Ground-based in situ measurements of near-surface aerosol mass concentration over Anantapur: Heterogeneity in source impacts

2012 ◽  
Vol 30 (1) ◽  
pp. 235-246 ◽  
Author(s):  
B. S. K. Reddy ◽  
K. R. Kumar ◽  
G. Balakrishnaiah ◽  
K. R. Gopal ◽  
R. R. Reddy ◽  
...  
Keyword(s):  
Mass Concentration ◽  
In Situ Measurements ◽  
Near Surface ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration

scholarly journals Vertical profiles of aerosol mass concentration derived by unmanned airborne in situ and remote sensing instruments during dust events

2018 ◽  
Vol 11 (5) ◽  
pp. 2897-2910 ◽  
Author(s):  
Dimitra Mamali ◽  
Eleni Marinou ◽  
Jean Sciare ◽  
Michael Pikridas ◽  
Panagiotis Kokkalis ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mass Concentration ◽  
Climate Models ◽  
In Situ Measurements ◽  
Saharan Dust ◽  
Dust Particles ◽  
Vertical Profiles ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration

Abstract. In situ measurements using unmanned aerial vehicles (UAVs) and remote sensing observations can independently provide dense vertically resolved measurements of atmospheric aerosols, information which is strongly required in climate models. In both cases, inverting the recorded signals to useful information requires assumptions and constraints, and this can make the comparison of the results difficult. Here we compare, for the first time, vertical profiles of the aerosol mass concentration derived from light detection and ranging (lidar) observations and in situ measurements using an optical particle counter on board a UAV during moderate and weak Saharan dust episodes. Agreement between the two measurement methods was within experimental uncertainty for the coarse mode (i.e. particles having radii >0.5 µm), where the properties of dust particles can be assumed with good accuracy. This result proves that the two techniques can be used interchangeably for determining the vertical profiles of aerosol concentrations, bringing them a step closer towards their systematic exploitation in climate models.

In situ measurements of aerosol mass concentration and radiative properties in Xianghe, southeast of Beijing

2007 ◽  
Vol 112 (D23) ◽  
Author(s):  
Zahra Chaudhry ◽  
J. Vanderlei Martins ◽  
Zhanqing Li ◽  
Si-Chee Tsay ◽  
Hongbin Chen ◽  
...  
Keyword(s):  
Mass Concentration ◽  
In Situ Measurements ◽  
Radiative Properties ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration

scholarly journals Retrieval of Vertical Mass Concentration Distributions—Vipava Valley Case Study

2019 ◽  
Vol 11 (2) ◽  
pp. 106 ◽  
Author(s):  
Longlong Wang ◽  
Samo Stanič ◽  
Klemen Bergant ◽  
William Eichinger ◽  
Griša Močnik ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Mass Concentration ◽  
Mineral Dust ◽  
Small Scale ◽  
Vertical Profiles ◽  
Total Uncertainty ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Aerosol Types

Aerosol vertical profiles are valuable inputs for the evaluation of aerosol transport models, in order to improve the understanding of aerosol pollution ventilation processes which drive the dispersion of pollutants in mountainous regions. With the aim of providing high-accuracy vertical distributions of particle mass concentration for the study of aerosol dispersion in small-scale valleys, vertical profiles of aerosol mass concentration for aerosols from different sources (including Saharan dust and local biomass burning events) were investigated over the Vipava valley, Slovenia, a representative hot-spot for complex mixtures of different aerosol types of both anthropogenic and natural origin. The analysis was based on datasets taken between 1–30 April 2016. In-situ measurements of aerosol size, absorption, and mass concentration were combined with lidar remote sensing, where vertical profiles of aerosol concentration were retrieved. Aerosol samples were characterized by SEM-EDX, to obtain aerosol morphology and chemical composition. Two cases with expected dominant presence of different specific aerosol types (mineral dust and biomass-burning aerosols) show significantly different aerosol properties and distributions within the valley. In the mineral dust case, we observed a decrease of the elevated aerosol layer height and subsequent spreading of mineral dust within the valley, while in the biomass-burning case we observed the lifting of aerosols above the planetary boundary layer (PBL). All uncertainties of size and assumed optical properties, combined, amount to the total uncertainty of aerosol mass concentrations below 30% within the valley. We have also identified the most indicative in-situ parameters for identification of aerosol type.

scholarly journals Size distribution of near-surface aerosols and its relation to the columnar aerosol optical depths

2004 ◽  
Vol 22 (10) ◽  
pp. 3347-3351 ◽  
Author(s):  
P. S. Pillai ◽  
K. Krishna Moorthy
Keyword(s):  
Size Distribution ◽  
Quartz Crystal Microbalance ◽  
Relative Abundance ◽  
Mass Concentration ◽  
Quartz Crystal ◽  
Near Surface ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Multi Wavelength ◽  
Aerosol Properties

Abstract. Simultaneous data on Aerosol Optical Depth (AOD) and size segregated, near-surface, aerosol mass concentration was obtained from a Multi wavelength Solar Radiometer (MWR) and Quartz Crystal Microbalance Impactor (QCM), respectively. These were used to examine the association between near-surface aerosol properties and columnar AOD. The spectral AODs were approximated to the Ångström relation τp=βλ-α, and the wavelength exponent α and turbidity coefficient β have been obtained. In general, α was found to be well associated with the relative abundance of accumulation mode aerosols (estimated from the simultaneous QCM data) while β followed the variations of the coarse mode aerosol mass concentration; the association being closer during periods of continental airmass.

scholarly journals Development of a three-dimensional variational assimilation system for lidar profile data based on a size-resolved aerosol model in WRF-Chem model v3.9.1 and its application in PM<sub>2.5</sub> forecasts across China

2020 ◽  
Author(s):  
Yanfei Liang ◽  
Zengliang Zang ◽  
Dong Liu ◽  
Peng Yan ◽  
Yiwen Hu ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Three Dimensional ◽  
Initial Field ◽  
Forecast Performance ◽  
Near Surface ◽  
Aerosol Model ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Particulate Matter 2.5 ◽  
Assimilation System

Abstract. For the aerosol variables in the model for simulating aerosol interactions and chemistry (MOSAIC)-4bin chemical scheme in the Weather Research and Forecasting–Chemistry (WRF–Chem) model, this study presents an observation forward aerosol extinction coefficient (AEC) and aerosol mass concentration (AMC) operator and corresponding adjoint based on the interagency monitoring of protected visual environments (IMPROVE) equation, and then a three-dimensional variational (3-DVAR) data assimilation system (DA) is developed for lidar AECs and AMCs. DA experiments are conducted based on AEC profiles measured by five light detection and ranging (lidar) systems as well as mass concentration (MC) data measured at over 1,500 ground environmental monitoring stations across China for particulate matter 2.5 µm or less in diameter (PM2.5) and PM between 2.5 and 10 µm in diameter (PM10). An experiment comparing assimilated and without assimilated measurements finds the following. While only five lidars were available within the simulation region (approximately 2.33 million km2 in size), assimilating lidar AEC data alone can effectively improve the accuracy of the initial field of the WRF–Chem as well as its forecast performance for PM2.5MCs. Compared to the without assimilated experiment, DA reduces the root mean square error of surface PM2.5MCs in the initial field of the model by 10.5 μg/m3 (17.6 %). Moreover, the positive effect resulting from the optimization of the initial field for AMCs can last for more than 24 h. By taking advantage of lidar aerosol vertical profile information and the near-surface PM MC observations, assimilating lidar AEC and surface PM2.5 (PM10) simultaneously can effectively integrate their observed information and generate a more accurate 3D aerosol analysis field.

scholarly journals Vertical profiles of aerosol mass concentrations observed during dust events by unmanned airborne in-situ and remote sensing instruments

2018 ◽  
Author(s):  
Dimitra Mamali ◽  
Eleni Marinou ◽  
Jean Sciare ◽  
Michael Pikridas ◽  
Panagiotis Kokkalis ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Atmospheric Aerosols ◽  
Climate Models ◽  
In Situ Measurements ◽  
Saharan Dust ◽  
Dust Particles ◽  
Vertical Profiles ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration

Abstract. In-situ measurements using Unmanned Aerial Vehicles (UAVs) and remote sensing observations can independently provide dense vertically-resolved measurements of atmospheric aerosols; information which is highly required in climate models. In both cases, inverting the recorded signals to useful information requires assumptions and constraints, and this can make the comparison of the results difficult. Here we compare, for the first time, vertical profiles of the aerosol mass concentration derived from Light Detection And Ranging (lidar) observations and in-situ measurements using an Optical Particle Counter (OPC) onboard a UAV during moderate and weak Saharan dust episodes. Agreement between the two measurement methods was within experimental uncertainty for the coarse-mode (i.e., particles having radii > 0.5 μm) where the properties of dust particles can be assumed with good accuracy. This result proves that the two techniques can be used interchangeably for determining the vertical profiles of the aerosol concentrations, bringing them a step closer towards their systematic exploitation in climate models.

scholarly journals Influence of the aerosol solar extinction on photochemistry during the 2010 Russian wildfires episode

2015 ◽  
Vol 15 (19) ◽  
pp. 10983-10998 ◽  
Author(s):  
J. C. Péré ◽  
B. Bessagnet ◽  
V. Pont ◽  
M. Mallet ◽  
F. Minvielle
Keyword(s):  
Transport Model ◽  
Regional Scale ◽  
Model Performance ◽  
Surface Concentration ◽  
Near Surface ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Air Quality Measurements ◽  
Photolysis Rates ◽  
Optical Module

Abstract. In this work, impact of aerosol solar extinction on the photochemistry over eastern Europe during the 2010 wildfires episode is discussed for the period from 5 to 12 August 2010, which coincides to the peak of fire activity. The methodology is based on an online coupling between the chemistry-transport model CHIMERE (extended by an aerosol optical module) and the radiative transfer code TUV. Results of simulations indicate an important influence of the aerosol solar extinction, in terms of intensity and spatial extent, with a reduction of the photolysis rates of NO2 and O3 up to 50 % (in daytime average) along the aerosol plume transport. At a regional scale, these changes in photolysis rates lead to a 3–15 % increase in the NO2 daytime concentration and to an ozone reduction near the surface of 1–12 %. The ozone reduction is shown to occur over the entire boundary layer, where aerosols are located. Also, the total aerosol mass concentration (PM10) is shown to be decreased by 1–2 %, on average during the studied period, caused by a reduced formation of secondary aerosols such as sulfates and secondary organics (4–10 %) when aerosol impact on photolysis rates is included. In terms of model performance, comparisons of simulations with air quality measurements at Moscow indicate that an explicit representation of aerosols interaction with photolysis rates tend to improve the estimation of the near-surface concentration of ozone and nitrogen dioxide as well as the formation of inorganic aerosol species such as ammonium, nitrates and sulfates.

Aerosol mass concentration measurements: Recent advancements of real-time nano/micro systems

2017 ◽  
Vol 114 ◽  
pp. 42-54 ◽  
Author(s):  
U. Soysal ◽  
E. Géhin ◽  
E. Algré ◽  
B. Berthelot ◽  
G. Da ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Concentration ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Concentration Measurements ◽  
Micro Systems

scholarly journals Numerical simulation of extreme snow melt observed at the SIGMA-A site, northwest Greenland, during summer 2012

2015 ◽  
Vol 9 (1) ◽  
pp. 495-539
Author(s):  
M. Niwano ◽  
T. Aoki ◽  
S. Matoba ◽  
S. Yamaguchi ◽  
T. Tanikawa ◽  
...  
Keyword(s):  
Heat Flux ◽  
Grain Size ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
In Situ Measurements ◽  
The Arctic ◽  
Snow Surface ◽  
Near Surface ◽  
Surface Snow

Abstract. The surface energy balance (SEB) from 30 June to 14 July 2012 at site SIGMA (Snow Impurity and Glacial Microbe effects on abrupt warming in the Arctic)-A, (78°03' N, 67°38' W; 1490 m a.s.l.) on the northwest Greenland Ice Sheet (GrIS) was investigated by using in situ atmospheric and snow measurements, as well as numerical modeling with a one-dimensional, multi-layered, physical snowpack model called SMAP (Snow Metamorphism and Albedo Process). At SIGMA-A, remarkable near-surface snowmelt and continuous heavy rainfall (accumulated precipitation between 10 and 14 July was estimated to be 100 mm) were observed after 10 July 2012. Application of the SMAP model to the GrIS snowpack was evaluated based on the snow temperature profile, snow surface temperature, surface snow grain size, and shortwave albedo, all of which the model simulated reasonably well. However, comparison of the SMAP-calculated surface snow grain size with in situ measurements during the period when surface hoar with small grain size was observed on-site revealed that it was necessary to input air temperature, relative humidity, and wind speed data from two heights to simulate the latent heat flux into the snow surface and subsequent surface hoar formation. The calculated latent heat flux was always directed away from the surface if data from only one height were input to the SMAP model, even if the value for roughness length of momentum was perturbed between the possible maximum and minimum values in numerical sensitivity tests. This result highlights the need to use two-level atmospheric profiles to obtain realistic latent heat flux. Using such profiles, we calculated the SEB at SIGMA-A from 30 June to 14 July 2012. Radiation-related fluxes were obtained from in situ measurements, whereas other fluxes were calculated with the SMAP model. By examining the components of the SEB, we determined that low-level clouds accompanied by a significant temperature increase played an important role in the melt event observed at SIGMA-A. These conditions induced a remarkable surface heating via cloud radiative forcing in the polar region.

scholarly journals In situ measurements of near-surface hydraulic conductivity in engineered clay slopes

2018 ◽  
Vol 52 (1) ◽  
pp. 123-135 ◽  
Author(s):  
N. Dixon ◽  
C. J. Crosby ◽  
R. Stirling ◽  
P. N. Hughes ◽  
J. Smethurst ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
In Situ Measurements ◽  
Near Surface ◽  
Clay Slopes
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