Altimetry-drived Antarctic Circumpolar Current fronts

an up-to-date map of the antarctic circumpolar current (acc) fronts is constructed from the latest version of mean dynamic topography from satellite altimetry (park et al., 2019, observations of the antarctic circumpolar current over the udintsev fracture zone, the narrowest choke point in the southern ocean, jgr-oceans, in review). these are derived from the 1/8°-resolution mean dynamic topography (mdt) of centre national d’etudes spatiales-collect localisation satellites 2018 (cnes-cls18) for the 1993-2012 reference period [rio et al., the new cnes-cls18 mean dynamic topography solution, in preparation]. the narrowest acc width in the udintsev fracture zone (ufz), with the strongest concentration of the three major acc fronts within a limited distance as short as 170 km, about 40% narrower than that at drake passage. at 144°w, at the entrance of the ufz, which lies between the pacific-antarctic ridge (par) and its eastwardly-offset segment (offset par segment), there is a triple confluence of the subantarctic front (saf), polar front (pf), and southern acc front. downstream of this longitude, the saf progressively meanders northward over the relatively shallow offset par segment before channeling through the eltanin fracture zone, thus diverging from the pf which proceeds through the ufz.

本数据集基于最新版的卫星测高平均动态地形（Park 等，2019，南极绕极流在乌迪涅夫断裂带（乌兹）的观测，南大洋最狭窄的瓶颈地带，JGR-Oceans，在审），构建了南极绕极流（ACC）前沿的最新地图。这些数据源自于1993-2012参考期间，由法国国家空间研究局-定位卫星中心（CNES-CLS18）提供的1/8°分辨率平均动态地形（MDT）。在乌兹断裂带（UZF）中，ACC最狭窄的宽度，三大ACC前沿在有限距离（至多170公里）内呈现出最强的集中，约比德雷克海峡窄40%。在144°W处，UZF的入口处，位于太平洋-南极脊（PAR）及其向东偏移的部分（偏移PAR段）之间，南极前寒带流（SAF）、极地流（PF）和南极ACC前沿形成了三重汇合。在此经度下游，SAF逐渐在相对较浅的偏移PAR段上蜿蜒向北，随后通过埃尔特林断裂带分流，从而与继续通过UZF的PF分开。