Xiang Yang

Research

Ocean carbon cycling from autonomous observations, ships, and physical-biogeochemical context.

Schematic of Antarctic Winter Water, mixing, and sea-ice processes

Antarctic Winter Water

I investigate how Antarctic Winter Water forms, evolves, and connects surface forcing, sea-ice variability, and subsurface carbon storage. My current work uses BGC-Argo observations and BSOSE to examine how recent Antarctic sea-ice decline affects Winter Water variability, DIC budgets, primary production, and air-sea CO2 exchange.

Image credit: Spira et al. (2024).

Monthly air-sea CO2 flux observations showing uptake and outgassing

Carbon observations and air-sea CO2 exchange

I study how physical and biological processes regulate carbon uptake, storage, and air-sea CO2 exchange in the Southern Ocean. My work integrates BGC-Argo floats, moorings, ship-based observations, and satellites to quantify CO2 fluxes, primary productivity, and organic carbon export.

Paper: Yang, X., Wynn-Edwards, C. A., Strutton, P. G., & Shadwick, E. H. (2024). Drivers of air-sea CO2 flux in the subantarctic zone revealed by time series observations. Global Biogeochemical Cycles, 38, e2023GB007766.

Report: https://aappartnership.org.au/down-the-sink-following-carbon-in-the-southern-ocean/

Schematic of carbon export, biological production, particles, eddies, BGC-Argo, and sediment traps

Carbon export and biological pump

I investigate how biological production, particle export, and vertical transport regulate the efficiency of the biological carbon pump. Using BGC-Argo optical and oxygen-based observations, my work quantifies multiple POC export pathways, including the gravitational, mixed-layer, and eddy subduction pumps.

Paper: Yang, X., Wynn-Edwards, C.A., Strutton, P.G., and Shadwick, E.H. (2024). Carbon export in the subantarctic zone revealed by multi-year observations from biogeochemical-Argo floats and sediment traps. Global Biogeochemical Cycles.

Report: https://aappartnership.org.au/under-the-pump-robot-floats-probe-carbon-pathways-in-the-southern-ocean/

Chlorophyll phenology curves and Antarctic sea-ice retreat timing

Phenology v.s. Antarctic Sea Ice changes

I examine how Antarctic sea-ice retreat influences biogeochemical variability in the seasonal sea-ice zone. My recent work uses machine-learning-enhanced BGC-Argo pCO2 estimates to assess how earlier sea-ice retreat affects phytoplankton phenology, primary production, and oceanic carbon uptake.

Satellite chlorophyll map south of Tasmania showing Southern Ocean variability and an observing transect

Physical drivers of Southern Ocean biogeochemical variability

I investigate how physical ocean processes, including fronts, mesoscale eddies, mixing, and water-mass variability, shape Southern Ocean biogeochemical patterns. My work links physical circulation and climate variability to changes in phytoplankton blooms, carbon cycling, and ecosystem responses.

Paper: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JC017863