F. Schütte et al.: Hidden vortices: near-equatorial low-oxygen extremes driven by high-baroclinic-mode vortices 141
Dilmahamod, A. F,, Karstensen, J., Dietze, H., Löptien, U., and
Fennel, K.: Generation Mechanisms of Mesoscale Eddies in the
Mauritanian Upwelling Region, J. Phys. Oceanogr., 52, 161-182,
https://doi.org/10.1175/JPO-D-21-0092.1, 2022.
Dufour, C. O., Griffies, S. M., de Souza, G. F., Frenger, I., Morrison,
A. K.,, Palter, J. B., Sarmiento, J. L., Galbraith, E. D., Dunne, J.
P., Anderson, W. G., and Slater, R. D.: Role of Mesoscale Eddies
in Cross-Frontal Transport of Heat and Biogeochemical Trac-
ers in the Southern Ocean, J. Phys. Oceanogr., 45, 3057-3081,
https://doi.org/10.1175/jpo-d-14-0240.1, 2015.
Duteil, O., Schwarzkopf, F. U., Böning, C. W., and Oschlies, A.:
Major role of the equatorial current system in setting 0Xy-
gen levels in the eastern tropical Atlantic Ocean: A high-
zesolution model study, Geophys. Res. Lett., 41, 2033-2040,
https://doi.org/10.1002/2013g1058888, 2014.
£den, C.: Eddy length scales in the North Atlantic Ocean, J. Geo-
phys. Res.-Oceans, 112, https://doi.0org/10.1029/2006jc003901,
2007.
E.U. Copernicus Marine Service Information: Global Ocean Grid-
ded L 4 Sea Surface Heights And Derived Variables Repro-
cessed 1993 Ongoing, Marine Data Store (MDS) [data set],
https://doi.0rg/10.48670/moi-00148, 2024.
Fiedler, B., Grundle, D. S., Schütte, F., Karstensen, J., Löscher, C.
R., Hauss, H., Wagner, H., Loginova, A., Kiko, R., Silva, P.,
Tanhua, T., and Körtzinger, A.: Oxygen utilization and down-
ward carbon flux in an oxygen-depleted eddy in the east-
ern tropical North Atlantic, Biogeosciences, 13, 5633-5647,
https://doi.org/10.5194/bg-13-5633-2016, 2016.
Fischer, J., Brandt, P., Dengler, M., Müller, M., and Symonds,
D.: Surveying the Upper Ocean with the Ocean Surveyor:
A New Phased Array Doppler Current Profiler, J. At-
mos. Ocean. Tech., 20, 742-751, https:/doi.org/10.1175/1520-
0426(2003)20<742: Stuowt>2.0.Co;2, 2003.
Frenger, I.: Supplementary model data to: Hidden vortices: Near-
equatorial lowoxygen extremes driven by high-baroclinic-mode
vortices [data set and code], GEOMAR Helmholtz Centre for
Ocean Research Kiel [distributor], https://hdl.handle.net/20.500.
12085/21ab7868-c112-4173-ada4-75b86f098f18,
Frenger, I., Bianchi, D., Stührenberg, C., Oschlies, A., Dunne,
J., Deutsch, C., Galbraith, E., and Schütte, FE: Biogeo-
chemical Role of Subsurface Coherent Eddies in the
Ocean: Tracer Cannonballs, Hypoxic Storms, and Micro-
»%al Stewpots?, Global Biogeochem. Cy., 32, 226-249,
attps://doi.0org/10.1002/2017GB005743, 2018.
(Galbraith, E. D., Dunne, J. P., Gnanadesikan, A., Slater, R.
D., Sarmiento, J. L., Dufour, C. O., de Souza, G. F,
Bianchi, D., Claret, M., Rodgers, K. B., and Marvasti,
S. S.: Complex functionality with minimal computation:
Promise and pitfalls of reduced-tracer ocean biogeochem-
istry models, J. Adv. Model. Earth Syst., 7, 2012-2028,
https://doi.org/10.1002/2015ms000463, 2015.
Garcia, H. E., Locarnini, R. A., Boyer, T. P., Antonov, J. I., Bara-
nova, O. K., Zweng, M. M., and Johnson, D. R.: World Ocean
Atlas 2009, in: Volume 3: Dissolved Oxygen, Apparent Oxygen
Utilization, and Oxygen Saturation, NOAA Atlas NESDIS 70,
edited by: Levitus, S., US Government Printing Office, Washing-
ton, D.C., 344 pp., https://doi.0org/10.25923/rb67-ns53, 2010a.
Garcia, H. E., Locarnini, R. A., Boyer, T. P., Antonov, J. IL, Zweng,
M. M.. Baranova. O. K.. and Johnson. D. R.: World Ocean At-
https:/doi.org/10.5194/os-22-119-2026
las 2009, in: Volume 4: Nutrients (phosphate, nitrate, silicate),
NOAA Atlas NESDIS 71, edited by: Levitus, S., US Govern-
ment Printing Office, Washington, D.C., 398 pp., http://www.
nodc.noaa.gov/OC5/indprod.html (last access: 15 June 2023).
2010b.
Garcia, H. E., Wang, Z., Bouchard, C., Cross, S. L., Paver, C. R.,
Reagan, J. R., Boyer, T. P., Locarnini, R. A., Mishonov, A. V.,
Baranova, O., Seidov, D., and Dukhovskoy, D.: World Ocean At-
las 2023, Volume 3: Dissolved Oxygen, Apparent Oxygen Uti-
lization, Dissolved Oxygen Saturation and 30 year Climate Nor-
mal, A. Mishonov, Tech. Ed. NOAA Atlas NESDIS 91 [data set].
https://doi.org/10.25923/rb67-ns53, 2024.
Gill, A. E.: Atmosphere-Ocean Dynamics, in: International Geo-
physics Series Volume 30, Academic Press, New York.
https://doi.org/10.1016/S0074-6142(08)60026-1, 1982.
Griffies, S. M., Winton, M., Anderson, W. G., Benson, R., Del-
worth, T. L., Dufour, C. O., Dunne, J. P., Goddard, P., Morri-
son, A. K., Rosati, A., Wittenberg, A. T., Yin, J., and Zhang,
R.: Impacts on Ocean Heat from Transient Mesoscale Eddies
in a Hierarchy of Climate Models, J. Climate, 28, 952-977,
https://doi.org/10.1175/jcli-d-14-00353.1, 2015.
Gula, J., Blacic, T. M., and Todd, R. E.: Submesoscale Coherent
Vortices in the Gulf Stream, Geophys. Res. Lett., 46, 2704-2714.
https://doi.org/10.1029/2019g108 1919, 2019.
Hahn, J., Brandt, P., Greatbatch, R. J., Krahmann, G., and Ko-
rtzinger, A.: Oxygen variance and meridional oxygen supply
in the Tropical North East Atlantic oxygen minimum zone,
Clim. Dynam., 43, 2999-3024, https://doi.org/10.1007/s00382-
014-2065-0, 2014.
Hahn, J., Brandt, P., Schmidtko, S., and Krahmann, G.: Decadal
oxygen change in the eastern tropical North Atlantic, Ocean Sci..
13, 551-576, https://doi.org/10.5194/os-13-551-2017, 2017.
Hauss, H., Christiansen, S., Schutte, F., Kiko, R., Lima, M. E., Ro-
drigues, E., Karstensen, J., Loscher, C. R., Kortzinger, A., and
Fiedler, B.: Dead zone or oasis in the open ocean? Zooplank-
ton distribution and migration in low-oxygen modewater eddies,
Biogeosciences, 13, 1977-1989, https://doi.org/10.5194/bg-13-
1977-2016, 2016.
Karstensen, J., Stramma, L., and Visbeck, M.: Oxy-
gen minimum zones in the eastern tropical Atlantic
and Pacific oceans, Prog. ÖOceanogr., 77, 331-350.
https://doi.org/10.1016/j.pocean.2007.05.009, 2008.
Karstensen, J., Fiedler, B., Schütte, F., Brandt, P., Körtzinger, A.,
Fischer, G., Zantopp, R., Hahn, J., Visbeck, M., and Wallace,
D.: Open ocean dead zones in the tropical North Atlantic Ocean.
Biogeosciences, 12, 2597-2605, https://doi.org/10.5194/bg-12-
2597-2015, 2015.
Karstensen, J., Schütte, F., Pietri, A., Krahmann, G., Fiedler.
B., Grundle, D., Hauss, H., Körtzinger, A., Löscher, C. R.,
Testor, P., Vieira, N., and Visbeck, M.: Upwelling and isola-
tion in oxygen-depleted anticyclonic modewater eddies and im-
plications for nitrate cycling, Biogeosciences, 14, 2167-2181.
https://doi.org/10.5194/bg-14-2167-2017, 2017.
Keppler, L., Cravatte, S., Chaigneau, A., Pegliasco, C., Gour-
deau, L., and Singh, A.: Observed Characteristics and Vertical
Structure of Mesoscale Eddies in the Southwest Tropical Pa-
cific, Journal of Geophysical Research: Oceans, 123, 2731-2756.
10.1002/2017jc013712, 2018.
Ocean Sci... 22. 119-143, 2026