401 results on '"Delanoë, Julien"'
Search Results
2. Airborne Radar
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Hagen, Martin, Delanoë, Julien, Ellis, Scott, Ewald, Florian, French, Jeffrey, Haimov, Samuel, Heymsfield, Gerald, Pazmany, Andrew L., and Foken, Thomas, editor
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- 2021
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3. Leveraging RALI‐THINICE Observations to Assess How the ICOLMDZ Model Simulates Clouds Embedded in Arctic Cyclones.
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Raillard, Lea, Vignon, Étienne, Rivière, Gwendal, Madeleine, Jean‐Baptiste, Meurdesoif, Yann, Delanoë, Julien, Caubel, Arnaud, Jourdan, Olivier, Baudoux, Antoine, Fromang, Sébastien, and Conesa, Philippe
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CLIMATE change models ,LIQUID crystals ,ICE crystals ,ATMOSPHERIC models ,RADAR in aeronautics ,ICE clouds ,SEA ice - Abstract
Despite their essential role in the high‐latitude climate, the representation of mixed‐phase clouds is still a challenge for Global Climate Models (GCMs)'s cloud schemes. In this study we propose a methodology for robustly assessing Arctic mixed‐phase cloud properties in a climate model using airborne measurements. We leverage data collected during the RALI‐THINICE airborne campaign that took place near Svalbard in August 2022 to evaluate the simulation of mid‐level clouds associated with Arctic cyclones. Simulations are carried out with the new limited‐area configuration of the ICOLMDZ model which combines the recent icosahedral dynamical core DYNAMICO and the physics of LMDZ, the atmospheric component of the IPSL‐CM Earth System Model. Airborne radar and microphysical probes measurements are then used to evaluate the simulated clouds. A comparison method has been set‐up to guarantee as much as possible the spatiotemporal co‐location between observed and simulated cloud fields. We mostly focus on the representation of ice and liquid in‐cloud contents and on their vertical distribution. Results show that the model overestimates the amount of cloud condensates and exhibits a poor cloud phase spatial distribution, with too much liquid water far from cloud top and too much ice close to it. The downward gradual increase in snowfall flux is also not captured by the model. This in‐depth model evaluation thereby pinpoints priorities for further improvements in the ICOLMDZ cloud scheme. Plain Language Summary: Mixed‐phase clouds, where ice crystals and supercooled liquid droplets coexist at sub‐zero temperatures, are ubiquitous in the polar regions. Albeit essential for the high‐latitude climate, they are still poorly represented by climate models. In this study, original measurements from the RALI‐THINICE airborne campaign, which took place in the Svalbard region in August 2022, are used to assess how the ICOLMDZ atmospheric model represents Arctic mixed phase clouds. A methodology is developed to make robust and co‐located model‐aircraft observation comparisons. In situ cloud probes and onboard radars are then used to evaluate the simulated amounts of liquid water and ice in clouds as well as the snowfall flux in deep clouds associated with the transit of Arctic cyclones. The results of the model evaluation show an overall overestimation of cloud condensates with too much liquid water far from cloud top and too much ice close to it. Key Points: Airborne RALI‐THINICE observations are used to evaluate Arctic clouds in the new limited area version of the ICOLMDZ modelA methodology has been developed to make robust and co‐located model‐observation comparisonsICOLMDZ simulates overly high amounts of liquid and ice in clouds particularly near cloud top [ABSTRACT FROM AUTHOR]
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- 2024
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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.
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Wendisch, Manfred, Crewell, Susanne, Ehrlich, André, Herber, Andreas, Kirbus, Benjamin, Lüpkes, Christof, Mech, Mario, Abel, Steven J., Akansu, Elisa F., Ament, Felix, Aubry, Clémantyne, Becker, Sebastian, Borrmann, Stephan, Bozem, Heiko, Brückner, Marlen, Clemen, Hans-Christian, Dahlke, Sandro, Dekoutsidis, Georgios, Delanoë, Julien, and De La Torre Castro, Elena
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AIR masses ,CLOUDINESS ,WATER vapor ,CIRRUS clouds ,ARCTIC climate ,SEA ice ,ICE clouds - Abstract
Global warming is amplified in the Arctic. However, numerical models struggle to represent key processes that determine Arctic weather and climate. To collect data that help to constrain the models, the HALO–(AC) 3 aircraft campaign was conducted over the Norwegian and Greenland seas, the Fram Strait, and the central Arctic Ocean in March and April 2022. The campaign focused on one specific challenge posed by the models, namely the reasonable representation of transformations of air masses during their meridional transport into and out of the Arctic via northward moist- and warm-air intrusions (WAIs) and southward marine cold-air outbreaks (CAOs). Observations were made over areas of open ocean, the marginal sea ice zone, and the central Arctic sea ice. Two low-flying and one long-range, high-altitude research aircraft were flown in colocated formation whenever possible. To follow the air mass transformations, a quasi-Lagrangian flight strategy using trajectory calculations was realized, enabling us to sample the same moving-air parcels twice along their trajectories. Seven distinct WAI and 12 CAO cases were probed. From the quasi-Lagrangian measurements, we have quantified the diabatic heating/cooling and moistening/drying of the transported air masses. During CAOs, maximum values of 3 K h -1 warming and 0.3 g kg -1 h -1 moistening were obtained below 1 km altitude. From the observations of WAIs, diabatic cooling rates of up to 0.4 K h -1 and a moisture loss of up to 0.1 g kg -1 h -1 from the ground to about 5.5 km altitude were derived. Furthermore, the development of cloud macrophysical (cloud-top height and horizontal cloud cover) and microphysical (liquid water path, precipitation, and ice index) properties along the southward pathways of the air masses were documented during CAOs, and the moisture budget during a specific WAI event was estimated. In addition, we discuss the statistical frequency of occurrence of the different thermodynamic phases of Arctic low-level clouds, the interaction of Arctic cirrus clouds with sea ice and water vapor, and the characteristics of microphysical and chemical properties of Arctic aerosol particles. Finally, we provide a proof of concept to measure mesoscale divergence and subsidence in the Arctic using data from dropsondes released during the flights. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Overview: Quasi-Lagrangian observations of Arctic air mass transformations – Introduction and initial results of the HALO–(AC)3 aircraft campaign
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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
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- 2024
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6. Cyclogenesis in the Tropical Atlantic: First Scientific Highlights from the Clouds–Atmospheric Dynamics–Dust Interactions in West Africa (CADDIWA) Field Campaign
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Flamant, Cyrille, primary, Chaboureau, Jean-Pierre, additional, Delanoë, Julien, additional, Gaetani, Marco, additional, Jamet, Cédric, additional, Lavaysse, Christophe, additional, Bock, Olivier, additional, Borne, Maurus, additional, Cazenave, Quitterie, additional, Coutris, Pierre, additional, Cuesta, Juan, additional, Menut, Laurent, additional, Aubry, Clémantyne, additional, Benedetti, Angela, additional, Bosser, Pierre, additional, Bounissou, Sophie, additional, Caudoux, Christophe, additional, Collomb, Hélène, additional, Donal, Thomas, additional, Febvre, Guy, additional, Fehr, Thorsten, additional, Fink, Andreas H., additional, Formenti, Paola, additional, Araujo, Nicolau Gomes, additional, Knippertz, Peter, additional, Lecuyer, Eric, additional, Andrade, Mateus Neves, additional, Langué, Cédric Gacial Ngoungué, additional, Jonville, Tanguy, additional, Schwarzenboeck, Alfons, additional, and Takeishi, Azusa, additional
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- 2024
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7. Lidar-radar synergistic method to retrieve ice, supercooled and mixed-phase clouds properties
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Aubry, Clémantyne, primary, Delanoë, Julien, additional, Groß, Silke, additional, Ewald, Florian, additional, Tridon, Frédéric, additional, Jourdan, Olivier, additional, and Mioche, Guillaume, additional
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- 2024
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8. Monte-Carlo simulations of active remote sensing instruments within a highly resolved 3D cloudy atmosphere
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Penide, Guillaume, primary, Szczap, Frédéric, additional, and Delanoë, Julien, additional
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- 2024
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9. Lidar–radar synergistic method to retrieve ice, supercooled water and mixed-phase cloud properties.
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Aubry, Clémantyne, Delanoë, Julien, Groß, Silke, Ewald, Florian, Tridon, Frédéric, Jourdan, Olivier, and Mioche, Guillaume
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ICE clouds , *TROPOSPHERIC aerosols , *PASSIVE radar , *RADAR in aeronautics , *SUPERCOOLING , *REMOTE sensing , *ICE - Abstract
Mixed-phase clouds are not well represented in climate and weather forecasting models, due to a lack of the key processes controlling their life cycle. Developing methods to study these clouds is therefore essential, despite the complexity of mixed-phase cloud processes and the difficulty of observing two cloud phases simultaneously. We propose in this paper a new method to retrieve the microphysical properties of mixed-phase clouds, ice clouds and supercooled water clouds using airborne or satellite radar and lidar measurements, called VarPy-mix. This new approach extends an existing variational method developed for ice cloud retrieval using lidar, radar and passive radiometers. We assume that the lidar attenuated backscatter β at 532 nm is more sensitive to particle concentration and is consequently mainly sensitive to the presence of supercooled water. In addition, radar reflectivity Z at 95 GHz is sensitive to the size of hydrometeors and hence more sensitive to the presence of ice particles. Consequently, in the mixed phase the supercooled droplets are retrieved with the lidar signal and the ice particles with the radar signal, meaning that the retrievals rely strongly on a priori and error values. This method retrieves simultaneously the visible extinction for ice αice and liquid αliq particles, the ice and liquid water contents IWC and LWC, the effective radius of ice re,ice and liquid re,liq particles, and the ice and liquid number concentrations Nice and Nliq. Moreover, total extinction αtot , total water content (TWC) and total number concentration Ntot can also be estimated. As the retrieval of ice and liquid is different, it is necessary to correctly identify each phase of the cloud. To this end, a cloud-phase classification is used as input to the algorithm and has been adapted for mixed-phase retrieval. The data used in this study are from DARDAR-MASK v2.23 products, based on the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Cloud Profiling Radar (CPR) observations from the CALIPSO and CloudSat satellites, respectively, belonging to the A-Train constellation launched in 2006. Airborne in situ measurements performed on 7 April 2007 during the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign and collected under the track of CloudSat–CALIPSO are compared with the retrievals of the new algorithm to validate its performance. Visible extinctions, water contents, effective radii and number concentrations derived from in situ measurements and the retrievals showed similar trends and are globally in good agreement. The mean percent error between the retrievals and in situ measurements is 39 % for αliq , 398 % for αice , 49 % for LWC and 75 % for IWC. It is also important to note that temporal and spatial collocations are not perfect, with a maximum spatial shift of 1.68 km and a maximum temporal shift of about 10 min between the two platforms. In addition, the sensitivity of remote sensing and that of in situ measurements is not the same, and in situ measurement uncertainties are between 25 % and 60 %. [ABSTRACT FROM AUTHOR]
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- 2024
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10. The first microwave and submillimetre closure study using particle models of oriented ice hydrometeors to simulate polarimetric measurements of ice clouds.
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McCusker, Karina, Baran, Anthony J., Westbrook, Chris, Fox, Stuart, Eriksson, Patrick, Cotton, Richard, Delanoë, Julien, and Ewald, Florian
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ICE clouds ,BRIGHTNESS temperature ,PASSIVE radar ,DENDRITIC crystals ,PARTICLE size distribution ,ATMOSPHERIC models - Abstract
The first closure study involving passive microwave and submillimetre measurements of ice clouds with the consideration of oriented particles is presented, using a unique combination of polarised observations from the ISMAR spectral-like radiometer, two radars with frequencies of 35 and 95 GHz , and a variety of in situ instruments. Of particular interest to this study are the large V–H polarised brightness temperature differences measured from ISMAR above a thick frontal ice cloud. Previous studies combining radar and passive submillimetre measurements have not considered polarisation differences. Moreover, they have assumed particle habits a priori. We aim to test whether the large V–H measurements can be simulated successfully by using an atmospheric model consistent with in situ microphysics. An atmospheric model is constructed using information from the in situ measurements, such as the ice water content, the particle size distribution, and the mass and shape of particles, as well as background information obtained from dropsonde profiles. Columnar and dendritic aggregate particle models are generated specifically for this case, and their scattering properties are calculated using the independent monomer approximation under the assumption of horizontal orientation. The scattering properties are used to perform polarised radiative transfer simulations using ARTS to test whether we can successfully simulate the measured large V–H differences. Radar measurements are used to extrapolate the 1-D microphysical profile to derive a time series of particle size distributions which are used to simulate ISMAR brightness temperatures. These simulations are compared to the observations. It is found that particle models that are consistent with in situ microphysics observations are capable of reproducing the brightness temperature depression and polarisation signature measured from ISMAR at the dual-polarised channel of 243 GHz. However, it was required that a proportion of the particles were changed in order to increase the V–H polarised brightness temperature differences. Thus, we incorporated millimetre-sized dendritic crystals, as these particles were observed in the probe imagery. At the second dual-polarised channel of 664 GHz , the brightness temperature depressions were generally simulated at the correct locations; however, the simulated V–H was too large. This work shows that multi-frequency polarisation information could be used to infer realistic particle shapes, orientations, and representations of the split between single crystals and aggregates within the cloud. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Vertical Profiles of Liquid Water Content in fog layers during the SOFOG3D experiment.
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Costabloz, Théophane, Burnet, Frédéric, Lac, Christine, Martinet, Pauline, Delanoë, Julien, Jorquera, Susana, and Fathalli, Maroua
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Observations collected during the SOuth west FOGs 3D experiment for processes study (SOFOG3D) field campaign are examined to document vertical profile of microphysical and thermodynamic properties of fog layers. In situ measurements collected under a tethered balloon provide 140 vertical profiles of liquid water content (LWC) from an adapted cloud droplet probe (CDP), which allow an exhaustive analysis of the life cycle of 8 thin fogs (thickness < 50 m) and 4 developed layers. We estimate thin-to-thick transition time from remote sensing instruments (microwave radiometer and Doppler cloud radar) and surface measurements, by using thresholds for longwave radiation flux, turbulent kinetic energy, vertical temperature gradient, fog top height and liquid water path (LWP) values. We found that a LWP threshold value of 15 g.m
-2 S is more suited for the thick fogs sampled at the super-site. CDP data are used to compute the equivalent fog adiabaticity from closure (αclosure eq ) and compare to value derived from remote sensing instruments, 2-m height visibility, and an one-column conceptual model of adiabatic continental fog assuming that LWC linearly increases with height. The comparison of αclosure eq shows a large variability that results mainly from the parameterization used to estimate LWC at ground, but their evolution as a function of the fog thickness follows the same trend. We found larger negative values of αclosure eq for thin layers, associated to low LWP values. CDP data reveal that reverse trend of LWC profile (LWC being maximal at the ground and decreasing with altitude) are ubiquitous in optically thin fogs, while quasi-adiabatic features with increasing LWC values with altitude are mainly observed in well-mixed optically thick fogs. We investigate the actual fog adiabaticity and lapse rate fraction by using linear regressions to best fit the vertical profiles of LWC and temperature, respectively. This analysis highligths that reverse LWC profiles, when stable temperature conditions exist during the optically thin phase of fogs, evolve towards quasi-adiabatic features with slightly unstable temperature lapse rate, when fogs become optically thick. We also found that LWC at ground is higher during the thin phase and significantly decreases as the profile is changing from reverse to increasing with height. But this trend could be balanced when collision-coalescence and sedimentation processes redistribute the LWC through the fog layer from the top to the ground. This study provides new insights on the evolution of LWC profile during the fog life cycle, that would help to constrain numerical simulations. [ABSTRACT FROM AUTHOR]- Published
- 2024
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12. Role of thermodynamic and turbulence processes on the fog life cycle during SOFOG3D experiment
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Dione, Cheikh, primary, Haeffelin, Martial, additional, Burnet, Frédéric, additional, Lac, Christine, additional, Canut, Guylaine, additional, Delanoë, Julien, additional, Dupont, Jean-Charles, additional, Jorquera, Susana, additional, Martinet, Pauline, additional, Ribaud, Jean-François, additional, and Toledo, Felipe, additional
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- 2023
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13. A HIGH-ALTITUDE LONG-RANGE AIRCRAFT CONFIGURED AS A CLOUD OBSERVATORY : The NARVAL Expeditions
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Stevens, Bjorn, Ament, Felix, Bony, Sandrine, Crewell, Susanne, Ewald, Florian, Gross, Silke, Hansen, Akio, Hirsch, Lutz, Jacob, Marek, Kölling, Tobias, Konow, Heike, Mayer, Bernhard, Wendisch, Manfred, Wirth, Martin, Wolf, Kevin, Bakan, Stephan, Bauer-Pfundstein, Matthias, Brueck, Matthias, Delanoë, Julien, Ehrlich, André, Farrell, David, Forde, Marvin, Gödde, Felix, Grob, Hans, Hagen, Martin, Jäkel, Evelyn, Jansen, Friedhelm, Klepp, Christian, Klingebiel, Marcus, Mech, Mario, Peters, Gerhard, Rapp, Markus, Wing, Allison A., and Zinner, Tobias
- Published
- 2019
14. Detecting Clouds Associated with Jet Engine Ice Crystal Icing
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Haggerty, Julie, Defer, Eric, De Laat, Adrianus, Bedka, Kristopher, Moisselin, Jean-Marc, Potts, Rodney, Delanoë, Julien, Parol, Frédéric, Grandin, Alice, and Divito, Stephanie
- Published
- 2019
15. A WORKSHOP ON REMOTE SENSING OF THE ATMOSPHERE IN ANTICIPATION OF THE EARTHCARE SATELLITE MISSION
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Luebke, Anna E., Delanoë, Julien, Noel, Vincent, Chepfer, Hélène, and Stevens, Bjorn
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- 2018
16. EUREC4A: A Field Campaign to Elucidate the Couplings Between Clouds, Convection and Circulation
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Bony, Sandrine, Stevens, Bjorn, Ament, Felix, Bigorre, Sebastien, Chazette, Patrick, Crewell, Susanne, Delanoë, Julien, Emanuel, Kerry, Farrell, David, Flamant, Cyrille, Gross, Silke, Hirsch, Lutz, Karstensen, Johannes, Mayer, Bernhard, Nuijens, Louise, Ruppert, James H., Jr., Sandu, Irina, Siebesma, Pier, Speich, Sabrina, Szczap, Frédéric, Totems, Julien, Vogel, Raphaela, Wendisch, Manfred, Wirth, Martin, Pincus, Robert, editor, Winker, David, editor, Bony, Sandrine, editor, and Stevens, Bjorn, editor
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- 2018
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17. Overview: Quasi-Lagrangian observations of Arctic air mass transformations – Introduction and initial results of the HALO–(AC)3 aircraft campaign.
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Wendisch, Manfred, Crewell, Susanne, Ehrlich, André, Herber, Andreas, Kirbus, Benjamin, Lüpkes, Christof, Mech, Mario, Abel, Steven J., Akansu, Elisa F., Ament, Felix, Aubry, Clémantyne, Becker, Sebastian, Borrmann, Stephan, Bozem, Heiko, Brückner, Marlen, Clemen, Hans-Christian, Dahlke, Sandro, Dekoutsidis, Georgios, Delanoë, Julien, and Castro, Elena De La Torre
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AIR masses ,MODEL airplanes ,SEA ice ,WATER vapor ,ATMOSPHERIC models ,RESEARCH aircraft - Abstract
The global warming is amplified in the Arctic. To collect data that help to constrain weather and climate models, which often do not realistically represent the enhanced Arctic warming, the HALO-(AC)³ aircraft campaign was conducted in March and April 2022 over the Norwegian and Greenland Seas, the Fram Strait, and the central Arctic Ocean. Observations were made over areas of open ocean, the marginal sea ice zone, and the central Arctic sea ice. Two low-flying and one long-range, high-altitude research aircraft have been employed. Whenever possible, the three aircraft were flown in collocated formation. The campaign focused on one specific challenge posed by the models: The reasonable representation of transformations of air masses during their meridional transport into (northward by moist and warm air intrusions, WAIs) and out of (southward via marine cold air outbreaks, CAOs) the Arctic. To observe the air mass transformations, a quasi-Lagrangian flight strategy using trajectory calculations was realized enabling to sample the moving air mass parcels twice along their trajectories. Eight distinct WAI and 12 CAO cases were probed extensively. From the quasi-Lagrangian measurements, we have derived the diabatic heating and moistening of the moving air masses during CAOs and WAIs, the development of cloud macrophysical and microphysical properties along the southward pathways of the air masses during CAOs, and the moisture budget of WAIs. As an example result, we have obtained typical values of the surface-driven diabatic heating between 1–3 K h
-1 and of the near-surface moistening between 0.05–0.3 g kg-1 h-1 within the lowest about 0.5 km. From the observations of WAIs, a weak diabatic cooling of up to 0.4 K h-1 and a moisture loss of up to 0.1 g kg-1 h-1 from the ground to about 5 km altitude were derived. In addition, we discuss the frequency of occurrence of the different thermodynamic phases of Arctic low-level clouds, the interaction of Arctic cirrus with sea ice, water vapor, and aerosol particles, and the characteristic microphysical and chemical properties of Arctic aerosol particles. Finally, we provide proof of a concept to measure mesoscale divergence and subsidence in the Arctic using data from dropsondes released during circular flight patterns. [ABSTRACT FROM AUTHOR]- Published
- 2024
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18. Calibration Transfer Methodology for Cloud Radars Based on Ice Cloud Observations
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Jorquera, Susana, primary, Toledo Bittner, Felipe, additional, Delanoë, Julien, additional, Berne, Alexis, additional, Billault-Roux, Anne-Claire, additional, Schwarzenboeck, Alfons, additional, Dezitter, Fabien, additional, Viltard, Nicolas, additional, and Martini, Audrey, additional
- Published
- 2023
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19. THE NORTH ATLANTIC WAVEGUIDE AND DOWNSTREAM IMPACT EXPERIMENT
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Schäfler, Andreas, Craig, George, Wernli, Heini, Arbogast, Philippe, Doyle, James D., McTaggart-Cowan, Ron, Methven, John, Rivière, Gwendal, Ament, Felix, Boettcher, Maxi, Bramberger, Martina, Cazenave, Quitterie, Cotton, Richard, Crewell, Susanne, Delanoë, Julien, Dörnbrack, Andreas, Ehrlich, André, Ewald, Florian, Fix, Andreas, Grams, Christian M., Gray, Suzanne L., Grob, Hans, Groß, Silke, Hagen, Martin, Harvey, Ben, Hirsch, Lutz, Jacob, Marek, Kölling, Tobias, Konow, Heike, Lemmerz, Christian, Lux, Oliver, Magnusson, Linus, Mayer, Bernhard, Mech, Mario, Moore, Richard, Pelon, Jacques, Quinting, Julian, Rahm, Stephan, Rapp, Markus, Rautenhaus, Marc, Reitebuch, Oliver, Reynolds, Carolyn A., Sodemann, Harald, Spengler, Thomas, Vaughan, Geraint, Wendisch, Manfred, Wirth, Martin, Witschas, Benjamin, Wolf, Kevin, and Zinner, Tobias
- Published
- 2018
20. ICE GENESIS: Synergetic Aircraft and Ground-Based Remote Sensing and In Situ Measurements of Snowfall Microphysical Properties
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Billault-Roux, Anne-Claire, Grazioli, Jacopo, Delanoë, Julien, Jorquera, Susana, Pauwels, Nicolas, Viltard, Nicolas, Martini, Audrey, Mariage, Vincent, Le Gac, Christophe, Caudoux, Christophe, Aubry, Clémantyne, Bertrand, Fabrice, Schwarzenboeck, Alfons, Jaffeux, Louis, Coutris, Pierre, Febvre, Guy, Pichon, Jean Marc, Dezitter, Fabien, Gehring, Josué, Untersee, Aude, Calas, Christophe, Figueras I Ventura, Jordi, Vie, Benoit, Peyrat, Adrien, Curat, Valentin, Rebouissoux, Simon, Berne, Alexis, Environmental Remote Sensing Laboratory [Lausanne], Ecole Polytechnique Fédérale de Lausanne (EPFL), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Airbus Helicopters, Aeroport International de Marseille-Provence, Federal Office of Meteorology and Climatology MeteoSwiss, and Météo-France
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Snowfall ,Atmospheric Science ,Cloud microphysics ,Precipitation ,Radars/Radar observations ,Remote sensing ,[SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology ,Icing - Abstract
An international field experiment took place in the Swiss Jura in January 2021 as a milestone of the European ICE GENESIS project (www.ice-genesis.eu/), which aims to better measure, understand, and model the ice/snow particle properties and mechanisms responsible for icing of rotor-craft and aircraft. The field campaign was designed to collect observations of clouds and snowfall at a prescribed range of temperatures (−10° to +2°C). The suite of in situ and remote sensing instruments included airborne probes and imagers on board a SAFIRE ATR-42 aircraft, able to sample liquid and ice particles from the micron to the millimeter size range, as well as icing sensors and cameras. Two 95 GHz Doppler cloud radars were installed on the SAFIRE ATR-42, while six Doppler weather radars operating at frequencies ranging from 10 to 95 GHz (and one lidar) were ground based. An operational polarimetric weather radar in nearby France (Montancy) complements the coverage. Finally, observations of standard meteorological variables as well as high-resolution pictures of falling snowflakes from a multiangle snowflake camera were collected at the ground level. The campaign showed its full potential during five (multihourly) flights where precipitation was monitored from cloud to ground. The originality of this campaign resides in the targeted specific temperature range for snowfall and in the synchronization between the ground-based remote sensing and the aircraft trajectories designed to maximize the collection of in situ observations within the column above the radar systems.
- Published
- 2023
21. The first microwave and submillimetre closure study using particle models of oriented ice hydrometeors to simulate polarimetric measurements of ice clouds
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McCusker, Karina, Baran, Anthony J., Westbrook, Chris, Fox, Stuart, Eriksson, Patrick, Cotton, Richard, Delanoë, Julien, and Ewald, Florian
- Abstract
The first closure study involving passive microwave and submillimetre measurements of ice clouds with the consideration of oriented particles is presented, using a unique combination of polarised observations from the ISMAR spectral-like radiometer, two radars with frequencies of 35 and 95 GHz, and a variety of in-situ instruments. Of particular interest to this study are the large V-H polarised brightness temperature differences measured from ISMAR above a thick frontal ice cloud. Previous studies combining radar and passive submillimetre measurements have not considered polarisation differences. Moreover, they have assumed particle habits a-priori. We aim to test whether the large V-H measurements can be simulated successfully by using an atmospheric model consistent with in-situ microphysics. An atmospheric model is constructed using information from the in-situ measurements, such as the ice water content, the particle size distribution, and the mass and shape of particles, as well as background information obtained from dropsonde profiles. Columnar and dendritic aggregate particle models are generated specifically for this case, and their scattering properties are calculated using the Independent Monomer Approximation under the assumption of horizontal orientation. The scattering properties are used to perform polarised radiative transfer simulations using ARTS to test whether we can successfully simulate the measured large V-H differences. Radar measurements are used to extrapolate the 1D microphysical profile to derive a time-series of particle size distributions which are used to simulate ISMAR brightness temperatures. These simulations are compared to the observations. It is found that particle models that are consistent with in-situ microphysics observations are capable of reproducing the brightness temperature depression and polarisation signature measured from ISMAR at the dual-polarised channel of 243 GHz. However, it was required that a proportion of the particles were changed in order to increase the V-H polarised brightness temperature differences. Thus we incorporated mm-sized dendritic crystals, as these particles were observed in the probe imagery. At the second dual-polarised channel of 664 GHz, the brightness temperature depressions were generally simulated at the correct locations, however the simulated V-H was too large. This work shows that multi-frequency polarisation information could be used to infer realistic particle shapes, orientations, and representations of the split between single crystals and aggregates within the cloud.
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- 2023
22. Impact of Mixed-Phase Cloud Parameterization on Warm Conveyor Belts and Upper-Tropospheric Dynamics
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Mazoyer, Marie, primary, Ricard, Didier, additional, Rivière, Gwendal, additional, Delanoë, Julien, additional, Riette, Sébastien, additional, Augros, Clotilde, additional, Borderies, Mary, additional, and Vié, Benoit, additional
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- 2023
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23. Water isotopic characterisation of the cloud–circulation coupling in the North Atlantic trades – Part 1: A process-oriented evaluation of COSMOiso simulations with EUREC4A observations.
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Villiger, Leonie, Dütsch, Marina, Bony, Sandrine, Lothon, Marie, Pfahl, Stephan, Wernli, Heini, Brilouet, Pierre-Etienne, Chazette, Patrick, Coutris, Pierre, Delanoë, Julien, Flamant, Cyrille, Schwarzenboeck, Alfons, Werner, Martin, and Aemisegger, Franziska
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CUMULUS clouds ,DEUTERIUM oxide ,STABLE isotopes ,ATMOSPHERIC circulation ,RAINFALL ,FIELD research ,PRECIPITATION scavenging - Abstract
Naturally available, stable, and heavy water molecules such as HDO and H 218 O have a lower saturation vapour pressure than the most abundant light water molecule H 216 O; therefore, these heavy water molecules preferentially condense and rain out during cloud formation. Stable water isotope observations thus have the potential to provide information on cloud processes in the trade-wind region, in particular when combined with high-resolution model simulations. In order to evaluate this potential, nested COSMO iso (isotope-enabled Consortium for Small Scale Modelling;) simulations with explicit convection and horizontal grid spacings of 10, 5, and 1 km were carried out in this study over the tropical Atlantic for the time period of the EUREC 4 A (Elucidating the role of clouds-circulation coupling in climate;) field experiment. The comparison to airborne in situ and remote sensing observations shows that the three simulations are able to distinguish between different mesoscale cloud organisation patterns as well as between periods with comparatively high and low rain rates. Cloud fraction and liquid water content show a better agreement with aircraft observations with higher spatial resolution, because they show strong spatial variations on the scale of a few kilometres. A low-level cold-dry bias, including too depleted vapour in the subcloud and cloud layer and too enriched vapour in the free troposphere, is found in all three simulations. Furthermore, the simulated secondary isotope variable d -excess in vapour is overestimated compared to observations. Special attention is given to the cloud base level, which is the formation altitude of shallow cumulus clouds. The temporal variability of the simulated isotope variables at cloud base agrees reasonably well with observations, with correlations of the flight-to-flight data as high as 0.7 for δ2 H and d -excess. A close examination of isotopic characteristics under precipitating clouds, non-precipitating clouds, clear-sky and dry-warm patches at the altitude of cloud base shows that these different environments are represented faithfully in the model with similar frequencies of occurrence, isotope signals, and specific-humidity anomalies as found in the observations. Furthermore, it is shown that the δ2 H of cloud base vapour at the hourly timescale is mainly controlled by mesoscale transport and not by local microphysical processes, while the d -excess is mainly controlled by large-scale drivers. Overall, this evaluation of COSMO iso , including the isotopic characterisation of different cloud base environments, suggests that the simulations can be used for investigating the role of atmospheric circulations on different scales for controlling the formation of shallow cumulus clouds in the trade-wind region, as will be done in part 2 of this study. [ABSTRACT FROM AUTHOR]
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- 2023
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24. Role of thermodynamic and turbulence processes on the fog life cycle during SOFOF3D experiment
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Dione, Cheikh, Haeffelin, Martial, Burnet, Frédéric, Lac, Christine, Canut, Guylaine, Delanoë, Julien, Dupont, Jean-Charles, Jorquera, Susana, Martinet, Pauline, Ribaud, Jean-François, and Toledo, Felipe
- Abstract
In this study, we use a synergy of in-situ and remote sensing measurements collected during the Southwest FOGs 3D experiment for processes study (SOFOG3D) field campaign in autumn 2019 and winter 2020, to analyze the thermodynamic and turbulence processes related to fog formation, evolution, and dissipation across southwestern France. Based on a unique dataset with a very high resolution and a fog conceptual model, an analysis of the four heaviest fog episodes (two radiation fogs and two advection-radiation fogs) is conducted. The results show that radiation and advection-radiation fogs form under deep and thin temperature inversion, respectively. For both fog categories, the transition period from stable to adiabatic fog and the fog adiabatic phase are driven by vertical mixing associated with an increase in turbulence in the fog layer due to mechanical production (turbulence kinetic energy (TKE) up to 0.4 m2 s-2 and vertical velocity variance (σw2) up to 0.04 m2 s-2) generated by brisk wind at the supersite (advection). The dissipation time is observed at night for the advection-radiation fog case studies and during the day for the radiation fog case studies. Night-time dissipation is driven by horizontal advection generating mechanical turbulence (TKE at least 0.3 m2 s-2 and σw2 larger than 0.04 m2 s-2). Daytime dissipation is linked to the combination of thermal and mechanical turbulence related respectively to solar heating (near surface sensible heat flux larger than 10 W m-2) and advection. Through a deficit of the fog reservoir of liquid water path, the fog conceptual model estimates the dissipation time at least one hour before the observed dissipation for radiation fog cases. It gives a better estimate of the fog dissipation time for advection-radiation cases. This study also demonstrates the importance of using instrumental synergy (with microwave radiometer, wind lidar, weather station, and cloud radar) and a fog conceptual model to better predict fog characteristics and dissipation time at nowcasting ranges.
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- 2023
25. Potential of microwave observations for the evaluation of rainfall and convection in a regional climate model in the frame of HyMeX and MED-CORDEX
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Rysman, Jean-François, Berthou, Ségolène, Claud, Chantal, Drobinski, Philippe, Chaboureau, Jean-Pierre, and Delanoë, Julien
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- 2018
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26. Water isotopic characterisation of the cloud-circulation coupling in the North Atlantic trades. Part 1: A process-oriented evaluation of COSMOiso simulations with EUREC4A observations
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Villiger, Leonie, primary, Dütsch, Marina, additional, Bony, Sandrine, additional, Lothon, Marie, additional, Pfahl, Stephan, additional, Wernli, Heini, additional, Brilouet, Pierre-Etienne, additional, Chazette, Patrick, additional, Coutris, Pierre, additional, Delanoë, Julien, additional, Flamant, Cyrille, additional, Schwarzenboeck, Alfons, additional, Werner, Martin, additional, and Aemisegger, Franziska, additional
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- 2023
- Full Text
- View/download PDF
27. Overview and first analysis of the in situ microphysical measurement dataset collected during the CADDIWA mission
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Coutris, Pierre, primary, Febvre, Guy, additional, Jaffeux, Louis, additional, Bazantay, Clément, additional, Aubry, Clémantyne, additional, Caudoux, Christophe, additional, Delanoë, Julien, additional, Schwarzenboeck, Alfons, additional, and Flamant, Cyrille, additional
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- 2023
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28. Three-dimensional pathways of Saharan dust export over the North Atlantic during the CADDIWA field campaign
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Cuesta, Juan, primary, Flamant, Cyrille, additional, Gaetani, Marco, additional, Delanoë, Julien, additional, Chaboureau, Jean-Pierre, additional, Menut, Laurent, additional, and Formenti, Paola, additional
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- 2023
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29. Development of Tropical Cyclones from African Easterly Waves : comparative study of three African Easterly Wave events during the CADDIWA campaign
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Jonville, Tanguy, primary, Flamant, Cyrille, additional, Lavaysse, Christophe, additional, Delanoë, Julien, additional, Richard, Pascal, additional, Bounissou, Sophie, additional, Cazenave, Quiterie, additional, Colomb, Hélène, additional, Caudoux, Christophe, additional, Peyrillé, Philippe, additional, and Cornillault, Erwan, additional
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- 2023
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30. EUREC4A: A Field Campaign to Elucidate the Couplings Between Clouds, Convection and Circulation
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Bony, Sandrine, Stevens, Bjorn, Ament, Felix, Bigorre, Sebastien, Chazette, Patrick, Crewell, Susanne, Delanoë, Julien, Emanuel, Kerry, Farrell, David, Flamant, Cyrille, Gross, Silke, Hirsch, Lutz, Karstensen, Johannes, Mayer, Bernhard, Nuijens, Louise, Ruppert, Jr., James H., Sandu, Irina, Siebesma, Pier, Speich, Sabrina, Szczap, Frédéric, Totems, Julien, Vogel, Raphaela, Wendisch, Manfred, and Wirth, Martin
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- 2017
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31. AIRCRAFT OBSERVATIONS OF DRY AIR, THE ITCZ, CONVECTIVE CLOUD SYSTEMS, AND COLD POOLS IN MJO DURING DYNAMO
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Chen, Shuyi S., Kerns, Brandon W., Guy, Nick, Jorgensen, David P., Delanoë, Julien, Viltard, Nicolas, Zappa, Christopher J., Judt, Falko, Lee, Chia-Ying, and Savarin, Ajda
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- 2016
32. SUPPLEMENT : AIRCRAFT OBSERVATIONS OF DRY AIR, THE ITCZ, CONVECTIVE CLOUD SYSTEMS, AND COLD POOLS IN MJO DURING DYNAMO
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Chen, Shuyi S., Kerns, Brandon W., Guy, Nick, Jorgensen, David P., Delanoë, Julien, Viltard, Nicolas, Zappa, Christopher J., Judt, Falko, Lee, Chia-Ying, and Savarin, Ajda
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- 2016
33. Sea2Cloud: from biogenic emission fluxes to cloud properties in the South West Pacific
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Sellegri, Karine, Harvey, Mike, Peltola, Maija, Saint-Macary, Alexia, Barthelmeß, Theresa, Rocco, Manon, Moore, Kathryn, Cristi, Antonia, Peyrin, Frederic, Barr, Neill, Labonnote, Laurent, Marriner, Andrew, Mcgregor, John, Safi, Karl, Deppeler, Stacy, Archer, Stephen, Dunne, Erin, Harnwell, James, Delanoë, Julien, Freney, Evelyn, Rose, Clémence, Bazantay, Clément, Planche, Céline, Saiz-Lopez, Alfonso, Quintanilla-López, Jesús, Lebrón-Aguilar, Rosa, Rinaldi, Matteo, Banson, Sandra, Joseph, Romain, Lupascu, Aurelia, Jourdan, Olivier, Mioche, Guillaume, Colomb, Aurélie, Olivares, Gus, Querel, Richard, Mcdonald, Adrian, Plank, Graeme, Bukosa, Beata, Dillon, Wayne, Pelon, Jacques, Picard, David, Baray, Jean-Luc, Tridon, Frederic, Donnadieu, Franck, Szczap, Frédéric, Engel, Anja, Demott, Paul, Law, Cliff, Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), National Institute of Water and Atmospheric Research [Wellington] (NIWA), Department of Marine Sciences [Dunedin], University of Otago [Dunedin, Nouvelle-Zélande], Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Department of Atmospheric Science [Fort Collins], Colorado State University [Fort Collins] (CSU), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Laboratoire d’Optique Atmosphérique - UMR 8518 (LOA), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), National Institute of Water and Atmosphere [Hamilton] (NIWA), University of Auckland [Auckland], CSIRO Marine and Atmospheric Research [Aspendale], Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), SPACE - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Istituto di Scienze dell'Atmosfera e del Clima [Bologna] (ISAC), Consiglio Nazionale delle Ricerche (CNR), Institute for Advanced Sustainability Studies [Potsdam] (IASS), National Institute of Water and Atmospheric Research [Auckland] (NIWA), National Institute of Water and Atmospheric Research [Lauder] (NIWA), University of Canterbury [Christchurch], Department of Chemistry [Dunedin], Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)
- Subjects
Atmospheric Science ,[SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology - Abstract
The goal of the Sea2Cloud project is to study the interplay between surface ocean biogeochemical and physical properties, fluxes to the atmosphere, and ultimately their impact on cloud formation under minimal direct anthropogenic influence. Here we present an interdisciplinary approach, combining atmospheric physics and chemistry with marine biogeochemistry, during a voyage between 41° and 47°S in March 2020. In parallel to ambient measurements of atmospheric composition and seawater biogeochemical properties, we describe semicontrolled experiments to characterize nascent sea spray properties and nucleation from gas-phase biogenic emissions. The experimental framework for studying the impact of the predicted evolution of ozone concentration in the Southern Hemisphere is also detailed. After describing the experimental strategy, we present the oceanic and meteorological context including provisional results on atmospheric thermodynamics, composition, and flux measurements. In situ measurements and flux studies were carried out on different biological communities by sampling surface seawater from subantarctic, subtropical, and frontal water masses. Air–Sea-Interface Tanks (ASIT) were used to quantify biogenic emissions of trace gases under realistic environmental conditions, with nucleation observed in association with biogenic seawater emissions. Sea spray continuously generated produced sea spray fluxes of 34% of organic matter by mass, of which 4% particles had fluorescent properties, and which size distribution resembled the one found in clean sectors of the Southern Ocean. The goal of Sea2Cloud is to generate realistic parameterizations of emission flux dependences of trace gases and nucleation precursors, sea spray, cloud condensation nuclei, and ice nuclei using seawater biogeochemistry, for implementation in regional atmospheric models.
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- 2023
34. Supplementary material to "The classification of atmospheric hydrometeors and aerosols from the EarthCARE radar and lidar: the A-TC, C-TC and AC-TC products"
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Irbah, Abdanour, primary, Delanoë, Julien, additional, van Zadelhoff, Gerd-Jan, additional, Donovan, David P., additional, Kollias, Pavlos, additional, Puigdomènech Treserras, Bernat, additional, Mason, Shannon, additional, Hogan, Robin J., additional, and Tatarevic, Aleksandra, additional
- Published
- 2022
- Full Text
- View/download PDF
35. The classification of atmospheric hydrometeors and aerosols from the EarthCARE radar and lidar: the A-TC, C-TC and AC-TC products
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Irbah, Abdanour, primary, Delanoë, Julien, additional, van Zadelhoff, Gerd-Jan, additional, Donovan, David P., additional, Kollias, Pavlos, additional, Puigdomènech Treserras, Bernat, additional, Mason, Shannon, additional, Hogan, Robin J., additional, and Tatarevic, Aleksandra, additional
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- 2022
- Full Text
- View/download PDF
36. Aerosol - Cloud Target Classification in HALO Lidar/Radar Collocated Measurements
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Marinou Eleni, Ewald Florian, Gross Silke, Wirth Martin, Schaefler Andreas, Cazenave Quitterie, and Delanoë Julien
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Physics ,QC1-999 - Abstract
Particle attenuated backscatter and depolarization ratio at 532 nm from the WALES (Water Vapor Lidar Experiment in Space) instrument are used in combination with the radar reflectivity from the 35 GHz MIRA35 cloud radar in order to perform an aerosol-cloud target classification on the lidar/radar collocated observations carried out with the High Altitude and LOng-range research aircraft (HALO), in high temporal and spatial resolution. The methodology is applied to the measurements conducted during the North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) in fall 2016. Here, we present one case study to show the feasibility and information context of the aerosol-cloud discrimination, which can serve as a good complement to the Cloud target categorization applied already in the measurements. Our results demonstrate that the developed mask is capable to identify complex stratifications with different aerosol and cloud types and even aerosol layers of low signal.
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- 2020
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37. Corrigendum: Characterizing Observed Midtopped Cloud Regimes Associated with Southern Ocean Shortwave Radiation Biases
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Mason, Shannon, Jakob, Christian, Protat, Alain, and Delanoë, Julien
- Published
- 2014
38. A Synergistic Analysis of Cloud Cover and Vertical Distribution from A-Train and Ground-Based Sensors over the High Arctic Station Eureka from 2006 to 2010
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Blanchard, Yann, Pelon, Jacques, Eloranta, Edwin W., Moran, Kenneth P., Delanoë, Julien, and Sèze, Geneviève
- Published
- 2014
39. An optimal estimation algorithm for the retrieval of fog and low cloud thermodynamic and micro-physical properties
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Bell, Alistair, primary, Martinet, Pauline, additional, Caumont, Olivier, additional, Burnet, Frédéric, additional, Delanoë, Julien, additional, Jorquera, Susana, additional, Seity, Yann, additional, and Unger, Vinciane, additional
- Published
- 2022
- Full Text
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40. ANAtOLIA : a new mobile site-testing station for astronomy and optical communications
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Ziad, Aziz, primary, Giordano, Christophe, additional, Aresta, Alessandro, additional, Aristidi, Eric, additional, Bailet, Christophe, additional, Berto, Filippo, additional, Bertolin, Chiara, additional, Carbillet, Marcel, additional, Cavazzani, Stefano, additional, Ceus, Damien, additional, Charbonnel, Thibaud, additional, Delanoë, Julien, additional, Descloitres, Jacques, additional, Fantéï-Caujolle, Yan, additional, Gillioën, Adrien, additional, Gonzalez-Ramos, Yenny, additional, Irbah, Abdanour, additional, Jacqmart, Estelle, additional, Le Kernec, Arnaud, additional, Liandrat, Olivier, additional, Poulenard, Sylvain, additional, Riedi, Jérôme, additional, Schmutz, Nicolas, additional, and Victori, Stephane, additional
- Published
- 2022
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41. Diabatic processes modulating the vertical structure of the jet stream above the cold front of an extratropical cyclone: sensitivity to deep convection schemes
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Wimmer, Meryl, primary, Rivière, Gwendal, additional, Arbogast, Philippe, additional, Piriou, Jean-Marcel, additional, Delanoë, Julien, additional, Labadie, Carole, additional, Cazenave, Quitterie, additional, and Pelon, Jacques, additional
- Published
- 2022
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42. Characterizing Observed Midtopped Cloud Regimes Associated with Southern Ocean Shortwave Radiation Biases
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Mason, Shannon, Jakob, Christian, Protat, Alain, and Delanoë, Julien
- Published
- 2014
43. SUPPLEMENT : HYMEX-SOPI The Field Campaign Dedicated to Heavy Precipitation and Flash Flooding in the Northwestern Mediterranean
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Ducrocq, Véronique, Braud, Isabelle, Davolio, Silvio, Ferretti, Rossella, Flamant, Cyrille, Jansa, Agustin, Kalthoff, Norbert, Richard, Evelyne, Taupier-Letage, Isabelle, Ayral, Pierre-Alain, Belamari, Sophie, Berne, Alexis, Borga, Marco, Boudevillain, Brice, Bock, Olivier, Boichard, Jean-Luc, Bouin, Marie-Noëlle, Bousquet, Olivier, Bouvier, Christophe, Chiggiato, Jacopo, Cimini, Domenico, Corsmeier, Ulrich, Coppola, Laurent, Cocquerez, Philippe, Defer, Eric, Delanoë, Julien, Di Girolamo, Paolo, Doerenbecher, Alexis, Drobinski, Philippe, Dufournet, Yann, Fourrié, Nadia, Gourley, Jonathan J., Labatut, Laurent, Lambert, Dominique, Le Coz, Jérôme, Marzano, Frank S., Molinié, Gilles, Montani, Andrea, Nord, Guillaume, Nuret, Mathieu, Ramage, Karim, Rison, William, Roussot, Odile, Said, Frédérique, Schwarzenboeck, Alfons, Testor, Pierre, Van Baelen, Joël, Vincendon, Béatrice, Aran, Montserrat, and Tamayo, Jorge
- Published
- 2014
44. HYMEX-SOPI : The Field Campaign Dedicated to Heavy Precipitation and Flash Flooding in the Northwestern Mediterranean
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Ducrocq, Véronique, Braud, Isabelle, Davolio, Silvio, Ferretti, Rossella, Flamant, Cyrille, Jansa, Agustin, Kalthoff, Norbert, Richard, Evelyne, Taupier-Letage, Isabelle, Ayral, Pierre-Alain, Belamari, Sophie, Berne, Alexis, Borga, Marco, Boudevillain, Brice, Bock, Olivier, Boichard, Jean-Luc, Bouin, Marie-Noëlle, Bousquet, Olivier, Bouvier, Christophe, Chiggiato, Jacopo, Cimini, Domenico, Corsmeier, Ulrich, Coppola, Laurent, Cocquerez, Philippe, Defer, Eric, Delanoë, Julien, Di Girolamo, Paolo, Doerenbecher, Alexis, Drobinski, Philippe, Dufournet, Yann, Fourrié, Nadia, Gourley, Jonathan J., Labatut, Laurent, Lambert, Dominique, Le Coz, Jérôme, Marzano, Frank S., Molinié, Gilles, Montani, Andrea, Nord, Guillaume, Nuret, Mathieu, Ramage, Karim, Rison, William, Roussot, Odile, Said, Frédérique, Schwarzenboeck, Alfons, Testor, Pierre, Van Baelen, Joël, Vincendon, Béatrice, Aran, Montserrat, and Tamayo, Jorge
- Published
- 2014
45. EUREC4A: A Field Campaign to Elucidate the Couplings Between Clouds, Convection and Circulation
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Bony, Sandrine, primary, Stevens, Bjorn, additional, Ament, Felix, additional, Bigorre, Sebastien, additional, Chazette, Patrick, additional, Crewell, Susanne, additional, Delanoë, Julien, additional, Emanuel, Kerry, additional, Farrell, David, additional, Flamant, Cyrille, additional, Gross, Silke, additional, Hirsch, Lutz, additional, Karstensen, Johannes, additional, Mayer, Bernhard, additional, Nuijens, Louise, additional, Ruppert, James H., additional, Sandu, Irina, additional, Siebesma, Pier, additional, Speich, Sabrina, additional, Szczap, Frédéric, additional, Totems, Julien, additional, Vogel, Raphaela, additional, Wendisch, Manfred, additional, and Wirth, Martin, additional
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- 2017
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46. The classification of atmospheric hydrometeors and aerosols from the EarthCARE radar and lidar: the A-TC, C-TC and AC-TC products.
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Irbah, Abdanour, Delanoë, Julien, van Zadelhoff, Gerd-Jan, Donovan, David P., Kollias, Pavlos, Puigdomènech Treserras, Bernat, Mason, Shannon, Hogan, Robin J., and Tatarevic, Aleksandra
- Subjects
- *
ATMOSPHERIC aerosols , *ICE clouds , *LIDAR , *MULTIPLE scattering (Physics) , *RADAR , *ATMOSPHERE , *PRECIPITATION scavenging - Abstract
The EarthCARE mission aims to probe the Earth's atmosphere by measuring cloud and aerosol profiles using its active instruments, the Cloud Profiling Radar (CPR) and ATmospheric LIDar (ATLID). The correct identification of hydrometeors and aerosols from atmospheric profiles is an important step in retrieving the properties of clouds, aerosols and precipitation. Ambiguities in the nature of atmospheric targets can be removed using the synergy of collocated radar and lidar measurements, which is based on the complementary spectral response of radar and lidar relative to atmospheric targets present in the profiles. The instruments are sensitive to different parts of the particle size distribution and provide independent but overlapping information in optical and microwave wavelengths. ATLID is sensitive to aerosols and small cloud particles, and CPR is sensitive to large ice particles, snowflakes and raindrops. It is therefore possible to better classify atmospheric targets when collocated radar and lidar measurements exist compared to using a single instrument. The cloud phase, precipitation and aerosol type within the column sampled by the two instruments can then be identified. ATLID-CPR target classification (AC-TC) is the product created for this purpose by combining the ATLID target classification (A-TC) and CPR target classification (C-TC). AC-TC is crucial for the subsequent synergistic retrieval of cloud, aerosol and precipitation properties. AC-TC builds upon previous target classifications using CloudSat and CALIPSO synergy while providing richer target classification using the enhanced capabilities of EarthCARE's instruments, specifically CPR's Doppler velocity measurements to distinguish snow and rimed snow from ice clouds and ATLID's lidar ratio measurements to objectively discriminate between different aerosol species and optically thin ice clouds. In this paper, we first describe how the single-instrument A-TC and C-TC products are derived from ATLID and CPR measurements. Then the AC-TC product, which combines the A-TC and C-TC classifications using a synergistic decision matrix, is presented. Simulated EarthCARE observations based on combined cloud-resolving and aerosol model data are used to test the processors generating the target classifications. Finally, the target classifications are evaluated by quantifying the fractions of ice and snow, liquid clouds, rain, and aerosols in the atmosphere that can be successfully identified by each instrument and their synergy. We show that radar–lidar synergy helps better detect ice and snow, with ATLID detecting radiatively important optically thin cirrus and cloud tops, while CPR penetrates most deep and highly concentrated ice clouds. The detection of rain and drizzle is entirely due to C-TC, while that of liquid clouds and aerosols is due to A-TC. The evaluation also shows that simple assumptions can be made to compensate for when the instruments are obscured by extinction (ATLID) or surface clutter and multiple scattering (CPR); this allows for the recovery of the majority of liquid cloud not detected by the active instruments. [ABSTRACT FROM AUTHOR]
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- 2023
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47. EUREC<sup>4</sup>A observations from the SAFIRE ATR42 aircraft
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Bony, Sandrine, primary, Lothon, Marie, additional, Delanoë, Julien, additional, Coutris, Pierre, additional, Etienne, Jean-Claude, additional, Aemisegger, Franziska, additional, Albright, Anna Lea, additional, André, Thierry, additional, Bellec, Hubert, additional, Baron, Alexandre, additional, Bourdinot, Jean-François, additional, Brilouet, Pierre-Etienne, additional, Bourdon, Aurélien, additional, Canonici, Jean-Christophe, additional, Caudoux, Christophe, additional, Chazette, Patrick, additional, Cluzeau, Michel, additional, Cornet, Céline, additional, Desbios, Jean-Philippe, additional, Duchanoy, Dominique, additional, Flamant, Cyrille, additional, Fildier, Benjamin, additional, Gourbeyre, Christophe, additional, Guiraud, Laurent, additional, Jiang, Tetyana, additional, Lainard, Claude, additional, Le Gac, Christophe, additional, Lendroit, Christian, additional, Lernould, Julien, additional, Perrin, Thierry, additional, Pouvesle, Frédéric, additional, Richard, Pascal, additional, Rochetin, Nicolas, additional, Salaün, Kevin, additional, Schwarzenboeck, Alfons, additional, Seurat, Guillaume, additional, Stevens, Bjorn, additional, Totems, Julien, additional, Touzé-Peiffer, Ludovic, additional, Vergez, Gilles, additional, Vial, Jessica, additional, Villiger, Leonie, additional, and Vogel, Raphaela, additional
- Published
- 2022
- Full Text
- View/download PDF
48. Water isotopic characterisation of the cloud-circulation coupling in the North Atlantic trades. Part 1: A process-oriented evaluation of COSMOiso simulations with EUREC4A observations.
- Author
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Villiger, Leonie, Dütsch, Marina, Bony, Sandrine, Lothon, Marie, Pfahl, Stephan, Wernli, Heini, Brilouet, Pierre-Etienne, Chazette, Patrick, Coutris, Pierre, Delanoë, Julien, Flamant, Cyrille, Schwarzenboeck, Alfons, Werner, Martin, and Aemisegger, Franziska
- Subjects
CUMULUS clouds ,STABLE isotopes ,ATMOSPHERIC circulation ,STRATOCUMULUS clouds ,FIELD research ,REMOTE sensing ,SPATIAL resolution - Abstract
Stable water isotope observations have the potential to provide information on cloud processes in the trade-wind region, in particular when combined with high-resolution model simulations. In order to evaluate this potential, nested convection-resolving COSMO
iso simulations with horizontal grid spacings of 10, 5, and 1 km were carried out in this study over the tropical Atlantic for the time period of the EUREC4 A field experiment. To keep the conditions in the domain as close as possible to the real meteorology, we applied a spectral nudging of horizontal winds towards reanalysis data. The comparison to airborne in situ and remote sensing observations shows that the three simulations are able to distinguish between different mesoscale cloud organisation patterns as well as between periods with comparably high and low rain rates. Precipitation, cloud fraction and liquid water content are sensitive to the grid spacing. Cloud fraction and liquid water content show a better agreement with aircraft observations with higher spatial resolution. Contrastingly, temperature, humidity, and isotopes in vapour remain fairly unaffected by the model resolution. A low-level cold-dry bias, including too depleted vapour in the subcloud and cloud layer and too enriched vapour in the free troposphere, is found in all three simulations. Furthermore, the simulated secondary isotope variable d-excess in vapour is overestimated compared to observations. Special attention is given to the cloud base level, the formation altitude of shallow cumulus clouds, which are rooted in the thermals of the subcloud layer. The temporal variability of the simulated isotope variables at cloud base agrees reasonably well with observations, with correlations of the flight-to-flight data as high as 0.69 for δ2 H and 0.74 for d-excess. A close examination of different mesoscale cloud base features, including clouds and clear-sky dry-warm patches, and their isotopic characteristics shows that i) these features are represented faithfully in the model with similar frequency of occurrence, isotope signals and specific humidity anomalies as found in the observations (+2 ‰ to +5 ‰ [+2 g kg−1 ] for precipitating clouds vs. −3 ‰ to −4 ‰ [−2 g kg−1 ] in dry-warm patches for δ2 H [ q ]) and ii) the δ2 H of cloud base vapour at the hourly time scale is mainly controlled by mesoscale transport and not by local microphysical processes while the d-excess is mainly controlled by large-scale drivers. Overall, this evaluation of COSMOiso , including the isotopic characterisation of cloud base features, suggests that the simulations can be used for investigating the role of atmospheric circulations on different scales for controlling the formation of shallow cumulus clouds in the trade-wind region, as will be done in part 2 of this study. Additionally, we provide explicit recommendations for adaptations of the modelling setup to be tested in future research. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
49. Climatology of estimated liquid water content and scaling factor for warm clouds using radar–microwave radiometer synergy.
- Author
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Vishwakarma, Pragya, Delanoë, Julien, Jorquera, Susana, Martinet, Pauline, Burnet, Frederic, Bell, Alistair, and Dupont, Jean-Charles
- Subjects
- *
CLIMATOLOGY , *MICROWAVE radiometers , *RADIOMETERS , *CLOUD droplets , *LIQUIDS , *ICE clouds , *FOG - Abstract
Cloud radars are capable of providing continuous high-resolution observations of clouds and now offer new capabilities within fog layers thanks to the development of frequency-modulated continuous-wave 95 GHz cloud radars. These observations are related to the microphysical properties of clouds. Power law relations in the form of Z=a⋅LWCb are generally used to estimate liquid water content (LWC) profiles. The constants a and b from the power law relation vary with the cloud type and cloud characteristics. Due to the variety of such parameterizations, selecting the most appropriate Z –LWC relation for a continuous cloud system is complicated. Additional information such as liquid water path (LWP) from a co-located microwave radiometer (MWR) is used to scale the LWC of the cloud profile. An algorithm for estimating the LWC of fog and warm clouds using 95 GHz cloud radar–microwave radiometer synergy in a variational framework is presented. This paper also aims to propose an algorithm configuration that retrieves the LWC of clouds and fog using radar reflectivity and a climatology of the power law parameters. To do so, variations in the scaling factor lna (the logarithm of pre-factor a from power law relation) when MWR observations are available are allowed in each cloud profile to build a climatology of the scaling factor lna that can be used when MWR observations are not available. The algorithm also accounts for attenuation due to cloud droplets. In this algorithm formulation, the measure of uncertainty in the observations, the forward model, and the a priori information of desired variables acts as weights in the retrieved quantities. These uncertainties in the retrieval are analyzed in the sensitivity analysis of the algorithm. The retrieval algorithm is first tested on a synthetic profile for different perturbations in sensitivity parameters. The sensitivity study has shown that this method is susceptible to LWP information because LWP is point information for the whole cloud column. By further investigating the sensitivity analysis of various biases in LWP information, it was found that it is beneficial to incorporate LWP, even if it is biased, rather than not assimilate any LWP. The algorithm is then implemented in various cloud and fog cases at the SIRTA observatory to estimate LWC and the scaling factor. The scaling factor (lna) changes for each cloud profile, and the range of lna is consistent with suggested values in the literature. The validation of such an algorithm is challenging, as we need reference measurements of LWC co-located with the retrieved values. During the SOFOG-3D campaign (southwest of France, October 2019 to March 2020), in situ measurements of LWC were collected in the vicinity of a cloud radar and a microwave radiometer, allowing comparison of retrieved and measured LWC. The comparison demonstrated that the cloud–fog heterogeneity played a key role in the assessment. The proposed synergistic retrieval algorithm is applied to 39 cloud and fog cases at SIRTA, and the behavior of the scaling factor is studied. This statistical analysis of scaling is carried out to develop a radar-only retrieval method. The climatology revealed that the scaling factor can be linked to the maximum reflectivity of the profile. From climatology, the statistical relations for the scaling factor are proposed for fog and clouds. Thanks to the variational framework, a stand-alone radar version of the algorithm is adapted from the synergistic retrieval algorithm, which incorporates the climatology of the scaling factor as a priori information to estimate the LWC of warm clouds. This method allows the LWC estimation using only radar reflectivity and climatology of the scaling factor. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
50. Optimal estimation of thermodynamic and microphysical profiles within fog events from ground-based microwave radiometer and cloud radar synergy.
- Author
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Martinet, Pauline, primary, Bell, Alistair, additional, Caumont, Olivier, additional, Vié, Benoit, additional, Burnet, Frédéric, additional, and Delanoë, Julien, additional
- Published
- 2022
- Full Text
- View/download PDF
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