Assessments of the effects of aerosols on the climate and environment still feature large uncertainties, and a better understanding of the spatiotemporal variation in these effects is needed. In this study, coincident observations of ground-based lidar and sun photometer measurements from March 2010 to February 2011 were selected to examine the sensible seasonal characteristics of the aerosol vertical

Since the past two decades, high aerosol loading is being observed over the Indian mainland. It becomes necessary to continuously monitor and understand the distribution of aerosol loading over the Indian landmass, as it might have serious health and climatic implications. Whereas there have been extensive studies reporting seasonal distribution and trends of columnar aerosol amounts over the Indian

To further improve the shelter effect of porous fences on the wind erosion of a triangular prism pile of coal, an aerodynamic optimization procedure has been developed, by coupling computational fluid dynamics (CFD) solver, kriging model and genetic algorithm. Two-dimensional Reynolds- Averaged Navier-Stokes equations with the RNG k-ε turbulence model were used for numerical simulation of the shelter

The spatiotemporal pattern of particulate matter (PM) concentrations is an important factor in predicting health issues in inhabitants of urban areas. The integration of satellite-derived aerosol optical depth (AOD) data with ground-level PM concentration data, obtained from monitoring networks, has contributed to better characterization of the spatiotemporal variability of aerosols worldwide. However

Eastern China has recently experienced frequent haze-fog events that are widely thought to be modulated by atmospheric conditions. Using the climatological pentad mean occurrence frequency of haze-fog, for the first time, we found that the haze-fog frequency in eastern China (115°–125°E, 20°–40°N) presents a statistically significant climatological intraseasonal oscillation (CISO) with a period of

The oil and natural gas sector is the second largest source of methane (CH4) emissions in the U.S. (28% in 2018), and several studies have suggested that real-world emissions from this sector may be higher than previously reported estimates. This study was designed to measure methane emissions from non-associated natural gas (NG) well pads in California, by applying a novel mobile measurement system

The diurnal evolution of the planetary boundary layer (PBL) is crucial to air quality studies as it impacts the exchange and distribution of pollutants close to the surface. This paper reports continuous detection of the daytime convective boundary layer height, the stable boundary layer height, and the residual layer height as estimated from the vertical profiles of virtual potential temperature,

PM2.5 and chemical species of water-soluble inorganic ions, carbon components as well as elements were simultaneously measured by online and offline methods in Tianjin, China. Online measured PM2.5, total carbon, and major ions showed good agreement with offline results (r > 0.7), while obvious differences were found for most elements with correlation coefficients lower than 0.6. Online measured ions

Cities often have a problem regarding the air quality because various emissions are produced within these cities and local emission sources among others relate directly to the air quality. As an addition to stationary monitoring stations, mobile measurements can provide valuable information regarding spatial distribution of pollutants. In this research, a case study is presented to illustrate the design

In this study, a numerical investigation is performed to simulate the evolution process of ultrafine particles emitted from diesel vehicle exhausts. The Taylor expansion method of moments (TEMOM)-CFD coupled model is primarily applied to the non-spherical particles for simultaneously simulating four kinds of particle dynamical behaviors including coagulation, deposition, condensation and nucleation

The NH3(g) concentration measured at multi-site network in Kobe and Kitakyushu, Japan by using passive method continuously for one year in the late 2000s (September 2008–August 2009) and March 2018–February 2019, respectively, was statistically analyzed from the viewpoint of its controlling factors for temporal variation and spatial distribution. Nine survey sites were established in a region of Kobe

The aim of this study is to reveal the direct radiative effect of aerosols on global solar shortwave radiation in the region of peak Musala, which has specific climatic and environmental conditions. Correlations between the measured global solar shortwave radiation and the total aerosol content, Ångström exponent in the visible spectrum, absorption of radiation by aerosols, scattering of radiation

The richness of measurements obtained by Proton-Transfer Reactions Mass Spectrometry (PTR-MS) has opened a new paradigm for the quantification of volatile organic compounds (VOCs). A wide range of compounds can be monitored, however, each detected signal is subject to a compound assignment instead of actual identification because PTR techniques are mass-selective and isomers cannot be separately measured

Measurements of volatile organic compounds (VOCs) were performed as well as other pollutants in Shanghai in winter. The whole measurements were classified into three types of periods, including particulate pollution episodes (PPE), VOC pollution episodes (VPE), and relatively clean periods based on the pollution characteristics. Of these types, PPE have the highest fine particulate matter (PM2.5) mass

Both quantitative and qualitative evaluation of pollutants can be achieved by biomonitoring, enabling the determination of persistent organic pollutants (POPs) with a natural substance. Similarly, passive air samplers (PASs) are among the commonly used methods for the determination of atmospheric POPs. However, in the literature, there are few studies in which both methods (Biomonitoring and PASs)

Exhaust aftertreatment systems are crucial to ensuring real-world NOₓ emission limits for motor vehicles. Operating conditions constrain the NOₓ reduction performance of aftertreatment devices. This study analysed real-world NOₓ emissions, tailpipe exhaust gas temperatures, and air-fuel ratios during cold start in a closed-loop urban route, followed by hot-start real driving emissions (RDE) tests.

Approximately half of satellite aerosol retrievals are missing that limits the application of satellite data in PM2.5 pollution monitoring. To obtain spatiotemporally continuous PM2.5 distributions, various gap-filling methods have been developed, but have rarely been evaluated. Here, we reviewed and summarized four types of gap-filling strategies, and applied them to a random forest PM2.5 prediction

This study characterizes concentrations and describes the spatiotemporal patterns of ambient air polycyclic aromatic compounds (PACs) between 2011 and 2015 in the Athabasca oil sands region (AOSR). 24-hour integrated ambient air samples were collected at multiple sites and analyzed for 110 PACs. Alkylated polycyclic aromatic hydrocarbons (alk-PAHs) formed the majority of the PACs in air and correlated

The stratospheric quasi-biennial oscillation (QBO) is known to cause variations in the transport of chemical tracers but the role of chemical processes in modulating their QBO signals remains unclear. Using ozone observations (Stratospheric Water and OzOne Satellite Homogenized, SWOOSH) and a chemical transport model (SLIMCAT), we analyze the role of chemical processes in the QBO impact on stratospheric

The Jack Rabbit II (JR II) chlorine field trials in 2015 and 2016 involved nine 5–20 ton releases of pressurized liquefied chlorine from a tank mounted 1 m above a broad flat desert sand surface. A model comparison study was initiated, where 17 widely-used dense-gas dispersion models were run by scientists in seven countries. Predictions were submitted following specified formats, using specified emissions

Indoor air particulate samples were collected in the first floor of the Xingyuan canteen of Nanjing University of Science and Technology (NJUST) in Nanjing during the winter season. Meanwhile, outdoor air particulate samples were collected on the roof of a building that is 28 m away from the canteen. The mean PM2.5 (fine particulate matter) concentrations of the indoor and outdoor samples were found

Recent revisions to our understanding of the oxidation chemistry of isoprene have been incorporated into a well-established global atmospheric chemistry and transport model, STOCHEM-CRI. These revisions have previously been shown to increase the production and recycling of HOx radicals at lower NOx levels characteristic of the remote troposphere. The main aim of this study is to assess the resultant

On-road emission remote sensing (OERS) is an ideal means to identify the on-road high-emitting vehicles, which can scan thousands of vehicles within a day without interfering the normal driving. Due to the complex and varying measuring environments and vehicular operating states, it is reasonable to determine the high-emitters not only by the OERS-output pollutant concentration, but also the other

The quantification of N2O reduction during denitrification is crucial to take measures reducing N2O emissions from arable soils. The analysis of site specific N2O isotopic composition may help to quantify the pathway of N2O reduction to N2 during denitrification process. In manure-amended soil (chicken manure, cow manure and sheep manure), N2O reduction was evaluated by examining the N2O emissions

Enhanced greenhouse effects by anthropogenic emissions of greenhouse gases (GHGs) resulted in global warming since the Industrial Revolution. However, the influence of the spectral characteristics of the Earth's surface radiation on the greenhouse effect has not been completely explored. This work uses the surface temperature as the variable of model and investigates the response mechanism of the greenhouse

This paper provides a summary of the methods used to quantify the mass release rate and thermodynamic state of the chlorine released during the Jack Rabbit II chlorine field experiments. In the two-year campaign, eight successful field trials were conducted in which chlorine was released in quantities of 5–10 tons (4540–9070 kg) through a 6-inch (0.152 m) circular breach in the test vessel (disseminator)

Interactions between clouds and black carbon (BC) represent a significant uncertainty in aerosol radiative forcing. To investigate the influence of cloud processing on the scavenging of BC, concurrent measurement of individual cloud droplet residue particles (cloud RES) and interstitial particles (cloud INT) throughout a cloud event was deployed at Mt. Tianjing (1690 m a.s.l.) in southern China. An

The ionic strength effect can influence the kinetics and products distribution within the liquid water content (LWC) of aerosol deliquescent particles. The heterogeneous reactions of atmospheric oxidants (O3, SO2, and NO2, among others) with liquid core of aerosols can be also influenced by ionic strength, which in turn can impact important atmospheric processes such as haze formation. However, the

Diffuse radiation can promote ecosystem gross primary productivity (GPP) and strengthen land carbon sink. However, measurements of diffuse radiation at carbon flux sites are rare, limiting the explorations of diffuse fertilization efficiency (DFE), the percentage changes of GPP per unit diffuse photosynthetically active radiation (PAR). Here, we derive diffuse radiative fraction (Kd) at >200 FLUXNET

Light-absorbing organic particulate matter (PM), or brown carbon (BrC), may constitute an important fraction of combustion PM. Here, we investigate the effect of combustion conditions on the molecular sizes of BrC, their light-absorption properties, and their cytotoxicity. We used toluene in a combustion reactor with highly controlled conditions to produce two different types of BrC under two conditions

This paper presents the climatology of aerosol optical properties and radiative forcing over the Arctic obtained within the framework of the iAREA (impact of absorbing aerosols on radiative forcing in the European Arctic) project. The presented data were obtained from the Navy Aerosol Analysis and Prediction System (NAAPS) and the Fu-Liou radiative transfer model. NAAPS was used to simulate particle

A PM2.5 high-volume impactor (HVI) sampler is developed, which has a flow rate of 1130 L per minute (lpm) (1.13 m3/min) and in it, the filter size used is of 8 inch × 10 inch. The major advantages of this sampler as compared to other low-volume sampler (flow rate 16.67 lpm) are lower uncertainty in mass measurement, higher PM2.5 mass collection and lesser sampling time. To develop this PM2.5 HVI sampler

This study uses the second Modern-Era Retrospective Analysis for Research and Applications (MERRA-2) reanalysis product to analyze the all-sky surface solar radiation (SSR) over the Yangtze River basin (YRB) and the quantitative impact of main factors from 1980 to 2018. Radiation data and multiple atmospheric factors were inputted into a multiple linear regression model. The regression results showed

Understanding the drivers of urban ozone (O3) formation is challenging and requires uncovering the non-linear relationship between O3 and its precursors. We used a novel method to differentiate between background O3 levels and local photochemical O3 generation using the observation-based O3 production efficiency (OPE) from decade-long observations including nitrogen dioxide (NO2), nitrogen monoxide

The daily pollen forecast provides crucial information for allergic patients to avoid exposure to specific pollen. Pollen counts are typically measured with air samplers and analyzed with microscopy by trained experts. In contrast, this study evaluated the effectiveness of identifying the component pollens using the metabolites extracted from an air-sampled pollen mixture. Ambient air-sampled pollen

We demonstrate a novel way to introduce a so-called Hg reference gas, produced by a gas generator, into an elemental detector, such as ICP-MS, and to directly measure gaseous oxidized mercury (GOM as HgCl2) at a wide range of concentrations, covering 4 orders of magnitude. The approach was tested using two types of generators based on the dilution of a gas saturated with mercury chloride vapours (from

The aerosol direct feedback effects (ADFEs) are neglected in traditional air quality modeling studies (where meteorology is used as input and not affected by the chemistry and aerosol microphysics) for estimating the impacts of aircraft emissions on air quality. In this study, aircraft landing and take-off (LTO) attributable change of O3 and PM2.5 concentrations through ADFEs for the year 2005 within