scholarly journals Microscale dynamics between dust and microorganisms in alpine snowpack

2021 ◽  
Author(s):  
Alison Thurston ◽  
Zoe Courville ◽  
Lauren Farnsworth ◽  
Ross Lieblappen ◽  
Shelby Rosten ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dust Particles ◽  
Dust Deposition ◽  
Dust Transport ◽  
Source Regions ◽  
Chemical Signatures ◽  
Scale Properties ◽  
Bacteria And Fungi ◽  
The Impact ◽  
Snow Samples

Dust particles carry microbial and chemical signatures from source regions to deposition regions. Dust and its occupying microorganisms are incorporated into, and can alter, snowpack physical properties including snow structure and resultant radiative and mechanical properties that in turn affect larger-scale properties, including surrounding hydrology and maneuverability. Microorganisms attached to deposited dust maintain genetic evidence of source substrates and can be potentially used as bio-sensors. The objective of this study was to investigate the impact of dust-associated microbial deposition on snowpack and microstructure. As part of this effort, we characterized the microbial communities deposited through dust transport, examined dust provenance, and identified the microscale location and fate of dust within a changing snow matrix. We found dust characteristics varied with deposition event and that dust particles were generally embedded in the snow grains, with a small fraction of the dust particles residing on the exterior of the snow matrix. Dust deposition appears to retard expected late season snow grain growth. Both bacteria and fungi were identified in the collected snow samples.

scholarly journals Chemical aging of atmospheric mineral dust during transatlantic transport

2016 ◽  
Author(s):  
Mohamed Abdelkader ◽  
Swen Metzger ◽  
Benedikt Steil ◽  
Klaus Klingmüller ◽  
Holger Tost ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Direct Effect ◽  
Dust Particles ◽  
Hygroscopic Growth ◽  
Aging Effects ◽  
Particle Sedimentation ◽  
Inter Tropical Convergence Zone ◽  
Dust Transport ◽  
Dust Fraction ◽  
The Impact

Abstract. Transatlantic dust transport has many implications for the atmosphere, ocean and climate. We present a modeling study on the impact of the key processes (dust emissions flux, convection and dust aging parameterizations) that control the transatlantic dust transport. Typically, the Inter-Tropical Convergence Zone (ITCZ) acts as a barrier for the meridional dust transport. To characterize the dust outflow over the Atlantic Ocean, we address two regional phenomena: (i) dust interactions with the ITCZ (DIZ) and (ii) the adjacent dust transport over the Atlantic Ocean (DTA). In the DTA zone, the dust loading shows a steep and linear gradient westward over the Atlantic Ocean where particle sedimentation is the dominant removal process, whereas in the DIZ zone cloud interactions and wet deposition predominate. To study the different impacts of aging, we present two case studies that exclude condensation and coagulation, and include dust aging at various levels of complexity. For dust aging, we consider the uptake of inorganic acids on the surface of mineral particles that form salt compounds. Calcium, used as a proxy for the overall chemically reactive dust fraction, drives the dust-related neutralization reactions leading to higher dust aerosol optical depth (AOD). The aged dust particles are transferred to the soluble aerosol modes in the model and are mixed with other species that originate from anthropogenic and natural sources. The neutralization products (salts) take up water vapor from the atmosphere and increase the dust AOD under subsaturated conditions. We define the "direct effect of dust aging" to refer to the increase in AOD as a result of hygroscopic growth. On the other hand, the aged dust is more efficiently removed (wet and dry) because of the increase in particle size and hygroscopicity. This more efficient removal reduces the dust AOD over the DIZ zone. We define this as the "indirect effect of dust aging", complementary to the direct effect that is dominant in the DTA zone. Distinction of the two aging effects helps develop insight into the regional importance of dust–air-pollution interactions.

scholarly journals The Physiological and Microbiological Characteristics of Cement Dust Polluted Soil Around Cement Industry

2021 ◽  
Author(s):  
Kehinde Oluwadamilare Sowunmi
Keyword(s):  
Heavy Metals ◽  
Microbial Population ◽  
Nutrient Status ◽  
Polluted Soil ◽  
Population Diversity ◽  
Cement Industry ◽  
Dust Deposition ◽  
Cement Dust ◽  
Bacteria And Fungi ◽  
The Impact

Abstract A study investigated impact of cement dust pollution from Ewekoro cement industry on soil microbes. pH of the soil ranged from 6.27±0.03- 6.47 and soil moisture content ranged from 15.78±2.52- 9.65±1.16. The levels of heavy metals except Mg, Zn and Na were higher within the factory than in the control. Microbial population diversity increased steadily away from the factory and this variation could be attributed to the impact of pH and heavy metals on microbial population. The lower counts of bacteria compared to fungi may be as a result of the nutrient status of the soil and the bacteria counts in polluted soil were lower than the fungal counts in control soil. The bacteria and fungi was influenced by the cement dust deposition. The study was published in the journal ‘Phenomenon: Microbes and the Cement Industry’.

scholarly journals Impact of the Aral Sea Syndrome - the Aralkum as a Man-Made Dust Source

2019 ◽  
Vol 99 ◽  
pp. 03003
Author(s):  
Christian Opp ◽  
Michael Groll ◽  
Oleg Semenov ◽  
Natalya Vereshagina ◽  
Asia Khamzina
Keyword(s):  
Temporal Dynamics ◽  
Monitoring Program ◽  
Ground Level ◽  
Aral Sea ◽  
Storm Events ◽  
Dust Deposition ◽  
Dust Source ◽  
Dust Transport ◽  
Wind Speeds ◽  
The Impact

Ground based dust monitoring is an important tool for the long-term monitoring of aeolian sediment transport in Central Asia as it provides valuable insights into the spatial and temporal dynamics of dust deposition as well as grants access to the transported material for further analyses. Between 2006 and 2012 such a monitoring was carried out in the Turan lowland to analyze the effects of the newly formed Aralkum. The detected spatial and temporal dust deposition variability was significant and encourages further studies. The dust deposition increased over time, which correlates with a decreasing trend in precipitation, increasing wind speeds and a shift towards northern winds. More than 50% of all dust samples collected exceed the health based deposition threshold and the most intense dust storm events reached ground level deposition rates of up to 150 g/m2 per hour. This study showed the impact of the Aralkum, but also that the Kyzylkum is a far more active dust source. With regard to climate change and an increasing aridity in the region it can be expected that the aeolian dust transport will continue to increase, making a wide-spread monitoring program even more important.

scholarly journals Laboratory investigations of the impact of mineral dust aerosol on cold cloud formation

2010 ◽  
Vol 10 (23) ◽  
pp. 11955-11968 ◽  
Author(s):  
K. A. Koehler ◽  
S. M. Kreidenweis ◽  
P. J. DeMott ◽  
M. D. Petters ◽  
A. J. Prenni ◽  
...  
Keyword(s):  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Dust Aerosol ◽  
Cloud Formation ◽  
Dust Particles ◽  
Source Regions ◽  
Radiative Impacts ◽  
Laboratory Investigations ◽  
Mixed Phase Clouds ◽  
The Impact

Abstract. Dust particles represent a dominant source of particulate matter (by mass) to the atmosphere, and their emission from some source regions has been shown to be transported on regional and hemispherical scales. Dust particles' potential to interact with water vapor in the atmosphere can lead to important radiative impacts on the climate system, both direct and indirect. We have investigated this interaction for several types of dust aerosol, collected from the Southwestern United States and the Saharan region. A continuous flow diffusion chamber was operated to measure the ice nucleation ability of the dust particles in the temperature range of relevance to cirrus and mixed-phase clouds (−65

scholarly journals Recent progress in understanding physical and chemical properties of African and Asian mineral dust

2011 ◽  
Vol 11 (16) ◽  
pp. 8231-8256 ◽  
Author(s):  
P. Formenti ◽  
L. Schütz ◽  
Y. Balkanski ◽  
K. Desboeufs ◽  
M. Ebert ◽  
...  
Keyword(s):  
Field Experiments ◽  
Mineral Dust ◽  
Internal State ◽  
Source Region ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Dust Particles ◽  
Regional Variability ◽  
Source Regions ◽  
The Impact

Abstract. This paper presents a review of recently acquired knowledge on the physico-chemical properties of mineral dust from Africa and Asia based on data presented and discussed during the Third International Dust Workshop, held in Leipzig (Germany) in September 2008. Various regional field experiments have been conducted in the last few years, mostly close to source regions or after short-range transport. Although significant progress has been made in characterising the regional variability of dust properties close to source regions, in particular the mineralogy of iron and the description of particle shape and mixing state, difficulties remain in estimating the range of variability of those properties within one given source region. As consequence, the impact of these parameters on aerosol properties like optical properties, solubility, hygroscopicity, etc. – determining the dust impact on climate – is only partly understood. Long-term datasets in remote regions such as the dust source regions remain a major desideratum. Future work should also focus on the evolution of dust properties during transport. In particular, the prediction of the mineral dust size distribution at emission and their evolution during transport should be considered as a high-priority. From the methodological point of view, a critical assessment and standardisation of the experimental and analytical techniques is highly recommended. Techniques to characterize the internal state of mixing of dust particles, particularly with organic material, should be further developed.

scholarly journals Dust–air pollution dynamics over the eastern Mediterranean

2015 ◽  
Vol 15 (16) ◽  
pp. 9173-9189 ◽  
Author(s):  
M. Abdelkader ◽  
S. Metzger ◽  
R. E. Mamouri ◽  
M. Astitha ◽  
L. Barrie ◽  
...  
Keyword(s):  
Air Pollution ◽  
Eastern Mediterranean ◽  
Tropospheric Chemistry ◽  
Saharan Dust ◽  
Dust Particles ◽  
Back Trajectory ◽  
Dust Deposition ◽  
Dust Transport ◽  
Frontal Systems ◽  
Scavenging Efficiency

Abstract. Interactions of desert dust and air pollution over the eastern Mediterranean (EM) have been studied, focusing on two distinct dust transport events on 22 and 28 September 2011. The atmospheric chemistry–climate model EMAC has been used at about 50 km grid spacing, applying an online dust emission scheme and calcium as a proxy for dust reactivity. EMAC includes a detailed tropospheric chemistry mechanism, aerosol microphysics and thermodynamics schemes to describe dust "aging". The model is evaluated using ground-based observations for aerosol concentrations and aerosol optical depth (AOD) as well as satellite observations. Simulation results and back trajectory analysis show that the development of synoptic disturbances over the EM can enhance dust transport from the Sahara and Arabian deserts in frontal systems that also carry air pollution to the EM. The frontal systems are associated with precipitation that controls the dust removal. Our results show the importance of chemical aging of dust, which increases particle size, dust deposition and scavenging efficiency during transport, overall reducing the lifetime relative to non-aged dust particles. The relatively long travel periods of Saharan dust result in more sustained aging compared to Arabian dust. Sensitivity simulations indicate 3 times more dust deposition of aged relative to pristine dust, which significantly decreases the dust lifetime and loading.

scholarly journals The impact of dust storms on the Arabian Peninsula and the Red Sea

2015 ◽  
Vol 15 (1) ◽  
pp. 199-222 ◽  
Author(s):  
P. Jish Prakash ◽  
G. Stenchikov ◽  
S. Kalenderski ◽  
S. Osipov ◽  
H. Bangalath
Keyword(s):  
United Arab Emirates ◽  
Red Sea ◽  
Arabian Peninsula ◽  
Regional Climate ◽  
Nutrient Balance ◽  
Dust Storms ◽  
Dust Particles ◽  
Dust Deposition ◽  
Large Area ◽  
The Impact

Abstract. Located in the dust belt, the Arabian Peninsula is a major source of atmospheric dust. Frequent dust outbreaks and some 15 to 20 dust storms per year have profound effects on all aspects of human activity and natural processes in this region. To quantify the effect of severe dust events on radiation fluxes and regional climate characteristics, we simulated the storm that occurred from 18 to 20 March 2012 using a regional weather research forecast model fully coupled with the chemistry/aerosol module (WRF–Chem). This storm swept over a remarkably large area affecting the entire Middle East, northeastern Africa, Afghanistan, and Pakistan. It was caused by a southward propagating cold front, and the associated winds activated the dust production in river valleys of the lower Tigris and Euphrates in Iraq; the coastal areas in Kuwait, Iran, and the United Arab Emirates; the Rub al Khali, An Nafud, and Ad Dahna deserts; and along the Red Sea coast on the west side of the Arabian Peninsula. Our simulation results compare well with available ground-based and satellite observations. We estimate the total amount of dust generated by the storm to have reached 94 Mt. Approximately 78% of this dust was deposited within the calculation domain. The Arabian Sea and Persian Gulf received 5.3 Mt and the Red Sea 1.2 Mt of dust. Dust particles bring nutrients to marine ecosystems, which is especially important for the oligotrophic Northern Red Sea. However, their contribution to the nutrient balance in the Red Sea remains largely unknown. By scaling the effect of one storm to the number of dust storms observed annually over the Red Sea, we estimate the annual dust deposition to the Red Sea, associated with major dust storms, to be 6 Mt.

scholarly journals The impact of dust storms on the Arabian Peninsula and the Red Sea

2014 ◽  
Vol 14 (13) ◽  
pp. 19181-19245 ◽  
Author(s):  
P. Jish Prakash ◽  
G. Stenchikov ◽  
S. Kalenderski ◽  
S. Osipov ◽  
H. Bangalath
Keyword(s):  
United Arab Emirates ◽  
Red Sea ◽  
Arabian Peninsula ◽  
Nutrient Balance ◽  
Dust Storms ◽  
Eastern Africa ◽  
Dust Particles ◽  
Dust Deposition ◽  
Large Area ◽  
The Impact

Abstract. Located in the dust belt, the Arabian Peninsula is a major source of atmospheric dust. Frequent dust outbreaks and some 15 to 20 dust storms per year have profound effects on all aspects of human activity and natural processes in this region. To quantify the effect of severe dust events on radiation fluxes and regional climate characteristics, we simulated the storm that occurred on 18–20 March 2012 using a regional weather research forecast model fully coupled with the chemistry/aerosol module (WRF-Chem). This storm swept over a remarkably large area affecting the entire Middle East, North-Eastern Africa, Afghanistan and Pakistan. It was caused by a southward propagating cold front and associated winds activated the dust production in river valleys of the lower Tigris and Euphrates in Iraq, the coastal areas in Kuwait, Iran, and the United Arab Emirates, Rub al Khali, An Nafud and Ad Dahna deserts, and along the Red Sea coast on the west side of the Arabian Peninsula. Our simulation results compare well with available ground-based and satellite observations. The total amount of dust generated by the storm reached 93.76 Mt. About 80% of this amount deposited within the calculation domain. The Arabian Sea and Persian Gulf received 5.3 Mt, and the Red Sea 1.2 Mt. Dust particles bring nutrients to marine ecosystems, which is especially important for the oligothrophic Northern Red Sea. However, their contribution to the nutrient balance in the Red Sea remains largely unknown. By scaling the effect of one storm to the number of dust storms observed annually over the Red Sea, we roughly estimate the annual dust deposition to the Red Sea to be 6 Mt.

scholarly journals Investigations of the impact of natural dust aerosol on cold cloud formation

2010 ◽  
Vol 10 (8) ◽  
pp. 19343-19380 ◽  
Author(s):  
K. A. Koehler ◽  
S. M. Kreidenweis ◽  
P. J. DeMott ◽  
M. D. Petters ◽  
A. J. Prenni ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Diffusion Chamber ◽  
Ice Nucleation ◽  
Dust Aerosol ◽  
Cloud Formation ◽  
Dust Particles ◽  
Source Regions ◽  
Radiative Impacts ◽  
Mixed Phase Clouds ◽  
The Impact

Abstract. Dust particles represent a dominant source of particulate matter (by mass) to the atmosphere, and their emission from some source regions has been shown to be transported on regional and hemispherical scales. Dust particles' potential to interact with water vapor in the atmosphere can lead to important radiative impacts on the climate system, both direct and indirect. We have investigated this interaction for several types of dust aerosol, collected from the Southwestern United States and the Saharan region. A continuous flow diffusion chamber was operated to measure the ice nucleation ability of the dust particles in the temperature range of relevance to cirrus and mixed-phase clouds (−65

scholarly journals Development of a global model of mineral dust aerosol microphysics

2009 ◽  
Vol 9 (7) ◽  
pp. 2441-2458 ◽  
Author(s):  
Y. H. Lee ◽  
K. Chen ◽  
P. J. Adams
Keyword(s):  
Mineral Dust ◽  
Dust Particles ◽  
Base Case ◽  
Dust Source ◽  
Deposition Fluxes ◽  
Surface Mass ◽  
Remote Areas ◽  
Source Regions ◽  
The Impact ◽  
Mass Concentrations

Abstract. A mineral dust module is developed and implemented into the global aerosol microphysics model, GISS-TOMAS. The model is evaluated against long-term measurements of dust surface mass concentrations and deposition fluxes. Predicted mass concentrations and deposition fluxes are in error on average by a factor of 3 and 5, respectively. The comparison shows that the model performs better near the dust source regions but underestimates surface concentrations and deposition fluxes in more remote regions. Including only sites with measured dust concentrations of at least 0.5 μg m−3, the model prediction agrees with observations to within a factor of 2. It was hypothesized that the lifetime of dust, 2.6 days in our base case, is too short and causes the underestimation in remote areas. However, a sensitivity simulation with smaller dust particles and increased lifetime, 3.7 days, does not significantly improve the comparison. These results suggest that the underestimation of mineral dust in remote areas may result from local factors/sources not well described by the global dust source function used here or the GCM meteorology. The effect of dust aerosols on CCN(0.2%) concentrations is negligible in most regions of the globe; however, CCN(0.2%) concentrations change decrease by 10–20% in dusty regions the impact of dust on CCN(0.2%) concentrations in dusty regions is very sensitive to the assumed size distribution of emissions. If emissions are predominantly in the coarse mode, CCN(0.2%) decreases in dusty regions up to 10–20% because dust competes for condensable H2SO4, reducing the condensational growth of ultrafine mode particles to CCN sizes. With significant fine mode emissions, however, CCN(0.2%) doubles in Saharan source regions because the direct emission of dust particles outweighs any microphysical feedbacks. The impact of dust on CCN concentrations active at various water supersaturations is also investigated. Below 0.1%, CCN concentrations increase significantly in dusty regions due to the presence of coarse dust particles. Above 0.2%, CCN concentrations show a similar behavior as CCN(0.2%).

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