Abstract Aerosol-cloud and aerosol-radiation interactions depend on several factors
such as the physico-chemical properties, geographical and temporal variability,
and vertical distribution of atmospheric aerosols. Of particular importance are cloud
condensation nuclei (CCN) and black carbon (BC) particles as a subset of the atmospheric
aerosol population. CCN are a prerequisite for cloud droplet formation, and
variations in CCN loading can modify cloud properties. BC can efficiently absorb solar
radiation, induce local heating and inhibit cloud formation. In order to determine
the effects of CCN and BC on clouds, precipitation, radiation and the Earth’s energy
budget, atmospheric loading and spatio-temporal distribution of aerosols are highly
relevant. Thus this dissertation addresses and helps to elucidate the spatio-temporal
variation and co-variability of CCN and BC with extensive field measurement data
from aircraft and ground-based measurements. The data analyses focus on anthropogenic
pollution, wildfire emissions and volcanic aerosols.
In the Anthropocene, the distribution and abundance of atmospheric aerosols have
changed drastically. Major sources of anthropogenic particulate pollution are the
combustion of fossil fuels and biofuels as well as emissions from open biomass burning.
The ubiquitous presence of anthropogenic air pollution, especially over continental
regions in the Northern Hemisphere, hampers the assessment of anthropogenic
influence on aerosol and climate due to a lack of unperturbed reference
measurements. The abrupt reduction in human activities during the first COVID-19
lockdown created unprecedented atmospheric conditions that allowed us to investigate
and quantify changes in the tropospheric composition in response to changes
in anthropogenic emissions. The results reflect a strong and immediate influence of
human activities on air quality, the role of BC as a major air pollutant in the Anthropocene,
and close links between the atmospheric burdens of CCN and BC.
Measurement data from five aircraft missions in polluted environments reveal characteristic
relationships between CCN and BC in urban haze from Europe and East
Asia, highly aged biomass burning smoke over the tropical Atlantic and the Amazon
rainforest, and lightly aged biomass burning smoke over Europe, Brazil, and Asia.
Over Europe and Asia, the vertical distribution of CCN in the lower troposphere up
to altitudes about 5 km is highly sensitive to regional anthropogenic emissions. Over
the tropical Atlantic ocean, the vertical distribution is strongly influenced by the longrange
transport of mineral dust and biomass burning smoke, but volcanic eruptions
also contribute to the aerosol load.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:87381 |
| Date | 11 October 2023 |
| Creators | Krüger, Ovid Oktavian |
| Contributors | Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English, German, German |
| Detected Language | English |
| Type | info:eu-repo/semantics/acceptedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | https://doi.org/10.17617/3.GKRXCN |
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