Topographic meandering of Antarctic Circumpolar Current and Antarctic Circumpolar Wave in the ice‐ocean‐ atmosphere system
نویسندگان
چکیده
[1] Topographic meandering of Antarctic Circumpolar Current (ACC) is found to be an impediment in the propagation of Antarctic Circumpolar Wave (ACW) in the Indian Ocean sector of Antarctica. Reasons for this are attributed to the southward advection of the ACW anomalies associated with the topographic meandering of the ACC. The southward meandering of ACC facilitates warming up of the region east of 20°E by about 1°C during winter, thereby reducing the sea ice; these processes interfere with the eastward propagating positive sea‐ice anomalies, and reduce its strength. Warming of ocean induced by topographic meandering leads to upward vertical velocities between 40°–60°E, where the ocean surface velocities are weak and southward, and the vertical/meridional advection of temperature dominates the zonal advection in the atmosphere. This results in the decoupling of the ACW in the region east of 40°E. In regions out side the Indian Ocean sector, vertical advection is minimum and zonal velocity of ACC becomes positive, which facilitates the ACW propagation in the Central Pacific, Ross and Weddell Seas. Citation: Nuncio, M., A. J. Luis, and X. Yuan (2011), Topographic meandering of Antarctic Circumpolar Current and Antarctic Circumpolar Wave in the ice‐ ocean‐atmosphere system, Geophys. Res. Lett., 38, L13708, doi:10.1029/2011GL046898.
منابع مشابه
Heat flux carried by the Antarctic Circumpolar Current mean flow
[1] A stream function projection of historical hydrographic data is applied to study the heat flux problem in the Antarctic Circumpolar Current (ACC). The ACC is defined as a circumpolar band consisting of mean streamlines passing through Drake Passage. Its mean path exhibits a globally meandering pattern. The calculation of zonal heat transport shows that the ACC warms along its equatorward se...
متن کاملSlow oceanic teleconnections linking the Antarctic Circumpolar Wave with the tropical El NioSouthern Oscillation
A case study for the period 1982-1994 shows that a major source for the Antarctic Circumpolar Wave is in the western subtropical South Pacific, where interannual anomalies in sea surface temperature (SST) and precipitable water (PrWat) form. Once established, these interannual anomalies, in tandem with anomalies in sea level pressure (SLP), move south toward the Southern Ocean. The system then ...
متن کاملA coupled ocean-atmosphere laboratory model of the Antarctic Circumpolar Current
A thermally-driven rotating annulus with two immiscible fluid layers is used as a laboratory analogue for ocean-atmosphere coupling in the Southern Ocean region. The laboratory facility can be tuned to produce a separation in scales between the two layers, and flow in each layer qualitatively resembles observed parameter regimes. The model effectively allows the lower (ocean) layer to be driven...
متن کاملStochastically forced variability in the Antarctic Circumpolar Current
Interannual fluctuations in the Antarctic Circumpolar Current (ACC) were considered. In the present study we analyze a mode of variability in the Hamburg Large-Scale Geostrophic ocean general circulation model which was driven by stochastic atmospheric forcing. The short-term atmospheric weather fluctuations were represented by a number of spatially coherent patterns of momentum, heat, and fres...
متن کاملThe Conrad Rise as an obstruction to the Antarctic Circumpolar Current
[1] The Antarctic Circumpolar Current (ACC) carries water freely around the whole continent of Antarctica, but not without obstructions. Some, such as the Drake Passage, constrict its path, while others, such as mid-ocean ridges, may induce meandering in the current’s cores and may cause the genesis of mesoscale turbulence. It has recently been demonstrated that some regions that are only relat...
متن کامل