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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 ∘ 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 ∘ N, with a "transitional HLD-source area" extending at latitudes 50–58 ∘ N in Eurasia and 50–55 ∘ N in Canada and a "cold HLD-source area" including areas north of 60 ∘ N in Eurasia and north of 58 ∘ 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. [ABSTRACT FROM AUTHOR]

Direct measurements of glacier hydrological processes are usually restricted to short periods and a limited number of sites due to logistical, financial, and meteorological constraints. As a result, the indirect study of glacier hydrology through remote sensing has gained traction while the accessibility of high-resolution publicly available remote sensing data has also increased. By quantifying the areal extents of key dynamic features of a tidewater glacier (i.e. the evolution of sea ice, supraglacial lakes, meltwater plumes) as proxies of its hydrological cycle using Sentinel-2 observations, a simple alternative amidst the outlined logistical constraints is potentially available. Here we demonstrate the usefulness of Sentinel-2 satellite images as a simple and accessible tool with high temporal coverage for studying glacier hydrology. To make this case for the Nordenskiöld tidewater glacier, the evolution of its supraglacial hydrological system and respective meltwater plumes areal extents were monitored for the 2016-2020 melting seasons. Hydrological connectivity of supra- and subglacial systems and the resulting meltwater plumes are illustrated. Meltwater is stored on the glacier surface at the beginning of the melt season (June) which is observed through the filling of the supraglacial lakes. The stored meltwater is later released (June/July), probably through englacial conduits and moulins, and consequently reaches the subglacial drainage system. The resulting occurrence of meltwater plumes clearly indicates the latter in Adolfbukta at the glacier terminus. This signals the transport of significant volumes of water in contact with the glacier bed. The meltwater plume activity peaks during late July, and its appearance continues until mid-September. The duration of the glacier melt season is reflected through the filling of supraglacial lakes and later in the appearance of meltwater plumes. The temporal pattern of the hydrologic processes is relatively uniform during the study period, contrasting the large variability of sea ice cover duration. The observed behavior of Nordenskiöld's supraglacial lakes is in good agreement with similar tidewater glaciers in Svalbard. [ABSTRACT FROM AUTHOR]

Dust particles emitted from high latitudes (> 50 °N and > 40 °S, including Arctic as a subregion > 60 °N), have a potentially large local, regional, and global significance to climate and environment as short-lived climate forcers, air pollutants and nutrient sources. To understand the multiple impacts of the High Latitude Dust (HLD) on the Earth systems, it is foremost to identify the geographic locations and characteristics of local dust sources. Here, we identify, describe, and quantify the Source Intensity (SI) values using the Global Sand and Dust Storms Source Base Map (G-SDS-SBM), for sixty-four HLD sources included in our collection in the Northern (Alaska, Canada, Denmark, Greenland, Iceland, Svalbard, Sweden, and Russia) and Southern (Antarctica and Patagonia) high latitudes. Activity from most of these HLD dust sources show seasonal character. The environmental and climatic effects of dust on clouds and climatic feedbacks, atmospheric chemistry, marine environment, and cryosphere-atmosphere feedbacks at high latitudes are discussed, and regional-scale modelling of dust atmospheric transport from potential Arctic dust sources is demonstrated. It is estimated that high latitude land area with higher (SI>0.5), very high (SI>0.7) and the highest potential (SI>0.9) for dust emission cover >1 670 000 km2,>560 000 km2, and >240 000 km2, respectively. In the Arctic HLD region, land area with SI>0.5 is 5.5 % (1 035 059 km2), area with SI>0.7 is 2.3 % (440 804 km2), and with SI>0.9 it is 1.1 % (208 701 km2). Minimum SI values in the north HLD region are about three orders of magnitude smaller, indicating that the dust sources of this region are highly dependable on weather conditions. In the south HLD region, soil surface conditions are favourable for dust emission during the whole year. Climate change can cause decrease of snow cover duration, retrieval of glaciers, permafrost thaw, and increase of drought and heat waves intensity and frequency, which all lead to the increasing frequency of topsoil conditions favourable for dust emission and thereby increasing probability for 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 in the future. [ABSTRACT FROM AUTHOR]