scholarly journals Application of positive matrix factorization and pollutants tracing for identification of dust sources: A case study in Khuzestan, Iran

2021 ◽  
Vol 27 (6) ◽  
pp. 210365-0
Author(s):  
Zahra Akbari ◽  
Omidreza Kakuee ◽  
Reza Shahbazi ◽  
Javad Darvishi Khatooni ◽  
Mahdi Mashal
Keyword(s):  
Power Plants ◽  
Early Spring ◽  
Nuclear Technique ◽  
Fine Sediments ◽  
Dust Sources ◽  
Internal Sources ◽  
Dust Events ◽  
Winter Dust ◽  
Southwest Of Iran ◽  
Oil Fuel

In this study for identification of internal and external origins of dust events in the southwest of Iran, for the first time, a comprehensive dust sampling was performed in nine regions of Khuzestan over the four seasons. The dust samples were analyzed using INAA nuclear technique. Factors obtained from applying the PMF Modeling indicated five kinds of pollutant sources which include 1) Sedimentary surface soil/dried bed of wetlands, 2) steel and metalworking industries, 3) refineries, 4) waste, and 5) solid fuel as well as oil fuel power plants. These identified sources were used as the tracers to identify the internal dust sources. Investigation of NASA AOT images and the synoptic data at the event dates showed that in the period of mid-autumn up to the early winter, dust events had external origins, that are mainly situated in Iraq and Saudi Arabia, while in the period of mid-summer to early autumn and mid-winter up to the early spring, the internal sources such as mud-salt zones or areas with fine sediments with evaporitic deposits and puffy grounds in the regions between Omidieh - Mahshahr, south, and southeast of Ahvaz, “Dasht-E-Azadegan,” and dried bed of Hoor-Al-Azim are more dominant.

scholarly journals New developments in the representation of Saharan dust sources in the aerosol–climate model ECHAM6-HAM2

2016 ◽  
Vol 9 (2) ◽  
pp. 765-777 ◽  
Author(s):  
Bernd Heinold ◽  
Ina Tegen ◽  
Kerstin Schepanski ◽  
Jamie R. Banks
Keyword(s):  
Climate Model ◽  
Dust Emission ◽  
Source Area ◽  
Saharan Dust ◽  
Moist Convection ◽  
Dust Source ◽  
New Developments ◽  
Infrared Imager ◽  
Dust Sources ◽  
Dust Events

Abstract. In the aerosol–climate model ECHAM6-HAM2, dust source activation (DSA) observations from Meteosat Second Generation (MSG) satellite are proposed to replace the original source area parameterization over the Sahara Desert. The new setup is tested in nudged simulations for the period 2007 to 2008. The evaluation is based on comparisons to dust emission events inferred from MSG dust index imagery, Aerosol Robotic Network (AERONET) sun photometer observations, and satellite retrievals of aerosol optical thickness (AOT).The model results agree well with AERONET measurements especially in terms of seasonal variability, and a good spatial correlation was found between model results and MSG-SEVIRI (Spinning-Enhanced Visible and InfraRed Imager) dust AOT as well as Multi-angle Imaging SpectroRadiometer (MISR) AOT. ECHAM6-HAM2 computes a more realistic geographical distribution and up to 20 % higher annual Saharan dust emissions, using the MSG-based source map. The representation of dust AOT is partly improved in the southern Sahara and Sahel. In addition, the spatial variability is increased towards a better agreement with observations depending on the season. Thus, using the MSG DSA map can help to circumvent the issue of uncertain soil input parameters.An important issue remains the need to improve the model representation of moist convection and stable nighttime conditions. Compared to sub-daily DSA information from MSG-SEVIRI and results from a regional model, ECHAM6-HAM2 notably underestimates the important fraction of morning dust events by the breakdown of the nocturnal low-level jet, while a major contribution is from afternoon-to-evening emissions.

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.

scholarly journals The transport history of two Saharan dust events archived in an Alpine ice core

2006 ◽  
Vol 6 (3) ◽  
pp. 667-688 ◽  
Author(s):  
H. Sodemann ◽  
A. S. Palmer ◽  
C. Schwierz ◽  
M. Schwikowski ◽  
H. Wernli
Keyword(s):  
Trajectory Analysis ◽  
Ice Core ◽  
Swiss Alps ◽  
Saharan Dust ◽  
Second Phase ◽  
Transport Pathway ◽  
Dust Sources ◽  
The Alps ◽  
The Mediterranean ◽  
Dust Events

Abstract. Mineral dust from the Saharan desert can be transported across the Mediterranean towards the Alpine region several times a year. When coinciding with snowfall, the dust can be deposited on Alpine glaciers and then appears as yellow or red layers in ice cores. Two such significant dust events were identified in an ice core drilled at the high-accumulation site Piz Zupó in the Swiss Alps (46°22' N, 9°55' E, 3850 m a.s.l.). From stable oxygen isotopes and major ion concentrations, the events were approximately dated as October and March 2000. In order to link the dust record in the ice core to the meteorological situation that led to the dust events, a novel methodology based on back-trajectory analysis was developed. It allowed the detailed analysis of the specific meteorologic flow evolution that was associated with Saharan dust transport into the Alps, and the identification of dust sources, atmospheric transport paths, and wet deposition periods for both dust events. Differences in the chemical signature of the two dust events were interpreted with respect to contributions from the dust sources and aerosol scavenging during the transport. For the October event, the trajectory analysis indicated that dust deposition took place during 13–15 October 2000. Mobilisation areas of dust were mainly identified in the Algerian and Libyan deserts. A combination of an upper-level potential vorticity streamer and a midlevel jet across Algeria first brought moist Atlantic air and later mixed air from the tropics and Saharan desert across the Mediterranean towards the Alps. The March event consisted of two different deposition phases which took place during 17–19 and 23–25 March 2000. The first phase was associated with an exceptional transport pathway past Iceland and towards the Alps from northerly directions. The second phase was similar to the October event. A significant peak of methanesulphonic acid associated with the March dust event was most likely caused by incorporation of biogenic aerosol while passing through the marine boundary layer of the western Mediterranean during a local phytoplankton bloom. From this study, we conclude that for a detailed understanding of the chemical signal recorded in dust events at Piz Zupó, it is essential to consider the whole transport sequence of mineral aerosol, consisting of dust mobilisation, transport, and deposition at the glacier.

scholarly journals Dust storm hazards

2019 ◽  
Vol 99 ◽  
pp. 04001
Author(s):  
Nick Middleton
Keyword(s):  
Power Plants ◽  
Physical Geography ◽  
Dust Storms ◽  
Human Society ◽  
Dust Deposition ◽  
Desert Dust ◽  
Aeolian Sediments ◽  
Range Transport ◽  
Solar Power Plants ◽  
Dust Events

Dust storms originate in many of the world's drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Desert dust hazards can occur where dust is entrained, during the transport phase, and on deposition. This paper draws on studies in physical geography, medical geology and geomorphology to discuss case studies of accelerated soil erosion, the health effects of air pollution caused by desert aerosols, injuries related to transport accidents caused by poor visibility during desert dust events, the spread of disease, and problems with water supplies and at solar power plants caused by dust deposition.

scholarly journals Evaluating the Relative Importance of Northern African Mineral Dust Sources Using Remote Sensing

2019 ◽  
Author(s):  
Natalie L. Bakker ◽  
Nick A. Drake ◽  
Charlie S. Bristow
Keyword(s):  
Remote Sensing ◽  
Mineral Dust ◽  
Boreal Winter ◽  
Relative Importance ◽  
Alluvial Deposits ◽  
Dust Source ◽  
Total Dust ◽  
Dust Sources ◽  
Dust Mass ◽  
Winter Dust

Abstract. Mineral dust from the Sahara and Sahel provides the Amazon Basin with essential nutrients, although the process is still poorly understood. There is little understanding where the dust is coming from, and thus what the concentration of nutrients in the dust is. This information, however, is vital to assess the impact it will have on the Amazon. This study analyses northern African dust sources of the boreal winter dust seasons between the years 2015–2017. It utilises high spatio-temporal resolution remote sensing data from SEVIRI, MODIS, VIIRS and Sentinel-2 to identify dust sources, classify them according to a geomorphic dust source scheme, and quantify the relative importance of source regions by calculating the total dust mass they produce. Results indicate that paleolakes emit the most dust, with the Bodélé Depression as the single largest dust source region, however, that alluvial deposits also produce a substantial amount of dust. During the boreal winter dust seasons of 2015–2017, ~ 36 % of the total dust mass emitted from northern Africa was associated to alluvial deposits, yet this geomorphic category has been relatively understudied to date. Furthermore, sand deposits were found to produce relatively little dust, in contrast to the results of other recent studies.

Freshwater Diatom Influx in Intertropical Atlantic: Relationships with Continental Records from Africa

1989 ◽  
Vol 32 (2) ◽  
pp. 229-243 ◽  
Author(s):  
Françoise Gasse ◽  
Bjørg Stabell ◽  
Elizabeth Fourtanier ◽  
Yolanda van Iperen
Keyword(s):  
Geographical Origin ◽  
Lacustrine Sediments ◽  
West African ◽  
Diatom Assemblages ◽  
Good Tool ◽  
Fine Sediments ◽  
Chloride Water ◽  
Winter Dust ◽  
Diatom Productivity ◽  
Freshwater Diatom

AbstractDiatom assemblages from modern West African rivers and from lacustrine sediments subjected to deflation represent the present-day sources of continental diatoms to the sea. Diatom productivity in large rivers is high, especially for the genus Melosira. Windblown diatoms derive mainly from the central and northern Sahara (summer dust plume) where saline chloride-water assemblages are widespread, or from the southern edge of the Sahara (winter dust plume) where Melosira-rich assemblages of dilute water predominate. Freshwater diatom peaks in Atlantic cores may reflect (1) phases of increased river influx, correlated with humid episodes on the continent or (2) phases of enhanced deflation and wind transport during arid episodes (the single hypothesis for fine sediments from mid-ocean sites). Genus Melosira dominates the freshwater assemblages of many modern and fossil marine samples, whatever the transport agent is. Therefore, it is not an accurate paleoclimate indicator by itself, but associated taxa may provide information on the environmental and geographical origin of the displaced diatoms. This tentative approach shows that freshwater diatoms in Atlantic cores may be a good tool for reconstructing paleoclimates and for establishing continent-ocean correlations if species analyses are made and if the continental distribution of the taxa encountered is considered.

The influence of the polar front jet stream on the formation of dust events in the southwest of Iran

2014 ◽  
Vol 8 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Koohzad Raispour ◽  
Mahmood Khosravi ◽  
Taghi Tavousi ◽  
Mohammad Sharifikiya
Keyword(s):  
Polar Front ◽  
Jet Stream ◽  
Dust Events ◽  
Southwest Of Iran ◽  
Polar Front Jet

The Influence of a Causeway on Oceanography and Foraminifera in the Strait of Canso, Nova Scotia

1975 ◽  
Vol 12 (12) ◽  
pp. 2086-2102 ◽  
Author(s):  
G. Vilks ◽  
C. T. Schafer ◽  
D. A. Walker
Keyword(s):  
Nova Scotia ◽  
Early Spring ◽  
Fine Sediments ◽  
The North ◽  
Surface Samples ◽  
Foraminiferal Species ◽  
Subsurface Layers ◽  
Characteristic Species ◽  
Free Interaction ◽  
Two Sides

In 1955, a causeway was built across the Strait of Canso, Nova Scotia, Canada, preventing in the Strait a free interaction between the Gulf of St. Lawrence and Atlantic waters. In order to evaluate a possible impact of this barrier on the marine environment, the distribution of foraminifera in sediments was investigated.Data were collected from early May to late August, 1973. During this period, the water on the Gulf of St. Lawrence side of the causeway was colder in early spring, but warmer and less saline during the summer as compared to the Atlantic side.At the causeway, the surface 1–3 cm of the bottom sediment consists of very soft and black to dark brown mud on both sides. On the Atlantic side, these fine sediments cover bedrock; but on the Gulf of St. Lawrence side, they cover sands and gravels.The 76 foraminiferal species collected in surface samples were subjected to cluster analysis, which defined two distinct groups of stations separating the fauna on the two sides-of the causeway. The characteristic species of the Gulf of St. Lawrence side is Ammonia beccarii. In the subsurface layers the dominance of this species decreases within a zone extending 4 km to the north of the causeway. On this evidence it was concluded that prior to the causeway, the Atlantic waters extended at least 4 km further to the north.

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.

Energy Saving in Operating Steam Power Plants Based on ASME Performance Test Codes

2005 ◽  
Author(s):  
Siamak Farhad ◽  
Maryam Younessi-Sinaki ◽  
M. Saffar-Avval
Keyword(s):  
Power Plant ◽  
Energy Saving ◽  
Power Plants ◽  
Performance Test ◽  
Low Cost ◽  
Steam Power ◽  
Steam Power Plants ◽  
Oil Fuel ◽  
Energy Survey ◽  
Operating Steam

The purpose of this paper is to show how the ASME performance test codes can be used as a low cost and efficient tool for energy survey in order to reduce fuel and power consumptions in operating steam power plants. In this regard, A 1000 MW steam power plant was selected and many studies were performed to evaluate the possibility and effects of performing such tests on this power plant. The results show that many of the instruments of this plant are suitable for the desired purpose and the tests can be applied for achieving energy saving. Also, the results show that the natural gas and heavy oil fuel consumptions have increased around 10 and 8.3 percent, respectively, relative to the design conditions of this plant and at least half of these increases can be reduced by proper adjustments of control devices and simple repairs.

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