Articles | Volume 13, issue 6
Research article 04 Dec 2017
Research article | 04 Dec 2017
Submesoscale CO2 variability across an upwelling front off Peru
Eike E. Köhn et al.
No articles found.
Jaard Hauschildt, Soeren Thomsen, Vincent Echevin, Andreas Oschlies, Yonss Saranga José, Gerd Krahmann, Laura A. Bristow, and Gaute Lavik
Biogeosciences, 18, 3605–3629,Short summary
In this paper we quantify the subduction of upwelled nitrate due to physical processes on the order of several kilometers in the coastal upwelling off Peru and its effect on primary production. We also compare the prepresentation of these processes in a high-resolution simulation (~2.5 km) with a more coarsely resolved simulation (~12 km). To do this, we combine high-resolution shipboard observations of physical and biogeochemical parameters with a complex biogeochemical model configuration.
Francesca Doglioni, Robert Ricker, Benjamin Rabe, and Torsten Kanzow
Earth Syst. Sci. Data Discuss.,
Manuscript not accepted for further reviewShort summary
This paper presents a new satellite-derived gridded dataset of sea surface height and geostrophic velocity, over the Arctic ice-covered and ice-free regions up to 88° N. The dataset includes velocities north of 82° N, which were not available before. We assess the dataset by comparison to one independent satellite dataset and to independent mooring data. Results show that the geostrophic velocity fields can resolve seasonal to interannual variability of boundary currents wider than about 50 km.
Gerd Krahmann, Damian L. Arévalo-Martínez, Andrew W. Dale, Marcus Dengler, Anja Engel, Nicolaas Glock, Patricia Grasse, Johannes Hahn, Helena Hauss, Mark Hopwood, Rainer Kiko, Alexandra Loginova, Carolin R. Löscher, Marie Maßmig, Alexandra-Sophie Roy, Renato Salvatteci, Stefan Sommer, Toste Tanhua, and Hela Mehrtens
Earth Syst. Sci. Data Discuss.,
Preprint withdrawnShort summary
The project "Climate-Biogeochemistry Interactions in the Tropical Ocean" (SFB 754) was a multidisciplinary research project active from 2008 to 2019 aimed at a better understanding of the coupling between the tropical climate and ocean circulation and the ocean's oxygen and nutrient balance. On 34 research cruises, mainly in the Southeast Tropical Pacific and the Northeast Tropical Atlantic, 1071 physical, chemical and biological data sets were collected.
Josefine Herrford, Peter Brandt, Torsten Kanzow, Rebecca Hummels, Moacyr Araujo, and Jonathan V. Durgadoo
Ocean Sci., 17, 265–284,Short summary
The Atlantic Meridional Overturning Circulation (AMOC) is an important component of the climate system. Understanding its structure and variability is a key priority for many scientists. Here, we present the first estimate of AMOC variations for the tropical South Atlantic from the TRACOS array at 11° S. Over the observed period, the AMOC was dominated by seasonal variability. We investigate the respective mechanisms with an ocean model and find that different wind-forced waves play a big role.
Samuel T. Wilson, Alia N. Al-Haj, Annie Bourbonnais, Claudia Frey, Robinson W. Fulweiler, John D. Kessler, Hannah K. Marchant, Jana Milucka, Nicholas E. Ray, Parvadha Suntharalingam, Brett F. Thornton, Robert C. Upstill-Goddard, Thomas S. Weber, Damian L. Arévalo-Martínez, Hermann W. Bange, Heather M. Benway, Daniele Bianchi, Alberto V. Borges, Bonnie X. Chang, Patrick M. Crill, Daniela A. del Valle, Laura Farías, Samantha B. Joye, Annette Kock, Jabrane Labidi, Cara C. Manning, John W. Pohlman, Gregor Rehder, Katy J. Sparrow, Philippe D. Tortell, Tina Treude, David L. Valentine, Bess B. Ward, Simon Yang, and Leonid N. Yurganov
Biogeosciences, 17, 5809–5828,Short summary
The oceans are a net source of the major greenhouse gases; however there has been little coordination of oceanic methane and nitrous oxide measurements. The scientific community has recently embarked on a series of capacity-building exercises to improve the interoperability of dissolved methane and nitrous oxide measurements. This paper derives from a workshop which discussed the challenges and opportunities for oceanic methane and nitrous oxide research in the near future.
Jan Lüdke, Marcus Dengler, Stefan Sommer, David Clemens, Sören Thomsen, Gerd Krahmann, Andrew W. Dale, Eric P. Achterberg, and Martin Visbeck
Ocean Sci., 16, 1347–1366,Short summary
We analyse the intraseasonal variability of the alongshore circulation off Peru in early 2017, this circulation is very important for the supply of nutrients to the upwelling regime. The causes of this variability and its impact on the biogeochemistry are investigated. The poleward flow is strengthened during the observed time period, likely by a downwelling coastal trapped wave. The stronger current causes an increase in nitrate and reduces the deficit of fixed nitrogen relative to phosphorus.
Alexandra N. Loginova, Andrew W. Dale, Frédéric A. C. Le Moigne, Sören Thomsen, Stefan Sommer, David Clemens, Klaus Wallmann, and Anja Engel
Biogeosciences, 17, 4663–4679,Short summary
We measured dissolved organic carbon (DOC), nitrogen (DON) and matter (DOM) optical properties in pore waters and near-bottom waters of the eastern tropical South Pacific off Peru. The difference between diffusion-driven and net fluxes of DOC and DON and qualitative changes in DOM optical properties suggested active microbial utilisation of the released DOM at the sediment–water interface. Our results suggest that the sediment release of DOM contributes to microbial processes in the area.
Claudia Frey, Hermann W. Bange, Eric P. Achterberg, Amal Jayakumar, Carolin R. Löscher, Damian L. Arévalo-Martínez, Elizabeth León-Palmero, Mingshuang Sun, Xin Sun, Ruifang C. Xie, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 17, 2263–2287,Short summary
The production of N2O via nitrification and denitrification associated with low-O2 waters is a major source of oceanic N2O. We investigated the regulation and dynamics of these processes with respect to O2 and organic matter inputs. The transcription of the key nitrification gene amoA rapidly responded to changes in O2 and strongly correlated with N2O production rates. N2O production by denitrification was clearly stimulated by organic carbon, implying that its supply controls N2O production.
Eric J. Morgan, Jost V. Lavric, Damian L. Arévalo-Martínez, Hermann W. Bange, Tobias Steinhoff, Thomas Seifert, and Martin Heimann
Biogeosciences, 16, 4065–4084,Short summary
Taking a 2-year atmospheric record of atmospheric oxygen and the greenhouse gases N2O, CO2, and CH4, made at a coastal site in the Namib Desert, we estimated the fluxes of these gases from upwelling events in the northern Benguela Current region. We compared these results with flux measurements made on a research vessel in the study area at the same time and found that the two approaches agreed well. The study region was a source of N2O, CO2, and CH4 to the atmosphere during upwelling events.
Tim Fischer, Annette Kock, Damian L. Arévalo-Martínez, Marcus Dengler, Peter Brandt, and Hermann W. Bange
Biogeosciences, 16, 2307–2328,Short summary
We investigated air–sea gas exchange in oceanic upwelling regions for the case of nitrous oxide off Peru. In this region, routine concentration measurements from ships at 5 m or 10 m depth prove to overestimate surface (bulk) concentration. Thus, standard estimates of gas exchange will show systematic error. This is due to very shallow stratified layers that inhibit exchange between surface water and waters below and can exist for several days. Maximum bias occurs in moderate wind conditions.
Qixing Ji, Mark A. Altabet, Hermann W. Bange, Michelle I. Graco, Xiao Ma, Damian L. Arévalo-Martínez, and Damian S. Grundle
Biogeosciences, 16, 2079–2093,Short summary
A strong El Niño event occurred in the Peruvian coastal region in 2015–2016, during which higher sea surface temperatures co-occurred with significantly lower sea-to-air fluxes of nitrous oxide, an important greenhouse gas and ozone depletion agent. Stratified water column during El Niño retained a larger amount of nitrous oxide that was produced via multiple microbial pathways; and intense nitrous oxide effluxes could occur when normal upwelling is resumed after El Niño.
Alexandra N. Loginova, Sören Thomsen, Marcus Dengler, Jan Lüdke, and Anja Engel
Biogeosciences, 16, 2033–2047,Short summary
High primary production in the Peruvian upwelling system is followed by rapid heterotrophic utilization of organic matter and supports the formation of one of the most intense oxygen minimum zones (OMZs) in the world. Here, we estimated vertical fluxes of oxygen and dissolved organic matter (DOM) from the surface to the OMZ. Our results suggest that DOM remineralization substantially reduces oxygen concentration in the upper water column and controls the shape of the upper oxycline.
Soeren Thomsen, Johannes Karstensen, Rainer Kiko, Gerd Krahmann, Marcus Dengler, and Anja Engel
Biogeosciences, 16, 979–998,Short summary
Physical and biogeochemical observations from an autonomous underwater vehicle in combination with ship-based measurements are used to investigate remote and local drivers of the oxygen and nutrient variability off Mauritania. Beside the transport of oxygen and nutrients characteristics from remote areas towards Mauritania also local remineralization of organic material close to the seabed seems to be important for the distribution of oxygen and nutrients.
Samuel T. Wilson, Hermann W. Bange, Damian L. Arévalo-Martínez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John L. Bullister, Macarena Burgos, David W. Capelle, Michael Casso, Mercedes de la Paz, Laura Farías, Lindsay Fenwick, Sara Ferrón, Gerardo Garcia, Michael Glockzin, David M. Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara C. Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John W. Pohlman, Andrew P. Rees, Alyson E. Santoro, Philippe D. Tortell, Robert C. Upstill-Goddard, David P. Wisegarver, Gui-Ling Zhang, and Gregor Rehder
Biogeosciences, 15, 5891–5907,Short summary
To determine the variability between independent measurements of dissolved methane and nitrous oxide, seawater samples were analyzed by multiple laboratories. The results revealed the influences of the different parts of the analytical process, from the initial sample collection to the calculation of the final concentrations. Recommendations are made to improve dissolved methane and nitrous oxide measurements to help preclude future analytical discrepancies between laboratories.
Amelie Driemel, Eberhard Fahrbach, Gerd Rohardt, Agnieszka Beszczynska-Möller, Antje Boetius, Gereon Budéus, Boris Cisewski, Ralph Engbrodt, Steffen Gauger, Walter Geibert, Patrizia Geprägs, Dieter Gerdes, Rainer Gersonde, Arnold L. Gordon, Hannes Grobe, Hartmut H. Hellmer, Enrique Isla, Stanley S. Jacobs, Markus Janout, Wilfried Jokat, Michael Klages, Gerhard Kuhn, Jens Meincke, Sven Ober, Svein Østerhus, Ray G. Peterson, Benjamin Rabe, Bert Rudels, Ursula Schauer, Michael Schröder, Stefanie Schumacher, Rainer Sieger, Jüri Sildam, Thomas Soltwedel, Elena Stangeew, Manfred Stein, Volker H Strass, Jörn Thiede, Sandra Tippenhauer, Cornelis Veth, Wilken-Jon von Appen, Marie-France Weirig, Andreas Wisotzki, Dieter A. Wolf-Gladrow, and Torsten Kanzow
Earth Syst. Sci. Data, 9, 211–220,Short summary
Our oceans are always in motion – huge water masses are circulated by winds and by global seawater density gradients resulting from different water temperatures and salinities. Measuring temperature and salinity of the world's oceans is crucial e.g. to understand our climate. Since 1983, the research icebreaker Polarstern has been the basis of numerous water profile measurements in the Arctic and the Antarctic. We report on a unique collection of 33 years of polar salinity and temperature data.
Sinikka T. Lennartz, Christa A. Marandino, Marc von Hobe, Pau Cortes, Birgit Quack, Rafel Simo, Dennis Booge, Andrea Pozzer, Tobias Steinhoff, Damian L. Arevalo-Martinez, Corinna Kloss, Astrid Bracher, Rüdiger Röttgers, Elliot Atlas, and Kirstin Krüger
Atmos. Chem. Phys., 17, 385–402,Short summary
We present new sea surface and marine boundary layer measurements of carbonyl sulfide, the most abundant sulfur gas in the atmosphere, and calculate an oceanic emission estimate. Our results imply that oceanic emissions are very unlikely to account for the missing source in the atmospheric budget that is currently discussed for OCS.
Carolin R. Löscher, Hermann W. Bange, Ruth A. Schmitz, Cameron M. Callbeck, Anja Engel, Helena Hauss, Torsten Kanzow, Rainer Kiko, Gaute Lavik, Alexandra Loginova, Frank Melzner, Judith Meyer, Sven C. Neulinger, Markus Pahlow, Ulf Riebesell, Harald Schunck, Sören Thomsen, and Hannes Wagner
Biogeosciences, 13, 3585–3606,Short summary
The ocean loses oxygen due to climate change. Addressing this issue in tropical ocean regions (off Peru and Mauritania), we aimed to understand the effects of oxygen depletion on various aspects of marine biogeochemistry, including primary production and export production, the nitrogen cycle, greenhouse gas production, organic matter fluxes and remineralization, and the role of zooplankton and viruses.
Damian L. Arévalo-Martínez, Annette Kock, Carolin R. Löscher, Ruth A. Schmitz, Lothar Stramma, and Hermann W. Bange
Biogeosciences, 13, 1105–1118,Short summary
We present the first measurements of N2O across three mesoscale eddies in the eastern tropical South Pacific. Eddie's vertical structure, offshore transport, properties during its formation and near-surface primary production determined the N2O distribution. Substantial depletion of N2O within the core of anticyclonic eddies suggests that although these are transient features, N-loss processes within their centres can lead to an enhanced N2O sink which is not accounted for in marine N2O budgets.
A. Kock, D. L. Arévalo-Martínez, C. R. Löscher, and H. W. Bange
Biogeosciences, 13, 827–840,Short summary
We measured the nitrous oxide (N2O) distribution in the water column in the oxygen minimum zone off Peru, an area with extremely high N2O emissions. Our data show very variable and often very high N2O concentrations in the water column at the coast, which lead to high N2O emissions when these waters are brought to the surface. The very high N2O production off Peru may be caused by high nutrient turnover rates together with rapid changes in the oxygen concentrations.
K. A. Reeve, O. Boebel, T. Kanzow, V. Strass, G. Rohardt, and E. Fahrbach
Earth Syst. Sci. Data, 8, 15–40,Short summary
We present spatially gridded, time-composite mapped data of temperature and salinity of the upper 2000m of the Weddell Gyre through the objective mapping of Argo float data. This was realized on fixed-pressure surfaces ranging from 50 to 2000 dbar. Pressure, temperature and salinity are also available at the level of the sub-surface temperature maximum, which represents the core of Warm Deep Water, the primary heat source of the Weddell Gyre. A detailed description of the methods is provided.
P. Brandt, H. W. Bange, D. Banyte, M. Dengler, S.-H. Didwischus, T. Fischer, R. J. Greatbatch, J. Hahn, T. Kanzow, J. Karstensen, A. Körtzinger, G. Krahmann, S. Schmidtko, L. Stramma, T. Tanhua, and M. Visbeck
Biogeosciences, 12, 489–512,Short summary
Our observational study looks at the structure of the eastern tropical North Atlantic (ETNA) oxygen minimum zone (OMZ) in comparison with the less-ventilated, eastern tropical South Pacific OMZ. We quantify the OMZ’s oxygen budget composed of consumption, advection, lateral and vertical mixing. Substantial oxygen variability is observed on interannual to multidecadal timescales. The deoxygenation of the ETNA OMZ during the last decades represents a substantial imbalance of the oxygen budget.
D. L. Arévalo-Martínez, M. Beyer, M. Krumbholz, I. Piller, A. Kock, T. Steinhoff, A. Körtzinger, and H. W. Bange
Ocean Sci., 9, 1071–1087,
Albert, A., Echevin, V., Lévy, M., and Aumont, O.: Impact of nearshore wind stress curl on coastal circulation and primary productivity in the Peru upwelling system, J. Geophys. Res.-Oceans, 115, C12033, https://doi.org/10.1029/2010JC006569, 2010.
Arévalo-Martínez, D. L., Beyer, M., Krumbholz, M., Piller, I., Kock, A., Steinhoff, T., Körtzinger, A., and Bange, H. W.: A new method for continuous measurements of oceanic and atmospheric N2O, CO and CO2: performance of off-axis integrated cavity output spectroscopy (OA-ICOS) coupled to non-dispersive infrared detection (NDIR), Ocean Sci., 9, 1071–1087, https://doi.org/10.5194/os-9-1071-2013, 2013.
Arévalo-Martínez, D. L., Kock, A., Löscher, C. R., Schmitz, R. A., and Bange, H. W.: Massive nitrous oxide emissions from the tropical South Pacific Ocean, Nat. Geosci., 8, 530–533, https://doi.org/10.1038/ngeo2469, 2015.
Bakker, D. C. E., Pfeil, B., Landa, C. S., Metzl, N., O'Brien, K. M., Olsen, A., Smith, K., Cosca, C., Harasawa, S., Jones, S. D., Nakaoka, S.-I., Nojiri, Y., Schuster, U., Steinhoff, T., Sweeney, C., Takahashi, T., Tilbrook, B., Wada, C., Wanninkhof, R., Alin, S. R., Balestrini, C. F., Barbero, L., Bates, N. R., Bianchi, A. A., Bonou, F., Boutin, J., Bozec, Y., Burger, E. F., Cai, W.-J., Castle, R. D., Chen, L., Chierici, M., Currie, K., Evans, W., Featherstone, C., Feely, R. A., Fransson, A., Goyet, C., Greenwood, N., Gregor, L., Hankin, S., Hardman-Mountford, N. J., Harlay, J., Hauck, J., Hoppema, M., Humphreys, M. P., Hunt, C. W., Huss, B., Ibánhez, J. S. P., Johannessen, T., Keeling, R., Kitidis, V., Körtzinger, A., Kozyr, A., Krasakopoulou, E., Kuwata, A., Landschützer, P., Lauvset, S. K., Lefèvre, N., Lo Monaco, C., Manke, A., Mathis, J. T., Merlivat, L., Millero, F. J., Monteiro, P. M. S., Munro, D. R., Murata, A., Newberger, T., Omar, A. M., Ono, T., Paterson, K., Pearce, D., Pierrot, D., Robbins, L. L., Saito, S., Salisbury, J., Schlitzer, R., Schneider, B., Schweitzer, R., Sieger, R., Skjelvan, I., Sullivan, K. F., Sutherland, S. C., Sutton, A. J., Tadokoro, K., Telszewski, M., Tuma, M., van Heuven, S. M. A. C., Vandemark, D., Ward, B., Watson, A. J., and Xu, S.: A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT), Earth Syst. Sci. Data, 8, 383–413, https://doi.org/10.5194/essd-8-383-2016, 2016.
Bentamy, A. and Fillon, D. C.: Gridded surface wind fields from Metop/ASCAT measurements, Int. J. Remote Sens., 33, 1729–1754, https://doi.org/10.1080/01431161.2011.600348, 2012.
Boccaletti, G., Ferrari, R., and Fox-Kemper, B.: Mixed Layer Instabilities and Restratification, J. Phys. Oceanogr., 37, 2228–2250, https://doi.org/10.1175/JPO3101.1, 2007.
Bourgault, D., Galbraith, P. S., and Chavanne, C. P.: Generation of internal solitary waves by frontally forced intrusions in geophysical flows, Nat. Comm., 7, 13606, https://doi.org/10.1038/ncomms13606, 2016.
Brüggemann, N. and Eden, C.: Evaluating Different Parameterizations for Mixed Layer Eddy Fluxes induced by Baroclinic Instability, J. Phys. Oceanogr., 44, 2524–2546, https://doi.org/10.1175/JPO-D-13-0235.1, 2014.
Capet, X., Roullet, G., Klein, P., and Maze, G.: Intensification of Upper-Ocean Submesoscale Turbulence through Charney Baroclinic Instability, J. Phys. Oceanogr., 46, 3365–3384, https://doi.org/10.1175/JPO-D-16-0050.1, 2016.
Capone, D. G. and Hutchins, D. A.: Microbial biogeochemistry of coastal upwelling regimes in a changing ocean, Nat. Geosci., 6, 711–717, https://doi.org/10.1038/ngeo1916, 2013.
Chaigneau, A., Gizolme, A., and Grados, C.: Mesoscale eddies off Peru in altimeter records: Identification algorithms and eddy spatio-temporal patterns, Prog. Oceanogr., 79, 106–119, https://doi.org/10.1016/j.pocean.2008.10.013, 2008.
Chavez, F. P., Takahashi, T., Cai, W.-J., Friederich, G., Hales, B., Wanninkhof, R., and Feely, R.: Coastal oceans, in: The First State of the Carbon Cycle Report (SOCCR): The North American Carbon Budget and Implications for the Global Carbon Cycle, edited by: King, A. W., Dilling, L., Zimmerman, G. P., Fairman, D. M., Houghton, R. A., Marland, G., Rose, A. Z., and Wilbanks, T. J., A report by the US Climate Change Science Program and the Subcommittee on Global Change Research, Washington, DC, 2007.
Colas, F., McWilliams, J. C., Capet, X., and Kurian, J.: Heat balance and eddies in the Peru-Chile current system, Clim. Dynam., 39, 509–529, https://doi.org/10.1007/s00382-011-1170-6, 2012.
Croquette, M., Eldin, G., Grados, C., and Tamayo, M.: On differences in satellite wind products and their effects in estimating coastal upwelling processes in the south-east Pacific, Geophys. Res. Lett., 34, L11608, https://doi.org/10.1029/2006GL027538, 2007.
Dale, A. C., Barth, J. A., Levine, M. D., and Austin, J. A.: Observations of mixed layer restratification by onshore surface transport following wind reversal in a coastal upwelling region, J. Geophys. Res.-Oceans, 113, C01010, https://doi.org/10.1029/2007JC004128, 2008.
Dickson, A. G., Sabine, C. L., and Christian, J. R., eds.: Guide to best practices for ocean CO2 measurements, PICES Special Publication, 3, 191 pp., 2007.
Espinoza-Morriberón, D., Echevin, V., Colas, F., Tam, J., Ledesma, J., Váquez, L., and Graco, M.: Impacts of El Niño events on the Peruvian upwelling system productivity, J. Geophys. Res.-Oceans, 122, 5423–5444, https://doi.org/10.1002/2016JC012439, 2017.
Fairall, C. W., Bradley, E. F., Godfrey, J. S., Wick, G. A., Edson, J. B., and Young, G. S.: Cool-skin and warm-layer effects on sea surface temperature, J. Geophys. Res.-Oceans, 101, 1295–1308, https://doi.org/10.1029/95JC03190, 1996a.
Fairall, C. W., Bradley, E. F., Rogers, D. P., Edson, J. B., and Young, G. S.: Bulk parameterization of air-sea fluxes for Tropical Ocean-Global Atmosphere Coupled-Ocean Atmosphere Response Experiment, J. Geophys. Res.-Oceans, 101, 3747–3764, https://doi.org/10.1029/95JC03205, 1996b.
Ferrari, R.: A frontal challenge for climate models, Science, 332, 316–317, https://doi.org/10.1126/science.1203632, 2011.
Fox-Kemper, B., Ferrari, R., and Hallberg, R.: Parameterization of Mixed Layer Eddies, Part I: Theory and Diagnosis, J. Phys. Oceanogr., 38, 1145–1165, https://doi.org/10.1175/2007JPO3792.1, 2008.
Friederich, G. E., Ledesma, J., Ulloa, O., and Chavez, F. P.: Air-sea carbon dioxide fluxes in the coastal southeastern tropical Pacific, Prog. Oceanogr., 79, 156–166, https://doi.org/10.1016/j.pocean.2008.10.001, 2008.
Gruber, N.: Ocean biogeochemistry: Carbon at the coastal interface, Nature, 517, 148–149, https://doi.org/10.1038/nature14082, 2015.
Haine, T. W. N. and Marshall, J.: Gravitational, Symmetric, and Baroclinic Instability of the Ocean Mixed Layer, J. Phys. Oceanogr., 28, 634–658, https://doi.org/10.1175/1520-0485(1998)028<0634:GSABIO>2.0.CO;2, 1998.
Kao, T. W., Park, C., and Pao, H.-P.: Buoyant surface discharge and small-scale oceanic fronts: A numerical study, J. Geophys. Res., 82, 1747–1752, https://doi.org/10.1029/JC082i012p01747, 1977.
Köhn, E., Thomsen, S., Arévalo-Martínez, D. L., and Kanzow, T.: Underway measurements for 2-day upwelling front experiment during METEOR cruise M93, PANGAEA, available at: https://doi.org/10.1594/PANGAEA.881049, 2017.
Körtzinger, A., Mintrop, L., Wallace, D. W., Johnson, K. M., Neill, C., Tilbrook, B., Towler, P., Inoue, H. Y., Ishii, M., Shaffer, G., Torres Saavedra, R. F., Ohtaki, E., Yamashita, E., Poisson, A., Brunet, C., Schauer, B., Goyet, C., and Eischeid, G.: The international at-sea intercomparison of fCO2 systems during the R/V Meteor Cruise 36/1 in the North Atlantic Ocean, Mar. Chem., 72, 171–192, https://doi.org/10.1016/S0304-4203(00)00080-3, 2000.
Landschützer, P., Gruber, N., and Bakker, D. C. E.: An updated observation-based global monthly gridded sea surface pCO2 and air-sea CO2 flux product from 1982 through 2015 and its monthly climatology (NCEI Accession 0160558), Version 2.2, NOAA National Centers for Environmental Information, Dataset, available at: https://www.nodc.noaa.gov/ocads/oceans/SPCO2_1982_2015_ETH_SOM_FFN.html, last access: 11 July, 2017.
Lapeyre, G. and Klein, P.: Impact of the small-scale elongated filaments on the oceanic vertical pump, J. Mar. Res., 64, 835–851, https://doi.org/10.1357/002224006779698369, 2006.
Laruelle, G. G., Lauerwald, R., Pfeil, B., and Regnier, P.: Regionalized global budget of the CO2 exchange at the air-water interface in continental shelf seas, Global Biogeochem. Cy., 28, 1199–1214, https://doi.org/10.1002/2014GB004832, 2014.
Lefèvre, N. and Merlivat, L.: Carbon and oxygen net community production in the eastern tropical Atlantic estimated from a moored buoy, Global Biogeochem. Cy., 26, GB1009, https://doi.org/10.1029/2010GB004018, 2012.
Lefèvre, N., Guillot, A., Beaumont, L., and Danguy, T.: Variability of fCO2 in the Eastern Tropical Atlantic from a moored buoy, J. Geophys. Res.-Oceans, 113, C01015, https://doi.org/10.1029/2007JC004146, 2008.
Lévy, M., Ferrari, R., Franks, P. J. S., Martin, A. P., and Rivière, P.: Bringing physics to life at the submesoscale, Geophys. Res. Lett., 39, L14602, https://doi.org/10.1029/2012GL052756, 2012.
Loginova, A. N., Thomsen, S., and Engel, A.: Chromophoric and fluorescent dissolved organic matter in and above the oxygen minimum zone off Peru, J. Geophys. Res.-Oceans, 121, 7973–7990, https://doi.org/10.1002/2016JC011906, 2016.
Mahadevan, A., Lévy, M., and Mémery, L.: Mesoscale variability of sea surface pCO2: What does it respond to?, Global Biogeochem. Cy., 18, GB1017, https://doi.org/10.1029/2003GB002102, 2004.
Mahadevan, A., Tandon, A., and Ferrari, R.: Rapid changes in mixed layer stratification driven by submesoscale instabilities and winds, J. Geophys. Res., 115, C03017, https://doi.org/10.1029/2008JC005203, 2010.
McWilliams, J. C., Colas, F., and Molemaker, M. J.: Cold filamentary intensification and oceanic surface convergence lines, Geophys. Res. Lett., 36, L18602, https://doi.org/10.1029/2009GL039402, 2009.
Merlivat, L., Gonzalez Davila, M., Caniaux, G., Boutin, J., and Reverdin, G.: Mesoscale and diel to monthly variability of CO2 and carbon fluxes at the ocean surface in the northeastern Atlantic, J. Geophys. Res., 114, C03010, https://doi.org/10.1029/2007JC004657, 2009.
Meyer, J., Löscher, C. R., Lavik, G., and Riebesell, U.: Mechanisms of P* Reduction in the Eastern Tropical South Pacific, Front. Mar. Sci., 4, 1–12, https://doi.org/10.3389/fmars.2017.00001, 2017.
Nash, J. D. and Moum, J. N.: River plumes as a source of large-amplitude internal waves in the coastal ocean, Nature, 437, 400–403, https://doi.org/10.1038/nature03936, 2005.
Nightingale, P. D., Malin, G., Law, C. S., Watson, A. J., Liss, P. S., Liddicoat, M. I., Boutin, J., and Upstill-Goddard, R. C.: In situ evaluation of air-sea gas exchange parameterizations using novel conservative and volatile tracers, Global Biogeoch. Cy., 14, 373–387, https://doi.org/10.1029/1999GB900091, 2000.
Ohman, M. D., Rudnick, D. L., Chekalyuk, A., Davis, R. E., Feely, R. A., Kahru, M., Kim, H.-J., Landry, M. R., Martz, T. R., Sabine, C. L., and Send, U.: Autonomous ocean measurements in the California Current Ecosystem, Oceanography, 26, 18–25, 2013.
Payne, R. E.: Albedo of the Sea Surface, J. Atmos. Sci., 29, 959–970, https://doi.org/10.1175/1520-0469(1972)029<0959:AOTSS>2.0.CO;2, 1972.
Peltier, W. R. and Caulfield, C. P.: Mixing efficiency in stratified shear flows, Annu. Rev. Fluid Mech., 35, 135–167, https://doi.org/10.1146/annurev.fluid.35.101101.161144, 2003.
Penven, P., Echevin, V., Pasapera, J., Colas, F., and Tam, J.: Average circulation, seasonal cycle, and mesoscale dynamics of the Peru Current System: A modeling approach, J. Geophys. Res., 110, C10021, https://doi.org/10.1029/2005JC002945, 2005.
Pierrot, D., Neill, C., Sullivan, K., Castle, R., Wanninkhof, R., Lüger, H., Johannessen, T., Olsen, A., Feely, R. A., and Cosca, C. E.: Recommendations for autonomous underway pCO2 measuring systems and data-reduction routines, Deep-Sea Res. Pt. II, 56, 512–522, https://doi.org/10.1016/j.dsr2.2008.12.005, 2009.
Pietri, A., Echevin, V., Testor, P., Chaigneau, A., Mortier, L., Grados, C., and Albert, A.: Impact of a coastal-trapped wave on the near-coastal circulation of the Peru upwelling system from glider data, J. Geophys. Res.-Oceans, 119, 2109–2120, https://doi.org/10.1002/2013JC009270, 2014.
Ramachandran, S., Tandon, A., and Mahadevan, A.: Enhancement in vertical fluxes at a front by mesoscale-submesoscale coupling, J. Geophys. Res.-Oceans, 119, 8495–8511, https://doi.org/10.1002/2014JC010211, 2014.
Resplandy, L., Lévy, M., D'Ovidio, F., and Merlivat, L.: Impact of submesoscale variability in estimating the air-sea CO2 exchange: Results from a model study of the POMME experiment, Global Biogeochem. Cy., 23, GB1017, https://doi.org/10.1029/2008GB003239, 2009.
Rudnick, D. L.: On the skewness of vorticity in the upper ocean, Geophys. Res. Lett., 28, 2045–2048, https://doi.org/10.1029/2000GL012265, 2001.
Shin, J., Dalziel, S., and Linden, P.: Gravity currents produced by lock exchange, J. Fluid Mech., 521, 1–34, https://doi.org/10.1017/S002211200400165X, 2004.
Smith, S. D.: Coefficients for sea surface wind stress, heat flux, and wind profiles as a function of wind speed and temperature, J. Geophys. Res.-Oceans, 93, 15467–15472, https://doi.org/10.1029/JC093iC12p15467, 1988.
Takahashi, T., Sutherland, S. C., Wanninkhof, R., Sweeney, C., Feely, R. A., Chipman, D. W., Hales, B., Friederich, G., Chavez, F., Sabine, C., Watson, A., Bakker, D. C., Schuster, U., Metzl, N., Yoshikawa-Inoue, H., Ishii, M., Midorikawa, T., Nojiri, Y., Körtzinger, A., Steinhoff, T., Hoppema, M., Olafsson, J., Arnarson, T. S., Tilbrook, B., Johannessen, T., Olsen, A., Bellerby, R., Wong, C., Delille, B., Bates, N., and de Baar, H. J.: Climatological mean and decadal change in surface ocean pCO2, and net sea-air CO2 flux over the global oceans, Deep-Sea Res. Pt. II, 56, 554–577, https://doi.org/10.1016/j.dsr2.2008.12.009, 2009.
Takahashi, T., Sutherland, S. C., Chipman, D. W., Goddard, J. G., Newberger, T., and Sweeney, C.: Climatological distributions of pH, pCO2, total CO2, alkalinity, and CaCO3 saturation in the global surface ocean, ORNL/CDIAC-160, NDP-094, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tennessee, https://doi.org/10.3334/CDIAC/OTG.NDP094, 2014.
Taylor, J. R. and Ferrari, R.: Ocean fronts trigger high latitude phytoplankton blooms, Geophys. Res. Lett., 38, L23601, https://doi.org/10.1029/2011GL049312, 2011.
Thomas, L. N. and Lee, C. M.: Intensification of Ocean Fronts by Down-Front Winds, J. Phys. Oceanogr., 35, 1086–1102, https://doi.org/10.1175/JPO2737.1, 2005.
Thomas, L. N., Tandon, A., and Mahadevan, A.: Submesoscale Processes and Dynamics, in: Ocean Modeling in an Eddying Regime, edited by: Hecht, M. W. and Hasumi, H., American Geophysical Union, Washington, DC, https://doi.org/10.1029/177GM04, 2008.
Thomsen, S., Eden, C., and Czeschel, L.: Stability Analysis of the Labrador Current, J. Phys. Oceanogr., 44, 445–463, https://doi.org/10.1175/JPO-D-13-0121.1, 2014.
Thomsen, S., Kanzow, T., Colas, F., Echevin, V., Krahmann, G., and Engel, A.: Do submesoscale frontal processes ventilate the oxygen minimum zone off Peru?, Geophys. Res. Lett., 43, 8133–8142, https://doi.org/10.1002/2016GL070548, 2016a.
Thomsen, S., Kanzow, T., Krahmann, G., Greatbatch, R. J., Dengler, M., and Lavik, G.: The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent and its impact on the near-coastal salinity, oxygen, and nutrient distributions, J. Geophys. Res.-Oceans, 121, 476–501, https://doi.org/10.1002/2015JC010878, 2016b.
Ungarish, M. and Huppert, H. E.: On gravity currents propagating at the base of a stratified ambient, J. Fluid Mech., 458, 283–301, https://doi.org/10.1017/S0022112002007978, 2002.
Walter, R. K., Stastna, M., Woodson, C. B., and Monismith, S. G.: Observations of nonlinear internal waves at a persistent coastal upwelling front, Cont. Shelf Res., 117, 100–117, https://doi.org/10.1016/j.csr.2016.02.007, 2016.
Wanninkhof, R.: Relationship between wind speed and gas exchange over the ocean, J. Geophys. Res.-Oceans, 97, 7373–7382, https://doi.org/10.1029/92JC00188, 1992.
Wanninkhof, R.: Relationship between wind speed and gas exchange over the ocean revisited, Limnol. Oceanogr.-Meth., 12, 351–362, https://doi.org/10.4319/lom.2014.12.351, 2014.
Weiss, R. F.: Carbon dioxide in water and seawater: the solubility of a non-ideal gas, Mar. Chem., 2, 203–215, https://doi.org/10.1016/0304-4203(74)90015-2, 1974.
Weiss, R. F. and Price, B. A.: Nitrous oxide solubility in water and seawater, Mar. Chem., 8, 347–359, https://doi.org/10.1016/0304-4203(80)90024-9, 1980.
White, B. L. and Helfrich, K. R.: Rapid gravitational adjustment of horizontal shear flows, J. Fluid Mech., 721, 86–117, https://doi.org/10.1017/jfm.2013.41, 2013.