Newly identified climatically and environmentally significant high-latitude dust sources
Newly identified climatically and environmentally significant high-latitude dust sources
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DOI：
10.5194/acp-22-11889-2022
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发表时间：
2022-09-14
影响因子：
6.3
通讯作者：
Vimic, Ana Vukovic
中科院分区：
文献类型：
--
作者：
Meinander, Outi;Dagsson-Waldhauserova, Pavla;Vimic, Ana Vukovic
来自高纬度地区的沙尘颗粒作为短期气候强迫因子、空气污染物和营养源，对气候和环境具有潜在的巨大的局部、区域和全球意义。确定本地沙尘源的位置及其排放，传输和沉积过程是重要的，了解高纬度灰尘（HLD）对地球系统的多重影响。在这里，我们确定，描述和量化的源强度（SI）值，这表明土壤表面的粉尘排放的潜力缩放到值0至1关于全球最好的生产源，使用全球沙尘暴源底图（G-SDS-SBM）。这包括我们收集的北方（阿拉斯加、加拿大、丹麦、格陵兰岛、冰岛、斯瓦尔巴群岛、瑞典和俄罗斯）和南方（南极洲和巴塔哥尼亚）高纬度地区的64个HLD源。大多数HLD来源的活动显示出季节性特征。高纬度地区沙尘排放潜力高（SI >= 0.5）、极高（SI >= 0.7）和最高（SI >= 0.9）的陆地面积分别为> 167万km（2）、> 56万km（2）和> 24万km（2）。在北极HLD区（≥ 60 ° N），SI ≥ 0.5的陆地面积占5.5%（1035059 km 2），SI ≥ 0.7的陆地面积占2.3%（440804 km 2），SI ≥ 0.9的陆地面积占1.1%（208701 km 2）。北方HLD区的最小SI值要小3个数量级左右，说明该地区的沙尘来源对天气条件有很大的依赖性。我们的空间尘源分布分析模拟结果显示，有证据支持北方HLD带，定义为北纬50度以北的区域，其中“过渡HLD源区”在欧亚大陆北纬50-58度和加拿大北纬50-55度延伸，“冷HLD源区”包括欧亚大陆北纬60度以北和加拿大北纬58度以北的区域，目前，除了不列颠哥伦比亚省之外，在HLD和低纬度尘埃（LLD）尘埃带之间存在“无尘源”区域。利用全球大气传输模式SILAM，我们估计全球沙尘排放的1.0%来自高纬度地区。在冰雪覆盖的北极地区，大约57%的灰尘沉积来自HLD源。在HLD南部地区，土壤表面条件全年都有利于粉尘排放。气候变化可导致积雪持续时间减少，冰川退缩，干旱，热浪强度和频率增加，导致有利于沙尘排放的表土条件频率增加，这增加了沙尘暴的概率。我们的研究为改善HLD在模型中的代表性以及监测，量化和评估HLD的环境和气候意义迈出了一步。
Dust particles from high latitudes have a potentially large local, regional, and global significance to climate and the environment as short-lived climate forcers, air pollutants, and nutrient sources. Identifying the locations of local dust sources and their emission, transport, and deposition processes is important for understanding the multiple impacts of high-latitude dust (HLD) on the Earth's systems. Here, we identify, describe, and quantify the source intensity (SI) values, which show the potential of soil surfaces for dust emission scaled to values 0 to 1 concerning globally best productive sources, using the Global Sand and Dust Storms Source Base Map (G-SDS-SBM). This includes 64 HLD sources in our collection for the northern (Alaska, Canada, Denmark, Greenland, Iceland, Svalbard, Sweden, and Russia) and southern (Antarctica and Patagonia) high latitudes. Activity from most of these HLD sources shows seasonal character. It is estimated that high-latitude land areas with higher (SI >= 0.5), very high (SI >= 0.7), and the highest potential (SI >= 0.9) for dust emission cover > 1670000 km(2), > 560000 km(2), and > 240000 km(2), respectively. In the Arctic HLD region (>= 60 degrees N), land area with SI >= 0.5 is 5.5% (1 035 059 km(2)), area with SI >= 0.7 is 2.3% (440 804 km(2)), and area with SI >= 0.9 is 1.1% (208 701 km(2)). Minimum SI values in the northern HLD region are about 3 orders of magnitude smaller, indicating that the dust sources of this region greatly depend on weather conditions. Our spatial dust source distribution analysis modeling results showed evidence supporting a northern HLD belt, defined as the area north of 50 degrees N, with a "transitional HLD-source area" extending at latitudes 50-58 degrees N in Eurasia and 50-55 degrees N in Canada and a "cold HLD-source area" including areas north of 60 degrees N in Eurasia and north of 58 degrees N in Canada, with currently "no dust source" area between the HLD and low-latitude dust (LLD) dust belt, except for British Columbia. Using the global atmospheric transport model SILAM, we estimated that 1.0% of the global dust emission originated from the high-latitude regions. About 57% of the dust deposition in snow- and ice-covered Arctic regions was from HLD sources. In the southern HLD region, soil surface conditions are favorable for dust emission during the whole year. Climate change can cause a decrease in the duration of snow cover, retreat of glaciers, and an increase in drought, heatwave intensity, and frequency, leading to the increasing frequency of topsoil conditions favorable for dust emission, which increases the probability of dust storms. Our study provides a step forward to improve the representation of HLD in models and to monitor, quantify, and assess the environmental and climate significance of HLD.