Articles | Volume 23, issue 12
https://doi.org/10.5194/bg-23-4037-2026
https://doi.org/10.5194/bg-23-4037-2026
Research article
 | 
22 Jun 2026
Research article |  | 22 Jun 2026

Revealing hidden oxygen variability in the North Pacific: a two-decade analysis using GOBAI-O2

Miho Ishizu and Tomomichi Ogata

Cited articles

Alkire, M. B., D'Asaro, E., Lee, C., Perry, M. J., Gray, A., Cetinić, I., Briggs, N., Rehm, E., Kallin, E., Kaiser, J., and González-Posada, A.: Estimates of net community production and export using high-resolution, Lagrangian measurements of O2, NO3-, and POC through the evolution of a spring diatom bloom in the North Atlantic, Deep-Sea Res. Pt. I, 64, 157–174, https://doi.org/10.1016/j.dsr.2012.01.012, 2012. 
Behringer, D. W. and Xue, Y.: Evaluation of the global ocean data assimilation system at NCEP: The Pacific Ocean, 8th Symposium on Integrated Observing and Assimilation Systems for Atmosphere, Oceans, and Land Surface, AMS 84th Annual Meeting, Washington State Convention and Trade Center, Seattle, Washington, 11–15, https://ams.confex.com/ams/pdfpapers/70720.pdf (last access: 16 June 2026), 2004. 
Behringer, D. W.: The Global Ocean Data Assimilation System (GODAS) at NCEP, 11th Symposium on Integrated Observing and Assimilation Systems for Atmosphere, Oceans, and Land Surface, San Antonio, TX, American Meteorological Society, 3.3, https://ams.confex.com/ams/pdfpapers/119541.pdf (last access: 16 June 2026), 2007. 
Berman-Frank, I., Chen, Y. B., Gao, Y., Fennel, K., Follows, M. J., Milligan, A. J., and Falkowski, P. G.: Feedbacks between the nitrogen, carbon and oxygen cycles, in: Nitrogen in the Marine Environment, Elsevier Inc., 1539–1563, ISBN 978-0-12-372522-6, 2008. 
Bittig, H. C., Fiedler, B., Scholz, R., Krahmann, G., and Körtzinger, A.: Time response of oxygen optodes on profiling platforms and its dependence on flow speed and temperature, Limnol. Oceanogr.-Meth., 12, 617–636, https://doi.org/10.4319/lom.2014.12.617, 2014. 
Download
Short summary
We used GOBAI (Gridded Ocean Biogeochemistry from Artificial Intelligence)-O₂ (Version 4.4), a new machine-learning-based dataset derived from Argo floats and shipboard observations, to examine 20-year linear trends in potential temperature, salinity, and dissolved oxygen in the North Pacific. Our results agree with prior studies and newly reveal spatially heterogeneous oxygen trends, including local increases. These are linked to physical processes such as the southward retreat of the oxygen minimum layer and a northward-shifting circulation front.
Share
Altmetrics
Final-revised paper
Preprint