The Atlantic Water (AW) Layer in the Arctic Subpolar gyre sTate Estimate Release 1 (ASTE R1), a data-constrained, regional, medium-resolution coupled ocean-sea ice model, is analyzed for the period 2004–2017 in combination with available hydrographic data. The study, focusing on AW defined as the waters between two bounding isopycnals, examines the time-average, mean seasonal cycle and interannual variability of AW Layer properties and circulation. A surge of AW, marked by rapid increases in mean AW Layer potential temperature and AW Layer thickness, begins two years into the state estimate and traverses the Arctic Ocean along boundary current pathways at a speed of 1–2 cm/s. The surge also alters AW circulation, including a reversal in flow direction along the Lomonosov Ridge, resulting in a new quasi-steady AW circulation from 2010 through the end of the state estimate period. The time-mean AW circulation during this latter time period indicates that a significant amount of AW spreads over the Lomonosov Ridge rather than directly returning along the ridge to Fram Strait. A three-layer depiction of the time-averaged ASTE R1 overturning circulation within the Arctic Ocean reveals that more AW is converted to colder, fresher Surface Layer water than is transformed to Deep and Bottom Water (1.2 Sv vs. 0.4 Sv). ASTE R1 also exhibits an increase in the volume of AW over the study period at a rate of 1.4 Sv, with near compensating decrease in Deep and Bottom Water volume. Observed AW properties compared to ASTE R1 output reveal increasing misfit during the simulated period with the ASTE R1 AW Layer generally being warmer and thicker than in observations.

北极次极地环流状态估计版本 1 (ASTE R1) 中的大西洋水 (AW) 层是一个数据受限的区域中分辨率耦合海-海冰模型，结合可用的数据分析了 2004-2017 年期间水文数据。该研究侧重于定义为两个边界等密度线之间水域的 AW，检查 AW 层特性和环流的时间平均、平均季节周期和年际变化。AW 激增，以平均 AW 层潜在温度和 AW 层厚度的快速增加为标志，在进入状态估计两年后开始，并以 1-2 厘米/秒的速度沿边界流路径穿越北冰洋。浪涌还改变了 AW 环流，包括沿罗蒙诺索夫海岭的水流方向逆转，导致从 2010 年到状态估计期结束的新的准稳定 AW 环流。后一时期的时间平均 AW 环流表明，大量 AW 散布在罗蒙诺索夫海脊上，而不是沿着海脊直接返回弗拉姆海峡。北冰洋内时间平均 ASTE R1 翻转环流的三层描述表明，更多的 AW 转化为更冷、更新鲜的表层水，而不是转化为深水和底水（1.2 Sv 对 0.4 Sv）。ASTE R1 还表现出在研究期间 AW 的体积以 1.4 Sv 的速率增加，而深水和底水体积的减少几乎是补偿性的。