scholarly journals Dust Deposition on the Gulf of California Caused by Santa Ana Winds

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 275 ◽  
Author(s):  
Christian A. Álvarez ◽  
José N. Carbajal ◽  
Luis F. Pineda-Martínez ◽  
José Tuxpan ◽  
David E. Flores
Keyword(s):  
Gulf Of California ◽  
Dust Emission ◽  
Positive Influence ◽  
Dust Particles ◽  
Weather Research And Forecasting ◽  
Western Coast ◽  
Emission Rates ◽  
Dust Deposition ◽  
Santa Ana ◽  
Santa Ana Winds

Numerical simulations revealed a profound interaction between the severe dust storm of 2007 caused by Santa Ana winds and the Gulf of California. The weather research and forecasting model coupled with a chemistry module (WRF-CHEM) and the hybrid single-particle Lagrangian integrated trajectory model (HYSPLIT) allowed for the estimation of the meteorological and dynamic aspects of the event and the dust deposition on the surface waters of the Gulf of California caused by the erosion and entrainment of dust particles from the surrounding desert regions. The dust emission rates from three chosen areas (Altar desert, Sonora coast, and a region between these two zones) and their contribution to dust deposition over the Gulf of California were analyzed. The Altar Desert had the highest dust emission rates and the highest contribution to dust deposition over the Gulf of California, i.e., it has the most critical influence with 96,879 tons of emission and 43,539 tons of dust deposition in the gulf. An increase of chlorophyll-a concentrations is observed coinciding with areas of high dust deposition in the northern and western coast of the gulf. This kind of event could have a significant positive influence over the mineralization and productivity processes in the Gulf of California, despite the soil loss in the eroded regions.

Dust distribution at a coal shearer in the face area

2020 ◽  
pp. 65-73
Author(s):  
A. S. Kobylkin
Keyword(s):  
Air Flow ◽  
Dust Emission ◽  
Sampling Procedure ◽  
Dust Particles ◽  
Dust Deposition ◽  
Particulate Emission ◽  
Face Area ◽  
Laboratory Test Results ◽  
The Face ◽  
Dust Distribution

Compliance with the Federal Code on Safety in Coal Mine, §22, No. 550 as of November 19, 2013 (as edited on January 1, 2020) dictates air dustiness and dust deposition control to be implemented in mines using stationary and mobile facilities. Application procedures of stationary controllers should be science-based and tested to provide reliable information. In particular, the procedures should indicate installation sites for the controllers and dictate revaluation of readings received from the controllers towards the dust explosion prevention in mines. Aimed to develop a framework for such procedures and to revise measurement areas for the movable controllers, dust distribution in roadways was studied. The studies have found out that particulate emission and dust distribution in the face area is complex due to mobility of the source of dust in the coal face area. Characteristics of dust particles govern their behavior in air flow. Thus, it is required to know characteristics of dust particles at the dust emission point to track their travel in roadways. A dust sampling procedure was developed to sample dust at a coal shearer. The data on characteristics of dust particles were also obtained. The mine and laboratory test results were used as the initial and boundary conditions in computational modeling. The mine researches and the modeling show that air flow is split into two parts in longwall. Dust produced by coal cutting by the shearer moves with air flow above the armored face conveyor. These results highlight the importance of taking into account local and head drags when selecting installation sites for controllers of air dust content and dust deposition in coal mines.

scholarly journals The global dust cycle and uncertainty in CMIP5 (Coupled Model Intercomparison Project phase 5) models

2020 ◽  
Vol 20 (17) ◽  
pp. 10401-10425
Author(s):  
Chenglai Wu ◽  
Zhaohui Lin ◽  
Xiaohong Liu
Keyword(s):  
Wet Deposition ◽  
Climate Models ◽  
Dust Emission ◽  
Coupled Model ◽  
Dust Particles ◽  
Earth System ◽  
Model Intercomparison ◽  
Dust Deposition ◽  
The Earth ◽  
Intercomparison Project

Abstract. The dust cycle is an important component of the Earth system and has been implemented in climate models and Earth system models (ESMs). An assessment of the dust cycle in these models is vital to address their strengths and weaknesses in simulating dust aerosol and its interactions with the Earth system and enhance the future model developments. This study presents a comprehensive evaluation of the global dust cycle in 15 models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The various models are compared with each other and with an aerosol reanalysis as well as station observations. The results show that the global dust emission in these models varies by a factor of 4–5 for the same size range. The models generally agree with each other and observations in reproducing the “dust belt”, which extends from North Africa, the Middle East, Central and South Asia to East Asia, although they differ greatly in the spatial extent of this dust belt. The models also differ in other dust source regions such as North America and Australia. We suggest that the coupling of dust emission with dynamic vegetation can enlarge the range of simulated dust emission. For the removal process, all the models estimate that wet deposition is smaller than dry deposition and wet deposition accounts for 12 %–39 % of total deposition. The models also estimate that most (77 %–91 %) dust particles are deposited onto continents and 9 %–23 % of dust particles are deposited into oceans. Compared to the observations, most models reproduce the dust deposition and dust concentrations within a factor of 10 at most stations, but larger biases by more than a factor of 10 are also noted at specific regions and for certain models. These results highlight the need for further improvements of the dust cycle especially on dust emission in climate models.

scholarly journals Test of Dust Emission Over the Middle East

2020 ◽  
Author(s):  
Mokhammad Suleiman Mostamandi ◽  
Georgiy Stenchikov ◽  
Alexander Ukhov ◽  
Illia Shevchenko ◽  
Johann Engelbrecht ◽  
...  
Keyword(s):  
Middle East ◽  
Dust Emission ◽  
Satellite Observations ◽  
Passive Samplers ◽  
Dust Particles ◽  
Grid Spacing ◽  
Dust Deposition ◽  
Regional Models ◽  
Order Of Magnitude ◽  
Micro Pulse Lidar

<p>Abstract</p><p>The dust emission simulated within the up-to-date global and regional models differs by almost an order of magnitude. The models are tuned to reproduce the observed aerosol optical depth (AOD) that, with some caveats, reflects the dust mass retained in the atmosphere. However, the amount of dust suspended in the atmosphere is controlled independently by the dust emission and deposition; therefore, only AOD observations are insufficient to constrain both these processes. To calculate the dust emission over the Middle East (ME), in this study, we employ dust deposition observations, AERONET AOD, micro-pulse lidar, and satellite observations to constrain the WRF-Chem simulations. The dust deposition is measured on a monthly bases for 2015-2019 using passive samplers over six sites over land and the sea. We compare the WRF-Chem simulations, conducted with 10-km grid spacing, with the recent MERRA-2 and CAMS reanalysis. WRF-Chem is configured with the GOCART dust scheme. We calculate the meteorological and aerosol initial and boundary conditions using the MERRA-2 reanalysis. </p><p>We evaluated the dust regional mass balance controlled by emission, deposition, and cross-boundary transport. The smallest dust particles are transported at vast distances while the heaviest ones deposit inside of the domain. Since the model accounts for dust particles with radii<10 um, we process the deposition samples to extract the weight of particles smaller than 10 um. WRF-Chem was tuned to reproduce the observed AOD and monthly deposition of dust particles with radii < 10 um. We found that the ME dust emission comprises about 30% of the global annual dust emission. MERRA-2 underestimates the ME dust emission by about 15%.</p>

scholarly journals Global dust cycle and uncertainty in CMIP5 models

2020 ◽  
Author(s):  
Chenglai Wu ◽  
Zhaohui Lin ◽  
Xiaohong Liu
Keyword(s):  
Wet Deposition ◽  
Climate Models ◽  
Dust Emission ◽  
Coupled Model ◽  
Dust Particles ◽  
Cmip5 Models ◽  
Earth System ◽  
Dust Deposition ◽  
Total Deposition ◽  
The Earth

Abstract. Dust cycle is an important component of the Earth system and have been implemented into climate models and Earth System Models (ESMs). An assessment of the dust cycle in these models is vital to address the strengths and weaknesses of these models in simulating dust aerosol and its interactions with the Earth system and enhance the future model developments. This study presents a comprehensive evaluation of global dust cycle in 15 models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The various models are compared with each other and with an aerosol reanalysis as well as station observations of dust deposition and concentrations. The results show that the global dust emission in these models ranges from 735 to 8186 Tg yr−1 and the annual mean dust burden ranges from 2.5 to 41.9 Tg, both of which scatter by a factor of about 10–20. The models generally agree with each other and observations in reproducing the dust belt that extends from North Africa, Middle East, Central and South Asia, to East Asia, although they differ largely in the spatial extent of this dust belt. The models also differ in other dust source regions such as North America and Australia, where the contributions of these sources to global dust emissions vary by a factor of more than 500. We suggest that the coupling of dust emission with dynamic vegetation can enlarge the range of simulated dust emission. For the removal process, all the models estimate that wet deposition is a smaller sink than dry deposition and wet deposition accounts for 12–39 % of total deposition. The models also estimate that most (77–91 %) of dust particles are deposited onto continents and 9–23 % of them are deposited into oceans. A linear relationship between dust burden, lifetime, and fraction of wet deposition to total deposition from these models suggests a general consistency among the models. Compared to the observations, most models reproduce the dust deposition and dust concentrations within a factor of 10 at most stations, but larger biases by more than a factor of 10 are also noted at specific regions and for certain models. These results cast a doubt on the interpretation of the simulations of dust-affected fields in climate models and highlight the need for further improvements of dust cycle especially on dust emission in climate models.

scholarly journals Odour, dust and non-methane volatile organic-compound emissions from tunnel-ventilated layer-chicken sheds: a case study of two farms

2013 ◽  
Vol 53 (12) ◽  
pp. 1309 ◽  
Author(s):  
Mark Dunlop ◽  
Zoran D. Ristovski ◽  
Erin Gallagher ◽  
Gavin Parcsi ◽  
Robin L. Modini ◽  
...  
Keyword(s):  
Dust Emission ◽  
Ventilation Rate ◽  
Gas Chromatography Mass Spectrometry ◽  
Emission Rates ◽  
Layer Chicken ◽  
Volatile Organic ◽  
Different Seasons ◽  
Odour Emissions ◽  
Cleaning Cycle ◽  
Study Sites

An observational study was undertaken to measure odour and dust (PM10 and PM2.5) emission rates and identify non-methane volatile organic compounds (NMVOCs) and odorants in the exhaust air from two tunnel-ventilated layer-chicken sheds that were configured with multi-tiered cages and manure belts. The study sites were located in south-eastern Queensland and the West Gippsland region of Victoria, Australia. Samples were collected in summer and winter on sequential days across the manure-belt cleaning cycle. Odour emissions ranged from 58 to 512 ou/s per 1000 birds (0.03–0.27 ou/s.kg) and dust emission rates ranged 0.014–0.184 mg/s per 1000 birds for PM10 and 0.001–0.190 mg/s per 1000 birds for PM2.5. Twenty NMVOCs were identified, including three that were also identified as odorants using thermal desorption–gas chromatography–mass spectrometry/olfactometry analysis. Odour emission rates were observed to vary with the amount of manure accumulation on the manure belts, being lowest 2–4 days after removing manure. Odour emission rates were also observed to vary with diurnal and seasonal changes in ventilation rate. Dust emissions were observed to increase with ventilation rate but not with manure accumulation. Some NMVOCs were identified at both farms and in different seasons whereas others were observed only at one farm or in one season, indicating that odorant composition was influenced by farm-specific practices and season.

scholarly journals Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire

2021 ◽  
Author(s):  
Alexander Gershunov ◽  
Janin Guzman Morales ◽  
Benjamin Hatchett ◽  
Kristen Guirguis ◽  
Rosana Aguilera ◽  
...  
Keyword(s):  
Great Basin ◽  
Heat Waves ◽  
Early Warning Systems ◽  
High Amplitude ◽  
Warming Trend ◽  
Snow Accumulation ◽  
Burned Area ◽  
Rossby Wave Breaking ◽  
Santa Ana ◽  
Santa Ana Winds

AbstractSanta Ana winds (SAWs) are associated with anomalous temperatures in coastal Southern California (SoCal). As dry air flows over SoCal’s coastal ranges on its way from the elevated Great Basin down to sea level, all SAWs warm adiabatically. Many but not all SAWs produce coastal heat events. The strongest regionally averaged SAWs tend to be cold. In fact, some of the hottest and coldest observed temperatures in coastal SoCal are linked to SAWs. We show that hot and cold SAWs are produced by distinct synoptic dynamics. High-amplitude anticyclonic flow around a blocking high pressure aloft anchored at the California coast produces hot SAWs. Cold SAWs result from anticyclonic Rossby wave breaking over the northwestern U.S. Hot SAWs are preceded by warming in the Great Basin and dry conditions across the Southwestern U.S. Precipitation over the Southwest, including SoCal, and snow accumulation in the Great Basin usually precede cold SAWs. Both SAW flavors, but especially the hot SAWs, yield low relative humidity at the coast. Although cold SAWs tend to be associated with the strongest winds, hot SAWs tend to last longer and preferentially favor wildfire growth. Historically, out of large (> 100 acres) SAW-spread wildfires, 90% were associated with hot SAWs, accounting for 95% of burned area. As health impacts of SAW-driven coastal fall, winter and spring heat waves and impacts of smoke from wildfires have been recently identified, our results have implications for designing early warning systems. The long-term warming trend in coastal temperatures associated with SAWs is focused on January–March, when hot and cold SAW frequency and temperature intensity have been increasing and decreasing, respectively, over our 71-year record.

The Santa Ana Winds of Southern California

Weatherwise ◽  
1962 ◽  
Vol 15 (3) ◽  
pp. 102-121 ◽  
Author(s):  
Leo A. Sergius ◽  
George R. Ellis ◽  
Richard M. Ogden
Keyword(s):  
Southern California ◽  
Santa Ana ◽  
Santa Ana Winds

Organochlorine pesticides in immature scalloped hammerheads Sphyrna lewini from the western coast of the Gulf of California, Mexico: Bioaccumulation patterns and human exposure

2021 ◽  
pp. 151369
Author(s):  
Ángela Ángel-Moreno Briones ◽  
Félix Augusto Hernández-Guzmán ◽  
Rogelio González-Armas ◽  
Felipe Galván-Magaña ◽  
Ana Judith Marmolejo-Rodríguez ◽  
...  
Keyword(s):  
Organochlorine Pesticides ◽  
Gulf Of California ◽  
Human Exposure ◽  
Western Coast ◽  
Sphyrna Lewini

scholarly journals Modeling volcanic ash resuspension – application to the 14–18 October 2011 outbreak episode in central Patagonia, Argentina

2014 ◽  
Vol 14 (1) ◽  
pp. 119-133 ◽  
Author(s):  
A. Folch ◽  
L. Mingari ◽  
M. S. Osores ◽  
E. Collini
Keyword(s):  
Air Quality ◽  
Volcanic Ash ◽  
Suspended Particle ◽  
Dust Emission ◽  
Vegetation Coverage ◽  
Weather Research And Forecasting ◽  
Test Case ◽  
Arid Environments ◽  
Strong Wind ◽  
Near Future

Abstract. Volcanic fallout deposits from the June 2011 Cordón Caulle eruption on central Patagonia were remobilized in several occasions months after their emplacement. In particular, during 14–18 October 2011, an intense outbreak episode generated widespread volcanic clouds that were dispersed across Argentina, causing multiple impacts in the environment, affecting the air quality and disrupting airports. Fine ash particles in volcanic fallout deposits can be resuspended under favorable meteorological conditions, particularly during strong wind episodes in arid environments with low soil moisture and poor vegetation coverage. As opposed to eruption-formed ash clouds, modeling of resuspension-formed ash clouds has received little attention. In consequence, there are no emission schemes specially developed and calibrated for resuspended volcanic ash, and few operational products exists to model and forecast the formation and dispersal of resuspension ash clouds. Here we implement three dust emission schemes of increasing complexity in the FALL3D tephra dispersal model and use the 14–18 October 2011 outbreak episode as a model test case. We calibrate the emission schemes and validate the results of the coupled WRF–ARW (Weather Research and Forecasting – Advanced Research WRF)/FALL3D modeling system using satellite imagery and measurements of visibility (a quantity related to total suspended particle concentration at the surface) and particulate matter (PM10) concentration at several meteorological and air quality stations located at Argentina and Uruguay. Our final goal is to test the capability of the modeling system to become, in the near future, an operational forecast product for volcanic ash resuspension events.

scholarly journals Why do models perform differently on particulate matter over East Asia? A multi-model intercomparison study for MICS-Asia III

2020 ◽  
Vol 20 (12) ◽  
pp. 7393-7410 ◽  
Author(s):  
Jiani Tan ◽  
Joshua S. Fu ◽  
Gregory R. Carmichael ◽  
Syuichi Itahashi ◽  
Zhining Tao ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
East Asia ◽  
Dust Emission ◽  
Sulfur Oxidation ◽  
Atmospheric Modeling ◽  
Weather Research And Forecasting ◽  
Forecasting Model ◽  
Air Quality Prediction ◽  
Weather Research

Abstract. This study compares the performance of 12 regional chemical transport models (CTMs) from the third phase of the Model Inter-Comparison Study for Asia (MICS-Asia III) on simulating the particulate matter (PM) over East Asia (EA) in 2010. The participating models include the Weather Research and Forecasting model coupled with Community Multiscale Air Quality (WRF-CMAQ; v4.7.1 and v5.0.2), the Regional Atmospheric Modeling System coupled with CMAQ (RAMS-CMAQ; v4.7.1 and v5.0.2), the Weather Research and Forecasting model coupled with chemistry (WRF-Chem; v3.6.1 and v3.7.1), Goddard Earth Observing System coupled with chemistry (GEOS-Chem), a non-hydrostatic model coupled with chemistry (NHM-Chem), the Nested Air Quality Prediction Modeling System (NAQPMS) and the NASA-Unified WRF (NU-WRF). This study investigates three model processes as the possible reasons for different model performances on PM. (1) Models perform very differently in the gas–particle conversion of sulfur (S) and oxidized nitrogen (N). The model differences in sulfur oxidation ratio (50 %) are of the same magnitude as that in SO42- concentrations. The gas–particle conversion is one of the main reasons for different model performances on fine mode PM. (2) Models without dust emission modules can perform well on PM10 at non-dust-affected sites but largely underestimate (up to 50 %) the PM10 concentrations at dust sites. The implementation of dust emission modules in the models has largely improved the model accuracies at dust sites (reduce model bias to −20 %). However, both the magnitude and distribution of dust pollution are not fully captured. (3) The amounts of modeled depositions vary among models by 75 %, 39 %, 21 % and 38 % for S wet, S dry, N wet and N dry depositions, respectively. Large inter-model differences are found in the washout ratios of wet deposition (at most 170 % in India) and dry deposition velocities (generally 0.3–2 cm s−1 differences over inland regions).

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