Investigation of ice particle and cloud drop residues using the counterflow virtual impactor technique onboard HALO (HALO-CVI)

• Applicant: Dr. Stephan Mertes
• Subject Area: Atmospheric Science
• Term: from 2007 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 48902976

The subset of atmospheric particles which serve as cloud condensation and ice nuclei (CCN and IN) determine the aerosol indirect effect, which has one of the largest uncertainties in predicting future climate. Especially the influence of anthropogenic particles on microphysical properties of liquid, mixed-phase and glaciated clouds and thus on their radiative properties and precipitation behavior is hardly known. The identification of CCN and IN measured as residues of drops and ice particles of different cloud types from aircraft will improve our understanding of these issues. An inlet system sampling liquid and frozen hydrometeors and releasing the contained residues for analysis, called HALO-CVI, has been developed within the first phase of the HALO SPP. Now, it is proposed to apply this inlet onboard HALO as part of the designated scientific payload of the three cloud missions ML-CIRRUS, ACRIDICON and NARVAL. As instrument of these missions, the HALO-CVI would contribute to investigate the influence of aerosol particles on the formation and evolution of aviation modified and natural cirrus, extra-tropical deep convective cloud systems and trade wind cumuli. Furthermore, concept studies of a drop pre-segregating CVI dedicated for IN analysis in mixed-phase clouds are proposed as a starting point for a new inlet development beyond the second phase of the HALO priority program.

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