Haichao Guo
I am a postdoctoral researcher in the HI-CYCLES group at the University of Hawai’i at Mānoa.
Project: InMOS.
Links:Google Scholar | ORCID | Linkedin
I am an ocean biogeochemist interested in understanding how physical and biogeochemical processes shape the distribution and variability of carbon and oxygen in the ocean. My research focuses particularly on how the ocean “breathes”—a process known as ocean ventilation—, how ocean ventilation is changing, and how these changes influence the ocean’s role in regulating carbon and oxygen cycles in climate system across different timescales. I used shipboard observations, autonomous measurements, and Earth System models to better understand the physical and biogeochemical processes that govern these changes.
Since September 2025, I have been a postdoctoral researcher in the HI-CYCLES group at the University of Hawai‘i at Mānoa, where I contribute to the Schmidt Sciences–funded InMOS project. My research focuses on three related questions: How much anthropogenic carbon is transported into the ocean interior by mode waters? How large is its temporal variability, and what controls this variability? Can global ocean biogeochemical models reproduce the observed trends and variability?
Education and Employment
Section titled “Education and Employment”2025.09 – present Postdoctoral Researcher, University of Hawai‘i at Mānoa, Honolulu, USA.
2025.03 – 2025.09 Postdoctoral Researcher, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
2022.01 – 2025.03 PhD student, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
2019.10 – 2021.12 M.Sc. Marine Geosciences, Kiel University, Kiel, Germany.
2014.09 – 2018.07 B.Sc. Marine Science, Ocean University of China, Qingdao, China.
Submitted / In review
Section titled “Submitted / In review”Guo, H., Tanhua, T., Frenger, I., Patara, L., Spence, P., Gou, R., Wu, L., Li. X., Oschlies, A. Systematic ocean ventilation biases in climate models indicated by Chlorofluorocarbon-12. JGR Oceans. Accepted.
Kriest, I., Kemena, T., Guo, H. Tuning ocean biogeochemistry for an Earth system model: approaches, challenges and impact on model performance. GMD. Under review. https://doi.org/10.5194/egusphere-2026-3423
Wey, H.-W., Moustakis, Y., Nützel, T., Oschlies, A., Pongratz, J., Guo, H. Impacts of Combined Ambitious Marine and Terrestrial Carbon Dioxide Removal on Major Ocean Stressors. ERL. Under review.
Published
Section titled “Published”Guo, H., Koeve, W., Kriest, I., Frenger, I., Tanhua, T., Brandt, P., He, Y., Xue, T., Oschlies, A. North Atlantic ventilation change over the past three decades is potentially driven by climate change. Nature Communications, 17, 200. https://doi.org/10.1038/s41467-025-67923-x
Guo, H., Koeve, W., Oschlies, A., He, Y. C., Kemena, T. P., Gerke, L., Kriest, I. Dual-tracer constraints on the inverse Gaussian transit time distribution improve the estimation of water mass ages and their temporal trends in the tropical thermocline. Ocean Science, 21(3), 1167–1182. https://doi.org/10.5194/os-21-1167-2025
Guo, H., Kriest, I., Oschlies, A., Koeve, W. Can oxygen utilization rate be used to track the long-term changes of aerobic respiration in the mesopelagic Atlantic Ocean? Geophysical Research Letters, 50, e2022GL102645. https://doi.org/10.1029/2022GL102645