Three-layer circulation in the world deepest hadal trench.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39419970.
- Also identified by DOI 10.1038/s41467-024-53370-7 and PMC identifier 11487184.
- Licence recorded as CC BY-NC-ND.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The Challenger Deep (CD) is the deepest known hadal trench in the world. Due to challenges in data sampling at extreme ocean depths, the Lower Circumpolar Deep Water (LCDW) transport and ocean circulation structure in the CD remain unclear. By analyzing data from an extra-deep current meter mooring array, here we find a three-layer circulation in the CD, transitioning downward from westward LCDW flow (about -1.866 ± 2.953 Sv, 1 Sv = 10<sup>6</sup> m<sup>3</sup>/s) to cyclonic circulation, and then to anticyclonic circulation. The westward flow reverses its direction during summer, giving evidence for bidirectional connectivity of deep-sea basins, while the cyclonic-anticyclonic circulation is relatively steady. The LCDW intrusion, local topography and turbulent mixing are crucial for modulating the three-layer circulation. Turbulent mixing plays a key role in driving the anticyclonic circulation. Our findings provide insights for understanding the hydrodynamic environment in the ocean's deepest areas.