Scientific publications

We lead research into the changing marine carbonate system in the present-day ocean. We also contribute to studies on related topics including ocean acidification impacts, palaeoceanographic proxies, and sensor development.

Our key outputs


Dissolution of a submarine carbonate platform by a submerged lake of acidic seawater

Humphreys, M. P., Meesters, E. H., de Haas, H., Karancz, S., Delaigue, L., Bakker, K., Duineveld, G., de Goeyse, S., Haas, A., Mienis, F., Ossebaar, S., and van Duyl, F. C. (2022). Biogeosciences 19, 347-358.

doi:10.5194/bg-19-347-2022

PyCO2SYS v1.8: marine carbonate system calculations in Python

Humphreys, M. P., Lewis, E. R., Sharp, J. D. and Pierrot, D. (2022). Geoscientific Model Development 15, 15-43.

doi:10.5194/gmd-15-15-2022

Air-sea CO2 exchange and ocean acidification in UK seas and adjacent waters

Humphreys, M. P., Artioli, Y., Bakker, D. C. E., Hartman, S. E., León, P., Wakelin, S., Walsham, P. and Williamson, P. (2020). MCCIP Science Review 2020, 54–75.

doi:10.14465/2020.arc03.oac

Mechanisms for a nutrient-conserving carbon pump in a seasonally stratified, temperate continental shelf sea

Humphreys, M. P., Achterberg, E. P., Hopkins, J. E., Chowdhury, M. Z. H., Griffiths, A. M., Hartman, S. E., Hull, T., Smilenova, A., Wihsgott, J., Woodward, E. M. S. and Moore, C. M. (2019). Progress in Oceanography 177, 101961.

doi:10.1016/j.pocean.2018.05.001

Modelling seawater carbonate chemistry in shellfish aquaculture regions: Insights into CO2 release associated with shell formation and growth

Morris, J. P. and Humphreys, M. P. (2019). Aquaculture 501, 338–344.

doi:10.1016/j.aquaculture.2018.11.028

On the influence of marine biogeochemical processes over CO2 exchange between the atmosphere and ocean

Humphreys, M. P., Daniels, C. J., Wolf-Gladrow, D. A., Tyrrell, T. and Achterberg, E. P. (2018). Marine Chemistry 199, 1–11.

doi:10.1016/j.marchem.2017.12.006

Climate sensitivity and the rate of ocean acidification: future impacts, and implications for experimental design

Humphreys, M. P. (2017). ICES Journal of Marine Science 74(4), 934–940.

doi:10.1093/icesjms/fsw189

Stable carbon isotopes of dissolved inorganic carbon for a zonal transect across the subpolar North Atlantic Ocean in summer 2014

Humphreys, M. P., Greatrix, F. M., Tynan, E., Achterberg, E. P., Griffiths, A. M., Fry, C. H., Garley, R., McDonald, A. and Boyce, A. J. (2016). Earth System Science Data 8, 221–233.

doi:10.5194/essd-8-221-2016

Multidecadal accumulation of anthropogenic and remineralized dissolved inorganic carbon along the Extended Ellett Line in the northeast Atlantic Ocean

Humphreys, M. P., Griffiths, A. M., Achterberg, E. P., Holliday, N. P., Rérolle, V. M. C., Menzel Barraqueta, J.-L., Couldrey, M. P., Oliver, K. I. C., Hartman, S. E., Esposito, M. and Boyce, A. J. (2016). Global Biogeochemical Cycles 30(2), 293–310.

doi:10.1002/2015GB005246


Collaborations and earlier work


Enhanced mercury reduction in the South Atlantic Ocean during carbon remineralization

Živković, I., Humphreys, M. P., Achterberg, E. P., Dumousseaud, C., Woodward, E. M. S., Bojanić, N., Šolić, M., Bratkič, A., Kotnik, J., Vahčič, M., Obu Vazner, K., Begu, E., Fajon, V., Shlyapnikov, Y. and Horvat, M. (2022). Marine Pollution Bulletin, 113644.

doi:10.1016/j.marpolbul.2022.113644

Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties. II. Tris buffers in artificial seawater at 25 °C, and an assessment of the seawater 'Total' pH scale

Clegg, S. L., Humphreys, M. P., Waters, J. F., Turner, D. R. and Dickson, A. G. (2022). Marine Chemistry, 104096.

doi:10.1016/j.marchem.2022.104096

Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties. I. Artificial seawater from 0 to 45 °C

Humphreys, M. P., Waters, J. F., Turner, D. R., Dickson, A. G. and Clegg, S. L. (2022). Marine Chemistry, 104095.

doi:10.1016/j.marchem.2022.104095

RADIv1: a non-steady-state early diagenetic model for ocean sediments in Julia and MATLAB/GNU Octave

Sulpis, O., Humphreys, M. P., Wilhelmus, M., Carroll, D., Berelson, W., Menemenlis, D., Middelburg, J. and Adkins, J. (2022). Geoscientific Model Development 15(5), 2105-2131.

doi:10.5194/gmd-15-2105-2022

Best Practice Data Standards for Discrete Chemical Oceanographic Observations

Jiang, L.-Q., Pierrot, D., Wanninkhof, R., Feely, R. A., Tilbrook, B., Alin, S., Barbero, L., Byrne, R. H., Carter, B. R., Dickson, A. G., Gattuso, J.-P., Greeley, D., Hoppema, M., Humphreys, M. P., Karstensen, J., Lange, N., Lauvset, S. K., Lewis, E. R., Olsen, A., Pérez, F. F., Sabine, C., Sharp, J. D., Tanhua, T., Trull, T. W., Velo, A., Allegra, A. J., Barker, P., Burger, E., Cai, W.-J., Chen, C.-T. A., Cross, J., Garcia, H., Hernandez-Ayon, J. M., Hu, X., Kozyr, A., Langdon, C., Lee, K., Salisbury, J., Wang, Z. A. and Xue, L (2022). Frontiers in Marine Science 8, 705638.

doi:10.3389/fmars.2021.705638

Equilibrium calculations of iron speciation and apparent iron solubility in the Celtic Sea at ambient seawater pH using the NICA-Donnan model

Zhu, K., Birchill, A. J., Milne, A., Ussher, S., Humphreys, M. P., Carr, N., Mahaffey, C., Lohan, M. C., Achterberg, E. P. and Gledhill, M. (2021). Marine Chemistry 237, 104038.

doi:10.1016/j.marchem.2021.104038

Air-Sea Gas Fluxes and Remineralization From a Novel Combination of pH and O2 Sensors on a Glider

Possenti, L., Humphreys, M. P., Bakker, D. C. E., Cobas-García, M., Fernand, L., Lee, G. A., Pallottino, F., Loucaides, S., Mowlem, M. C. and Kaiser, J. (2021). Frontiers in Marine Science 8, 696772.

doi:10.3389/fmars.2021.696772

Norwegian Sea net community production estimated from O2 and prototype CO2 optode measurements on a Seaglider

Possenti, L., Skjelvan, I., Atamanchuk, D., Tengberg, A., Humphreys, M. P., Loucaides, S., Fernand, L. and Kaiser, J. (2021). Ocean Science 17, 593–614.

doi:10.5194/os-17-593-2021

Short-term responses to ocean acidification: effects on relative abundance of eukaryotic plankton from the tropical Timor Sea

Rahlff, J., Khodami, S., Voskuhl, L., Humphreys, M. P., Stolle, C., Martinez Arbizu, P., Wurl, O. and Ribas-Ribas, M. (2021). Marine Ecology Progress Series 658, 59–74.

doi:10.3354/meps13561

The pH dependency of the boron isotopic composition of diatom opal (Thalassiosira weissflogii)

Donald, H. K., Foster, G. L., Fröhberg, N., Swann, G. E. A., Poulton, A., Moore, C. M. and Humphreys, M. P. (2020). Biogeosciences 17, 2825–2837.

doi:10.5194/bg-17-2825-2020

Seasonality and spatial heterogeneity of the surface ocean carbonate system in the northwest European continental shelf

Hartman, S. E., Humphreys, M. P., Kivimäe, C., Woodward, E. M. S., Kitidis, V., McGrath, T., Hydes, D. J., Greenwood, N., Hull, T., Ostle, C., Pearce, D. J., Sivyer, D., Stewart, B. M., Walsham, P., Painter, S. C., McGovern, E., Harris, C., Griffiths, A., Smilenova, A., Clarke, J., Davis, C., Sanders, R. and Nightingale, P. (2019). Progress in Oceanography 177, 101909.

doi:10.1016/j.pocean.2018.02.005

Winter weather controls net influx of atmospheric CO2 on the north-west European shelf

Kitidis, V., Shutler, J. D., Ashton, I., Warren, M., Brown, I., Findlay, H., Hartman, S. E., Sanders, R., Humphreys, M., Kivimäe, C., Greenwood, N., Hull, T., Pearce, D., McGrath, T., Stewart, B. M., Walsham, P., McGovern, E., Bozec, Y., Gac, J.-P., van Heuven, S. M. A. C., Hoppema, M., Schuster, U., Johannessen, T., Omar, A., Lauvset, S. K., Skjelvan, I., Olsen, A., Steinhoff, T., Körtzinger, A., Becker, M., Lefevre, N., Diverrès, D., Gkritzalis, T., Cattrijsse, A., Petersen, W., Voynova, Y.G., Chapron, B., Grouazel, A., Land, P. E., Sharples, J. and Nightingale, P. D. (2019). Scientific Reports 9, 20153.

doi:10.1038/s41598-019-56363-5

Impact of Nonzero Intercept Gas Transfer Velocity Parameterizations on Global and Regional Ocean–Atmosphere CO2 Fluxes

Ribas-Ribas, M., Battaglia, G., Humphreys, M. P. and Wurl, O. (2019). Geosciences 9(5), 230.

doi:10.3390/geosciences9050230

Isotopic fractionation of carbon during uptake by phytoplankton across the South Atlantic subtropical convergence

Tuerena, R. E., Ganeshram, R. S., Humphreys, M. P., Browning, T. J., Bouman, H. and Piotrowski, A. P. (2019). Biogeosciences 16, 3621–3635.

doi:10.5194/bg-16-3621-2019

What drives the latitudinal gradient in open ocean surface dissolved inorganic carbon concentration?

Wu, Y., Hain, M. P., Humphreys, M. P., Hartman, S. and Tyrrell, T. (2019). Biogeosciences 16, 2661–2681.

doi:10.5194/bg-16-2661-2019

Controls on open-ocean North Atlantic ΔpCO2 at seasonal and interannual timescales are different

Henson, S. A., Humphreys, M. P., Land, P., Shutler, J., Goddijn-Murphy, L., Warren, M. and Schuster, U. (2018). Geophysical Research Letters 45.

doi:10.1029/2018GL078797

Geographical CO2 sensitivity of phytoplankton correlates with ocean buffer capacity

Richier, S., Achterberg, E. P., Humphreys, M. P., Poulton, A. J., Suggett, D. J., Tyrrell, T. and Moore, C. M. (2018). Global Change Biology 24, 4438–4452.

doi:10.1111/gcb.14324

The GEOTRACES Intermediate Data Product 2017

Schlitzer, R. et al. [286 authors incl. Humphreys, M. P.] (2018). Chemical Geology 493, 210–223.

doi:10.1016/j.chemgeo.2018.05.040

Biological Pump

Giering, S. L. and Humphreys, M. P. (2017). Encylopedia of Geochemistry, ed. White, W. M., Springer, 1–6.

doi:10.1007/978-3-319-39193-9_154-1

Characterization of a Time-Domain Dual Lifetime Referencing pCO2 Optode and Deployment as a High-Resolution Underway Sensor across the High Latitude North Atlantic Ocean

Clarke, J. S., Humphreys, M. P., Tynan, E., Kitidis, V., Brown, I., Mowlem, M. C. and Achterberg, E. P. (2017). Frontiers in Marine Science 4(396).

doi:10.3389/fmars.2017.00396

A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

Bakker, D. C. E. et al. [92 authors incl. Humphreys, M. P.] (2016). Earth System Science Data 8, 383–413.

doi:10.5194/essd-8-383-2016

An internally consistent dataset of δ13C-DIC in the North Atlantic Ocean – NAC13v1

Becker, M., Andersen, N., Erlenkeuser, H., Humphreys, M. P., Tanhua, T. and Körtzinger, A. (2016). Earth System Science Data 8, 559–570.

doi:10.5194/essd-8-559-2016

Species-specific calcite production reveals Coccolithus pelagicus as the key calcifier in the Arctic Ocean

Daniels, C. J., Poulton, A. J., Young, J. R., Esposito, M., Humphreys, M. P., Ribas Ribas, M., Tynan, E. and Tyrrell, T. (2016). Marine Ecology Progress Series 555, 29–47.

doi:10.3354/meps11820

Carbon dioxide and ocean acidification observations in UK waters: Synthesis report with a focus on 2010–2015

Ostle, C., Williamson, P., Artoli, Y., Bakker, D. C. E., Birchenough, S., Davis, C. E., Dye, S., Edwards, M., Findlay, H. S., Greenwood, N., Hartman, S., Humphreys, M. P., Jickells, T., Johnson, M., Landschützer, P., Parker, R., Pearce, D., Pinnegar, J., Robinson, C., Schuster, U., Silburn, B., Thomas, R., Wakelin, S., Walsham, P. and Watson, A. J. (2016). Department for Environment, Food and Rural Affairs, pp. 44.

doi:10.13140/RG.2.1.4819.4164

Production of dissolved organic carbon by Arctic plankton communities: Responses to elevated carbon dioxide and the availability of light and nutrients

Poulton, A. J., Daniels, C. J., Esposito, M., Humphreys, M. P., Mitchell, E., Ribas-Ribas, M., Russell, B. C., Stinchcombe, M. C., Tynan, E. and Richier, S. (2016). Deep-Sea Research Part II 127, 60–74.

doi:10.1016/j.dsr2.2016.01.002

Physical and biogeochemical controls on the variability in surface pH and calcium carbonate saturation states in the Atlantic sectors of the Arctic and Southern Oceans

Tynan, E., Clarke, J. S., Humphreys, M. P., Ribas-Ribas, M., Esposito, M., Rérolle, V. M. C., Schlosser, C., Thorpe, S. E., Tyrrell, T. and Achterberg, E. P. (2016). Deep-Sea Research Part II 127, 7–27.

doi:10.1016/j.dsr2.2016.01.001

Measurements of the stable carbon isotope composition of dissolved inorganic carbon in the northeastern Atlantic and Nordic Seas during summer 2012

Humphreys, M. P., Achterberg, E. P., Griffiths, A. M., McDonald, A. and Boyce, A. J. (2015). Earth System Science Data 7, 127–135.

doi:10.5194/essd-7-127-2015