Project Details
Projekt
Aerosol-Cloud Interactions over the Southern Ocean: In-situ Mass Spectrometric Analysis of Aerosol and Cloud Residual Particles
Applicant
Dr. Johannes Schneider
Subject Area
Atmospheric Science
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 552807738
Aerosol-cloud interaction is one of the major uncertainties in predicting future climate scenarios. Unknowns include the question which aerosol particles can act as cloud condensation nuclei (CCN) and ice nucleating particles (INP), but also how aerosol particles grow to CCN sizes and how particles are processed through cloud passages, i.e. how the chemical properties of particles are modified after cloud evaporation. The HALO-South mission will contribute to answering these questions by making airborne measurements of aerosol and clouds over the Southern Ocean, representing a region with frequent pristine aerosol conditions where the effect of aerosols on clouds is greatest. The mission is scheduled to fly from Christchurch, New Zealand, in August-September 2025. Our specific objectives during this mission are: - To study cloud residuals from liquid and ice clouds. - To study the growth of newly formed particles (especially in the upper troposphere). - To study the composition of aerosol particles after cloud evaporation. For this, we will use two aerosol mass spectrometers that have already been operated on HALO several times: The single particle laser ablation instrument ALABAMA (operated during ML-CIRRUS, CAFE-Africa, CIRRUS-HL) and the quantitative ensemble analysis instrument C-ToF-AMS (operated during ACRIDICON, EMeRGe, CAFE-Africa, CAFE-EU/BLUESKY, CAFE-Brazil, CAFE-Pacific). The combination of these two complementary instruments allows for a detailed description of the particle chemistry: The C-ToF-AMS provides a quantitative analysis of non-refractory aerosol compounds (sulfate, nitrate, ammonium, organics), while the ALABAMA is also sensitive to refractory material (e.g., dust, soot) and provides single-particle-based information on particle types and composition. Cloud element sampling will be performed with a counterflow virtual impactor (CVI) provided by one of the project partners.
DFG Programme
Infrastructure Priority Programmes
