Investigation of Aerosol Types and Vertical Distributions Using Polarization Raman Lidar over Vipava Valley

Abstract

Aerosol direct radiative forcing is strongly dependent on aerosol distributions and aerosol types. A detailed understanding of such information is still missing at the Alpine region, which currently undergoes amplified climate warming. Our goal was to study the vertical variability of aerosol types within and above the Vipava valley (45.87°N, 13.90°E, 125 m a.s.l.) to reveal the vertical impact of each particular aerosol type on this region, a representative complex terrain in the Alpine region which often suffers from air pollution in the wintertime. This investigation was performed using the entire dataset of a dual-wavelength polarization Raman lidar system, which covers 33 nights from September to December 2017. The lidar provides measurements from midnight to early morning (typically from 00:00 to 06:00 CET) to provide aerosol-type dependent properties, which include particle linear depolarization ratio, lidar ratio at 355 nm and the aerosol backscatter Ångström exponent between 355 nm and 1064 nm. These aerosol properties were compared with similar studies, and the aerosol types were identified by the measured aerosol optical properties. Primary anthropogenic aerosols within the valley are mainly emitted from two sources: individual domestic heating systems, which mostly use biomass fuel, and traffic emissions. Natural aerosols, such as mineral dust and sea salt, are mostly transported over large distances. A mixture of two or more aerosol types was generally found. The aerosol characterization and statistical properties of vertical aerosol distributions were performed up to 3 km.

Characteristics of Air Pollutant Distribution and Sources in the East China Sea and the Yellow Sea in Spring Based on Multiple Observation Methods

“…3,4 MAAP represents Multi Angle Absorption Photometer (Model 5012, Thermo Scientific, Franklin, MA, USA). 5,6 In this table, both AE31 and AE33 are aethalometers (Magee Scientific, Berkeley, CA, USA). 7 The BC concentration in Xiamen is the annual average.…”

“…Long-range transport includes particle matter generated by biomass burning (BB), volcanic eruptions, deserts, etc., and sea salt from elsewhere such as the secondary generation of sulfate (SO 4 2− ), as well as gases such as nitrogen oxides (NO x ) and sulfur dioxide (SO 2 ) generated through anthropogenic activities [3][4][5][6]. Marine aerosol study not only helps to understand the extent of the impact of human activities on aerosol pollution, but also provides background data to support the transboundary transport of air pollutants [1,[7][8][9].…”

A Numerically Sensitive Study of Two Continuous Heavy-Pollution Episodes in the Southern Sichuan Basin of China

“…Such weather conditions are not conducive to the diffusion of pollutants [1], often causing serious pollution problems [2,3]. Affected by terrain factors, the vertical distribution and diffusion mechanisms of pollutants are more complex, and the observation is more difficult [4,5]. Thus, the Sichuan Basin has become one of the four major polluted regions in China [6].…”