Coastal Upwelling Dynamics and Environmental Interactions

Coastal upwelling arises where wind-driven Ekman transport forces deep, nutrient-rich waters toward the surface, fuelling one of the ocean’s most productive ecosystems. Predominantly found along eastern ocean boundaries, these systems are governed by the interplay of alongshore winds, earth rotation and regional pressure gradients. Upwelled waters modulate sea‐surface temperature, support rich fisheries and serve as refugia against basin-scale warming, yet they are sensitive to alterations in wind patterns, stratification and large-scale climate variability. Recent observations and high-resolution modelling reveal complex responses to greenhouse forcing, including shifts in seasonal timing, spatial heterogeneity in upwelling intensity and competing effects of enhanced stratification. These changes hold profound implications for biogeochemical cycling, marine heatwave frequency and the sustainability of coastal fisheries. Understanding these dynamics is critical for coastal resource management, climate adaptation strategies and the conservation of marine biodiversity across the globe.

Research from Nature Portfolio

Recent studies have demonstrated that southern hemisphere eastern boundary systems, once regarded as thermal refuges, are projected to become hotspots for marine heatwave stress as weakened boundary currents overwhelm upwelling’s cooling effect. High-resolution climate simulations under elevated greenhouse gas scenarios reveal that cumulative heatwave intensity may rise more rapidly within these upwelling zones than in adjacent open waters. Parallel investigations have shown that future changes in coastal wind strength diverge markedly between hemispheres: southern systems are likely to experience intensification of upwelling-favourable winds alongside rapid coastal warming, whereas northern systems may face wind weakening. These findings challenge the classical Bakun hypothesis and underscore the importance of horizontal heat advection and fine-scale wind stress curl. Foundational work on the California Current System further illustrates how enhanced alongshore winds, deeper isotherms and strengthened eddy activity could amplify nutrient flux, while also generating nonlinear responses in plankton community structure under a warming climate.

Coastal Upwelling Dynamics and Environmental Interactions publication trend

The graph below shows the total number of articles in coastal upwelling dynamics and environmental interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Coastal upwelling: The wind-driven process by which deep, cooler, nutrient-rich waters are brought to the ocean surface along coastlines.

Eastern Boundary Upwelling System: A region along the eastern margins of ocean basins where prevailing winds and the Coriolis effect induce persistent coastal upwelling.

Ekman transport: The net movement of water at right angles to the wind direction, resulting from the balance of wind stress and the Coriolis force.

Water-column stratification: The layering of water masses of differing density, often due to temperature or salinity gradients, which can inhibit vertical mixing.

Marine heatwave: A prolonged period of anomalously high sea-surface temperatures that can stress marine ecosystems and alter species distributions.

References

1. Southern hemisphere eastern boundary upwelling systems emerging as future marine heatwave hotspots under greenhouse warming. Nature Communications (2023).
2. Uncertain future of sustainable fisheries environment in eastern boundary upwelling zones under climate change. Communications Earth & Environment (2023).
3. Climate change in the Canary/Iberia upwelling region: the role of ocean stratification and wind. Environmental Research Letters (2024).
4. Physical and Biogeochemical Phenology of Coastal Upwelling in the California Current System. Geophysical Research Letters (2024).
5. Future changes in coastal upwelling ecosystems with global warming: The case of the California Current System. Scientific Reports (2018).
6. Climate Change Impacts on Eastern Boundary Upwelling Systems. Annual Review of Marine Science (2022).
7. Reduced Nearshore Warming Associated With Eastern Boundary Upwelling Systems. Frontiers in Marine Science (2019).