scholarly journals Aerosols dynamics in the atmosphere over Eastern Europe by means of AERONET according to weather conditions during summer 2010

2017 ◽  
pp. 5-16
Author(s):  
E. Galytska ◽  
V. Danylevsky ◽  
S. Snizhko
Keyword(s):  
Optical Properties ◽  
Eastern Europe ◽  
Forest Fires ◽  
Complex Analysis ◽  
Aerosol Particles ◽  
Weather Conditions ◽  
Transport Processes ◽  
Synoptic Situation ◽  
Aerosol Layer ◽  
Hysplit Model

Introduction. Aerosols in the Earth's atmosphere are not only air pollutants but also a factor that affects the climate. The study of the dynamics of aerosol layer properties and aerosol particles properties, and revealing sources of the atmosphere pollution by aerosols is one of the urgent problems of modern environmental sciences. Monitoring of the air pollution caused by aerosols contributes to the determination of its effects on the climate and to the reduction of its negative impacts on the health of the population. The purpose of this paper is to present the analysis of the dynamics of aerosols in the atmosphere over Eastern Europe. Thus, latest technologies and approaches are used: remote ground-based measurements of the optical properties of aerosol particles with the international sun photometers network AERONET; analysis of fires distribution during summer 2010 with the data application from satellite instrument MODIS; atmospheric dynamics research with the analysis of synoptic situation and modeling of transport of particles with the application of HYSPLIT model. Results. The peculiarities of changes of aerosol optical depth at 500 nm spectral channel and Angstrom parameter 440-870 nm for 10 AERONET stations in Eastern Europe are discussed in the article. The authors provide complex analysis of aerosols distribution together with natural processes as forest fires and overview these processes considering weather conditions that were conducive for aerosols accumulation during that time. HYSPLIT back trajectories for mentioned stations in the altitude 0.5, 1.5, 3, 4 and 5 km are used as the improvement of results of synoptic analysis. Clear advantage of modelling of transport processes give the ability to receive detailed transport paths, which makes easier to distinguish the origin of aerosols. Conclusion. Detailed research of aerosols with the application of up-to-date technologies makes the analysis of the optical properties of aerosols over large area quite efficient. The obvious effect of forest fires in European territory of Russia (UTR) on air quality of observational stations of Ukraine, Russia, Moldova, Romania, Poland, Belarus and Estonia is detected and analysed. The further application of satellite measurements of optical properties of aerosols are attempted to be implemented to the further research.

scholarly journals Direct radiative effect of the Russian wildfires and their impact on air temperature and atmospheric dynamics during August 2010

2013 ◽  
Vol 13 (6) ◽  
pp. 15829-15866
Author(s):  
J. C. Péré ◽  
B. Bessagnet ◽  
M. Mallet ◽  
F. Waquet ◽  
I. Chiapello ◽  
...  
Keyword(s):  
Optical Properties ◽  
Eastern Europe ◽  
Air Temperature ◽  
Regional Scale ◽  
Air Entrainment ◽  
Atmospheric Dynamics ◽  
Aerosol Layer ◽  
Satellite Measurements ◽  
Near Surface ◽  
Aerosol Plume

Abstract. The present study aims at investigating the shortwave aerosol direct radiative forcing (ADRF) and its feedback on air temperature and atmospheric dynamics during a major fire event that occurred in Russia during August 2010. The methodology is based on an off-line coupling between the CHIMERE chemistry-transport and the Weather Research and Forecasting (WRF) models. First, simulations for the period 5–12 August 2010 have been evaluated by using AERONET and satellite measurements of the POLarization and Directionality of the Earth's Reflectance (POLDER) and the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) sensors. During this period, elevated POLDER AOT are found over a large part of Eastern Europe with values above 2 (at 550 nm) in the aerosol plume. According to CALIOP observations, particles remain confined within the first five kilometres of the atmospheric layer. Comparisons with satellite measurements show the ability of CHIMERE to reproduce the regional and vertical distribution of aerosols during their transport from the source region. Over Moscow, AERONET measurements indicate an important increase of AOT (340 nm) from 0.7 on 5 August to 2–4 between 6 and 10 August when the aerosol plume is advected over the city. Particles are mainly observed in the fine size mode (radius in the range 0.2–0.4 μm) and are characterized by elevated SSA (0.95–0.96 between 440 and 1020 nm). Also, comparisons of simulations with AERONET measurements show that aerosol physical-optical properties (size distribution, AOT, SSA) have been well simulated over Moscow in term of intensity and/or spectral dependence. Secondly, modelled aerosol optical properties have been used as input in the radiative transfer code of WRF to evaluate their direct radiative impact. Simulations indicate a significant reduction of solar radiation at the ground (up to 80–150 W m−2 in diurnal-averaged) over a large part of Eastern Europe due to the presence of the aerosol plume. This ADRF causes an important reduction of the near-surface air temperature between 0.2 and 2.6°C at a regional scale. Moscow has been also affected by the aerosol plume, especially between 6 and 10 August. During this period, aerosol causes a significant reduction of surface shortwave radiation (up to 70–84 W m−2 in diurnal-averaged) with a moderate part (20–30%) due to solar absorption within the aerosol layer. The resulting feedbacks lead to a cooling of the air up to 1.6°C at the surface and 0.1°C at an altitude of 1500–2000 m (in diurnal-averaged), that contribute to stabilize the atmospheric boundary layer (ABL). Indeed, a reduction of the ABL height of 13 to 65% have been simulated during daytime in presence of aerosols. This decrease is the result of a lower air entrainment as the vertical wind speed in the ABL is shown to be reduced by 5 to 80% (at midday) when the feedback of the ADRF is taken into account. In turn, CHIMERE simulations driven by the WRF meteorological fields including this ADRF feedback result in a large increase in the modeled near-surface PM10 concentrations (up to 99%) due to their lower vertical dilution in the ABL, which tend to reduce model biases with the ground PM10 values observed over Moscow during this specific period.

scholarly journals Retrieval of aerosol optical properties over Beijing: a comparison between SKYNET and AERONET

2019 ◽  
Author(s):  
Xianyi Yang ◽  
Huizheng Che ◽  
Hitoshi Irie ◽  
Quanliang Chen ◽  
Ke Gui ◽  
...  
Keyword(s):  
Optical Properties ◽  
Meteorological Data ◽  
Aerosol Particles ◽  
Fine Particulate Matter ◽  
Correlation Coefficients ◽  
Weather Conditions ◽  
Distribution Patterns ◽  
Single Scattering ◽  
Aerosol Optical Properties ◽  
Pollution Event

Abstract. This study assesses the performance of SKYNET in comparison to AERONET (Aerosol Robotic Network) for retrieving aerosol optical properties (AOPs) in Beijing, China. The results obtained from simultaneous measurements show high correlation coefficients (> 0.994) for aerosol optical depth (AOD) at each wavelength. The highest correlation coefficient for Ångström exponent is 0.825, at 500–870 nm. The single scattering albedo (SSA) of SKYNET is systematically larger than that of AERONET at each wavelength, and adjusting the SVA (solid view angle) and SA (surface albedo) input values can easily affect the value of SKYNET SSA. The volume size distribution patterns derived from the two networks’ instruments are both bimodal, which is typical, while the coarse-mode volume of SKYNET is larger than that of AERONET on average. According to the frequency distribution of aerosol particles, coarser aerosol particles often present in autumn and finer particles usually exist in winter, and there are more absorbent aerosol particles in winter. SKYNET data, combined with meteorological data, CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations) data, backward trajectories, and WPSCF (weighted potential source contribution function) and WCWT (weighted concentrated weighted trajectory) analyses are used to analyze a serious pollution event in winter over Beijing. The results suggest that it was not only affected by local emissions but also by regional transport. The AOPs under three weather conditions (clean, dusty, haze) in Beijing are discussed. The values of AOD on haze days are about 10.3, 10.0, 8.7, 6.3 and 6.2 times larger than those on clean days at 400, 500, 670, 870 and 1020 nm, respectively; and under haze conditions, the PM2.5 (fine particulate matter) is about 7.6 times larger than that under clean conditions. The values of AOD on dusty days are about 7.1, 7.4, 7.0, 5.3 and 5.2 times larger than those on clean days at 400, 500, 670, 870 and 1020 nm, respectively; and under haze conditions, the PM2.5 is about 5.2 times larger than that under clean conditions.

scholarly journals Regional aerosol optical properties and radiative impact of the extreme smoke event in the European Arctic in spring 2006

2007 ◽  
Vol 7 (4) ◽  
pp. 9519-9559 ◽  
Author(s):  
C. Lund Myhre ◽  
C. Toledano ◽  
G. Myhre ◽  
K. Stebel ◽  
K. E. Yttri ◽  
...  
Keyword(s):  
Air Pollution ◽  
Optical Properties ◽  
Eastern Europe ◽  
Radiative Forcing ◽  
Arctic Region ◽  
The Arctic ◽  
Synoptic Situation ◽  
Aerosol Optical Properties ◽  
Modis Aod ◽  
European Arctic

Abstract. In spring 2006 a special meteorological situation occurred in the European Arctic region giving record high levels of air pollution. The synoptic situation resulted in extensive transport of pollution predominantly from agricultural fires in Eastern Europe into the Arctic region and record high air-pollution levels were measured at the Zeppelin observatory at Ny-Ålesund (78°54' N, 11°53' E) in the period from 25 April to 12 May. In the present study we investigate the optical properties of the aerosols from this extreme event and we estimate the radiative forcing of this episode. We examine the aerosol optical properties from the source region and into the European Arctic and explore the evolution of the episode and the changes in the optical properties. A number of sites in Eastern Europe, Northern Scandinavia and Svalbard are included in the study. In addition to AOD measurements, we explored lidar measurements from Minsk, ALOMAR (Arctic Lidar Observatory for Middle Atmosphere Research at Andenes) and Ny-Ålesund. For the AERONET sites included (Minsk, Toravere, Hornsund) we have further studied the evolution of the aerosol size. Importantly, at Svalbard it is consistency between the AERONET measurements and calculations of single scattering albedo based on aerosol chemical composition. We have found strong agreement between the satellite daily MODIS AOD and the ground-based AOD observations. This agreement is crucial for the radiative forcing calculations. We calculate a strong negative radiative forcing for the most polluted days employing the analysed ground based data, MODIS AOD and a multi-stream model for radiative transfer of solar radiation.

scholarly journals Impact of wild forest fires in Eastern Europe on aerosol composition and particle optical properties

Oceanologia ◽  
2016 ◽  
Vol 58 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Tymon Zielinski ◽  
Tomasz Petelski ◽  
Agata Strzalkowska ◽  
Paulina Pakszys ◽  
Przemyslaw Makuch
Keyword(s):  
Optical Properties ◽  
Eastern Europe ◽  
Forest Fires ◽  
Aerosol Composition

Potential Impacts of Extreme Heat and Bushfires on Dementia

2021 ◽  
Vol 79 (3) ◽  
pp. 969-978
Author(s):  
Taya L. Farugia ◽  
Carla Cuni-Lopez ◽  
Anthony R. White
Keyword(s):  
Rural Communities ◽  
Natural Disasters ◽  
Low Socioeconomic Status ◽  
Forest Fires ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Extreme Heat ◽  
Indigenous Populations ◽  
Future Research ◽  
Diagnosis Of Dementia

Australia often experiences natural disasters and extreme weather conditions such as: flooding, sandstorms, heatwaves, and bushfires (also known as wildfires or forest fires). The proportion of the Australian population aged 65 years and over is increasing, alongside the severity and frequency of extreme weather conditions and natural disasters. Extreme heat can affect the entire population but particularly at the extremes of life, and patients with morbidities. Frequently identified as a vulnerable demographic in natural disasters, there is limited research on older adults and their capacity to deal with extreme heat and bushfires. There is a considerable amount of literature that suggests a significant association between mental disorders such as dementia, and increased vulnerability to extreme heat. The prevalence rate for dementia is estimated at 30%by age 85 years, but there has been limited research on the effects extreme heat and bushfires have on individuals living with dementia. This review explores the differential diagnosis of dementia, the Australian climate, and the potential impact Australia’s extreme heat and bushfires have on individuals from vulnerable communities including low socioeconomic status Indigenous and Non-Indigenous populations living with dementia, in both metropolitan and rural communities. Furthermore, we investigate possible prevention strategies and provide suggestions for future research on the topic of Australian bushfires and heatwaves and their impact on people living with dementia. This paper includes recommendations to ensure rural communities have access to appropriate support services, medical treatment, awareness, and information surrounding dementia.

Le feu : agent de contrôle des insectes

1994 ◽  
Vol 70 (4) ◽  
pp. 468-472
Author(s):  
M. Martin Dupuis
Keyword(s):  
Forest Fires ◽  
Insect Pests ◽  
Weather Conditions ◽  
Fire Intensity ◽  
Fire Control ◽  
Fire Use ◽  
Wild Fire ◽  
Controlled Burning ◽  
Long Run ◽  
Evolution Understanding

For millenia, fire and insects have played an important role in forested land evolution. Understanding the roles they play can be important in helping us not only to control them, but to use them as an ecological tool. Also, we notice some important interactions between these two agents. As insects affect fire, fire may control insect pests. Controlled burning may provide excellent results, but allows a very slight margin for possible errors. Fire use as an insect mangement tool, requires a very precise and wide knowledge of weather conditions, fire intensity, insect's life cycle, available fuels, and type of ecosystem involved.After a long run of experiences and research, we notice that fire has been and will always be an important factor in equilibrium of some ecosystems. Since wild fire prevention campaigns and the emergence of insecticides, some forests have become excessively vulnerable to insect pests. Proper knowledge, and use of fire control, rather than immediate suppression of forest fires, would allow us to conserve various ecosystems in a healthy balance.

scholarly journals One year of Raman lidar observations of free-tropospheric aerosol layers over South Africa

2015 ◽  
Vol 15 (10) ◽  
pp. 5429-5442 ◽  
Author(s):  
E. Giannakaki ◽  
A. Pfüller ◽  
K. Korhonen ◽  
T. Mielonen ◽  
L. Laakso ◽  
...  
Keyword(s):  
South Africa ◽  
Optical Properties ◽  
Biomass Burning ◽  
Mean Value ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Tropospheric Aerosol ◽  
Wide Range ◽  
Significant Difference ◽  
532 Nm

Abstract. Raman lidar data obtained over a 1 year period has been analysed in relation to aerosol layers in the free troposphere over the Highveld in South Africa. In total, 375 layers were observed above the boundary layer during the period 30 January 2010 to 31 January 2011. The seasonal behaviour of aerosol layer geometrical characteristics, as well as intensive and extensive optical properties were studied. The highest centre heights of free-tropospheric layers were observed during the South African spring (2520 ± 970 m a.g.l., also elsewhere). The geometrical layer depth was found to be maximum during spring, while it did not show any significant difference for the rest of the seasons. The variability of the analysed intensive and extensive optical properties was high during all seasons. Layers were observed at a mean centre height of 2100 ± 1000 m with an average lidar ratio of 67 ± 25 sr (mean value with 1 standard deviation) at 355 nm and a mean extinction-related Ångström exponent of 1.9 ± 0.8 between 355 and 532 nm during the period under study. Except for the intensive biomass burning period from August to October, the lidar ratios and Ångström exponents are within the range of previous observations for urban/industrial aerosols. During Southern Hemispheric spring, the biomass burning activity is clearly reflected in the optical properties of the observed free-tropospheric layers. Specifically, lidar ratios at 355 nm were 89 ± 21, 57 ± 20, 59 ± 22 and 65 ± 23 sr during spring (September–November), summer (December–February), autumn (March–May) and winter (June–August), respectively. The extinction-related Ångström exponents between 355 and 532 nm measured during spring, summer, autumn and winter were 1.8 ± 0.6, 2.4 ± 0.9, 1.8 ± 0.9 and 1.8 ± 0.6, respectively. The mean columnar aerosol optical depth (AOD) obtained from lidar measurements was found to be 0.46 ± 0.35 at 355 nm and 0.25 ± 0.2 at 532 nm. The contribution of free-tropospheric aerosols on the AOD had a wide range of values with a mean contribution of 46%.

scholarly journals An Advanced Numerical Trajectory Model Tracks a Corn Earworm Moth Migration Event in Texas, USA

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 115 ◽  
Author(s):  
Qiu-Lin Wu ◽  
Gao Hu ◽  
John Westbrook ◽  
Gregory Sword ◽  
Bao-Ping Zhai
Keyword(s):  
Helicoverpa Zea ◽  
Wrf Model ◽  
Weather Conditions ◽  
Computational Design ◽  
Corn Earworm ◽  
Long Distance ◽  
Hysplit Model ◽  
Trajectory Model ◽  
Trajectory Simulation ◽  
Migration Event

Many methods for trajectory simulation, such as Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT), have been developed over the past several decades and contributed greatly to our knowledge in insect migratory movement. To improve the accuracy of trajectory simulation, we developed a new numerical trajectory model, in which the self-powered flight behaviors of insects are considered and trajectory calculation is driven by high spatio-temporal resolution weather conditions simulated by the Weather Research and Forecasting (WRF) model. However, a rigorous evaluation of the accuracy of different trajectory models on simulated long-distance migration is lacking. Hence, in this study our trajectory model was evaluated by a migration event of the corn earworm moth, Helicoverpa zea, in Texas, USA on 20–22 March 1995. The results indicate that the simulated migration trajectories are in good agreement with occurrences of all pollen-marked male H. zea immigrants monitored in pheromone traps. Statistical comparisons in the present study suggest that our model performed better than the popularly-used HYSPLIT model in simulating migration trajectories of H. zea. This study also shows the importance of high-resolution atmospheric data and a full understanding of migration behaviors to the computational design of models that simulate migration trajectories of highly-flying insects.

scholarly journals Using the OMI Aerosol Index and Absorption Aerosol Optical Depth to evaluate the NASA MERRA Aerosol Reanalysis

2014 ◽  
Vol 14 (23) ◽  
pp. 32177-32231 ◽  
Author(s):  
V. Buchard ◽  
A. M. da Silva ◽  
P. R. Colarco ◽  
A. Darmenov ◽  
C. A. Randles ◽  
...  
Keyword(s):  
Optical Properties ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Biomass Burning ◽  
Saharan Dust ◽  
Aerosol Layer ◽  
Anthropogenic Aerosols ◽  
Aerosol Absorption ◽  
Modis Aod ◽  
Aerosol Index

Abstract. A radiative transfer interface has been developed to simulate the UV Aerosol Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and Aerosol Absorption Optical Depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the Aerosol Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the South African and South American biomass burning regions indicates that revising the spectrally-dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons. Finally, during a period where the Asian region was mainly dominated by anthropogenic aerosols, we have performed a qualitative analysis in which the specification of anthropogenic emissions in GEOS-5 is adjusted to provide insight into discrepancies observed in AI comparisons.

scholarly journals Lidar profiling of aerosol optical properties from Paris to Lake Baikal (Siberia)

2015 ◽  
Vol 15 (9) ◽  
pp. 5007-5026 ◽  
Author(s):  
E. Dieudonné ◽  
P. Chazette ◽  
F. Marnas ◽  
J. Totems ◽  
X. Shang
Keyword(s):  
Optical Properties ◽  
Lake Baikal ◽  
Forest Fires ◽  
Western Europe ◽  
Lower Boundary ◽  
Aerosol Optical Properties ◽  
Imaging Spectrometer ◽  
Moderate Resolution ◽  
The Difference ◽  
First Time

Abstract. In June 2013, a ground-based mobile lidar performed the ~10 000 km ride from Paris to Ulan-Ude, near Lake Baikal, profiling for the first time aerosol optical properties all the way from western Europe to central Siberia. The instrument was equipped with N2-Raman and depolarization channels that enabled an optical speciation of aerosols in the low and middle troposphere. The extinction-to-backscatter ratio (also called lidar ratio or LR) and particle depolarization ratio (PDR) at 355 nm have been retrieved. The LR in the lower boundary layer (300–700 m) was found to be 63 ± 17 sr on average during the campaign with a distribution slightly skewed toward higher values that peaks between 50 and 55 sr. Although the difference is small, PDR values observed in Russian cities (>2%, except after rain) are systematically higher than the ones measured in Europe (<1%), which is probably an effect of the lifting of terrigenous aerosols by traffic on roads. Biomass burning layers from grassland or/and forest fires in southern Russia exhibit LR values ranging from 65 to 107 sr and from 3 to 4% for the PDR. During the route, desert dust aerosols originating from the Caspian and Aral seas regions were characterized for the first time, with a LR (PDR) of 43 ± 14 sr (23 ± 2%) for pure dust. The lidar observations also showed that this dust event extended over 2300 km and lasted for ~6 days. Measurements from the Moderate Resolution Imaging Spectrometer (MODIS) show that our results are comparable in terms of aerosol optical thickness (between 0.05 and 0.40 at 355 nm) with the mean aerosol load encountered throughout our route.

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