In order to support the evaluation of coupled atmospheric–land-surface models we investigated spatial patterns of energy fluxes in relation to land-surface properties and upscaled airborne flux measurements to high resolution flux maps. A machine learning technique allows us to estimate environmental response functions between spatially and temporally resolved flux observations and corresponding biophysical and meteorological drivers.
Qianqian Huang, Xuhui Cai, Jian Wang, Yu Song, and Tong Zhu
Atmos. Chem. Phys., 18, 7573–7593, https://doi.org/10.5194/acp-18-7573-2018, https://doi.org/10.5194/acp-18-7573-2018, 2018
Short summary
Short summary
Air stagnation index is a vital meteorological measure of the atmosphere's ability to dilute air pollutants. We propose a Boundary-layer air Stagnation Index (BSI) based on daily maximal ventilation, real latent instability and precipitation. The BSI is positively correlated with API during 2000–2012, tracks the day-by-day variation of PM2.5 concentration during January 2013 in Beijing well, and successfully represents the improved air quality during November and December in 2017.
Zhiheng Liao, Jiaren Sun, Jialin Yao, Li Liu, Haowen Li, Jian Liu, Jielan Xie, Dui Wu, and Shaojia Fan
Atmos. Chem. Phys., 18, 6771–6783, https://doi.org/10.5194/acp-18-6771-2018, https://doi.org/10.5194/acp-18-6771-2018, 2018
Short summary
Short summary
This paper investigates the modulation effect of ABL meteorology on Beijing’s surface air quality based on self-organizing maps. The self-organized ABL types correspond to significantly distinct pollutant loadings and diurnal evolution, particularly in winter. Anomalous stable ABL conditions are estimated to contribute 58.3 %, 46.4 % and 73.3 % of the elevated PM2.5 concentrations in January 2013, December 2015 and December 2016.
Zhicong Yin and Huijun Wang
Atmos. Chem. Phys., 18, 4753–4763, https://doi.org/10.5194/acp-18-4753-2018, https://doi.org/10.5194/acp-18-4753-2018, 2018
Short summary
Short summary
In China, the haze pollution in December has become increasingly serious over recent decades. The relationship between the snow cover and the December haze days was analyzed. This relationship significantly strengthened after the mid-1990s, which is attributed to the effective connections between the snow cover and the Eurasian atmospheric circulations.
Ju Li, Jielun Sun, Mingyu Zhou, Zhigang Cheng, Qingchun Li, Xiaoyan Cao, and Jingjiang Zhang
Atmos. Chem. Phys., 18, 3919–3935, https://doi.org/10.5194/acp-18-3919-2018, https://doi.org/10.5194/acp-18-3919-2018, 2018
Short summary
Short summary
A rapid increase in the PM2.5 concentration in Beijing, China, on 30 November 2015 was found to be transported from south of Beijing by both turbulent mixing and advection processes. The nighttime relatively clean air was from the downslope flow northwest of Beijing; the rapid increase in the PM2.5 concentration in the morning resulted from the downward convective turbulent transfer of the polluted air that was rapidly advected over the nighttime stable boundary layer.
William Neff, Jim Crawford, Marty Buhr, John Nicovich, Gao Chen, and Douglas Davis
Atmos. Chem. Phys., 18, 3755–3778, https://doi.org/10.5194/acp-18-3755-2018, https://doi.org/10.5194/acp-18-3755-2018, 2018
Short summary
Short summary
Our study examined the effect of the seasonal cycle in meteorology from November through December and the role of stratospheric ozone depletion in the photochemical production of nitrogen oxide (NO) from nitrate in the snow at the South Pole. We found that ozone depletion which now extends into late November–early December coincides with optimum meteorological conditions (clear skies, a stable shallow boundary layer, and light winds) for high concentrations of NO to accumulate at the surface.
Romy Heller, Christiane Voigt, Stuart Beaton, Andreas Dörnbrack, Andreas Giez, Stefan Kaufmann, Christian Mallaun, Hans Schlager, Johannes Wagner, Kate Young, and Markus Rapp
Atmos. Chem. Phys., 17, 14853–14869, https://doi.org/10.5194/acp-17-14853-2017, https://doi.org/10.5194/acp-17-14853-2017, 2017
Gopa Dutta, Palla Vinay Kumar, and Salauddin Mohammad
Atmos. Chem. Phys., 17, 14811–14819, https://doi.org/10.5194/acp-17-14811-2017, https://doi.org/10.5194/acp-17-14811-2017, 2017
Short summary
Short summary
Gravity wave stress is crucial for weather prediction purposes. It is found that proper filtering of the data is essential to reduce uncertainties in the popular hodograph method to delineate low-frequency gravity wave parameters. Our research helped in improving the estimates of gravity wave stress by reducing errors.
Florian Berkes, Patrick Neis, Martin G. Schultz, Ulrich Bundke, Susanne Rohs, Herman G. J. Smit, Andreas Wahner, Paul Konopka, Damien Boulanger, Philippe Nédélec, Valerie Thouret, and Andreas Petzold
Atmos. Chem. Phys., 17, 12495–12508, https://doi.org/10.5194/acp-17-12495-2017, https://doi.org/10.5194/acp-17-12495-2017, 2017
Short summary
Short summary
This study highlights the importance of independent global measurements with high and long-term accuracy to quantify long-term changes, especially in the UTLS region, and to help identify inconsistencies between different data sets of observations and models. Here we investigated temperature trends over different regions within a climate-sensitive area of the atmosphere and demonstrated the value of the IAGOS temperature observations as an anchor point for the evaluation of reanalyses.
Peter Knippertz, Andreas H. Fink, Adrien Deroubaix, Eleanor Morris, Flore Tocquer, Mat J. Evans, Cyrille Flamant, Marco Gaetani, Christophe Lavaysse, Celine Mari, John H. Marsham, Rémi Meynadier, Abalo Affo-Dogo, Titike Bahaga, Fabien Brosse, Konrad Deetz, Ridha Guebsi, Issaou Latifou, Marlon Maranan, Philip D. Rosenberg, and Andreas Schlueter
Atmos. Chem. Phys., 17, 10893–10918, https://doi.org/10.5194/acp-17-10893-2017, https://doi.org/10.5194/acp-17-10893-2017, 2017
Short summary
Short summary
In June–July 2016 DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa), a large, EU-funded European–African project, organised an international field campaign in densely populated southern West Africa, including measurements from ground sites, research aircraft, weather balloons and urban sites. This paper gives an overview of the atmospheric evolution during this period focusing on meteorological (precipitation, cloudiness, winds) and composition (gases, particles) aspects.
Andrea Mues, Maheswar Rupakheti, Christoph Münkel, Axel Lauer, Heiko Bozem, Peter Hoor, Tim Butler, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 8157–8176, https://doi.org/10.5194/acp-17-8157-2017, https://doi.org/10.5194/acp-17-8157-2017, 2017
Short summary
Short summary
Ceilometer measurements taken in the Kathmandu Valley, Nepal, were used to study the temporal and spatial evolution of the mixing layer height in the valley. This provides important information on the vertical structure of the atmosphere and can thus also help to understand the mixing of air pollutants (e.g. black carbon) in the valley. The seasonal and diurnal cycles of the mixing layer were found to be highly dependent on meteorology and mainly anticorrelated to black carbon concentrations.
Qianqian Huang, Xuhui Cai, Yu Song, and Tong Zhu
Atmos. Chem. Phys., 17, 7793–7805, https://doi.org/10.5194/acp-17-7793-2017, https://doi.org/10.5194/acp-17-7793-2017, 2017
Short summary
Short summary
Air stagnation is an important meteorological measure of unfavorable air conditions, and previous studies have found that stagnation events are usually related to air pollution episodes. China is currently experiencing heavy air pollution, but to our knowledge, little is known about air stagnation in the country. In this paper, we conducted a comprehensive investigation of air stagnation climatology in China based on sounding and surface observations across the country.
Jennie Bukowski, Derek J. Posselt, Jeffrey S. Reid, and Samuel A. Atwood
Atmos. Chem. Phys., 17, 4611–4626, https://doi.org/10.5194/acp-17-4611-2017, https://doi.org/10.5194/acp-17-4611-2017, 2017
Short summary
Short summary
The Maritime Continent (MC) exhibits tremendous meteorological variability. In this study, multiple years of atmospheric soundings over the MC are analyzed to identify key sources of variability in the region's temperature, water vapor, and wind structure. Coherent vertical structures are found among profiles sampled from different geographic locations. The results indicate that the complex meteorology of the region can be described using a few simple structure functions.
Sanjay Kumar Mehta, Madineni Venkat Ratnam, Sukumarapillai V. Sunilkumar, Daggumati Narayana Rao, and Boddapaty V. Krishna Murthy
Atmos. Chem. Phys., 17, 531–549, https://doi.org/10.5194/acp-17-531-2017, https://doi.org/10.5194/acp-17-531-2017, 2017
Short summary
Short summary
Study of the diurnal variation of the atmospheric boundary layer (ABL) height is important for the knowledge of pollutant dispersion, crucial for all living beings. The most difficult part in the study of the diurnal variation is in identification of the stable boundary layer which occurs ~ 50% of times only and mostly during nighttime winter. Surface temperature and clouds directly affect the diurnal pattern of the ABL. Thus, stronger (weaker) diurnal variation found during pre-monsoon (winter).
Manisha Ganeshan and Dong L. Wu
Atmos. Chem. Phys., 16, 13173–13184, https://doi.org/10.5194/acp-16-13173-2016, https://doi.org/10.5194/acp-16-13173-2016, 2016
Short summary
Short summary
The amplified Arctic warming has seen a rapid decline in sea ice with serious implications for global climate. The loss of heat from the ocean to the atmosphere is considered important for the recovery of the diminishing sea ice. Yet there is little observational evidence regarding the efficiency of this process. In our study, we explore and quantify the ability of the open ocean to lose heat through sensible heat fluxes. It is found to depend on the prevailing cloud and wind regime.
Tjarda J. Roberts, Marina Dütsch, Lars R. Hole, and Paul B. Voss
Atmos. Chem. Phys., 16, 12383–12396, https://doi.org/10.5194/acp-16-12383-2016, https://doi.org/10.5194/acp-16-12383-2016, 2016
Short summary
Short summary
We present Controlled Meteorological (CMET) balloon flights in the Arctic. CMETs are a novel balloon that can be controlled (by satellite link) to change altitude during the flight and remain in the troposphere up to several days. We performed automated repeated soundings in the Arctic boundary layer during the flight and compared the observations (temperature, humidity, wind) to output from two atmospheric models. CMETs are a valuable tool for probing the lower atmosphere in remote regions.
Narendra Singh, Raman Solanki, Narendra Ojha, Ruud H. H. Janssen, Andrea Pozzer, and Surendra K. Dhaka
Atmos. Chem. Phys., 16, 10559–10572, https://doi.org/10.5194/acp-16-10559-2016, https://doi.org/10.5194/acp-16-10559-2016, 2016
Short summary
Short summary
Our study presents measurements and model simulations of boundary layer evolution over a mountain peak in the central Himalayas. The observations were made as a part of the Ganges Valley Aerosol Experiment. The implications of biases in model simulated boundary layer towards simulations of trace species is investigated.
Joan Cuxart, Burkhard Wrenger, Daniel Martínez-Villagrasa, Joachim Reuder, Marius O. Jonassen, Maria A. Jiménez, Marie Lothon, Fabienne Lohou, Oscar Hartogensis, Jens Dünnermann, Laura Conangla, and Anirban Garai
Atmos. Chem. Phys., 16, 9489–9504, https://doi.org/10.5194/acp-16-9489-2016, https://doi.org/10.5194/acp-16-9489-2016, 2016
Short summary
Short summary
Estimations of the effect of thermal advection in the surface energy budget are provided. Data from the experimental campaign BLLAST, held in Southern France in summer 2011, are used, including airborne data by drones and surface-based instrumentation. Model data outputs and satellite information are also inspected. Surface heterogeneities of the order of the kilometer or larger seem to have little effect on the budget, whereas hectometer-scale structures may contribute significantly to it.
Thomas Trickl, Hannes Vogelmann, Andreas Fix, Andreas Schäfler, Martin Wirth, Bertrand Calpini, Gilbert Levrat, Gonzague Romanens, Arnoud Apituley, Keith M. Wilson, Robert Begbie, Jens Reichardt, Holger Vömel, and Michael Sprenger
Atmos. Chem. Phys., 16, 8791–8815, https://doi.org/10.5194/acp-16-8791-2016, https://doi.org/10.5194/acp-16-8791-2016, 2016
Short summary
Short summary
A rather homogeneous deep stratospheric intrusion event was mapped by vertical sounding over central Europe and by model calculations along the transport path. The very low minimum H2O mixing ratios demonstrate almost negligible mixing with tropospheric air during the downward transport. The vertical distributions of O3 and aerosol were transferred from the source region to Europe without major change. A rather shallow outflow from the stratosphere was found.
Thomas M. Freismuth, Blake Rutherford, Mark A. Boothe, and Michael T. Montgomery
Atmos. Chem. Phys., 16, 8511–8519, https://doi.org/10.5194/acp-16-8511-2016, https://doi.org/10.5194/acp-16-8511-2016, 2016
Short summary
Short summary
Numerical model analyses are used to investigate the role of dry, environmental air in the failed redevelopment of a tropical cyclone (ex-Gaston, 2010). As early as 12:00 UTC 2 September 2010, a dry layer at and above 600 hPa results in a decrease in the vertical mass flux and vertical, relative vorticity. The intrusion of dry air led to a reduction in vorticity and a compromised pouch at these middle levels. This study supports work looking at the role of dry air in moist convection.
Astrid Lampert, Falk Pätzold, Maria Antonia Jiménez, Lennart Lobitz, Sabrina Martin, Gerald Lohmann, Guylaine Canut, Dominique Legain, Jens Bange, Dani Martínez-Villagrasa, and Joan Cuxart
Atmos. Chem. Phys., 16, 8009–8021, https://doi.org/10.5194/acp-16-8009-2016, https://doi.org/10.5194/acp-16-8009-2016, 2016
Short summary
Short summary
For a large field experiment in summer 2011 in southern France (BLLAST campaign), the development of turbulence in the atmosphere was analysed during the afternoon and evening. Besides ground-based remote sensing and in situ observations, turbulence parameters were measured with an unmanned aerial vehicle and analysed by numerical simulation. Turbulence decreased during the afternoon, but increased after sunset due to local wind systems. Turbulent eddies lost symmetry during the transition.
Fernando Chouza, Oliver Reitebuch, Michael Jähn, Stephan Rahm, and Bernadett Weinzierl
Atmos. Chem. Phys., 16, 4675–4692, https://doi.org/10.5194/acp-16-4675-2016, https://doi.org/10.5194/acp-16-4675-2016, 2016
Short summary
Short summary
This study presents the analysis of island induced gravity waves observed by an airborne Doppler wind lidar (DWL). First, the instrumental corrections required for the retrieval vertical wind measurements from an airborne DWL are presented. Then, the method is applied to two case studies to determine, in combination with numerical models and in situ measurements, the main characteristics of the observed waves.
A. D. Elvidge, I. A. Renfrew, A. I. Weiss, I. M. Brooks, T. A. Lachlan-Cope, and J. C. King
Atmos. Chem. Phys., 16, 1545–1563, https://doi.org/10.5194/acp-16-1545-2016, https://doi.org/10.5194/acp-16-1545-2016, 2016
Short summary
Short summary
Rare aircraft observations of surface momentum flux over the Arctic marginal ice zone provide the best means yet to constrain model representation of MIZ surface roughness. The sensitivity of surface roughness to ice concentration over the Arctic MIZ is presented; these results do not support the values used in many models. However, a leading parameterization scheme (that of Lüpkes et al., 2012) is found to provide a good representation of form drag, after some parameter alterations.
Cited articles
Albertson, J., Parlange, M., Kiely, G., and Eichinger, W.: The average dissipation rate of turbulent kinetic energy in the neutral and unstable atmospheric surface layer, J. Geophys. Res., 102, 13423–13432, 1997.
Billesbach, D.: Estimating uncertainties in individual eddy covariance flux measurements: A comparison of methods and a proposed new method, J. Agr. Forest Meteorol., 151, 394–405, 2011.
Blay-Carreras, E.: Day-by-day description of the IOPs, available at: http://bllast.sedoo.fr/documents/Blay-Carreras_IOPs-description.pdf (last access date: 18 May 2016), 2013.
Blay-Carreras, E., Pino, D., Vilà-Guerau de Arellano, J., van de Boer, A., De Coster, O., Darbieu, C., Hartogensis, O., Lohou, F., Lothon, M., and Pietersen, H.: Role of the residual layer and large-scale subsidence on the development and evolution of the convective boundary layer, Atmos. Chem. Phys., 14, 4515–4530, https://doi.org/10.5194/acp-14-4515-2014, 2014a.
Blay-Carreras, E., Pardyjak, E. R., Pino, D., Alexander, D. C., Lohou, F., and Lothon, M.: Countergradient heat flux observations during the evening transition period, Atmos. Chem. Phys., 14, 9077–9085, https://doi.org/10.5194/acp-14-9077-2014, 2014b.
BLLAST: Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) website, available at: http://bllast.sedoo.fr/database/ (last access: 18 May 2016), 2015.
Bonin, T., Chilson, P., Zielke, B., and Fedorovitch, E.: Observations of the Early Evening Boundary-Layer Transition Using a Small Unmanned Aerial System, Bound.-Lay. Meteorol., 146, 119–132, 2013.
Busse, J. and Knupp, K.: Observed Characteristics of the Afternoon-Evening Boundary Layer Transition Based on Sodar and Surface Data, J. Appl. Meteorol. Climatol., 51, 571–582, 2012.
Caughy, S. and Wyngaard, J.: The turbulence kinetic energy budget in convective conditions, Q. J. Roy. Meteor. Soc., 105, 231–239, 1979.
Cohn, S. and Angevine, W.: Boundary Layer Height and Entrainment Zone Thickness Measured by Lidars and Wind-Profiling Radars, J. Appl. Meteor., 39, 1233–1247, 2000.
Darbieu, C., Lohou, F., Lothon, M., Vilà-Guerau de Arellano, J., Couvreux, F., Durand, P., Pino, D., Patton, E. G., Nilsson, E., Blay-Carreras, E., and Gioli, B.: Turbulence vertical structure of the boundary layer during the afternoon transition, Atmos. Chem. Phys., 15, 10071–10086, https://doi.org/10.5194/acp-15-10071-2015, 2015.
Dupuis, H., Taylor, P. K., Weill, A., and Katsaros, K.: Inertial dissipation method applied to derive turbulent fluxes over the ocean during the Surface of the Ocean, Fluxes and Interactions with the Atmosphere/Atlantic Stratocumulus Transition Experiment (SOFIA/ASTEX) and Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiments with low to moderate wind speeds, J. Geophys. Res., 102, 21115–21129, 1997.
Fedorovich, E. and Conzemius, R.: Effects of wind shear on the atmospheric convective boundary layer structure and evolution, Acta Geophys., 56, 114–141, 2008.
Frentzen, P. and Vogel, C.: The turbulent kinetic energy budget in the atmospheric surface layer: a review and an experimental reexamination in the field, Bound.-Lay. Meteorol., 60, 49–76, 1992.
Garcia, D.: Robust smoothing of gridded data in one and higher dimensions with missing values, Comput. Stat. Data Anal., 54, 1167–1178, 2010.
Goulart, A., Degrazia, G., Rizza, U., and Anfossi, D.: A theoretical model for the study of convective turbulence decay and comparison with large-eddy simulation data, Bound.-Lay. Meteorol., 107, 143–155, 2003.
Goulart, A., Bodmann, B., de Vilhena, M., Soares, P., and Moreira, D.: On the Time Evolution of the Turbulent Kinetic Energy Spectrum for Decaying Turbulence in the Convective Boundary Layer, Bound.-Lay. Meteorol., 138, 61–75, 2010.
Grant, A. L. M.: An observational study of the evening transition boundary-layer, Q. J. Roy. Meteor. Soc., 123, 657–677, 1997.
Högström, U.: Analysis of Turbulence Structure in the Surface layer with a Modified Similarity Formulation for Near Neutral Conditions, J. Atmos. Sci., 47, 1949–1972, 1990.
Högström, U.: Review of some basic characteristics of the atmospheric surface layer, Bound.-Lay. Meteorol., 78, 215–246, 1996.
Jensen, D., Pardyjak, E., and Hoch, S.: Toward understanding surface sensible heat fluxes during transitional stability over contrasting surfaces, in: 21st AMS Symposium on Boundary Layers and Turbulence, 9–13 June 2014, Leeds, United Kingdom, 2014.
Jensen, D., Nadeu, D., Hoch, S., and Pardyjak, E.: Observations of Near-Surface Heat-Flux and Temperature Profiles Through the Early Evening Transition over Contrasting Surfaces, Bound.-Lay. Meteorol., 159, 567–587, https://doi.org/10.1007/s10546-015-0067-z, 2015.
Jiménez, M. and Cuxart, J.: A study of the nocturnal flows generated in the north side of the Pyrénées, Atmos. Res., 145–146, 244–254, 2014.
Jiménez, M. and Cuxart, J.: Observed downslope winds during BLLAST'11 and their representation in the MesoNH model, in: Barcelona BLLAST workshop, 2–3 February 2015, Barcelona, Spain, 2015.
Kaimal, J. C. and Finnigan, J. J.: Amospheric Boundary Layer Flows: Their Structure and Measurement, Oxford University Press, New York, 1994.
Kolmogoroff, A.: Local structure of turbulence in an incompressible viscous fluid at very high Reynolds numbers, Dokl. Akad. Nauk SSSR, 30, 299–303, 1941.
Kumar, V., Kleissl, J., Meneveau, C., and Parlange, M.: Large eddy simulation of a diurnal cycle of the atmospheric boundary layer: Atmospheric stability and scaling issues, Water Resour. Res., 42, 3–18, 2006.
Lothon, M., Lohou, F., Pino, D., Couvreux, F., Pardyjak, E. R., Reuder, J., Vilà-Guerau de Arellano, J., Durand, P., Hartogensis, O., Legain, D., Augustin, P., Gioli, B., Lenschow, D. H., Faloona, I., Yagüe, C., Alexander, D. C., Angevine, W. M., Bargain, E., Barrié, J., Bazile, E., Bezombes, Y., Blay-Carreras, E., van de Boer, A., Boichard, J. L., Bourdon, A., Butet, A., Campistron, B., de Coster, O., Cuxart, J., Dabas, A., Darbieu, C., Deboudt, K., Delbarre, H., Derrien, S., Flament, P., Fourmentin, M., Garai, A., Gibert, F., Graf, A., Groebner, J., Guichard, F., Jiménez, M. A., Jonassen, M., van den Kroonenberg, A., Magliulo, V., Martin, S., Martinez, D., Mastrorillo, L., Moene, A. F., Molinos, F., Moulin, E., Pietersen, H. P., Piguet, B., Pique, E., Román-Cascón, C., Rufin-Soler, C., Saïd, F., Sastre-Marugán, M., Seity, Y., Steeneveld, G. J., Toscano, P., Traullé, O., Tzanos, D., Wacker, S., Wildmann, N., and Zaldei, A.: The BLLAST field experiment: Boundary-Layer Late Afternoon and Sunset Turbulence, Atmos. Chem. Phys., 14, 10931–10960, https://doi.org/10.5194/acp-14-10931-2014, 2014.
Mahrt, L.: Stratified atmospheric boundary layers, Bound.-Lay. Meteorol., 90, 375–396, 1999.
Moeng, C.-H. and Sullivan, P. P.: A comparison of shear and buoyancy driven planetary-boundary-layer flows, J. Atmos. Sci., 51, 999–1022, 1994.
Moeng, C.-H. and Wyngaard, J.: Evaluation of Turbulent Transport and Dissipation Closures in Second-Order Modeling, J. Atmos. Sci., 46, 2311–2330, 1989.
Nadeau, D. F., Pardyjak, E. R., Higgins, C. W., Fernando, H. J. S., and Parlange, M. B.: A simple model for the afternoon and early evening decay of convective turbulence over different land surfaces, Bound.-Lay. Meteorol., 141, 301–324, 2011.
Nauta, L.: Shallow Drainage Flows over Light Sloping Terrain during BLLAST 2011: Two Case Studies, Master's thesis, Wageningen University, Wageningen, the Netherlands, 2013.
Nieuwstadt, F. T. M. and Brost, R. A.: The decay of convective turbulence, J. Atmos. Sci., 43, 532–546, 1986.
Nilsson, E.: Day-by-day analysis of synoptic and meteorological conditions, available at: http://bllast.sedoo.fr/documents/Synoptic_BLLAST_ECMWF_and_IR_low_winds_fisheye_surface_obs_radiation_60mbasic_60mtempRH.pdf (last access: 18 May 2016), 2014.
Nilsson, E., Lothon, M., Lohou, F., Pardyjak, E., Hartogensis, O., and Darbieu, C.: Turbulence kinetic energy budget during the afternoon transition – Part 2: A simple TKE model, Atmos. Chem. Phys., 16, 8873–8898, https://doi.org/10.5194/acp-16-8873-2016, 2016.
Pahlow, M., Parlange, M., and Porté-Agel, F.: On Monin-Obukhov Similarity in the Stable Atmospheric Boundary Layer, Bound.-Lay. Meteorol., 99, 225–248, 2001.
Pietersen, H. P., Vilà-Guerau de Arellano, J., Augustin, P., van de Boer, A., de Coster, O., Delbarre, H., Durand, P., Fourmentin, M., Gioli, B., Hartogensis, O., Lohou, F., Lothon, M., Ouwersloot, H. G., Pino, D., and Reuder, J.: Study of a prototypical convective boundary layer observed during BLLAST: contributions by large-scale forcings, Atmos. Chem. Phys., 15, 4241–4257, https://doi.org/10.5194/acp-15-4241-2015, 2015.
Pino, D., Vilà-Guerau de Arellano, J., and Duynkerke, P.: The contribution of shear to the evolution of a convective boundary layer, J. Atmos. Sci., 60, 1913–1926, 2003.
Pino, D., Jonker, H. J. J., Vilà de Arellano, J., and Dosio, A.: Role of shear and the inversion strength during sunset turbulence over land: characteristic length scales, Bound.-Lay. Meteorol., 121, 537–556, 2006.
Puhales, F., Rizza, U., Degrazia, G., and Acevedo, O.: A simple parameterization for the turbulent kinetic energy transport terms in the convective boundary layer derived from large eddy simulation, Physica A, 392, 583–595, 2013.
Rizza, U., Miglietta, M., Degrazia, G., Acevedo, O., and Marques, E.: Sunset decay of the convective turbulence with Large-Eddy Simulation under realistic conditions, Physica A, 392, 4481–4490, 2013.
Román-Cascón, C., Yague, C., Mahrt, L., Sastre, M., Steeneveld, G.-J., Pardyjak, E., and van de Boer, A.: Interactions among Drainage flows, Gravity waves and Turbulence: 2nd July, in: Barcelona BLLAST workshop, 2–3 February 2015, Barcelona, Spain, 2015.
Said, F., Donier, J., Campistron, B., Bezombes, Y., Bousquet, O., Derrien, S. Douffet, T., and Garrouste, O.: CNRM and CRA UHF profilers Site 1 and 2: 15 June–5 July 2011, Internal report 2012/1, Tech. rep., 2012.
Stull, R. B.: An Introduction to Boundary Layer Meteorology, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1988.
Taylor, A., Beare, R., and Thomson, D.: Simulating Dispersion in the Evening-Transition Boundary Layer, Bound.-Lay. Meteorol., 153, 389–407, 2014.
van Driel, R. and Jonker, H. J. J.: Convective boundary layers driven by nonstationary surface heat fluxes, J. Atmos. Sci., 68, 727–738, 2011.
Wingo, S. M. and Knupp, K. R.: Multi-platform observations characterizing the afternoon-to-evening transition of the planetary boundary layer in northern Alabama, USA, Bound.-Lay. Meteorol., 155, 29–53, 2015.
Wyngaard, J. C. and Coté, O. R.: The Budgets of Turbulent Kinetic Energy and Temperature Variance in the Atmospheric Surface Layer, J. Atmos. Sci., 28, 190–201, 1971.
Short summary
The evolution of near-surface turbulence kinetic energy (TKE) and its budget in the afternoon transition has been studied based on field measurements. The study shows that TKE transport is an important budget term that needs to be taken into account in modeling of TKE. A non-local parametrization of dissipation using a TKE–length scale model which takes into account of boundary layer depth also gave improved results compared to a local parametrization.
The evolution of near-surface turbulence kinetic energy (TKE) and its budget in the afternoon...
Altmetrics
Final-revised paper
Preprint