scholarly journals The Implementation of a Mineral Dust Wet Deposition Scheme in the GOCART-AFWA Module of the WRF Model

2018 ◽  
Vol 10 (10) ◽  
pp. 1595 ◽  
Author(s):  
Konstantinos Tsarpalis ◽  
Anastasios Papadopoulos ◽  
Nikolaos Mihalopoulos ◽  
Christos Spyrou ◽  
Silas Michaelides ◽  
...  
Keyword(s):  
Wet Deposition ◽  
Large Scale ◽  
Eastern Mediterranean ◽  
Wrf Model ◽  
Saharan Dust ◽  
Near Surface ◽  
Dust Transport ◽  
Wet Scavenging ◽  
Aerosol Module

The principal objective of this study is to present and evaluate an advanced dust wet deposition scheme in the Weather and Research Forecasting model coupled with Chemistry (WRF-Chem). As far as the chemistry component is concerned, the Georgia Tech Goddard Global Ozone Chemistry Aerosol Radiation and Transport of the Air Force Weather Agency (GOCART-AFWA) module is applied, as it supports a binary scheme for dust emissions and transport. However, the GOCART-AFWA aerosol module does not incorporate a wet scavenging scheme, nor does it interact with cloud processes. The integration of a dust wet deposition scheme following Seinfeld and Pandis into the WRF-Chem model is assessed through a case study of large-scale Saharan dust transport over the Eastern Mediterranean that is characterized by severe wet deposition over Greece. An acceptable agreement was found between the calculated and measured near surface PM10 concentrations, as well as when model estimated atmospheric optical depth (AOD) was validated against the AERONET measurements, indicating the validity of our dust wet deposition scheme.

scholarly journals An Assessment of the Efficiency of Dust Regional Modelling to Predict Saharan Dust Transport Episodes

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
D. K. Papanastasiou ◽  
A. Poupkou ◽  
E. Katragkou ◽  
V. Amiridis ◽  
D. Melas ◽  
...  
Keyword(s):  
Air Quality ◽  
Eastern Mediterranean ◽  
Surface Concentration ◽  
Atmospheric Model ◽  
Saharan Dust ◽  
Regional Modelling ◽  
Limit Values ◽  
Near Surface ◽  
Dust Transport ◽  
Winter Dust

Aerosol levels at Mediterranean Basin are significantly affected by desert dust that is eroded in North Africa and is transported northwards. This study aims to assess the performance of the Dust REgional Atmospheric Model (BSC-DREAM8b) in the prediction of dust outbreaks near the surface in Eastern Mediterranean. For this purpose, model PM10 predictions covering a 7-year period and PM10 observations at five surface monitoring sites in Greece are used. A quantitative criterion is set to select the significant dust outbreaks defined as those when the predicted PM10 surface concentration exceeds 12 μg/m3. The analysis reveals that significant dust transport is usually observed for 1–3 consecutive days. Dust outbreak seasons are spring and summer, while some events are also forecasted in autumn. The seasonal variability of dust transport events is different at Finokalia, where the majority of events are observed in spring and winter. Dust contributes by 19–25% to the near surface observed PM10 levels, which can be increased to more than 50 μg/m3during dust outbreaks, inducing violations of the air quality standards. Dust regional modeling can be regarded as a useful tool for air quality managers when assessing compliance with air quality limit values.

scholarly journals Synergetic monitoring of Saharan dust plumes and potential impact on surface: a case study of dust transport from Canary Islands to Iberian Peninsula

2011 ◽  
Vol 11 (7) ◽  
pp. 3067-3091 ◽  
Author(s):  
C. Córdoba-Jabonero ◽  
M. Sorribas ◽  
J. L. Guerrero-Rascado ◽  
J. A. Adame ◽  
Y. Hernández ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Particle Deposition ◽  
Ground Level ◽  
In Situ Measurements ◽  
Saharan Dust ◽  
Dust Transport ◽  
Air Masses ◽  
Potential Impact

Abstract. The synergetic use of meteorological information, remote sensing both ground-based active (lidar) and passive (sun-photometry) techniques together with backtrajectory analysis and in-situ measurements is devoted to the characterization of dust intrusions. A case study of air masses advected from the Saharan region to the Canary Islands and the Iberian Peninsula, located relatively close and far away from the dust sources, respectively, was considered for this purpose. The observations were performed over three Spanish geographically strategic stations within the dust-influenced area along a common dust plume pathway monitored from 11 to 19 of March 2008. A 4-day long dust event (13–16 March) over the Santa Cruz de Tenerife Observatory (SCO), and a linked short 1-day dust episode (14 March) in the Southern Iberian Peninsula over the Atmospheric Sounding Station "El Arenosillo" (ARN) and the Granada station (GRA) were detected. Meteorological conditions favoured the dust plume transport over the area under study. Backtrajectory analysis clearly revealed the Saharan region as the source of the dust intrusion. Under the Saharan air masses influence, AERONET Aerosol Optical Depth at 500 nm (AOD500) ranged from 0.3 to 0.6 and Ångström Exponent at 440/675 nm wavelength pair (AE440/675) was lower than 0.5, indicating a high loading and predominance of coarse particles during those dusty events. Lidar observations characterized their vertical layering structure, identifying different aerosol contributions depending on altitude. In particular, the 3-km height dust layer transported from the Saharan region and observed over SCO site was later on detected at ARN and GRA stations. No significant differences were found in the lidar (extinction-to-backscatter) ratio (LR) estimation for that dust plume over all stations when a suitable aerosol scenario for lidar data retrieval is selected. Lidar-retrieved LR values of 60–70 sr were obtained during the main dust episodes. These similar LR values found in all the stations suggest that dust properties were kept nearly unchanged in the course of its medium-range transport. In addition, the potential impact on surface of that Saharan dust intrusion over the Iberian Peninsula was evaluated by means of ground-level in-situ measurements for particle deposition assessment together with backtrajectory analysis. However, no connection between those dust plumes and the particle sedimentation registered at ground level is found. Differences on particle deposition processes observed in both Southern Iberian Peninsula sites are due to the particular dust transport pattern occurred over each station. Discrepancies between columnar-integrated and ground-level in-situ measurements show a clear dependence on height of the dust particle size distribution. Then, further vertical size-resolved observations are needed for evaluation of the impact on surface of the Saharan dust arrival to the Iberian Peninsula.

In-cloud scavenging scheme for sectional aerosol modules – implementation in the framework of the Sectional Aerosol module for Large Scale Applications version 2.0 (SALSA2.0) global aerosol module

2021 ◽  
Author(s):  
Eemeli Holopainen ◽  
Harri Kokkola ◽  
Anton Laakso ◽  
Thomas Kühn
Keyword(s):  
Wet Deposition ◽  
Large Scale ◽  
Climate Model ◽  
Radiation Budget ◽  
Cloud Formation ◽  
The Arctic ◽  
Vertical Profiles ◽  
Size Classes ◽  
Aerosol Emission ◽  
Aerosol Module

<p><span>Black carbon (BC) affects the radiation budget of the Earth by absorbing solar radiation, darkening snow and ice covers, and influencing cloud formation and life cycle. Modelling BC in remote regions, such as the Arctic, has large inter-model variability which causes variation in the modelled aerosol effect over the Arctic. This variability can be due to differences in the transport of aerosol species which is affected by how wet deposition is modelled. </span></p><p><span> In this study we developed an aerosol size-resolved in-cloud wet deposition scheme for liquid and ice clouds for models which use a size-segregated aerosol description. This scheme was tested in the ECHAM-HAMMOZ global aerosol-climate model. The scheme was compared to the original wet deposition scheme which uses fixed scavenging coefficients for different sized particles. The comparison included vertical profiles and mass and number wet deposition fluxes, and it showed that the current scheme produced spuriously long BC lifetimes when compared to the estimates made in other studies. Thus, to find a better setup for simulating aerosol lifetimes and vertical profiles we conducted simulations where we altered the aerosol emission distribution and hygroscopicity.</span></p><p><span> We compared the modelled BC vertical profiles to the ATom aircraft campaign measurements. In addition, we compared the aerosol lifetimes against those from AEROCOM model means. We found that, without further tuning, the current scheme overestimates the BC concentrations and lifetimes more than the fixed scavenging scheme when compared to the measurements. Sensitivity studies showed that the model skill of reproducing the measured vertical BC mass concentrations improved when BC emissions were directed to larger size classes, they were mixed with soluble compounds during emission, or BC-containing particles were transferred to soluble size classes after aging. These changes also produced atmospheric BC lifetimes which were closer to AEROCOM model means. The best comparison with the measured vertical profiles and estimated BC lifetimes was when BC was mixed with soluble aerosol compounds during emission.</span></p>

scholarly journals The pulsating nature of large-scale Saharan dust transport as a result of interplays between mid-latitude Rossby waves and the North African Dipole Intensity

2017 ◽  
Vol 167 ◽  
pp. 586-602 ◽  
Author(s):  
E. Cuevas ◽  
A.J. Gómez-Peláez ◽  
S. Rodríguez ◽  
E. Terradellas ◽  
S. Basart ◽  
...  
Keyword(s):  
Large Scale ◽  
Rossby Waves ◽  
Saharan Dust ◽  
North African ◽  
Dust Transport ◽  
The North

scholarly journals Large Contribution of Coarse Mode to Aerosol Microphysical and Optical Properties: Evidence from Ground-Based Observations of a Transpacific Dust Outbreak at a High-Elevation North American Site

2017 ◽  
Vol 74 (5) ◽  
pp. 1431-1443 ◽  
Author(s):  
E. Kassianov ◽  
M. Pekour ◽  
C. Flynn ◽  
L. K. Berg ◽  
J. Beranek ◽  
...  
Keyword(s):  
North American ◽  
High Elevation ◽  
Saharan Dust ◽  
Large Contribution ◽  
Near Surface ◽  
Dust Transport ◽  
Aerosol Mass ◽  
Coarse Mode ◽  
Median Diameter ◽  
Transpacific Transport

Abstract This work is motivated by previous studies of transatlantic transport of Saharan dust and the observed quasi-static nature of coarse mode aerosol with a volume median diameter (VMD) of approximately 3.5 μm. The authors examine coarse mode contributions from transpacific transport of dust to North American aerosol properties using a dataset collected at the high-elevation Storm Peak Laboratory (SPL) and the nearby Atmospheric Radiation Measurement (ARM) Mobile Facility. Collected ground-based data are complemented by quasi-global model simulations and satellite and ground-based observations. The authors identify a major dust event associated mostly with a transpacific plume (about 65% of near-surface aerosol mass) in which the coarse mode with moderate (~3 μm) VMD is distinct and contributes substantially to total aerosol volume (up to 70%) and scattering (up to 40%). The results demonstrate that the identified plume at the SPL site has a considerable fraction of supermicron particles (VMD ~3 μm) and, thus, suggest that these particles have a fairly invariant behavior despite transpacific transport. If confirmed in additional studies, this invariant behavior may simplify considerably parameterizations for size-dependent processes associated with dust transport and removal.

scholarly journals Dust–air pollution dynamics over the Eastern Mediterranean

2015 ◽  
Vol 15 (5) ◽  
pp. 7493-7534
Author(s):  
M. Abdelkader ◽  
S. Metzger ◽  
M. Astitha ◽  
Z. Levin ◽  
J. Lelieveld
Keyword(s):  
Air Pollution ◽  
Atmospheric Chemistry ◽  
Climate Model ◽  
Eastern Mediterranean ◽  
Tropospheric Chemistry ◽  
Saharan Dust ◽  
Back Trajectory ◽  
Dust Deposition ◽  
Dust Transport ◽  
Frontal Systems

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 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 control the dust removal. Our results show the importance of chemical aging and deposition of the dust during transport. The relatively long travel periods of Saharan dust result in more sustained aging compared to Arabian dust. Sensitivity simulations indicate three times more rapid dust deposition of aged relative to pristine dust, which significantly decreases the dust lifetime and loading.

scholarly journals BAYWRF: a high-resolution present-day climatological atmospheric dataset for Bavaria

2020 ◽  
Vol 12 (4) ◽  
pp. 3097-3112
Author(s):  
Emily Collier ◽  
Thomas Mölg
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Large Scale ◽  
Wrf Model ◽  
Atmospheric Model ◽  
Climate Impact ◽  
Reanalysis Data ◽  
Near Surface ◽  
Local Climate ◽  
The Impact

Abstract. Climate impact assessments require information about climate change at regional and ideally also local scales. In dendroecological studies, this information has traditionally been obtained using statistical methods, which preclude the linkage of local climate changes to large-scale drivers in a process-based way. As part of recent efforts to investigate the impact of climate change on forest ecosystems in Bavaria, Germany, we developed a high-resolution atmospheric modelling dataset, BAYWRF, for this region over the thirty-year period of September 1987 to August 2018. The atmospheric model employed in this study, the Weather Research and Forecasting (WRF) model, was configured with two nested domains of 7.5 and 1.5 km grid spacing centred over Bavaria and forced at the outer lateral boundaries by ERA5 reanalysis data. Using an extensive network of observational data, we evaluate (i) the impact of using grid analysis nudging for a single-year simulation of the period of September 2017 to August 2018 and (ii) the full BAYWRF dataset generated using nudging. The evaluation shows that the model represents variability in near-surface meteorological conditions generally well, although there are both seasonal and spatial biases in the dataset that interested users should take into account. BAYWRF provides a unique and valuable tool for investigating climate change in Bavaria with high interdisciplinary relevance. Data from the finest-resolution WRF domain are available for download at daily temporal resolution from a public repository at the Open Science Framework (Collier, 2020; https://doi.org/10.17605/OSF.IO/AQ58B).

Eastern Mediterranean Drying: Projected Changes in Dynamics and Thermodynamics and Their Relation to Large-Scale Processes

2021 ◽  
Author(s):  
Eilat Elbaum ◽  
Chaim I. Garfinkel ◽  
Ori Adam ◽  
Efrat Morin
Keyword(s):  
Surface Temperature ◽  
Large Scale ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Coupled Model ◽  
Past Century ◽  
Stratospheric Polar Vortex ◽  
Dynamic Component ◽  
Near Surface ◽  
Projected Changes

<p>Observations from the past century and projections for the end of this century show a decrease in precipitation over the eastern Mediterranean Sea and surrounding land areas. Changes in precipitation are controlled by both thermodynamic and dynamic processes, but the relative contributions of these processes, in particular on regional scales, is not well understood. Models included in the fifth and sixth phases of the Coupled Model Intercomparison Project (CMIP5 and CMIP6) exhibit a wide spread in the magnitude of expected drying in the eastern Mediterranean region, as well as in other meteorological variables. By decomposing projected changes in the moisture budget in 48 models into mean dynamic and mean thermodynamic components, we explore the contribution of each of these components to the model spread in regional drying. In the eastern Mediterranean, the dynamic component explains 64% and the thermodynamic component explains 9% of the variance in net precipitation change. We further examine the relation of the regional components to changes in five large-scale mechanisms: tropical vertical stratification, global near-surface temperature, latitude of the eddy-driven jet, stratospheric polar vortex, and arctic amplification. Of these, we find that a decrease in the dynamical contribution in the eastern Mediterranean, causing regional drying, is most strongly related to a northward shift of the eddy-driven jet and a rise in global near-surface temperature.</p>

scholarly journals Analysis of the Surface Subsidence Induced by Mining Near-Surface Thick Lead-Zinc Deposit Based on Numerical Simulation

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 717
Author(s):  
Yifan Zhao ◽  
Xingdong Zhao ◽  
Jiajia Dai ◽  
Wenlong Yu
Keyword(s):  
Large Scale ◽  
Surface Subsidence ◽  
Ecological Benefits ◽  
Near Surface ◽  
Economic Operation ◽  
Lead Zinc ◽  
Zinc Mine ◽  
Scale Surface ◽  
Good Agreement

This paper describes a case study of surface subsidence in the Hongling Lead-Zinc Mine. Hongling Lead-Zinc Mine is located in Inner Mongolia, China, about 240 km away from the border between China and Mongolia. There is a batch of outcrops of the near-surface thick steep-dip metamorphic orebody. The large-scale surface subsidence induced by underground excavation has brought some impact on the safety of herdsmen and their daily husbandry activities nearby. The requirements of reclamation for subsidence areas in the relevant laws and regulations, raise enormous pressure and risk on safe and economic operation. In this paper, a 3D numerical model of this mine was built by 3DMine and FLAC3D to analyse the excavation procedure and mechanism. The results of the simulation were in good agreement with the field subsidence data collected by satellites and unmanned aerial vehicles from 2009 to 2019. The analysis showed that the current mining method—an integrated underground method of stoping and caving—accelerated the surface subsidence, and some measures of monitoring, controlling and management were expected to take in order to improve economic and ecological benefits.

Sign in / Sign up

Export Citation Format

Share Document