scholarly journals Newly identified climatically and environmentally significant high latitude dust sources

2021 ◽  
Author(s):  
Outi Meinander ◽  
Pavla Dagsson-Waldhauserova ◽  
Pavel Amosov ◽  
Elena Aseyeva ◽  
Cliff Atkins ◽  
...  
Keyword(s):  
High Latitude ◽  
Heat Waves ◽  
Regional Scale ◽  
Dust Emission ◽  
Dust Storms ◽  
The Arctic ◽  
Dust Particles ◽  
High Latitudes ◽  
Land Area ◽  
Dust Sources

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.

scholarly journals Simulation of a severe dust storm with different dust emission schemes

2019 ◽  
Vol 99 ◽  
pp. 02013 ◽  
Author(s):  
Nasim Hossein Hamzeh ◽  
Sara Karami ◽  
Abbas Ranjbar
Keyword(s):  
Middle East ◽  
Land Surface ◽  
Regional Scale ◽  
Dust Emission ◽  
High Sensitivity ◽  
Surface Concentration ◽  
Dust Storms ◽  
Dust Particles ◽  
Dust Transport ◽  
Prediction And Simulation

Dust storms are natural hazards and affect many countries of the world especially the Middle East. So in order to prevent dustdamages, to a certain extent, dust prediction and simulation should be deemed vital. For this purpose, regional-scale simulations are compared in this study, by means of WRF-Chem using five emission schemes. Based on the model outputs, satellite imagery, and backtrajectory analysis, it is shown that the dust particles transfer from Iran into Iraq. Furthermore, over Ilam province (south-west of Iran), the comparison of the surface concentration from different model outputs shows the results depend on the considered dust emission scheme. In general, it can be stated that choosing different dust emission schemes has a significant effect on the output of the model. Shao schemes have high sensitivity to the land surface data and the low resolution of this data in the Middle East causes some errors in dust flux simulation in the region. AFWA and GOCART schemes show more accurate results in the dust transport in the whole area compared to Shao schemes in the presented case study.

High Latitude Dust: contemporary emissions and geomorphic interactions

2021 ◽  
Author(s):  
Joanna Bullard
Keyword(s):  
Remote Sensing ◽  
Environmental Change ◽  
High Latitude ◽  
Cold Climate ◽  
Sediment Supply ◽  
Future Research ◽  
Similar Proportion ◽  
High Latitudes ◽  
Dust Emissions ◽  
Dust Sources

<div> <p>The world’s largest contemporary dust sources are in low-lying, hot, arid regions, however the processes of dust production and emission also operate in cold climate regions at high latitudes and altitudes.  This lecture focuses on contemporary dust emissions originating from the high latitudes (≥50°N and ≥40°S) and explores three themes before setting out an integrated agenda for future research.  The first theme considers how much dust originates from the high latitudes and methods for determining this.  Estimates from field studies, remote sensing and modelling all suggest around 5% of contemporary global dust emissions originate in the high latitudes, a similar proportion to that from the USA (excluding Alaska) or Australia.  This estimate is a proportion of a highly uncertain figure as quantification of dust emissions from Eurasian high latitudes is limited, and the contribution of local and regional emissions (from any latitude) to the global total is thought to be considerably under-estimated.  Emissions are particularly likely to be under-estimated where dust sources are topographically constrained, and where cold climates reduce vertical mixing of dust plumes restricting the altitudes to which the dust can rise, because both these characteristics present particular challenges for modelling and remote sensing approaches. The second theme considers the drivers of contemporary high latitude dust emissions that reflect complex interactions among sediment supply, sediment availability and transport capacity across different geomorphic sub-systems.  These interactions determine the magnitude, frequency and timing of dust emissions at a range of time scales (diurnal, seasonal, decadal) but both the drivers and response can be nonlinear and hard to predict.  The third and final theme explores the importance of high latitude dust cycling for facilitating cross-boundary material fluxes and its impact in the atmosphere, cryosphere, and terrestrial and marine ecosystems.  This is influenced not only by the quantity and timing of dust emissions but also by dust properties such as particle-size and geochemistry.  Landscape sensitivity, spatial environmental transitions and temporal environmental change are highlighted for their importance in determining how the interactions among drivers and cycles are likely to change in response to future environmental change.</p> </div>

scholarly journals Upper tropospheric water vapour variability at high latitudes – Part 1: Influence of the annular modes

2015 ◽  
Vol 15 (16) ◽  
pp. 22291-22329 ◽  
Author(s):  
C. E. Sioris ◽  
J. Zou ◽  
D. A. Plummer ◽  
C. D. Boone ◽  
C. T. McElroy ◽  
...  
Keyword(s):  
Water Vapour ◽  
Atmospheric Chemistry ◽  
High Latitude ◽  
Lower Stratosphere ◽  
Southern Annular Mode ◽  
The Arctic ◽  
Boreal Winter ◽  
High Latitudes ◽  
Annular Mode ◽  
Annular Modes

Abstract. Seasonal and monthly zonal medians of water vapour in the upper troposphere and lower stratosphere (UTLS) are calculated for both Atmospheric Chemistry Experiment (ACE) instruments for the northern and southern high-latitude regions (60–90 and 60–90° S). Chosen for the purpose of observing high-latitude processes, the ACE orbit provides sampling of both regions in eight of 12 months of the year, with coverage in all seasons. The ACE water vapour sensors, namely MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) and the Fourier Transform Spectrometer (ACE-FTS) are currently the only satellite instruments that can probe from the lower stratosphere down to the mid-troposphere to study the vertical profile of the response of UTLS water vapour to the annular modes. The Arctic oscillation (AO), also known as the northern annular mode (NAM), explains 64 % (r = −0.80) of the monthly variability in water vapour at northern high-latitudes observed by ACE-MAESTRO between 5 and 7 km using only winter months (January to March 2004–2013). Using a seasonal timestep and all seasons, 45 % of the variability is explained by the AO at 6.5 ± 0.5 km, similar to the 46 % value obtained for southern high latitudes at 7.5 ± 0.5 km explained by the Antarctic oscillation or southern annular mode (SAM). A large negative AO event in March 2013 produced the largest relative water vapour anomaly at 5.5 km (+70 %) over the ACE record. A similarly large event in the 2010 boreal winter, which was the largest negative AO event in the record (1950–2015), led to > 50 % increases in water vapour observed by MAESTRO and ACE-FTS at 7.5 km.

scholarly journals Quantification of iron-rich volcanogenic dust emissions and deposition over the ocean from Icelandic dust sources

2014 ◽  
Vol 11 (23) ◽  
pp. 6623-6632 ◽  
Author(s):  
O. Arnalds ◽  
H. Olafsson ◽  
P. Dagsson-Waldhauserova
Keyword(s):  
Large Scale ◽  
Dust Emission ◽  
Dust Storms ◽  
Dust Event ◽  
Dust Deposition ◽  
Dust Emissions ◽  
Dust Sources ◽  
Basaltic Composition ◽  
Limiting Nutrient ◽  
Dust Events

Abstract. Iceland has extremely active dust sources that result in large-scale emissions and deposition on land and at sea. The dust has a volcanogenic origin of basaltic composition with about 10% Fe content. We used two independent methods to quantify dust emission from Iceland and dust deposition at sea. Firstly, the aerial extent (map) of deposition on land was extended to ocean areas around Iceland. Secondly, surveys of the number of dust events over the past decades and calculations of emissions and sea deposition for the dust storms were made. The results show that total emissions range from 30.5 (dust-event-based calculation) to 40.1 million t yr−1 (map calculation), which places Iceland among the most active dust sources on Earth. Ocean deposition ranges between 5.5 (dust event calculations) and 13.8 million tons (map calculation). Calculated iron deposition from Icelandic dust ranges between 0.567 and 1.4 million tons, which are distributed over wide areas (>370 000 km2) and consist of fine reactive volcanic materials. The paper provides the first quantitative estimate of total dust emissions and oceanic deposition from Iceland. Iron is a limiting nutrient for primary production in the oceans around Iceland, and the dust is likely to affect Fe levels in Icelandic ocean waters.

Human Influences on Changes in the Temperature Seasonality in Mid- to High-Latitude Land Areas

2015 ◽  
Vol 28 (15) ◽  
pp. 5908-5921 ◽  
Author(s):  
Cheng Qian ◽  
Xuebin Zhang
Keyword(s):  
Annual Cycle ◽  
High Latitude ◽  
Climate Models ◽  
Regional Scale ◽  
Coupled Model ◽  
Surface Air Temperature ◽  
High Latitudes ◽  
Time Pattern ◽  
Detection And Attribution ◽  
Temperature Seasonality

Abstract The annual cycle is the largest variability for many climate variables outside the tropics. Whether human activities have affected the annual cycle at the regional scale is unclear. In this study, long-term changes in the amplitude of surface air temperature annual cycle in the observations are compared with those simulated by the climate models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5). Different spatial domains ranging from hemispheric to subcontinental scales in mid- to high-latitude land areas for the period 1950–2005 are considered. Both the optimal fingerprinting and a nonoptimal detection and attribution technique are used. The results show that the space–time pattern of model-simulated responses to the combined effect of anthropogenic and natural forcings is consistent with the observed changes. In particular, models capture not only the decrease in the temperature seasonality in the northern high latitudes and East Asia, but also the increase in the Mediterranean region. A human influence on the weakening in the temperature seasonality in the Northern Hemisphere is detected, particularly in the high latitudes (50°–70°N) where the influence of the anthropogenic forcing can be separated from that of the natural forcing.

The ice-nucleating efficacy of glacial dust from the Copper River, Alaska

2020 ◽  
Author(s):  
Sarah Barr ◽  
Bethany Wyld ◽  
Natalie Ratcliffe ◽  
Jim McQuaid ◽  
Benjamin Murray
Keyword(s):  
Dust Emission ◽  
Particle Size Analysis ◽  
River Valley ◽  
Dust Storms ◽  
Radiative Properties ◽  
Size Analysis ◽  
Climate Projections ◽  
High Latitudes ◽  
Near Surface ◽  
Field Campaign

<p>Ice nucleating particles (INPs) play an important role in the climate system by influencing cloud radiative properties, cloud lifetime and precipitation. An understanding of the interaction between INPs and clouds is needed in order to improve the accuracy of both climate projections and short term weather forecasts. In the high latitudes the influence of mid and low latitude sources of INPs (such as potassium feldspar from desert dust) is reduced and local sources could be important for ice nucleation. However, there is a scarcity of field observations and many dust sources which could be important sources of INPs have not been quantified. The south coast of Alaska, in particular the Copper River valley in the Valdez-Cordova region, is one such area where there are regular dust storms. These can clearly be seen from satellite imagery, which provides information on the frequency and extent of these outbreaks. In order to investigate the potential importance of the Copper River valley as a source of INPs we undertook a field campaign to collect samples in October 2019. During this campaign size segregated aerosol samples from the near surface (1.5  metre) were collected on to polycarbonate filter substrates using a multistage cascade impactor with 5 size categories in the range <0.25 μm to >2.5 μm. We collected samples during 7 dust emission events over a 10 day period. In addition, samples of dry sediment were collected from the surface. We used the University of Leeds Microlitre Nucleation by Immersed Particle Instrument (μL-NIPI) to quantify the ice nucleating ability of these samples. We also used laser diffraction particle size analysis to determine the surface area of particles to allow the subsequent calculation of ice active surface site density (n<sub>s</sub>). In addition, surface samples were separated in order to isolate the atmospherically relevant fraction (<10 μm) and used to determine the chemical composition of the dust using x-ray diffraction. This, combined with further work such as heat testing, will be used to identify what controls the ice nucleating efficacy in this dust and if there is an active biological contribution.  We will present the results from the field campaign and subsequent analysis. These results show high ice nucleating activity of the samples, comparable to glacial dust from other regions, and highlight the importance of glacial dust as a source of INPs in the high latitudes.</p>

scholarly journals Technical Note: Minerals in dust productive soils – impacts and global distribution

2011 ◽  
Vol 11 (9) ◽  
pp. 26009-26034 ◽  
Author(s):  
S. Nickovic ◽  
A. Vukovic ◽  
M. Vujadinovic ◽  
V. Djurdjevic ◽  
G. Pejanovic
Keyword(s):  
High Resolution ◽  
Mineral Composition ◽  
Atmospheric Transport ◽  
Dust Emission ◽  
Technical Note ◽  
Dust Storms ◽  
Dust Particles ◽  
Atmospheric Conditions ◽  
Airborne Dust ◽  
Aerosol Process

Abstract. Dust storms and associated mineral aerosol transport are mainly driven by meso and synoptic scale atmospheric processes. It is therefore essential that the dust aerosol process and background atmospheric conditions that drive the dust emission and atmospheric transport be represented with sufficiently well resolved spatial and temporal features. Effects of airborne dust interactions with the environment are determent by the mineral composition of dust particles. Fractions of various minerals in the aerosol are determined by the mineral composition of arid soils, therefore high-resolution specification of mineral and physical properties of dust sources is needed as well. Most current dust atmospheric models simulate/predict the evolution of dust concentration but in most cases they do not consider fractions of minerals in dust. Accumulated knowledge on impacts of mineral composition in dust on weather and climate processes emphasizes the importance of considering minerals in modelling systems. Following such needs, in this study we developed a global dataset on mineral composition of potentially dust productive soils. In our study (a) we mapped mineral data into a high-resolution 30-s grid, (b) we included mineral carrying soil types in dust productive regions that were not considered in previous studies, and (c) included phosphorus having in mind their importance for terrestrial and marine nutrition processes.

scholarly journals Iceland is an episodic source of atmospheric ice-nucleating particles relevant for mixed-phase clouds

2020 ◽  
Vol 6 (26) ◽  
pp. eaba8137 ◽  
Author(s):  
A. Sanchez-Marroquin ◽  
O. Arnalds ◽  
K. J. Baustian-Dorsi ◽  
J. Browse ◽  
P. Dagsson-Waldhauserova ◽  
...  
Keyword(s):  
High Latitude ◽  
Active Site ◽  
Climate Feedback ◽  
High Latitudes ◽  
Density Measurements ◽  
Dust Emissions ◽  
Aerosol Model ◽  
Site Density ◽  
Dust Sources ◽  
Mixed Phase Clouds

Ice-nucleating particles (INPs) have the potential to remove much of the liquid water in climatically important mid- to high-latitude shallow supercooled clouds, markedly reducing their albedo. The INP sources at these latitudes are very poorly defined, but it is known that there are substantial dust sources across the high latitudes, such as Iceland. Here, we show that Icelandic dust emissions are sporadically an important source of INPs at mid to high latitudes by combining ice-nucleating active site density measurements of aircraft-collected Icelandic dust samples with a global aerosol model. Because Iceland is only one of many high-latitude dust sources, we anticipate that the combined effect of all these sources may strongly contribute to the INP population in the mid- and high-latitude northern hemisphere. This is important because these emissions are directly relevant for the cloud-phase climate feedback and because high-latitude dust emissions are expected to increase in a warmer climate.

A comparative evaluation of water uptake on several mineral dust sources

2010 ◽  
Vol 7 (2) ◽  
pp. 162 ◽  
Author(s):  
Juan G. Navea ◽  
Haihan Chen ◽  
Min Huang ◽  
Gregory R. Carmichel ◽  
Vicki H. Grassian
Keyword(s):  
Chemical Composition ◽  
Relative Humidity ◽  
Dust Particle ◽  
Water Uptake ◽  
Mineral Dust ◽  
Dust Storms ◽  
Dust Aerosol ◽  
Dust Particles ◽  
Particle Interactions ◽  
Dust Sources

Environmental context. Dust particles produced from wind blown soils are of global significance as these dust particles not only impact visibility, as evident in the recent 2009 Australian dust storm, but also atmospheric chemistry, climate and biogeochemical cycles. The amount of water vapour in the atmosphere (relative humidity) can play a role in these global processes yet there are few studies and little quantitative data on water-dust particle interactions. The focus of this research is on quantifying water-dust particle interactions for several dust sources including Asia and Africa where dust storms are most prevalent. Abstract. Mineral dust aerosol provides a reactive surface in the troposphere. The reactivity of mineral dust depends on the source region as chemical composition and mineralogy of the aerosol affects its interaction with atmospheric gases. Furthermore, the impact of mineral dust aerosol in atmospheric processes and climate is a function of relative humidity. In this study, we have investigated water uptake of complex dust samples. In particular, water uptake as a function of relative humidity has been measured on three different dust sources that have been characterised using a variety of bulk and surface techniques. For these well-characterised dust samples, it is shown that although there are variations in chemical composition and mineralogy, on a per mass basis, water uptake capacities for the three dusts are very similar and are comparable to single component clay samples. These results suggest that the measured uptake of water of these bulk samples is dominated by the clay component.

scholarly journals Identification of dust sources and hotspots in East Asia during 2000–2015: implications for numerical modeling and forecasting

2016 ◽  
Author(s):  
Xuelei Zhang ◽  
Daniel Q. Tong ◽  
Guangjian Wu ◽  
Xin Wang ◽  
Aijun Xiu ◽  
...  
Keyword(s):  
East Asia ◽  
Anthropogenic Activities ◽  
Regional Scale ◽  
Far East ◽  
The Arctic ◽  
Taklimakan Desert ◽  
Detailed Knowledge ◽  
Dust Sources ◽  
Dust Events ◽  
Dust Modeling

Abstract. More detailed knowledge regarding recent variations in the characteristics of East Asian dust events and dust sources can effectively improve regional dust modeling and forecasts. Here we reassess the accuracy of previous predictions of trends in dust variations in East Asia, and establish a relatively detailed inventory of dust events based on satellite observations from 2000 to 2015. More than 2000 Moderate Resolution Imaging Spectroradiometer (MODIS) images of 462 sand and dust storm events over East Asia were collected and analyzed, and individual events were tracked back to their sources through a combination of color RGB images, brightness temperature difference, and trajectory simulations using the HYSPLIT model. Decreased dust event frequency in spring but increased frequencies in summer and autumn were observed. Of the identified dust emission sources, sandy lands and lake beds, rather than the sandy and stone deserts, were found to be the dominant dust sources. Dust hotspots in East Asia are mainly dry lake and river beds and alluvial fans. Recent changes in land use associated with anthropogenic activities (mining and excessive exploitation of water resources) are revealed as one of the major factors leading to an expansion of dust source regions, especially for the northeastern part of Taklimakan desert. Trajectory analysis also shows that dust can even be transported northwards by the Mongolia Cyclone, to the Far East region and even the Arctic Circle, potentially affecting the climate and ecosystem of the Arctic region. Recent physically-based dynamic approaches adopted in dust models reduce the reliance on empirical source functions in dust modeling; however, the validity of down-scaling these schemes to regional scale needs to be further verified with "ground-truth" information as reported here.

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