We studied the water age and transport of passive tracers in the Archipelago Sea, Baltic Sea, using the COHERENS 3D hydrodynamic model and the OpenDrift Lagrangian particle model. The mean water age, which was calculated with COHERENS over a period of 6 years, varied between 1 and 3 months in the outer archipelago and between 3 and 6 months in the middle archipelago. The water age was highest in the inner archipelago, up to 7 months. As the density stratification is weak in large parts of this area, except for the seasonal thermocline, significant differences in the water age between the surface and bottom layers were seen only in the river mouths and in the deep channels of the middle archipelago. The Lagrangian particle simulations showed that the middle archipelago is more open towards the north than south. From the northern boundary, the Bothnian Sea, the largest transport to the middle archipelago occurred with NW winds. Due to the geometry and density of the islands in the area, the prevailing wind direction, SW, alone is not optimal for transporting tracer particles to the middle archipelago. From the southern boundary, the Baltic Proper, transport to the middle archipelago occurred mainly with SE winds and during events when the wind direction shifted from SW to SE or vice versa. The transport further into the inner archipelago was limited to only a few cases, indicating that the inner archipelago is fairly sheltered from transport from the outer archipelago.

我们使用COHERENS 3D流体动力模型和OpenDrift拉格朗日粒子模型研究了波罗的海群岛海中被动示踪剂的水龄和运输。用COHERENS计算的6年内的平均水龄在外群岛1到3个月之间，在中群岛3到6个月之间变化。内群岛的水龄最高，长达7个月。由于该地区的大部分地区的密度分层很弱，除了季节性的温跃层以外，仅在河口和中群岛的深水沟中才发现表层和底层之间水年龄的显着差异。拉格朗日粒子模拟显示，中群岛向北比南向开放。从北部边界 西北海最大的运输是博特尼亚海，是西北风。由于该区域中岛屿的几何形状和密度，盛行的风向SW并不是将示踪剂颗粒运输到中群岛的最佳选择。从南部边界波罗的海适当地，向中群岛的运输主要发生于东南风，并且在风向从西南偏南或相反时发生。进一步进入内群岛的运输仅限于少数情况，这表明该内群岛相当不受外群岛的运输。仅将示踪剂颗粒运输到中群岛并不是最佳选择。从南部边界波罗的海适当地，向中群岛的运输主要发生于东南风，并且在风向从西南偏南或相反时发生。进一步进入内群岛的运输仅限于少数情况，这表明该内群岛相当不受外群岛的运输。仅将示踪剂颗粒运输到中群岛并不是最佳选择。从南部边界波罗的海适当地，向中群岛的运输主要发生于东南风，并且在风向从西南偏南或相反时发生。进一步进入内群岛的运输仅限于少数情况，这表明该内群岛相当不受外群岛的运输。