Hydrography, biogeochemistry, and biology of "dead-zone eddies" in the eastern tropical North Atlantic
Hydrography, biogeochemistry, and biology of "dead-zone eddies" in the eastern tropical North Atlantic
Editor(s): S. W. A. Naqvi, D. Gilbert, T. Treude, and L. Cotrim da Cunha
The eastern tropical North Atlantic (ETNA) is characterized by a moderate O2 minimum zone (OMZ) with lowest O2 concentrations just under 40μmol kg−1 (Stramma et al., GRL, 2009). Current understanding is that the ETNA OMZ has been expanding over the past decades both in terms of vertical extent and intensity (Stramma et al., Science, 2008). The recent discovery of isolated low-oxygen (O2) eddy-associated water bodies, ranging from hypoxic (<20 μmol kg−1) to even suboxic (<1 μmol kg−1) conditions, in the generally well ventilated open ocean region near the Cape Verde Archipelago changed our understanding of oceanic processes in this area (Karstensen et al., BGD, 2014, doi:10.5194/bgd-11-17391-2014). In order to better understand the origin and development of these extreme dead-zone eddies as well as their biogeochemical and biological properties, a multi-facetted, multi-platform, interdisciplinary field study in the eastern tropical North Atlantic was designed to investigate biogeochemical and ecological processes in these eddies. This so-called "Dead Zone Eddy Hunt Study" was carried out most successfully in 2013/2014 and yielded a wide range of excellent results featuring unique and surprising findings. The special issue will cover the whole range of concerted hydrographic, biogeochemical, and biological observations carried out in the interdisciplinary study.

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27 Apr 2017
Upwelling and isolation in oxygen-depleted anticyclonic modewater eddies and implications for nitrate cycling
Johannes Karstensen, Florian Schütte, Alice Pietri, Gerd Krahmann, Björn Fiedler, Damian Grundle, Helena Hauss, Arne Körtzinger, Carolin R. Löscher, Pierre Testor, Nuno Vieira, and Martin Visbeck
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28 Oct 2016
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10 Oct 2016
Oxygen utilization and downward carbon flux in an oxygen-depleted eddy in the eastern tropical North Atlantic
Björn Fiedler, Damian S. Grundle, Florian Schütte, Johannes Karstensen, Carolin R. Löscher, Helena Hauss, Hannes Wagner, Alexandra Loginova, Rainer Kiko, Péricles Silva, Toste Tanhua, and Arne Körtzinger
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02 Jun 2016
Bathypelagic particle flux signatures from a suboxic eddy in the oligotrophic tropical North Atlantic: production, sedimentation and preservation
Gerhard Fischer, Johannes Karstensen, Oscar Romero, Karl-Heinz Baumann, Barbara Donner, Jens Hefter, Gesine Mollenhauer, Morten Iversen, Björn Fiedler, Ivanice Monteiro, and Arne Körtzinger
Biogeosciences, 13, 3203–3223, https://doi.org/10.5194/bg-13-3203-2016,https://doi.org/10.5194/bg-13-3203-2016, 2016
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01 Apr 2016
Dead zone or oasis in the open ocean? Zooplankton distribution and migration in low-oxygen modewater eddies
Helena Hauss, Svenja Christiansen, Florian Schütte, Rainer Kiko, Miryam Edvam Lima, Elizandro Rodrigues, Johannes Karstensen, Carolin R. Löscher, Arne Körtzinger, and Björn Fiedler
Biogeosciences, 13, 1977–1989, https://doi.org/10.5194/bg-13-1977-2016,https://doi.org/10.5194/bg-13-1977-2016, 2016
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21 Dec 2015
Hidden biosphere in an oxygen-deficient Atlantic open-ocean eddy: future implications of ocean deoxygenation on primary production in the eastern tropical North Atlantic
C. R. Löscher, M. A. Fischer, S. C. Neulinger, B. Fiedler, M. Philippi, F. Schütte, A. Singh, H. Hauss, J. Karstensen, A. Körtzinger, S. Künzel, and R. A. Schmitz
Biogeosciences, 12, 7467–7482, https://doi.org/10.5194/bg-12-7467-2015,https://doi.org/10.5194/bg-12-7467-2015, 2015
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