Abstract. 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 >1 670 000 km2, >560 000 km2, and >240 000 km2, respectively. In the Arctic HLD region (≥60∘ N), 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 area with SI ≥0.9 is 1.1 % (208 701 km2). 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. 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.

Recently, there has been a marked increase in the use of large-volume workings, both in the development of deposits and in the construction of underground chambers for various purposes, transport tunnels, etc.For normal operating conditions, definite parameters of the atmosphere must be maintained; this is associated with the supply of considerable volumes of fresh air and hence with increase in the energy consumption.It is of great practical value to know the velocity field and turbulent viscosity over the volume of the underground chamber, since these factors determine the conditions for the creation of normalized parameters of the mine atmosphere.In most cases, the ventilation of chamber-like workings is calculated analogously to the approach in [i, 2], which permits the analysis of the scattering and entrainment of harmful impurities by ventilation jets, without taking account of inhomogeneities in the velocity field and the turbulent diffusion coefficients.The aim of the present work, a continuation of [3, 4], is to create methods of mathematical modeling of the turbulent ventilation of slot-like chambers and large-volume workings.Existing methods of calculating mine-working ventilation are based on the mean velocity of mine-air motion. At the same time, almost all investigations of mine ventilation in large chambers [2, 3, 5, 6] conclude that the velocity field there is complex, because of the presence of recirculation zones and breakaway flows.It is evident that detailed calculation of the velocity field is required to solve the impurity-transport equations.The fastest and simplest way to find the velocityfield in a chamber-like working of arbitrary form is to construct a mathematical model of the turbulent motion of an incompressible atmosphere [3, 5]. In the simplest two-dimensional case, following [3], the nonsteady NavierStokes and continuity equations, averaged over the time and one coordinate (the chamber height, in the present case) according to the Reynolds rule, can be written in the form 8UOV aU + U.~ + V. a-F =-----a--~where U and V are the components of the mean velocity along the coordinate axes x and y; ~ij is the Reynolds stress; P is the mean pressure; p is the density of the mine atmosphere (assumed constant): t is the time.The expression for the Reynolds stress introduced by Boussinesq for a flow of general form includes the turbulent viscosity, ~t, specification of which permits closure of the system in Eq. (i). A great variety of methods of such closure is known.Four models are realized for the problem of the ventilation of chamber-like workings. A: Simplest ModelConstant turbulent viscosity is assumed.Although this hypothesis is invalid at the axis of the jet flows, it can be used in the recirculation zones and the near-wall flow for approximate calculation of some simple turbulent flows.S. M. Kirov Mining Institute, Academy of Sciences of the USSR, Kazan' Branch, Apatity.

The results of numerical simulation of atmospheric pollution in Apatity are presented with variations in the dusting area of discrete spatially spaced areas selected randomly and the wind flow velocity. CFD modeling in the volumetric formulation was performed using the COMSOL program. To calculate the aerodynamic characteristics, an incompressible fluid approximation was used using the standard ( k -ε) turbulence model. The process of fine dust propagation is modeled by numerical solution of the convective-diffusion impurity transfer equation taking into account the deposition rate. Numerical experiments (with a total number of more than 1,400) were carried out with a variation of the wind flow velocity from 5 to 23 m/s and a dusting area from 2 to 10 ha with a random selection of 20 discrete sites. Dynamic velocity distributions for specific areas of dusting, interval and total spatial distributions of dust pollution (dust particles with a diameter from 0 to 70 microns in increments of 10 microns) are obtained. The peculiarities of the influence on the levels of atmospheric pollution of specific areas of Apatity depending on the location of dusty areas on the surface of the beach of the tailings dump are noted. The calculated levels of atmospheric pollution in the center of Apatity averaged by the number of combinations of dusting sites are analyzed and generalized to functional dependencies. The calculated dependences of the dust concentration on the dusting area at a fixed wind speed are described by linear functions. The dependence of the dust concentration on the wind flow velocity at a fixed dusting area can be approximated by a power function. The generalized functional dependence makes it possible to predict the dust concentration in Apatity depending on the dusting area of randomly selected discrete areas on the surface of the tailings dump and the wind flow velocity. The obtained dependence permits to make a forecast of the critical dusting area at which the level of atmospheric pollution reaches the maximum permissible concentrations, depending on the speed of the wind flow.

Results of evaluation of tailing dumps dust intensityАннотация. На основе анализа существующих подходов по оценке интенсивности пыления (пустыни, хвостохранилища и др.) определен и апробирован круг наиболее приемлемых и общепризнанных методов (зависимость Westphal D. L. et al. и схема DEAD). Представлено описание выбранных подходов. Продемонстрирован переход к определению динамической скорости u * и скорости на высоте +10 м над пылящей поверхностью u 10 , необходимых для выполнения оценок интенсивности пыления. Методический подход реализован на базе двухмерной численной модели аэродинамики атмосферы района "хвостохранилище АНОФ-2 -г. Апатиты". Представлены результаты расчетов и обработки горизонтальной скорости на высоте +10 м над пылящей поверхностью при вариации скорости ветрового потока от 5 до 23 м/с. Приведены результаты обработки графической информации гранулометрического состава отвальных хвостов с поверхности устоявшегося пляжа хвостохранилища АНОФ-2. Выполнен сравнительный анализ и указаны особенности поинтервальной (по размерам песчинок) интенсивности пыления хвостохранилища АНОФ-2 с использованием зависимости Westphal D. L. et al. и схемы DEAD при вариации скорости ветра. Полученные значения интенсивности пыления в нижней части диапазона скорости ветрового потока близки показателю "максимальной удельной сдуваемости пыли", используемому специалистами проектных организаций при разработке документации.Abstract. A set of most acceptable and well-known methods of dust intensity evaluation has been defined and tested (dependence of Westphal D. L. et al. and DEAD scheme) based on the analysis of exiting approaches (deserts, tailing dumps, etc.). The description of the chosen methods has been given. The determination of dynamic velocity u * and velocity at the height of +10 m above the dusting surface u 10 which are necessary to evaluate the dust intensity has been demonstrated. The method is based on two-dimensional numerical model of atmosphere aerodynamics in the area of "tailing dumps of ANOF-2 -the town of Apatity". The study provides calculations of horizontal velocity at the height of +10 m above the dusting surface at the wind speed varying from 5 to 23 m/sec. The work also suggests the results of graphical data processing related to tailing grain size distribution from the surface of the firmly established surface of the tailing dumps of ANOF-2. Comparative analysis has been given and the peculiarities of interval (based on grains sizes) dust intensity of the tailing dumps of ANOF-2 have been shown using the dependence of Westphal D. L. et al. and DEAD scheme within the wind speed range. The received values of dust intensity at the lower range limit are close to the "maximum specific dust off" value which is used by project specialists for documentation development.Ключевые слова: пылящие поверхности, поинтервальная интенсивность пыления, численное моделирование.