The Fram Strait is the only deep connection between the Arctic and Atlantic Oceans. The main water and mercury (Hg) fluxes between these oceans occur via the Fram Strait and Barents Sea Opening. Several Hg mass balance studies indicated a net Hg export from the Arctic to the Atlantic Ocean. However, in the absence of Hg measurements in the Fram Strait and Barents Sea Opening, these estimates were based on North Atlantic and central Arctic Ocean data alone. Here, we refine the Arctic total Hg (tHg) and methylated Hg (MeHg) mass budgets using new data acquired during the 2015 GEOTRACES (section GN04) TransArcII cruise in the Barents Sea Opening and the 2016 GEOTRACES (section GN05) GRIFF cruise, which covered the Fram Strait and Northeast Greenland Shelf. Total Hg increased westward along the Fram Strait transect, reaching the highest concentrations on the Northeast Greenland Shelf. Concentrations of tHg averaged 1.29 ± 0.43 pM in the East Greenland Current, while core waters of the West Spitsbergen Current had average values of 0.80 ± 0.26 pM. Using our new data, we estimate that 43 ± 9 Mg y⁻¹ of tHg is transported to the Arctic Ocean in the core of the West Spitsbergen Current, while 54 ± 13 Mg y⁻¹ of tHg is exported from the Arctic Ocean in the East Greenland Current and Recirculated Atlantic Water. This results in a net tHg export of 11 ± 8 Mg y⁻¹via the Fram Strait. We find a shallow MeHg maximum (at 150 m depth) in the East Greenland Current, in agreement to what was reported for the central Arctic Ocean and Canadian Arctic Archipelago. The West Spitsbergen Current is characterized by lower MeHg concentrations and a deeper MeHg maximum, that is located at approximately 1000 m depth. We estimate a net MeHg export of 6 ± 2 Mg y⁻¹ from the Arctic Ocean via the Fram Strait, which is nearly half of the exported tHg. Most of the exported MeHg is in the form of DMHg (2:1 ratio of dimethylmercury to monomethylmercury). Previous studies reported lower MeHg proportions. Our observations show that the Arctic Ocean is producing and exporting MeHg to the Atlantic Ocean. In total, the Arctic Ocean exports about 18 Mg y⁻¹ of tHg to the Nordic Seas and North Atlantic via the Fram Strait and Davis Strait, of which 7.5 Mg y⁻¹ is in the MeHg form.

弗拉姆海峡是北冰洋和大西洋之间的唯一深层连接。这些海洋之间的主要水和汞（Hg）通量通过弗拉姆海峡和巴伦支海开放。几项汞质量平衡研究表明，从北极到大西洋的汞净出口量为净值。但是，在弗拉姆海峡和巴伦支海口没有汞的测量值时，这些估算仅基于北大西洋和北冰洋中部的数据。在这里，我们使用在巴伦支海开口处的2015 GEOTRACES（第GN04节）TransArcII巡洋舰和2016年GEOTRACES（第GN05节）GRIFF巡洋舰期间获得的新数据，完善了北极的总Hg（tHg）和甲基化Hg（MeHg）质量预算。覆盖了弗拉姆海峡和东北格陵兰大陆架。总汞沿弗拉姆海峡横断面向西增加，达到东北格陵兰大陆架上的最高浓度。东格陵兰洋流中的tHg浓度平均为1.29±0.43 pM，西斯匹次卑尔根海流的核心水域平均值为0.80±0.26 pM。使用我们的新数据，我们估算出43±9 Mg y^-1 tHg的tHg被输送到西斯匹次卑尔根流的核心，北冰洋，而54±13 Mg y ^-1 tHg则从北格陵兰的东部格陵兰流和再循环的大西洋水输出。这导致经由弗拉姆海峡的净tHg出口为11±8 Mg y ^-1。我们在东格陵兰洋流中发现了一个浅的MeHg最大值（在150 m深度处），这与北冰洋中部和加拿大北冰洋群岛的报道一致。西斯匹次卑尔根海流的特征是，其MeHg浓度较低，而MeHg的最大值较大，位于约1000 m的深度。我们估计6±2镁y的净出口甲基汞^-1从北冰洋通过弗拉姆海峡（Fram Strait），几乎占出口总汞的一半。大部分出口的MeHg为DMHg形式（二甲基汞与一甲基汞的比例为2：1）。先前的研究报道了较低的MeHg比例。我们的观察结果表明，北冰洋正在生产MeHg，并将其出口到大西洋。总的来说，北冰洋通过弗拉姆海峡和戴维斯海峡向北欧海和北大西洋出口约18 Mg y ^-1的tHg ，其中7.5 Mg y ^-1的MeHg形式。