Contrasting Trends of Surface PM, O, and NO and Their Relationships with Meteorological Parameters in Typical Coastal and Inland Cities in the Yangtze River Delta.

The contrasting trends of surface particulate matter (PM), ozone (O), and nitrogen dioxide (NO) and their relationships with meteorological parameters from 2015 to 2019 were investigated in the coastal city of Shanghai (SH) and the inland city of Hefei (HF), located in the Yangtze River Delta (YRD). In both cities, PM declined substantially, while O and NO showed peak values during 2017 when the most frequent extreme high-temperature events occurred. Wind speed was correlated most negatively with PM and NO concentrations, while surface temperature and relative humidity were most closely related to O.

The different sensitivities of aerosol optical properties to particle concentration, humidity, and hygroscopicity between the surface level and the upper boundary layer in Guangzhou, China.

This study investigates the impact of aerosol liquid water content (ALWC) and related factors, i.e., relative humidity (RH), aerosol mass concentration (PM), and aerosol hygroscopicity, on aerosol optical properties, based on field measurements made in the Pearl River Delta (PRD) region of China at the surface (1 November 2019 to 21 January 2020) and in the upper boundary layer (the 532-m Guangzhou tower from 1 February to 21 March 2020).

New global aerosol fine-mode fraction data over land derived from MODIS satellite retrievals.

The space-borne measured fine-mode aerosol optical depth (fAOD) is a gross index of column-integrated anthropogenic particulate pollutants, especially over the populated land. The fAOD is the product of the AOD and the fine-mode fraction (FMF). While there exist numerous global AOD products derived from many different satellite sensors, there have been much fewer, if any, global FMF products with a quality good enough to understand their spatiotemporal variations.

The ChinaHighPM dataset: generation, validation, and spatiotemporal variations from 2015 to 2019 across China.

Respirable particles with aerodynamic diameters ≤ 10 µm (PM) have important impacts on the atmospheric environment and human health. Available PM datasets have coarse spatial resolutions, limiting their applications, especially at the city level. A tree-based ensemble learning model, which accounts for spatiotemporal information (i.

The impact of the atmospheric turbulence-development tendency on new particle formation: a common finding on three continents.

A new mechanism of new particle formation (NPF) is investigated using comprehensive measurements of aerosol physicochemical quantities and meteorological variables made in three continents, including Beijing, China; the Southern Great Plains site in the USA; and SMEAR II Station in Hyytiälä, Finland. Despite the considerably different emissions of chemical species among the sites, a common relationship was found between the characteristics of NPF and the stability intensity. The stability parameter (ζ = /, where is the height above ground and is the Monin-Obukhov length) is found to play an important role; it drops significantly before NPF as the atmosphere becomes more unstable, which may serve as an indicator of nucleation bursts.

Satellite-Derived 1-km-Resolution PM Concentrations from 2014 to 2018 across China.

Particulate matter with aerodynamic diameters ≤1 μm (PM) has a greater impact on the human health but has been less studied due to fewer ground observations. This study attempts to improve the retrieval accuracy and spatial resolution of satellite-based PM estimates using the new ground-based monitoring network in China. Therefore, a space-time extremely randomized trees (STET) model is first developed to estimate PM concentrations at a 1 km spatial resolution from 2014 to 2018 across mainland China.