On the formation and spreading of the Bass Strait cascade

Wintertime circulation off southeast Australia: Strong forcing by the East Australian Current

“…Indeed, in agreement with the observations of Luick et al [1994], the model develops a front near the northeast corner of the strait and Cape Howe that separates the warm Tasman Seawater from the cold dense strait water. For this region (∼38°S), both model and observations indicate the denser strait water to gravitationally cascade to depths of 300 m and as a plume that is some 5–10 km wide.…”

“…The numerical model results presented here represent years in which the EAC has strong southward extension, with a transport of 17 Sv that is 50% larger than that indicated by hydrographic data. As noted, evidence for such a strong southward penetration of the EAC comes from the study of Luick et al [1994] where the observed temperature and density fields during July 1989 were similar to those obtained here: relatively warm, salty water was found off the east coast of Bass Strait. Cresswell [2000] also reports strong southward currents (40 cm s −1 ) off the east coast of Tasmania.…”

“…The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations. However, the width of the front and density difference (0.6–0.8 kg m −3 ) between Bass Strait and the Tasman Sea are both in good agreement with the transect data of Luick et al [1994]. Results for the cascade below should therefore be applicable to the real ocean.…”

“…The 2° increase is due to the southward advection of warm 19° water by the model EAC, where over 50 days or so, the 10–20 cm s −1 currents will move water 350 km or more to the south. The model salinities within the Tasman Sea are about 35.3 ppt and 0.1–0.2 ppt fresher than CARS or the results of Luick et al [1994]. The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations.…”

“…This result is in agreement with that expected for atmospheric cooling (see Section 2). The temperature of 14.5° is slightly larger than that indicated by CARS (∼13.5°) and the wintertime hydrographic data obtained by Luick et al [1994] where T ∼ 14°. The model salinity here is 35.4 ppt and unchanged from day zero since the freshwater fluxes are negligible.…”

Wintertime circulation off southeast Australia: Strong forcing by the East Australian Current

“…Indeed, in agreement with the observations of Luick et al [1994], the model develops a front near the northeast corner of the strait and Cape Howe that separates the warm Tasman Seawater from the cold dense strait water. For this region (∼38°S), both model and observations indicate the denser strait water to gravitationally cascade to depths of 300 m and as a plume that is some 5–10 km wide.…”

“…The numerical model results presented here represent years in which the EAC has strong southward extension, with a transport of 17 Sv that is 50% larger than that indicated by hydrographic data. As noted, evidence for such a strong southward penetration of the EAC comes from the study of Luick et al [1994] where the observed temperature and density fields during July 1989 were similar to those obtained here: relatively warm, salty water was found off the east coast of Bass Strait. Cresswell [2000] also reports strong southward currents (40 cm s −1 ) off the east coast of Tasmania.…”

“…The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations. However, the width of the front and density difference (0.6–0.8 kg m −3 ) between Bass Strait and the Tasman Sea are both in good agreement with the transect data of Luick et al [1994]. Results for the cascade below should therefore be applicable to the real ocean.…”

“…The 2° increase is due to the southward advection of warm 19° water by the model EAC, where over 50 days or so, the 10–20 cm s −1 currents will move water 350 km or more to the south. The model salinities within the Tasman Sea are about 35.3 ppt and 0.1–0.2 ppt fresher than CARS or the results of Luick et al [1994]. The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations.…”

“…This result is in agreement with that expected for atmospheric cooling (see Section 2). The temperature of 14.5° is slightly larger than that indicated by CARS (∼13.5°) and the wintertime hydrographic data obtained by Luick et al [1994] where T ∼ 14°. The model salinity here is 35.4 ppt and unchanged from day zero since the freshwater fluxes are negligible.…”

Wintertime circulation off southeast Australia: Strong forcing by the East Australian Current

“…Indeed, in agreement with the observations of Luick et al [1994], the model develops a front near the northeast corner of the strait and Cape Howe that separates the warm Tasman Seawater from the cold dense strait water. For this region (∼38°S), both model and observations indicate the denser strait water to gravitationally cascade to depths of 300 m and as a plume that is some 5–10 km wide.…”

“…The numerical model results presented here represent years in which the EAC has strong southward extension, with a transport of 17 Sv that is 50% larger than that indicated by hydrographic data. As noted, evidence for such a strong southward penetration of the EAC comes from the study of Luick et al [1994] where the observed temperature and density fields during July 1989 were similar to those obtained here: relatively warm, salty water was found off the east coast of Bass Strait. Cresswell [2000] also reports strong southward currents (40 cm s −1 ) off the east coast of Tasmania.…”

“…The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations. However, the width of the front and density difference (0.6–0.8 kg m −3 ) between Bass Strait and the Tasman Sea are both in good agreement with the transect data of Luick et al [1994]. Results for the cascade below should therefore be applicable to the real ocean.…”

“…The 2° increase is due to the southward advection of warm 19° water by the model EAC, where over 50 days or so, the 10–20 cm s −1 currents will move water 350 km or more to the south. The model salinities within the Tasman Sea are about 35.3 ppt and 0.1–0.2 ppt fresher than CARS or the results of Luick et al [1994]. The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations.…”

“…This result is in agreement with that expected for atmospheric cooling (see Section 2). The temperature of 14.5° is slightly larger than that indicated by CARS (∼13.5°) and the wintertime hydrographic data obtained by Luick et al [1994] where T ∼ 14°. The model salinity here is 35.4 ppt and unchanged from day zero since the freshwater fluxes are negligible.…”

Wintertime circulation off southeast Australia: Strong forcing by the East Australian Current

“…Indeed, in agreement with the observations of Luick et al [1994], the model develops a front near the northeast corner of the strait and Cape Howe that separates the warm Tasman Seawater from the cold dense strait water. For this region (∼38°S), both model and observations indicate the denser strait water to gravitationally cascade to depths of 300 m and as a plume that is some 5–10 km wide.…”

“…The numerical model results presented here represent years in which the EAC has strong southward extension, with a transport of 17 Sv that is 50% larger than that indicated by hydrographic data. As noted, evidence for such a strong southward penetration of the EAC comes from the study of Luick et al [1994] where the observed temperature and density fields during July 1989 were similar to those obtained here: relatively warm, salty water was found off the east coast of Bass Strait. Cresswell [2000] also reports strong southward currents (40 cm s −1 ) off the east coast of Tasmania.…”

“…The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations. However, the width of the front and density difference (0.6–0.8 kg m −3 ) between Bass Strait and the Tasman Sea are both in good agreement with the transect data of Luick et al [1994]. Results for the cascade below should therefore be applicable to the real ocean.…”

“…The 2° increase is due to the southward advection of warm 19° water by the model EAC, where over 50 days or so, the 10–20 cm s −1 currents will move water 350 km or more to the south. The model salinities within the Tasman Sea are about 35.3 ppt and 0.1–0.2 ppt fresher than CARS or the results of Luick et al [1994]. The resultant model density at the surface and near (38.5°S, 149°E) is about 25.6 kg m −3 and again 0.2 kg m −3 smaller than that indicated by the observations.…”

“…This result is in agreement with that expected for atmospheric cooling (see Section 2). The temperature of 14.5° is slightly larger than that indicated by CARS (∼13.5°) and the wintertime hydrographic data obtained by Luick et al [1994] where T ∼ 14°. The model salinity here is 35.4 ppt and unchanged from day zero since the freshwater fluxes are negligible.…”