Paleoceanographic Dynamics in the Pacific Region

Paleoceanographic investigations in the Pacific encompass the study of past ocean circulation, sea‐surface conditions, biogeochemical cycles and sedimentary processes to reconstruct how the marine environment has responded to climatic and tectonic forcings over glacial–interglacial and longer timescales. Key elements include shifts in the Intertropical Convergence Zone (ITCZ), variability of western boundary currents such as the Kuroshio, fluctuations in sea‐surface temperature (SST) and salinity driven by monsoon and wind‐stress changes, as well as deep‐ocean phenomena such as thermocline depth variations and carbonate compensation depth shoaling. Sedimentary archives—ranging from ferromanganese crusts and pelagic sediments to coastal diatom assemblages and foraminiferal proxies—provide high‐resolution records of dust input, nutrient cycling, productivity and water‐mass properties. These records reveal the interplay between Northern Hemisphere cooling events, shifts in atmospheric circulation belts, alterations in ocean gateways and changes in greenhouse gas concentrations. Understanding these dynamics is critical for constraining the mechanisms that govern heat redistribution, biogeochemical feedbacks and the resilience of marine ecosystems, thereby informing predictive models of future climate–ocean interactions.

Research from Nature Portfolio

Recent analyses of alkenone‐ and foraminiferal‐based temperature proxies in the East China Sea demonstrate that seasonal contrasts in SST evolve distinctly under insolation and CO₂ forcings, with summer and winter temperatures exhibiting phase shifts during glacial terminations and interglacials. These findings emphasise the necessity of considering proxy seasonality when estimating climate sensitivity. Investigations of a western Pacific ferromanganese crust reveal a progressive change in eolian dust provenance—from a dominantly Gobi Desert source in the early Pliocene to mixed Gobi–Taklimakan inputs during the Pleistocene—linked to an equatorward migration of westerly winds and Central Asian humidification, thereby illustrating terrestrial‐marine coupling over millions of years. Foundational work tracking large, rapid meridional shifts of the ITCZ during deglacial stadials has provided a spatially resolved benchmark for constraining tropical hydrological responses to hemispheric heat imbalances, underscoring abrupt climate connectivity between the North Atlantic and equatorial Pacific.

Paleoceanographic Dynamics in the Pacific Region publication trend

The graph below shows the total number of articles in paleoceanographic dynamics in the pacific region across all publications each year (not limited to Nature Index journals).

Technical terms

Intertropical Convergence Zone (ITCZ): A tropical atmospheric feature where trade winds converge, influencing rainfall patterns and acting as a barrier to dust transport.

Thermocline: A subsurface ocean layer characterised by a rapid temperature gradient that separates warmer surface water from colder deep water.

Carbonate compensation depth (CCD): The depth in the ocean below which carbonate minerals dissolve more rapidly than they accumulate, affecting sediment composition.

Alkenone unsaturation index: A proxy based on organic compounds produced by certain phytoplankton, used to estimate past annual mean SST.

Foraminiferal Mg/Ca ratio: A geochemical proxy derived from the magnesium to calcium ratio in foraminiferal calcite, used to reconstruct past seawater temperatures.

References

1. Response of the Central Pacific Intertropical Convergence Zone to Northern Hemisphere Cooling During the Last Glacial Maximum and Heinrich Stadial 1. Geophysical Research Letters (2024).
2. Large deglacial shifts of the Pacific Intertropical Convergence Zone. Nature Communications (2016).
3. Humidification of Central Asia and equatorward shifts of westerly winds since the late Pliocene. Communications Earth & Environment (2022).
4. Changes in surface water masses in the northern East China Sea since the Last Glacial Maximum based on diatom assemblages. Progress in Earth and Planetary Science (2021).
5. Roles of insolation forcing and CO2 forcing on Late Pleistocene seasonal sea surface temperatures. Nature Communications (2021).
6. Geochronological Evidence Inferring Carbonate Compensation Depth Shoaling in the Philippine Sea after the Mid-Brunhes Event. Journal of Marine Science and Engineering (2022).