Thomas J. Browning

Group leader ERC Starting Grant / Senior Scientist

GEOMAR Helmholtz Centre for Ocean Research Kiel,
Wischhofstraße 1-3 | Bld. 12 / r.321 / D-24148 Kiel,

Tel: +49 431 600-1289
Email: tbrowning(at)

Research division 2: Marine Biogeochemistry (Chemical Oceanography)


Research profile

2022–          Group leader ERC Starting Grant

2021–          Senior scientist permanent position (GEOMAR, Kiel, Germany)

2017–2021  Senior scientist (GEOMAR, Kiel, Germany)

2015–2017  Marie Sklodowska-Curie Fellow (GEOMAR, Kiel, Germany)

2010–2014  DPhil (University of Oxford, UK)

2006–2010  MSci (University of Bristol, UK)


I am interested in the controls on phytoplankton abundance, ecology and physiology in the ocean. To do this, our team uses a highly multidisciplinary combination of fieldwork (mostly open ocean research cruises), phytoplankton culturing experiments, diverse analytical techniques, numerical analysis and simple modelling. This is supplemented by a combination of satellite remote sensing and analysis of climate model output.

Postdoctoral researchers:

•    Jenna Balaguer (2023-): ERC Starting Grant (Ocean Glow) postdoctorial researcher
•    Brandy Robinson (2022-): ERC Starting Grant (Ocean Glow) postdoctorial researcher
•    Zuozhu Wen (2021-): CSC Postdoctoral fellow working on the controls on oceanic N2 fixation

Current students:

•    Angele Nicolas (2023–): Masters supervisor, Project: Nutrient biogeochemistry of SE Atlantic filaments
•    Anjala Gammanpila (2022–): Ph. D. co-supervisor, Project: Phytoplanton-trace metal interactions
•    Haoran Liu (2022–): Ph. D. co-supervisor, Project: Nutrient limitation in the South Pacific Ocean
•    Zhongwei Yuan (2021–): Ph. D. co-supervisor, Project: Nutrient limitation of phytoplankton growth rates

Previous postdocs/students:

•    Juliane Tammen (2022–2023): Masters supervisor, Project: Decoupling nutrient limitation regimes using active fluorescence signatures
•    Xuechao Wang (2018–2022): Ph. D. co-supervisor, Thesis title: ‘Resolving iron co-limitation of phytoplankton productivity in the oligotrophic ocean’
•    Caroline Utermann (2015) was a MSci student helper for one of my projects in 2015, leading to her co-authorship on a manuscript.
•    Callum Higgins (2013–2014, University of Oxford): MSci thesis co-supervisor (1st class); phytoplankton culturing project investigating the impact of pH on calcification/photophysiology.


If you are interested in our research – as a student, postdoc, or collaborating scientist, don’t hesitate to get in touch with me.


Browning, T.J., Saito, M.A., Garaba, S.P., Wang, X., Achterberg, E.P., Moore, C.M., Engel, A., Mcllvin, M.R., Moran, D., Voss, D. and Zielinski, O., 2023. Persistent equatorial Pacific iron limitation under ENSO forcing. Nature.

Browning, T.J. and Moore, C.M., 2023. Global analysis of ocean phytoplankton nutrient limitation reveals high prevalence of co-limitation. Nature Communications, 14, 5014.

Browning, T.J., Al-Hashem, A.A., Achterberg, E.P., Carvalho, P.C., Catry, P., Matthiopoulos, J., Miller, J.A. and Wakefield, E.D., 2023. The role of seabird guano in maintaining North Atlantic summertime productivity. Science of The Total Environment, 897, 165309.

Dai, M., Luo, Y.W., Achterberg, E.P., Browning, T.J., et al. 2023. Upper ocean biogeochemistry of the oligotrophic North Pacific Subtropical Gyre: from nutrient sources to carbon export. Reviews of Geophysics, e2022RG000800.

Yuan, Z., Achterberg, E.P., Engel, A., Wen, Z., Zhou, L., Zhu, X., Dai, M. and Browning, T.J., 2023. Phytoplankton community response to episodic wet and dry aerosol deposition in the subtropical North Atlantic. Limnology and Oceanography.

Yuan, Z., Browning, T.J., Zhang, R., Wang, C., Du, C., Wang, Y., Chen, Y., Liu, Z., Liu, X., Shi, D. and Dai, M., 2023. Potential drivers and consequences of regional phosphate depletion in the western subtropical North Pacific. Limnology and Oceanography Letters.

Wen, Z., Browning, T.J., Dai, R., Wu, W., Li, W., Hu, X., Lin, W., Wang, L., Liu, X., Cao, Z. and Hong, H., 2022. The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific. Biogeosciences19(22), 5237-5250.

Liu, H., Xie, Y., Browning, T.J., Xu, F. and Huang, B., 2022. Phytoplankton photophysiology across tropical eddies: Deconvolving nutrient, light, and community signals. Frontiers in Marine Science9.

Wang, X., Browning, T.J., Achterberg, E.P. and Gledhill, M., 2022. Phosphorus Limitation Enhances Diazotroph Zinc Quotas. Frontiers in microbiology13.

Wen, Z.*, Browning, T.J*., Cai, Y., Dai, R., Zhang, R., Du, C., Jiang, R., Lin, W., Liu, X., Cao, Z, Hong, H., Dai, M., Shi, D. Nutrient regulation of biological nitrogen fixation across the tropical western North Pacific. In press Science Advances.        *Co-lead authors

Zhu, Y., Feng, Y., Browning, T.J., Wen, Z., Hughes, D.J., Hao, Q., Zhang, R., Meng, Q., Wells, M.L., Jiang, Z. and Dissanayake, P.A.K.N., 2022. Exploring Variability of Trichodesmium Photophysiology Using Multi-Excitation Wavelength Fast Repetition Rate Fluorometry. Frontiers in microbiology13.

Browning, T.J., Liu X., Zhang, R., Wen, Z., Liu, J., Zhou, Y., Xu, F., Cai, Y., Zhou, K., Cao, Z., Zhu, Y., Shi, D., Achterberg, E.P., and Dai M. (2021). Nutrient co-limitation in the Subtropical Northwest Pacific. Limnology and Oceanography Letters 7, 52–61 (2022).

Zitoun, R., Achterberg, E.P., Browning, T.B., Hoffmann, L.J., Krisch, S., Sander, S.G., A. Koschinsky, A. The complex provenance of Cu-binding ligands in the South-East Atlantic. Marine Chemistry 237, 104047 (2021).

Vergara-Jara, M.J., Hopwood, M.J., Browning, T.J., Rapp, I., Torres, R., Reid, B., Achterberg, E.P. and Iriarte, J.L. A mosaic of phytoplankton responses across Patagonia, the SE Pacific and SW Atlantic Ocean to ash deposition and trace metal release from the Calbuco 2015 volcanic eruption. Ocean Science 17, 561-578 (2021).

Browning, T.J., E.P. Achterberg, A. Engel, and E. Mawji. Manganese co-limitation of phytoplankton growth and major nutrient drawdown in the Southern Ocean. Nature Communications, 12, 884 (2021).

Browning, T.J., A.A. Al-Hashem, M.J. Hopwood, A. Engel, I.M. Belkin, E.D. Wakefield, T. Fischer, E.P. Achterberg. Iron regulation of North Atlantic eddy phytoplankton productivity. Geophysical Research Letters, 48, p.e2020GL091403 (2021).

Wyatt, N.J., Milne, A., Achterberg, E.P., Browning, T.J., Bouman, H.A., Woodward, E.M.S. and Lohan, M.C Seasonal cycling of zinc and cobalt in the Southeast Atlantic along the GEOTRACES GA10 section. Biogeosciences 18, 4265–4280 (2021).

Marki, A., Fischer, R., Browning, T.J., Louropoulou, E., Ptacnik, R. and Gledhill, M. Stoichiometry of Fe, Mn and Co in the marine diazotroph Crocosphaera subtropica ATCC51142 in Fe-and P-limited continuous cultures. Marine Ecology Progress Series656, 19-33 (2020).

Achterberg, E.P., Steigenberger, S., Klar, J.K., Browning, T.J., Marsay, C.M., Painter, S.C., Vieira, L.H., Baker, A.R., Hamilton, D.S., Tanhua, T. and Moore, C.M. Trace element biogeochemistry in the high latitude North Atlantic Ocean: seasonal variations and volcanic inputs. Global Biogeochemical Cycles, p.e2020GB006674 (2020).

Krisch, S., Browning, T.J., Graeve, M., Ludwichowski, K.U., Lodeiro, P., Hopwood, M.J., Roig, S., Yong, J.C., Kanzow, T. and Achterberg, E.P. The influence of Arctic Fe and Atlantic fixed N on summertime primary production in Fram Strait, North Greenland Sea. Scientific Reports, 10, 15230 (2020).

Rapp, I., Schlosser, C., Browning, T.J., Wolf, F., Le Moigne, F.A., Gledhill, M. and Achterberg, E.P. El Niño‐driven oxygenation impacts Peruvian shelf iron supply to the South Pacific Ocean. Geophysical Research Letters, 47, e2019GL086631 (2020).

Louropoulou, E., Gledhill, M., Achterberg, E.P., Browning, T.J., Honey, D.J., Schmitz, R.A. and Tagliabue, A. Heme b distributions through the Atlantic Ocean: evidence for “anemic” phytoplankton populations. Scientific Reports, 10, 4551 (2020).

Browning, T.J., Al-Hashem, A.A., Hopwood, M.J., Engel, A., Wakefield, E.D. and Achterberg, E.P. Nutrient regulation of late spring phytoplankton blooms in the mid-latitude North Atlantic. Limnology and Oceanography 65, 1136-1148 (2020).

Tuerena, R.E., Ganeshram, R.S., Humphreys, M.P., Browning, T.J., Bouman, H. and Piotrowski, A.P., Isotopic fractionation of carbon during uptake by phytoplankton across the South Atlantic subtropical convergence. Biogeosciences 16, 3621–3635 (2019).

Louropoulou, E., Gledhill, M., Browning, T.J., Desai, D.K., Menzel Barraqueta, J.L., Tonnard, M., Sarthou, G., Planquette, H., Bowie, A.R., Schmitz, R.A., LaRoche, J., Achterberg, E.P. Regulation of the phytoplankton heme b iron pool during the North Atlantic spring bloom. Front. Microbiol. - Aquatic Microbiology 10, 1566 (2019).

Browning, T.J., Rapp, I., Schlosser C., Gledhill M., Achterberg E.P., Bracher A. & Le Moigne F.A.C. Influence of iron, cobalt, and vitamin B12 supply on phytoplankton growth in the tropical East Pacific during the 2015 El Niño.  Geophysical Research Letters, doi:10.1029/2018GL077972 (2018).

Schlitzer, R. et al. The GEOTRACES Intermediate Data Product 2017. Chemical Geology 493, 210-223 (2018).

Hopwood, M.J., Carroll, D., Browning, T.J., Meire, L., Mortensen, J., Krisch, S. and Achterberg, E.P. Non-linear response of summertime marine productivity to increased meltwater discharge around Greenland. Nature Communications, 9, 3256 (2018).

Berube, P.M., Biller, S.J., Hackl, T., Hogle, S.L., Satinsky, B.M., Becker, J.W., Braakman, R., Collins, S.B., Kelly, L., Berta-Thompson, J., Coe, A., Bergauer, K., Bouman, H.A., Browning, T.J., De Corte, D., Hassler, C., Hulata, Y., Jacquot, J.E., Maas, E.W., Reinthaler, T., Sintes, E., Yokokawa, T., Lindell, D., Stepanauskas, R., & Chisholm, S.W. Single cell genomes of Prochlorococcus, Synechococcus, and sympatric microbes from diverse marine environments. Scientific Data 5, 180154 (2018).

Biller, S.J., Berube, P.M., Dooley, K., Williams, M., Satinsky, B.M., Hackl, T., Hogle, S.L., Coe, A., Bergauer, K., Bouman, H.A., Browning, T.J., De Corte, D., Hassler, C., Hulston, D., Jacquot, J.E., Maas, E.W., Reinthaler, T., Sintes, E., Yokokawa, T., Chisholm, S.W. Marine microbial metagenomes sampled across space and time. Scientific Data 5, 180176 (2018).

Browning, T.J., Achterberg, E.P., Rapp, I., Bertrand, E.M., Engel, A., Tagliabue, A., & Moore, C.M. Nutrient co-limitation at the boundary of an oceanic gyre.  Nature, 550, 242–246 (2017).

Browning, T. J., Achterberg, E. A., Yong, J. C., Rapp, I., Engel, A., Moore, C. M. Iron limitation of microbial phosphorus acquisition in the tropical North Atlantic. Nature Communications, 8, 15465 (2017).

Lodeiro, P., Browning, T.J., Achterberg, E.A., Guillou, A., El-Shahawi, M.S. Mechanisms of silver nanoparticle toxicity to the coastal marine diatom Chaetoceros curvisetus. Scientific Reports, 7, 10777 (2017).

Sabadel, A.J.M., Browning, T.J.,  Kruimer, D., Airs, R.L., Woodward, E.M.S., Van Hale, R., Frew, R.D. (2017). Determination of picomolar dissolved free amino acids along a South Atlantic transect using reversed-phase high-performance liquid chromatography. Marine Chemistry, 196, 173-180.

Browning T.J., Stone K., Bouman H.A., Mather T.A., Pyle D.M., Moore C.M., & Martinez-Vicente V. Volcanic ash supply to the surface ocean – remote sensing of biological responses and their wider biogeochemical significance. Frontiers in Marine Science, 2, 00014 (2015).

Hermoso, M., Candelier, Y. Browning, T.J. and Minoletti, F. (2015). Environmental control of the isotopic composition of subfossil coccolith calcite: Are laboratory culture data transferable to the natural environment? GeoResJ, 7, doi:10.1016/j.grj.2015.05.002.

Browning, T.J., Bouman, H.A., & Moore, C.M. Satellite detected fluorescence: decoupling non-photochemical quenching from iron stress signals in the Southern Ocean.  Global Biogeochemical Cycles, 28, 510–524 (2014).

Browning, T.J., Bouman, H.A., Henderson, G.M., Mather, T., Pyle, D.M., Schlosser, C., Woodward, E. M. S., & Moore, C. M. Strong responses of Southern Ocean phytoplankton communities to volcanic ash. Geophysical Research Letters, 41, 2851–2857 (2014).

Browning, T.J., Bouman, H.A., Moore, C.M., Schlosser, C., Tarran, G.A., Woodward, E.M.S., & Henderson, G.M. Nutrient regimes control phytoplankton ecophysiology in the South Atlantic. Biogeosciences, 11, 463–479 (2014).

Hernández-Sánchez, M. T., LaRowe, D. E., Deng, F., Homoky, W. B., Browning, T. J., Pabortsava, K., Henderson, G. M., Mills, R. A., & Pancost, R. D. Further insights into how sediment redox status controls the preservation and composition of sedimentary organic biomarkers. Organic Geochemistry, 76, 220-234 (2014).

Wyatt, N.J., Milne, A., Woodward, E.M.S., Rees, A.P., Browning, T.J., Bouman, H.A., Worsfold, P.J. & Lohan, M.C. Biogeochemical cycling of dissolved zinc along the GEOTRACES South Atlantic transect GA10 at 40ºS.  Global Biogeochemical Cycles, 28, 44–56 (2014).

Book chapters

Achterberg, E.P., Browning, T.J., Gledhill, M., Schlosser, C. Transition Metals and Heavy Metal Speciation (2019). Encyclopedia of Ocean Sciences (3rd Edition). K. Cochran (Ed.).


Contributing author to IPCC Special Report on the Ocean and Cryosphere 2020 (Chapter 5: Changing Ocean, Marine Ecosystems, and Dependent Communities)

Invited seminars

'Oceanic nutrient limitation: Recent discoveries in the Atlantic', AWI, Bremerhaven, Germany (14th May 2018)

'Oceanic nutrient limitation: Recent discoveries in the Atlantic', Xiamen University, China (7th May 2018)

‘Phytoplankton response to volcanic ash fertilisation in the Southern Ocean’, Atmospheric and Marine Biogeochemistry seminar series, School of Environmental Sciences, University of East Anglia, UK (13th October 2014)

‘Southern Ocean phytoplankton: mapping iron stressed communities from space and strong responses to volcanic ash supply’, Polar Oceans seminar series, British Antarctic Survey, Cambridge, UK (July 16th 2014)

‘Mapping iron stress from space and potential manganese limitation in the Southern Ocean’, POETS seminar series, National Oceanography Centre, Southampton, UK (June 26th 2014)

INDO-MARECLIM winter school winter school on climate change and variability, marine ecosystems and coastal zone management: ‘Strong responses of Southern Ocean phytoplankton communities to volcanic ash’, Cochin, India, (2–7th November 2013)

Current community contributions

Second speaker for POF Subtopic 6.3 (The future biological carbon pump)

Lead session chair: ‘Distribution and impacts of ocean nutrient limitation’, ASLO Summer Meeting Palma de Mallorca, Spain, June 2021 (rescheduled to online meeting)

Associate Editor for Frontiers in Marine Science (Marine Biogeochemistry)

Reviewer for >20 journals