Data from repeat hydrographic surveys over the 25‐year period 1993 to 2017, together with satellite altimetry data, are used to quantify the temporal and spatial variability of the North Icelandic Irminger Current (NIIC), East Icelandic Current (EIC), and the water masses they advect around northern Iceland. We focus on the warm, salty Atlantic Water (AW) flowing northward through Denmark Strait and the cooler, fresher, denser Atlantic‐origin Overflow Water (AtOW) which has circulated cyclonically around the rim of the Nordic Seas before being advected to the Iceland slope via the EIC. The absolute geostrophic velocities reveal that approximately half of the NIIC recirculates just north of Denmark Strait, while the remaining half merges with the EIC to form a single current that extends to the northeast of Iceland, with no further loss in transport of either component. The AW percentage decreases by 75% over this distance, while the AtOW percentage is higher than that of the AW in the merged current. The NIIC and merged NIIC‐EIC are found to be baroclinically unstable, which causes the flow to become increasingly barotropic as it progresses around Iceland. A seasonal accounting of the water masses within the currents indicates that only in springtime is the NIIC dominated by AW inflow north of Denmark Strait. Overall, there is considerably more seasonal and along‐stream variability in the properties of the flow prior to the merging of the NIIC and EIC. Over the 25‐year time period, the NIIC became warmer, saltier, and increased in volume transport.

中文翻译：

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冰岛北部的北爱明格洋流和东冰岛的洋流的沿流，季节性和年际变化

从1993年至2017年的25年期间重复进行的水文勘测数据与卫星测高仪数据一起用于量化北冰岛艾明格潮流（NIIC），东冰岛潮流（EIC）和水的时间和空间变异性他们在冰岛北部大批拥护群众。我们关注的是温暖咸咸的大西洋水（AW）向北流经丹麦海峡，以及凉爽，新鲜，密集的大西洋源头溢水（AtOW），该水在北欧海域周围绕圈地循环，然后被平流到冰岛斜坡。通过EIC。绝对的地转速度表明，NIIC约有一半在丹麦海峡以北再循环，而其余一半与EIC合并形成了一条单一的洋流，延伸到冰岛东北部，不会进一步损失任何一种成分的运输。在此距离上，AW百分比降低了75％，而AtOW百分比高于合并电流中的AW百分比。NIIC和合并后的NIIC-EIC被发现是斜压不稳定的，这导致该流量随着在冰岛周围的发展而变得越来越正压。对水流中水团的季节性核算表明，仅在春季，NIIC才受到丹麦海峡以北的AW流入的支配。总体而言，在合并NIIC和EIC之前，流量属性的季节性和沿河变化较大。在25年的时间里，NIIC变得更温暖，更咸，并且运输量增加了。而AtOW百分比高于合并电流中的AW百分比。NIIC和合并后的NIIC-EIC被发现是斜压不稳定的，这导致该流量随着在冰岛周围的发展而变得越来越正压。对水流中水团的季节性核算表明，仅在春季，NIIC才受到丹麦海峡以北的AW流入的支配。总体而言，在合并NIIC和EIC之前，流量属性的季节性和沿河变化较大。在25年的时间里，NIIC变得更温暖，更咸，并且运输量增加了。而AtOW百分比高于合并电流中的AW百分比。NIIC和合并后的NIIC-EIC被发现是斜压不稳定的，这导致该流量随着在冰岛周围的发展而变得越来越正压。对水流中水团的季节性核算表明，仅在春季，NIIC才受到丹麦海峡以北的AW流入的支配。总体而言，在合并NIIC和EIC之前，流量属性的季节性和沿河变化较大。在25年的时间里，NIIC变得更温暖，更咸，并且运输量增加了。对水流中水团的季节性核算表明，仅在春季，NIIC才受到丹麦海峡以北的AW流入的支配。总体而言，在合并NIIC和EIC之前，流量属性的季节性和沿河变化较大。在25年的时间里，NIIC变得更温暖，更咸，并且运输量增加了。对水流中水团的季节性核算表明，仅在春季，NIIC才受到丹麦海峡以北的AW流入的支配。总体而言，在合并NIIC和EIC之前，流量属性的季节性和沿河变化较大。在25年的时间里，NIIC变得更温暖，更咸，并且运输量增加了。