A Comparison of the Different Stages of Dust Events over Beijing in March 2021: The Effects of the Vertical Structure on Near-Surface Particle Concentration

Mineral dust is of great importance to climate change, air quality, and human health. In this study, multisource data, including the reanalysis data and remote sensing data, were used to compare the three dust events that occurred in the March of 2021 over Beijing and reveal the effects of atmospheric vertical structure on near-surface dust concentration. The combined effect of the Mongolian cyclone and a wide persistent cold-front induced two events (E1: from March 15 to 16 and E3: from March 28 to 29). E1 was more intense, more extensive, and longer-lasting than E3 due to the combination of the stronger Mongolian cyclone, slower high/cold surface pressure, and the low-level jet. However, under the appropriate configurations of temperature and pressure fields between high and low altitudes, weak updrafts were still induced and could elevate dust up to 850 hPa, as occurred during E2 on March 22 and 23. The dust emission was inferior to E1 and E3, which contributes to the low dust concentration near the surface in E2. On the other hand, the downdraft strength directly affected both the vertical distribution of dust and the concentration of surface particles. There was a strong temporal consistency between the occurrence of the downdraft and the dust touchdown. In E1, the continuous strong downdraft caused the maximum dust concentration to be above 4000 μg/m3 at around 200 m. In contrast, the maximum height of the dust mass concentration in E3 occurred at about 800 m due to the transient downdraft, which weakened its effect on surface visibility. Besides, the weak vertical motion in E2 caused most of the dust to become suspended in the air. Overall, the large dust emission resulted from active updrafts in the source region, and the lengthy strong downdrafts led to the ultrahigh particle concentration near the surface.

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

Geoscientific Model Development ◽

10.5194/gmd-9-765-2016 ◽

2016 ◽

Vol 9 (2) ◽

pp. 765-777 ◽

Cited By ~ 8

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.

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Emission, transport, and radiative effects of mineral dust from the Taklimakan and Gobi deserts: comparison of measurements and model results

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-2401-2017 ◽

2017 ◽

Vol 17 (3) ◽

pp. 2401-2421 ◽

Cited By ~ 39

Author(s):

Siyu Chen ◽

Jianping Huang ◽

Litai Kang ◽

Hao Wang ◽

Xiaojun Ma ◽

...

Keyword(s):

East Asia ◽

Dust Emission ◽

Dust Concentration ◽

Dust Particles ◽

Storm Event ◽

Gobi Desert ◽

Radiative Effects ◽

Dust Aerosols ◽

Budget Analysis ◽

Westerly Jets

Abstract. The Weather Research and Forecasting Model with chemistry (WRF-Chem model) was used to investigate a typical dust storm event that occurred from 18 to 23 March 2010 and swept across almost all of China, Japan, and Korea. The spatial and temporal variations in dust aerosols and the meteorological conditions over East Asia were well reproduced by the WRF-Chem model. The simulation results were used to further investigate the details of processes related to dust emission, long-range transport, and radiative effects of dust aerosols over the Taklimakan Desert (TD) and Gobi Desert (GD). The results indicated that weather conditions, topography, and surface types in dust source regions may influence dust emission, uplift height, and transport at the regional scale. The GD was located in the warm zone in advance of the cold front in this case. Rapidly warming surface temperatures and cold air advection at high levels caused strong instability in the atmosphere, which strengthened the downward momentum transported from the middle and low troposphere and caused strong surface winds. Moreover, the GD is located in a relatively flat, high-altitude region influenced by the confluence of the northern and southern westerly jets. Therefore, the GD dust particles were easily lofted to 4 km and were the primary contributor to the dust concentration over East Asia. In the dust budget analysis, the dust emission flux over the TD was 27.2 ± 4.1 µg m−2 s−1, which was similar to that over the GD (29 ± 3.6 µg m−2 s−1). However, the transport contribution of the TD dust (up to 0.8 ton d−1) to the dust sink was much smaller than that of the GD dust (up to 3.7 ton d−1) because of the complex terrain and the prevailing wind in the TD. Notably, a small amount of the TD dust (PM2.5 dust concentration of approximately 8.7 µg m−3) was lofted to above 5 km and transported over greater distances under the influence of the westerly jets. Moreover, the direct radiative forcing induced by dust was estimated to be −3 and −7 W m−2 at the top of the atmosphere, −8 and −10 W m−2 at the surface, and +5 and +3 W m−2 in the atmosphere over the TD and GD, respectively. This study provides confidence for further understanding the climate effects of the GD dust.

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HYDROFLASH: A 2-D Nuclear EMP Code Founded on Finite Volume Techniques

Advanced Electromagnetics ◽

10.7716/aem.v6i2.472 ◽

2017 ◽

Vol 6 (2) ◽

pp. 14 ◽

Cited By ~ 1

Author(s):

R. Roussel-Dupre

Keyword(s):

Finite Volume ◽

Message Passing ◽

Maxwell Equations ◽

Message Passing Interface ◽

Hyperbolic Equations ◽

Source Region ◽

Multiprocessor Systems ◽

Near Surface ◽

First Approximation ◽

Hydrodynamic Code

The basic mechanisms that govern the generation of an electromagnetic pulse (EMP) following a nuclear detonation in the atmosphere, including heights of burst (HOB) relevant to surface bursts (0 km), near surface bursts (0-2 km), air bursts (2-20 km) and high-altitude bursts (> 20 km), are reviewed. Previous computational codes developed to treat the source region and predict the EMP are discussed. A new 2-D hydrodynamic code (HYDROFLASH) that solves the fluid equations for electron and ion transport in the atmosphere and the coupled Maxwell equations using algorithms extracted from the Conservation Law (CLAW) package for solving multi-dimensional hyperbolic equations with finite volume techniques has been formulated. Simulations include the ground, atmospheric gradient, and an azimuthal applied magnetic field as a first approximation to the geomagnetic field. HYDROFLASH takes advantage of multiprocessor systems by using domain decomposition together with the Message Passing Interface (MPI) protocol for parallel processing. A detailed description of the model is presented along with computational results for a generic 10 kiloton (kT) burst detonated at 0 and 10 km altitude.

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Dust emission source characterization for visibility hazard assessment on Lordsburg Playa in Southwestern New Mexico, USA

Geoenvironmental Disasters ◽

10.1186/s40677-020-00171-x ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

R. Scott Van Pelt ◽

John Tatarko ◽

Thomas E. Gill ◽

Chunping Chang ◽

Junran Li ◽

...

Keyword(s):

New Mexico ◽

Dust Emission ◽

Source Area ◽

Dust Storms ◽

Economic Losses ◽

Source Characterization ◽

Dust Clouds ◽

Regional Sources ◽

Dust Events ◽

Flooded Areas

AbstractIn drylands around the world, ephemeral lakes (playas) are common. Dry, wind-erodible playa sediments are potent local and regional sources of dust and PM10 (airborne particles with diameters less than 10 μm). Dust clouds often cause sudden and/or prolonged loss of visibility to travelers on downwind roadways. Lordsburg Playa, in southwestern New Mexico, USA is bisected by Interstate Highway 10. Dust storms emanating from the playa have been responsible for numerous visibility-related road closures (including 39 road closures between 2012 and 2019) causing major economic losses, in addition to well over a hundred dust-related vehicle crashes causing at least 41 lost lives in the last 53 years. In order to improve understanding of the surfaces responsible for the dust emissions, we investigated the critical wind friction velocity thresholds and the dust emissivities of surfaces representing areas typical of Lordsburg Playa’s stream deltas, shorelines, and ephemerally flooded lakebed using a Portable In-Situ Wind ERosion Laboratory (PI-SWERL). Mean threshold friction velocities for PM10 entrainment ranged from less than 0.30 m s− 1 for areas in the delta and shoreline to greater than 0.55 m s− 1 for ephemerally flooded areas of the lakebed. Similarly, we quantified mean PM10 vertical flux rates ranging from less than 500 μg m− 2 s− 1 for ephemerally flooded areas of lakebed to nearly 25,000 μg m− 2 s− 1 for disturbed delta surfaces. The unlimited PM10 supply of the relatively coarse sediments along the western shoreline is problematic and indicates that this may be the source area for longer-term visibility reducing dust events and should be a focus area for dust mitigation efforts.

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On the fine vertical structure of the low troposphere over the coastal margins of East Antarctica

10.5194/acp-2018-1197 ◽

2019 ◽

Author(s):

Étienne Vignon ◽

Olivier Traullé ◽

Alexis Berne

Keyword(s):

Pressure Gradient ◽

Vertical Structure ◽

East Antarctica ◽

Radiosonde Data ◽

Gradient Force ◽

Pressure Gradient Force ◽

Near Surface ◽

Ice Shelves ◽

Low Level ◽

Humidity Profiles

Abstract. Eight years of high-resolution radiosonde data at nine Antarctic stations are analysed to provide the first large scale characterization of the fine scale vertical structure of the low troposphere up to 3 km of altitude over the coastal margins of East Antarctica. Radiosonde data show a large spatial variability of wind, temperature and humidity profiles, with different features between stations in katabatic regions (e.g., Dumont d'Urville and Mawson stations), stations over two ice shelves (Neumayer and Halley stations) and regions with complex orography (e.g., Mc Murdo). At Dumont d'Urville, Mawson and Davis stations, the yearly median wind speed profiles exhibit a clear low-level katabatic jet. During precipitation events, the low-level flow generally remains of continental origin and its speed is even reinforced due to the increase in the continent- ocean pressure gradient. Meanwhile, the relative humidity profiles show a dry low troposphere, suggesting the occurence of low-level sublimation of precipitation in katabatic regions but such a phenomenon does not appreciably occur over the ice-shelves near Halley and Neumayer. Although ERA-Interim and ERA5 reanalyses assimilate radiosoundings at most stations considered here, substantial – and sometimes large – low-level wind and humidity biases are revealed but ERA5 shows overall better performances. A free simulation with the regional model Polar WRF (at a 35-km resolution) over the entire continent shows too strong and too shallow near-surface jets in katabatic regions especially in winter. This may be a consequence of an understimated coastal cold air bump and associated sea-continent pressure gradient force due to the coarse 35 km resolution of the Polar WRF simulation. Beyond documenting the vertical structure of the low troposphere over coastal East-Antarctica, this study gives insights into the reliability and accuracy of two major reanalysis products in this region on the Earth and it raises the difficulty of modeling the low-level flow over the margins of the ice sheet with a state-of-the-art climate model.

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Transport, vertical structure and radiative properties of dust events in southeast China determined from ground and space sensors

Atmospheric Environment ◽

10.1016/j.atmosenv.2011.04.031 ◽

2011 ◽

Vol 45 (35) ◽

pp. 6469-6480 ◽

Cited By ~ 33

Author(s):

Jianjun Liu ◽

Youfei Zheng ◽

Zhanqing Li ◽

Connor Flynn ◽

E.J. Welton ◽

...

Keyword(s):

Vertical Structure ◽

Radiative Properties ◽

Southeast China ◽

Dust Events

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Lidar signal simulation for the evaluation of aerosols in chemistry transport models

Geoscientific Model Development ◽

10.5194/gmd-5-1543-2012 ◽

2012 ◽

Vol 5 (6) ◽

pp. 1543-1564 ◽

Cited By ~ 7

Author(s):

S. Stromatas ◽

S. Turquety ◽

L. Menut ◽

H. Chepfer ◽

J. C. Péré ◽

...

Keyword(s):

Optical Properties ◽

Vertical Structure ◽

Simulation Software ◽

Lidar Signal ◽

Transport Models ◽

Signal Simulation ◽

Level 1 ◽

Dust Events ◽

Level 2

Abstract. We present an adaptable tool, the OPTSIM (OPTical properties SIMulation) software, for the simulation of optical properties and lidar attenuated backscattered profiles (β') from aerosol concentrations calculated by chemistry transport models (CTM). It was developed to model both Level 1 observations and Level 2 aerosol lidar retrievals in order to compare model results to measurements: the level 2 enables to estimate the main properties of aerosols plume structures, but may be limited due to specific assumptions. The level 1, originally developed for this tool, gives access to more information about aerosols properties (β') requiring, at the same time, less hypothesis on aerosols types. In addition to an evaluation of the aerosol loading and optical properties, active remote sensing allows the analysis of aerosols' vertical structures. An academic case study for two different species (black carbon and dust) is presented and shows the consistency of the simulator. Illustrations are then given through the analysis of dust events in the Mediterranean region during the summer 2007. These are based on simulations by the CHIMERE regional CTM and observations from the CALIOP space-based lidar, and highlight the potential of this approach to evaluate the concentration, size and vertical structure of the aerosol plumes.

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Regional Hydrological Cycle over the Red Sea in ERA-Interim

Journal of Hydrometeorology ◽

10.1175/jhm-d-16-0048.1 ◽

2016 ◽

Vol 18 (1) ◽

pp. 65-83 ◽

Cited By ~ 15

Author(s):

Olga Zolina ◽

Ambroise Dufour ◽

Sergey K. Gulev ◽

Georgiy Stenchikov

Keyword(s):

Surface Layer ◽

Red Sea ◽

Vertical Structure ◽

Arabian Peninsula ◽

Hydrological Cycle ◽

Lower Layer ◽

Sea Surface ◽

Atmospheric Moisture ◽

Near Surface ◽

Moisture Advection

Abstract The major sources of atmospheric moisture over the Red Sea are analyzed using ERA-Interim for the 1979–2013 period. The vertical structure of moisture transports across the coastlines has been computed separately for the western and eastern coasts of the Red Sea. The vertical structure of the moisture transport from the Red Sea to the continents is dominated by a breeze-like circulation in the near-surface layer and the Arabian high above 850 hPa. The lower-layer, breeze-like circulation is acting to export the moisture to the northwest of Africa and to the Arabian Peninsula and contributes about 80% of the moisture exports from the Red Sea, dominating over the transport in the upper layer, where the moisture is advected to the Arabian Peninsula in the northern part of the sea and to the African continent in the southern part. Integrated moisture divergence over the Red Sea decreased from the early 1980s to 1997 and then increased until the 2010s. Associated changes in the moisture export were provided primarily by the increasing intensity of the breeze-associated transports. The transports above the boundary layer, while being strong across the western and the eastern coasts, have a smaller effect on the net moisture export. The interannual variability of the moisture export in the near-surface layer was found to be closely correlated with the variability in sea surface temperature, especially in summer. Implications of the observed changes in the moisture advection for the hydrological cycle of the Middle East are discussed.

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Performance of KMA-ADAM3 in Identifying Asian Dust Days over Northern China

Atmosphere ◽

10.3390/atmos11060593 ◽

2020 ◽

Vol 11 (6) ◽

pp. 593

Author(s):

Sang-Boom Ryoo ◽

Jinwon Kim ◽

Jeong Hoon Cho

Keyword(s):

Dust Emission ◽

Northern China ◽

Asian Dust ◽

Probability Of Detection ◽

Soil Types ◽

Dust Source ◽

Aerosol Model ◽

Dust Generation ◽

Source Regions ◽

Dust Events

Recently, the Korea Meteorological Administration developed Asian Dust Aerosol Model version 3 (ADAM3) by incorporating additional parameters into ADAM2, including anthropogenic particulate matter (PM) emissions, modification of dust generation by considering real-time surface vegetation, and assimilations of surface PM observations and satellite-measured aerosol optical depth. This study evaluates the performance of ADAM3 in identifying Asian dust days over the dust source regions in Northern China and their variations according to regions and soil types by comparing its performance with ADAM2 (from January to June of 2017). In all regions the performance of ADAM3 was markedly improved, especially for Northwestern China, where the threat score (TS) and the probability of detection (POD) improved from 5.4% and 5.5% to 30.4% and 34.4%, respectively. ADAM3 outperforms ADAM2 for all soil types, especially for the sand-type soil for which TS and POD are improved from 39.2.0% and 50.7% to 48.9% and 68.2%, respectively. Despite these improvements in regions and surface soil types, Asian dust emission formulas in ADAM3 need improvement for the loess-type soils to modulate the overestimation of Asian dust events related to anthropogenic emissions in the Huabei Plain and Manchuria.

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

Biogeosciences ◽

10.5194/bg-11-6623-2014 ◽

2014 ◽

Vol 11 (23) ◽

pp. 6623-6632 ◽

Cited By ~ 25

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.

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