Active layer thickening and controls on interannual variability in the Nordic Arctic compared to the circum‐Arctic
Active layer thickening and controls on interannual variability in the Nordic Arctic compared to the circum‐Arctic
复制标题
与环北极相比，北欧北极的活动层增厚和对年际变化的控制
DOI：
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发表时间：
2020
影响因子：
5
通讯作者：
O. Humlum
中科院分区：
文献类型：
--
作者：
S. Strand;H. Christiansen;M. Johansson;J. Åkerman;O. Humlum
瑞典北方、格陵兰东北部和斯瓦尔巴群岛中部的活动层探测表明，自1978年、1996年和2000年分别在这些地点建立活动层监测站以来，通过长期、连续的观测，在环极活动层监测站（CALM）发生了活动层增厚。研究区的平均活动层厚度（ALT），这是由网站的地貌和气候解释呈现出反向的纬度梯度。具体而言，斯瓦尔巴群岛的海洋性气候更强，因此是研究区域中最厚的活动层（平均ALT = 99厘米，2000-2018年）。瑞典北方场地的活动层最薄，因为它主要局限于表层泥炭。ALT的年际变化在整个北欧北极地区并不同步，但同一地区的研究地点对当地气象的反应相似。在瑞典和格陵兰，ALT与解冻天数呈正相关，在其他北极地区也观察到了这一点。然而，斯瓦尔巴特群岛的ALT与冰冻度日相关，那里的海洋性北极气候导致冬季气温相对较高且变化不定。邻近地点年ALT的差异归因于积雪和地貌的差异。从2000年到2018年，北欧北极CALM探测站点的活动层增厚的平均速率为0.5厘米/年。北欧北极CALM数据库站点的平均速率为1厘米/年，具有显著趋势，其中包括钻孔和探测站点。这一范围与2000年至2018年的环北极平均值0.8厘米/年一致。
Active layer probing in northern Sweden, northeast Greenland, and central Svalbard indicates active layer thickening has occurred at Circumpolar Active Layer Monitoring (CALM) sites with long‐term, continuous observations, since the sites were established at these locations in 1978, 1996, and 2000, respectively. The study areas exhibit a reverse latitudinal gradient in average active layer thickness (ALT), which is explained by site geomorphology and climate. Specifically, Svalbard has a more maritime climate and thus the thickest active layer of the study areas (average ALT = 99 cm, 2000–2018). The active layer is thinnest at the northern Sweden sites because it is primarily confined to superficial peat. Interannual variability in ALT is not synchronous across this Nordic Arctic region, but study sites in the same area respond similarly to local meteorology. ALT correlates positively with thawing degree days in Sweden and Greenland, as has been observed in other Arctic regions. However, ALT in Svalbard correlates with freezing degree days, where the maritime Arctic climate results in relatively high and variable winter air temperatures. The difference in annual ALT at adjacent sites is attributed to differences in snow cover and geomorphology. From 2000 to 2018, the average rate of active layer thickening at the Nordic Arctic CALM probing sites was 0.5 cm/yr. The average rate was 1 cm/yr for Nordic Arctic CALM database sites with significant trends, which includes a borehole in addition to probing sites. This range is in line with the circum‐Arctic average of 0.8 cm/yr from 2000 to 2018.
末次间冰期期间，大西洋水通过北极门户（弗拉姆海峡）进行热传递
影响因子：
3.9
作者：
Zhuravleva;Spielhagen
通讯作者：
Spielhagen