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Jim
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Jim
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ArticleOverview of the Arctic Sea state and boundary layer physics program(American Geophysical Union, 2018-04-16) Thomson, Jim ; Ackley, Stephen ; Girard-Ardhuin, Fanny ; Ardhuin, Fabrice ; Babanin, Alexander ; Boutin, Guillaume ; Brozena, John ; Cheng, Sukun ; Collins, Clarence ; Doble, Martin ; Fairall, Christopher W. ; Guest, Peter ; Gebhardt, Claus ; Gemmrich, Johannes ; Graber, Hans C. ; Holt, Benjamin ; Lehner, Susanne ; Lund, Björn ; Meylan, Michael ; Maksym, Ted ; Montiel, Fabien ; Perrie, Will ; Persson, Ola ; Rainville, Luc ; Rogers, W. Erick ; Shen, Hui ; Shen, Hayley ; Squire, Vernon ; Stammerjohn, Sharon E. ; Stopa, Justin ; Smith, Madison M. ; Sutherland, Peter ; Wadhams, PeterA large collaborative program has studied the coupled air‐ice‐ocean‐wave processes occurring in the Arctic during the autumn ice advance. The program included a field campaign in the western Arctic during the autumn of 2015, with in situ data collection and both aerial and satellite remote sensing. Many of the analyses have focused on using and improving forecast models. Summarizing and synthesizing the results from a series of separate papers, the overall view is of an Arctic shifting to a more seasonal system. The dramatic increase in open water extent and duration in the autumn means that large surface waves and significant surface heat fluxes are now common. When refreezing finally does occur, it is a highly variable process in space and time. Wind and wave events drive episodic advances and retreats of the ice edge, with associated variations in sea ice formation types (e.g., pancakes, nilas). This variability becomes imprinted on the winter ice cover, which in turn affects the melt season the following year.
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ArticleMeasurements from the RV Ronald H. Brown and related platforms as part of the Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC)(Copernicus Publications, 2021-04-29) Quinn, Patricia K. ; Thompson, Elizabeth ; Coffman, Derek J. ; Baidar, Sunil ; Bariteau, Ludovic ; Bates, Timothy S. ; Bigorre, Sebastien P. ; Brewer, Alan ; de Boer, Gijs ; de Szoeke, Simon P. ; Drushka, Kyla ; Foltz, Gregory R. ; Intrieri, Janet ; Iyer, Suneil ; Fairall, Christopher W. ; Gaston, Cassandra J. ; Jansen, Friedhelm ; Johnson, James E. ; Krüger, Ovid O. ; Marchbanks, Richard D. ; Moran, Kenneth P. ; Noone, David ; Pezoa, Sergio ; Pincus, Robert ; Plueddemann, Albert J. ; Pöhlker, Mira L. ; Pöschl, Ulrich ; Quinones Melendez, Estefania ; Royer, Haley M. ; Szczodrak, Malgorzata ; Thomson, Jim ; Upchurch, Lucia M. ; Zhang, Chidong ; Zhang, Dongxiao ; Zuidema, PaquitaThe Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC) took place from 7 January to 11 July 2020 in the tropical North Atlantic between the eastern edge of Barbados and 51∘ W, the longitude of the Northwest Tropical Atlantic Station (NTAS) mooring. Measurements were made to gather information on shallow atmospheric convection, the effects of aerosols and clouds on the ocean surface energy budget, and mesoscale oceanic processes. Multiple platforms were deployed during ATOMIC including the NOAA RV Ronald H. Brown (RHB) (7 January to 13 February) and WP-3D Orion (P-3) aircraft (17 January to 10 February), the University of Colorado's Robust Autonomous Aerial Vehicle-Endurant Nimble (RAAVEN) uncrewed aerial system (UAS) (24 January to 15 February), NOAA- and NASA-sponsored Saildrones (12 January to 11 July), and Surface Velocity Program Salinity (SVPS) surface ocean drifters (23 January to 29 April). The RV Ronald H. Brown conducted in situ and remote sensing measurements of oceanic and atmospheric properties with an emphasis on mesoscale oceanic–atmospheric coupling and aerosol–cloud interactions. In addition, the ship served as a launching pad for Wave Gliders, Surface Wave Instrument Floats with Tracking (SWIFTs), and radiosondes. Details of measurements made from the RV Ronald H. Brown, ship-deployed assets, and other platforms closely coordinated with the ship during ATOMIC are provided here. These platforms include Saildrone 1064 and the RAAVEN UAS as well as the Barbados Cloud Observatory (BCO) and Barbados Atmospheric Chemistry Observatory (BACO). Inter-platform comparisons are presented to assess consistency in the data sets. Data sets from the RV Ronald H. Brown and deployed assets have been quality controlled and are publicly available at NOAA's National Centers for Environmental Information (NCEI) data archive (https://www.ncei.noaa.gov/archive/accession/ATOMIC-2020, last access: 2 April 2021). Point-of-contact information and links to individual data sets with digital object identifiers (DOIs) are provided herein.
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ArticleEUREC4A(Copernicus Publications, 2021-08-25) Stevens, Bjorn ; Bony, Sandrine ; Farrell, David ; Ament, Felix ; Blyth, Alan ; Fairall, Christopher W. ; Karstensen, Johannes ; Quinn, Patricia K. ; Speich, Sabrina ; Acquistapace, Claudia ; Aemisegger, Franziska ; Albright, Anna Lea ; Bellenger, Hugo ; Bodenschatz, Eberhard ; Caesar, Kathy-Ann ; Chewitt-Lucas, Rebecca ; de Boer, Gijs ; Delanoë, Julien ; Denby, Leif ; Ewald, Florian ; Fildier, Benjamin ; Forde, Marvin ; George, Geet ; Gross, Silke ; Hagen, Martin ; Hausold, Andrea ; Heywood, Karen J. ; Hirsch, Lutz ; Jacob, Marek ; Jansen, Friedhelm ; Kinne, Stefan ; Klocke, Daniel ; Kölling, Tobias ; Konow, Heike ; Lothon, Marie ; Mohr, Wiebke ; Naumann, Ann Kristin ; Nuijens, Louise ; Olivier, Léa ; Pincus, Robert ; Pöhlker, Mira L. ; Reverdin, Gilles ; Roberts, Gregory ; Schnitt, Sabrina ; Schulz, Hauke ; Siebesma, Pier ; Stephan, Claudia Christine ; Sullivan, Peter P. ; Touzé-Peiffer, Ludovic ; Vial, Jessica ; Vogel, Raphaela ; Zuidema, Paquita ; Alexander, Nicola ; Alves, Lyndon ; Arixi, Sophian ; Asmath, Hamish ; Bagheri, Gholamhossein ; Baier, Katharina ; Bailey, Adriana ; Baranowski, Dariusz ; Baron, Alexandre ; Barrau, Sébastien ; Barrett, Paul A. ; Batier, Frédéric ; Behrendt, Andreas ; Bendinger, Arne ; Beucher, Florent ; Bigorre, Sebastien P. ; Blades, Edmund ; Blossey, Peter ; Bock, Olivier ; Böing, Steven ; Bosser, Pierre ; Bourras, Denis ; Bouruet-Aubertot, Pascale ; Bower, Keith ; Branellec, Pierre ; Branger, Hubert ; Brennek, Michal ; Brewer, Alan ; Brilouet, Pierre-Etienne ; Brügmann, Björn ; Buehler, Stefan A. ; Burke, Elmo ; Burton, Ralph ; Calmer, Radiance ; Canonici, Jean-Christophe ; Carton, Xavier ; Cato, Gregory, Jr. ; Charles, Jude Andre ; Chazette, Patrick ; Chen, Yanxu ; Chilinski, Michal T. ; Choularton, Thomas ; Chuang, Patrick ; Clarke, Shamal ; Coe, Hugh ; Cornet, Céline ; Coutris, Pierre ; Couvreux, Fleur ; Crewell, Susanne ; Cronin, Timothy W. ; Cui, Zhiqiang ; Cuypers, Yannis ; Daley, Alton ; Damerell, Gillian M. ; Dauhut, Thibaut ; Deneke, Hartwig ; Desbios, Jean-Philippe ; Dörner, Steffen ; Donner, Sebastian ; Douet, Vincent ; Drushka, Kyla ; Dütsch, Marina ; Ehrlich, André ; Emanuel, Kerry A. ; Emmanouilidis, Alexandros ; Etienne, Jean-Claude ; Etienne-Leblanc, Sheryl ; Faure, Ghislain ; Feingold, Graham ; Ferrero, Luca ; Fix, Andreas ; Flamant, Cyrille ; Flatau, Piotr Jacek ; Foltz, Gregory R. ; Forster, Linda ; Furtuna, Iulian ; Gadian, Alan ; Galewsky, Joseph ; Gallagher, Martin ; Gallimore, Peter ; Gaston, Cassandra J. ; Gentemann, Chelle L. ; Geyskens, Nicolas ; Giez, Andreas ; Gollop, John ; Gouirand, Isabelle ; Gourbeyre, Christophe ; de Graaf, Dörte ; de Graaf, Geiske E. ; Grosz, Robert ; Güttler, Johannes ; Gutleben, Manuel ; Hall, Kashawn ; Harris, George ; Helfer, Kevin C. ; Henze, Dean ; Herbert, Calvert ; Holanda, Bruna ; Ibanez-Landeta, Antonio ; Intrieri, Janet ; Iyer, Suneil ; Julien, Fabrice ; Kalesse, Heike ; Kazil, Jan ; Kellman, Alexander ; Kidane, Abiel T. ; Kirchner, Ulrike ; Klingebiel, Marcus ; Körner, Mareike ; Kremper, Leslie Ann ; Kretzschmar, Jan ; Krüger, Ovid O. ; Kumala, Wojciech ; Kurz, Armin ; L'Hégareta, Pierre ; Labaste, Matthieu ; Lachlan-Cope, Thomas ; Laing, Arlene ; Landschützer, Peter ; Lang, Theresa ; Lange, Diego ; Lange, Ingo ; Laplace, Clément ; Lavik, Gauke ; Laxenaire, Rémi ; Le Bihan, Caroline ; Leandro, Mason ; Lefevre, Nathalie ; Lena, Marius ; Lenschow, Donald ; Li, Qiang ; Lloyd, Gary ; Los, Sebastian ; Losi, Niccolò ; Lovell, Oscar ; Luneau, Christopher ; Makuch, Przemyslaw ; Malinowski, Szymon ; Manta, Gaston ; Marinou, Eleni ; Marsden, Nicholas ; Masson, Sebastien ; Maury, Nicolas ; Mayer, Bernhard ; Mayers-Als, Margarette ; Mazel, Christophe ; McGeary, Wayne ; McWilliams, James C. ; Mech, Mario ; Mehlmann, Melina ; Meroni, Agostino Niyonkuru ; Mieslinger, Theresa ; Minikin, Andreas ; Minnett, Peter J. ; Möller, Gregor ; Morfa Avalos, Yanmichel ; Muller, Caroline ; Musat, Ionela ; Napoli, Anna ; Neuberger, Almuth ; Noisel, Christophe ; Noone, David ; Nordsiek, Freja ; Nowak, Jakub L. ; Oswald, Lothar ; Parker, Douglas J. ; Peck, Carolyn ; Person, Renaud ; Philippi, Miriam ; Plueddemann, Albert J. ; Pöhlker, Christopher ; Pörtge, Veronika ; Pöschl, Ulrich ; Pologne, Lawrence ; Posyniak, Michał ; Prange, Marc ; Quinones Melendez, Estefania ; Radtke, Jule ; Ramage, Karim ; Reimann, Jens ; Renault, Lionel ; Reus, Klaus ; Reyes, Ashford ; Ribbe, Joachim ; Ringel, Maximilian ; Ritschel, Markus ; Rocha, Cesar B. ; Rochetin, Nicolas ; Röttenbacher, Johannes ; Rollo, Callum ; Royer, Haley M. ; Sadoulet, Pauline ; Saffin, Leo ; Sandiford, Sanola ; Sandu, Irina ; Schäfer, Michael ; Schemann, Vera ; Schirmacher, Imke ; Schlenczek, Oliver ; Schmidt, Jerome M. ; Schröder, Marcel ; Schwarzenboeck, Alfons ; Sealy, Andrea ; Senff, Christoph J. ; Serikov, Ilya ; Shohan, Samkeyat ; Siddle, Elizabeth ; Smirnov, Alexander ; Späth, Florian ; Spooner, Branden ; Stolla, M. Katharina ; Szkółka, Wojciech ; de Szoeke, Simon P. ; Tarot, Stéphane ; Tetoni, Eleni ; Thompson, Elizabeth ; Thomson, Jim ; Tomassini, Lorenzo ; Totems, Julien ; Ubele, Alma Anna ; Villiger, Leonie ; von Arx, Jan ; Wagner, Thomas ; Walther, Andi ; Webber, Ben ; Wendisch, Manfred ; Whitehall, Shanice ; Wiltshire, Anton ; Wing, Allison A. ; Wirth, Martin ; Wiskandt, Jonathan ; Wolf, Kevin ; Worbes, Ludwig ; Wright, Ethan ; Young, Shanea ; Zhang, Chidong ; Zhang, Dongxiao ; Ziemen, Florian ; Zinner, Tobias ; Zöger, MartinThe science guiding the EUREC4A campaign and its measurements is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC4A marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200 km) and larger (500 km) scales, roughly 400 h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10 000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC4A explored – from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation – are presented along with an overview of EUREC4A's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement.
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ArticleA warm jet in a cold ocean(Nature Research, 2021-04-23) MacKinnon, Jennifer A. ; Simmons, Harper L. ; Hargrove, John ; Thomson, Jim ; Peacock, Thomas ; Alford, Matthew H. ; Barton, Benjamin I. ; Boury, Samuel ; Brenner, Samuel D. ; Couto, Nicole ; Danielson, Seth L. ; Fine, Elizabeth C. ; Graber, Hans C. ; Guthrie, John D. ; Hopkins, Joanne E. ; Jayne, Steven R. ; Jeon, Chanhyung ; Klenz, Thilo ; Lee, Craig M. ; Lenn, Yueng-Djern ; Lucas, Andrew J. ; Lund, Björn ; Mahaffey, Claire ; Norman, Louisa ; Rainville, Luc ; Smith, Madison M. ; Thomas, Leif N. ; Torres-Valdes, Sinhue ; Wood, Kevin R.Unprecedented quantities of heat are entering the Pacific sector of the Arctic Ocean through Bering Strait, particularly during summer months. Though some heat is lost to the atmosphere during autumn cooling, a significant fraction of the incoming warm, salty water subducts (dives beneath) below a cooler fresher layer of near-surface water, subsequently extending hundreds of kilometers into the Beaufort Gyre. Upward turbulent mixing of these sub-surface pockets of heat is likely accelerating sea ice melt in the region. This Pacific-origin water brings both heat and unique biogeochemical properties, contributing to a changing Arctic ecosystem. However, our ability to understand or forecast the role of this incoming water mass has been hampered by lack of understanding of the physical processes controlling subduction and evolution of this this warm water. Crucially, the processes seen here occur at small horizontal scales not resolved by regional forecast models or climate simulations; new parameterizations must be developed that accurately represent the physics. Here we present novel high resolution observations showing the detailed process of subduction and initial evolution of warm Pacific-origin water in the southern Beaufort Gyre.
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ArticleComparing observations and parameterizations of ice-ocean drag through an annual cycle across the Beaufort Sea(American Geophysical Union, 2021-03-29) Brenner, Samuel D. ; Rainville, Luc ; Thomson, Jim ; Cole, Sylvia T. ; Lee, Craig M.Understanding and predicting sea ice dynamics and ice-ocean feedback processes requires accurate descriptions of momentum fluxes across the ice-ocean interface. In this study, we present observations from an array of moorings in the Beaufort Sea. Using a force-balance approach, we determine ice-ocean drag coefficient values over an annual cycle and a range of ice conditions. Statistics from high resolution ice draft measurements are used to calculate expected drag coefficient values from morphology-based parameterization schemes. With both approaches, drag coefficient values ranged from ∼1 to 10 × 10−3, with a minimum in fall and a maximum at the end of spring, consistent with previous observations. The parameterizations do a reasonable job of predicting the observed drag values if the under ice geometry is known, and reveal that keel drag is the primary contributor to the total ice-ocean drag coefficient. When translations of bulk model outputs to ice geometry are included in the parameterizations, they overpredict drag on floe edges, leading to the inverted seasonal cycle seen in prior models. Using these results to investigate the efficiency of total momentum flux across the atmosphere-ice-ocean interface suggests an inter-annual trend of increasing coupling between the atmosphere and the ocean.
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ArticleAcoustic sensing of ocean mixed layer depth and temperature from uplooking ADCPs(American Meteorological Society, 2023-01-01) Brenner, Samuel ; Thomson, Jim ; Rainville, Luc ; Torres, Daniel ; Doble, Martin ; Wilkinson, Jeremy ; Lee, CraigProperties of the surface mixed layer (ML) are critical for understanding and predicting atmosphere–sea ice–ocean interactions in the changing Arctic Ocean. Mooring measurements are typically unable to resolve the ML in the Arctic due to the need for instruments to remain below the surface to avoid contact with sea ice and icebergs. Here, we use measurements from a series of three moorings installed for one year in the Beaufort Sea to demonstrate that upward-looking acoustic Doppler current profilers (ADCPs) installed on subsurface floats can be used to estimate ML properties. A method is developed for combining measured peaks in acoustic backscatter and inertial shear from the ADCPs to estimate the ML depth. Additionally, we use an inverse sound speed model to infer the summer ML temperature based on offsets in ADCP altimeter distance during open-water periods. The ADCP estimates of ML depth and ML temperature compare favorably with measurements made from mooring temperature sensors, satellite SST, and from an autonomous Seaglider. These methods could be applied to other extant mooring records to recover additional information about ML property changes and variability.
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ArticleAcoustic backscattering at a tidal intrusion front(Elsevier, 2023-11-08) Bassett, Christopher ; Lavery, Andone C. ; Ralston, David K. ; Geyer, Wayne Rockwell ; Jurisa, Joseph T. ; Thomson, Jim M. ; Honegger, David A. ; Simpson, Alexandra J. ; Scully, Malcolm E. ; Haller, Merrick C.Strong spatial gradients and rapidly evolving, three-dimensional structure make estuarine fronts difficult to sample. Echosounders can be used near fronts to provide nearly synoptic images of water column processes and, with sufficient bandwidth, can provide quantitative information about dynamical variables derived from forward and inverse methods using acoustic backscattering measurements. This manuscript discusses measurements using broadband (50-420 kHz) echosounders from the James River (Virginia, USA) tidal intrusion front. The dominant backscattering mechanisms observed at the site include bubbles, turbulent microstructure, interfaces associated with stratification, suspended sediment, and biota. Existing analytical models are used to interpret contributions from these sources with acoustic inversions providing quantitative information about the physical structure and processes that compare favorably with conventional, in situ measurements. Supporting data sets for this analysis include measurements of temperature, salinity, velocity, and turbidity; X-band radar images of sea surface roughness; aerial optical imagery; Lagrangian measurements of waves, turbulence, and velocity structure; and Regional Ocean Modeling System circulation model simulations. A notable advantage of acoustic remote sensing is the ability to resolve processes at considerably higher spatial resolution (<1 m horizontal; <5 cm vertical) than other in situ sampling approaches.
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ArticleObservations of ocean surface wave attenuation in sea ice using seafloor cables(American Geophysical Union, 2023-10-13) Smith, Madison M. ; Thomson, Jim ; Baker, Michael G. ; Abbott, Robert E. ; Davis, JakeThe attenuation of ocean surface waves during seasonal ice cover is an important control on the evolution of Arctic coastlines. The spatial and temporal variations in this process have been challenging to resolve with conventional sampling using sparse arrays of moorings or buoys. We demonstrate a novel method for persistent observation of wave-ice interactions using distributed acoustic sensing (DAS) along existing seafloor fiber optic telecommunications cables. DAS measurements span a 36-km cross-shore cable on the Beaufort Shelf from Oliktok Point, Alaska. DAS optical sensing of fiber strain-rate provides a proxy for seafloor pressure, which we calibrate with wave buoy measurements during the ice-free season (August 2022). We apply this calibration during the ice formation season (November 2021) to obtain unprecedented resolution of variable wave attenuation rates in new, partial ice cover. The location and strength of wave attenuation serve as proxies for ice coverage and thickness, especially during rapidly evolving events.