Aerosol microphysical properties for selected case studies during the EMeRGe-EU and EMeRGe-Asia campaigns

Aerosols can have a great impact on air quality and human health. In addition they can affect air transport by causing damage in aircraft engines.

To study the transport and transformation of anthropogenic pollutants from major population centers, two airborne measurement campaigns were conducted in the framework of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) Project using the German High Altitude-Long-Range (HALO) research aircraft. The aircraft was equipped with a wide range of instrumentation to measure atmospheric constituents. Here we report on results from the measurements characterizing aerosol microphysical properties. Measurements included particle number concentration and size distributions in a size range between 10 nm and ~3 µm as well as absorption properties. Aerosols were measured in the outflow of major population centers in Europe in summer 2017 (EMeRGe-EU) and along the Asian Pacific coast in spring 2018 (EMeRGe-Asia). In selected case studies we investigated detected aerosol layers, their likely source regions and transport paths. Case studies include the pollution along the west coast of Taiwan as well as the outflows of Manila (Philippines) and London (United Kingdom). Differences and similarities between Europe and Asia and the correlations with trace gases such as SO₂, CO₂ and CH₄ are discussed.