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STUDY OF ATMOSPHERIC AEROSOL PROPERTIES IN THE VIPAVA VALLEYLonglong Wang, doctoral dissertation
Abstract: The aim of the dissertation was to study aerosol loading distributions and properties over the Vipava valley, a representative hot-spot for complex mixtures of different aerosol types of both anthropogenic and natural origin.
An infrared Mie and a two-wavelength polarization Raman lidar systems
were used as main detection tools. The polarization Raman lidar, which
provides the capability to extract the extinction coefficient, backscatter coefficients, depolarization ratio, backscatter Ångström exponent, lidar ratio and
water vapor mixing ratio profiles, was itself designed, built and calibrated as
a part of this thesis. Lidar data, combined with in-situ measurements, was
used to determine detailed information on different aerosol types. Vertical
profiles of aerosol mass concentration were extracted from the Mie lidar data
taken in April 2016, where the in-situ measurements of aerosol size distribution and number concentration as well as aerosol absorption coefficient and black carbon mass concentration were used to estimate the mass extinction efficiency (MEE). Aerosol morphology and chemical composition determined by SEM-EDX on sampled particles were used for the identification
of primary aerosol types. Two cases with different atmospheric conditions
(long range mineral dust transport and local biomass burning) and different
expected the dominant presence of specific aerosol types (mineral dust and
soot) were investigated in more detail. They revealed significantly different
aerosol properties and distributions within the valley, affecting radiative heat
exchange.
A more detailed investigation of aerosol properties throughout the troposphere in different atmospheric conditions was made possible by the two-wavelength polarization Raman lidar system, deployed in Ajdovščina (town
of Vipava valley) from September 2017. Using its aerosol identification capabilities, based on particle depolarization ratio and lidar ratio measurements,
it was possible to identify predominant aerosol types in the observed atmospheric structures, for example in different atmospheric layers in the case of
the stratified atmosphere. Primary anthropogenic aerosols within the valley were found to be mainly emitted from two sources: individual domestic
heating systems, which mostly use biomass fuel and traffic. Natural aerosols,
transported over large distances, such as mineral dust and sea salt, were observed both above and entering into the planetary boundary layer. Backscatter contribution of each aerosol type was separated and the corresponding
extinction contribution was derived from lidar observations.
Found in: ključnih besedah
Summary of found: ...of this thesis. Lidar data, combined with in- situ measurements, was
used to determine detailed information on... ...Vipava valley, aerosol distribution, aerosol characterization, lidar
remote sensing, in-situ measurements, aerosol loading....
Keywords: Vipava valley, aerosol distribution, aerosol characterization, lidar
remote sensing, in-situ measurements, aerosol loading.
Published: 23.10.2018; Views: 6087; Downloads: 145
Fulltext (29,39 MB)
