Hygroscopic Growth of Accumulation Mode Particles Measured with HALO (HyGroPart)

• Applicant: Dr. Markus Hermann
• Subject Area: Atmospheric Science
• Term: from 2007 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 47387451

Atmospheric aerosol partials in the size range 0.1 to 10 μm contribute to direct and indirect radiative forcing of climate. Two important particle properties in this context are their hygroscopicity (growth behavior at changing relative humidity) and their mixing state (distribution of chemical components among the particles). In situ measurements of these particles properties in the free troposphere are needed in order to improve atmospheric models and for validating remote sensing instruments. In this project, we propose the application of the Micrometer Aerosol Inlet (MAI) and the Tandem Optical Particles Counter (TOPC), developed in phase 1 of the HALO SPP, during two HALO demo missions (ACRIDICON and NARVAL). The TOPC downstream MAI will measure the particle size and the hygroscopic growth of accumulation mode particles. These measurements can help to quantify the direct aerosol forcing, to understand particle aging, and to determine the particle mixing state. During ACRIDICON the focus is on the influence deep convective clouds have on aerosol particles. During NARVAL in particular particle aging with long-range transport and the influence of particles on trade wind clouds shall be investigated.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1294: Atmospheric and Earth System Research with the "High Altitude and Long Range Research Aircraft" (HALO)