Observations of Centimeter-Scale Cloud Microphysics in Marine Stratocumulus Clouds measured during the CSET Field Study
Abstract
Cloud microphysical relationships observed during the Cloud System Evolution in the Trades (CSET) campaign held off between Northern California and Hawaii are analyzed to study the effects of entrainment and subsequent mixing of free-tropospheric and cloudy air on cloud microphysical properties at the top of marine stratocumulus clouds. Here, we used HOLODEC (Holographic Detector for Clouds) data that can provide a close look into the three-dimensional spatial structure of clouds at the fine-scale of approximately 1~10 cm, which was not previously possible. This implies that individual clusters of droplets within a filamented hologram could reveal directly whether the mixing of surrounding dry and cloudy air is homogeneous or inhomogeneous. Because HOLODEC data are not affected by spatial averaging, homogeneously mixed clouds would not appear to be inhomogeneously mixed. In this study, we attempted to investigate the effects of entrainment and subsequent mixing on droplet spatial structure and spectra at centimeter scales within the observational framework for homogeneous and inhomogeneous mixing. Holograms were classified into two types, depending on whether they were affected by entrainment and mixing. The holograms of Type 1 were from the regions affected by entrainment and mixing (e.g., near the cloud top) and they showed relatively high confidence in the significance test for droplet clustering. Moreover, clustered holograms of Type 1 appeared to exhibit stronger visual signatures of inhomogeneous mixing (will be explained in the conference) than uniformly distributed holograms. On the other hand, these characteristics did not appear for holograms of Type 2 that were from the regions not affected by entrainment and mixing (e.g., away from the cloud top). More detailed results will be discussed at the conference.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA180.0009L
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3310 Clouds and cloud feedbacks;
- ATMOSPHERIC PROCESSES;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES