Model analysis of vertical exchange of boundary layer ozone and its impact on surface air quality over the North China Plain.

In addition to photochemical production and horizontal regional transport, surface O concentration can also likely be affected by vertical transport, which is not well known so far. The process analysis was conducted by using the Regional Atmospheric Modeling System Community Multiscale Air Quality (RAMS-CMAQ) model to investigate photochemical production and the vertical transport mechanism of boundary-layer O during a typical O pollution episode in the North China Plain (NCP), and further quantify the contribution of vertical transport to surface O. The diurnal variations of vertical budgets of O and NO in the boundary layer at multiple sites showed that there were substantial differences in the vertical distribution of O production and transport between urban and suburban/rural areas.

Spatial and temporal distribution of the cloud optical depth over China based on MODIS satellite data during 2003-2016.

The cloud optical depth (COD) is one of the important parameters used to characterize atmospheric clouds. We analyzed the seasonal variations in the COD over East Asia in 2011 using cloud mode data from the AERONET (Aerosol Robotic Network) ground-based observational network. The applicability of the MODIS (Moderate Resolution Imaging Spectroradiometer) COD product was verified and compared with the AERONET cloud mode dataset.

[Observation study on aerosol optical properties and radiative forcing using the ground-based and satellite remote sensing at background station during the regional pollution episodes].

The significant effect of anthropogenic pollutants transportation on the physical and optical properties of regional background atmospheric aerosol was studied by using ground-based and satellite remote sensing data obtained at the atmospheric background station (Shangdianzi, Beijing) of North China during October 1 to 15 in 2011. The aerosol mass concentration and reactive gases concentration increased obviously during periods of October 4-5, October 7-9, and October 11-12. Comparing with the background period of October 1-3, volume concentration increased by a factor of 3-6 for reactive gases such as NO(x), and CO, and a factor of 10-20 for SO2.

Validation of MODIS aerosol retrievals and evaluation of potential cloud contamination in East Asia.

MODIS aerosol retrievals onboard Terra/Aqua and ground truth data obtained from AERONET (Aerosol Robtic Network) solar direct radiance measurements are collocated to evaluate the quality of the former in East Asia. AERONET stations in East Asia are separated into two groups according to their locations and the preliminary validation results for each station. The validation results showed that the accuracy of MODIS aerosol retrievals in East Asia is a little worse than that obtained in other regions such as Eastern U.

Evaluation of dust activity and climate effects in North China.

TOMS/AI data with nearly 20 years are utilized in the paper to evaluate dust activities in North China. Combined with simultaneous NCEP reanalysis climate data, climate effects on dust activities are assessed. The results showed that the whole North China suffers impact by dust aerosols, with three centers standing out in TOMS/AI spring average map that are western three basins, which are characterized by lower annual precipitation and elevation.

Automatic and continuous measurement of aerosol properties in Dunhuang, China.

Ground-based simultaneous observations of sun direct and scattering radiation were carried out in Dunhuang for nearly 2 years. Aerosol optical depth, Angstrom wavelength exponent and size distribution were obtained from solar extinction and sky radiation. Water vapor content was obtained from sun direct radiation measurement at 940 nm.

Chemical composition of aerosols in winter/spring in Beijing.

In 1999 aerosol samples were collected by cascade at Meteorological Tower in Beijing. The 12 group aerosol samples obtained were analyzed using PIXE method, which resulted in 20 elemental concentrations and size distribution of elemental concentrations. From the observation, the elemental concentrations, size distribution of elemental concentrations and their variations are analyzed.