Tidal and internal tidal impacts in the Tasman Sea

Geoscience Letters

Research Letter

Robin Robertson¹ 

[1] Xiamen University Malaysia, Jalan Sunsuria, Sepang, 43900, Sunsuria, Selangor, Malaysia;

关键词: Internal tides;    Eddies;    Tidal mixing;    Tasman Sea;   

DOI  :  10.1186/s40562-023-00262-1

 received in 2021-12-01, accepted in 2023-01-02,  发布年份 2023

来源: Springer

【 摘 要 】

Barotropic and baroclinic tides were simulated for the Coral and Tasman Seas off eastern Australia and compared to a simulation without tides. Both simulations included geostrophic currents and replicated a current analogous to the East Australian Current (EAC). Tides and tidal currents in most of this region are weak, generally 1–2 cm s−1, with the exception of the far northwest portion of the Coral Sea. Even these weak tides were found to impact the mean EAC-like current transport, enhancing it by 1–4 Sv in some areas. Southward flow increased over the continental shelf. Tides did not appear to impact eddy formation, size, or rotational speed; however, they affected eddy propagation. Cyclonic eddies propagated northward faster with tides than without tides. Tides impacted cross-shelf transport of colder water, with significantly more on-shore transport occurring with tides, particularly equatorward of the diurnal critical latitudes. Cross-shelf transport of nutrient rich water onto the shelf is important in this oligotrophic region. Although the prime source of vertical shear and mixing were mean currents and eddies, tides played a secondary role. Tides influenced mixing by increasing vertical temperature diffusivities to 10−4 to 10−3 m2 s−1 over portions of the continental slope and over rough topography, particularly in regions near the diurnal critical latitudes (27°–30°). In conclusion, even small tides can significantly impact the circulation through their effects on the mean currents, eddy rotation velocities, eddy propagation, and mixing.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

41116_2022_35_Article_IEq296.gif

Fig. 3

41116_2022_35_Article_IEq287.gif

Fig. 1

41116_2022_35_Article_IEq281.gif

41116_2022_35_Article_IEq278.gif

Fig. 1

41116_2022_35_Article_IEq255.gif

41116_2022_35_Article_IEq252.gif

41116_2022_35_Article_IEq243.gif

Fig. 2

41116_2022_35_Article_IEq229.gif

41116_2022_35_Article_IEq225.gif

41116_2022_35_Article_IEq223.gif