Research Summaries

Back Collaborative Research: Physics of Stratocumulus Top (POST)

Fiscal Year 2010
Division Graduate School of Engineering & Applied Science
Department Meteorology
Investigator(s) Wang, Qing
Sponsor National Science Foundation (NSF)
Summary Stratocumulus clouds (SC) off the West Coast of California are studied using a combination of aircraft measurements and modeling. The objective is to improve the understanding of the physical processes that occur near SC top, and that influence the entrainment process and boundary-layer evolution. The processes include wind shear, entrainment rate, CTEI (Cloud-Top Entrainment Instability), solar and infrared radiation, hydrometeor and CCN (Cloud Condensation Nuclei) effects, and the formation and role played by the ELL (Entrainment Interface Layer).
The study is a combination of field measurements and modeling. For the former, the CIRPAS Twin Otter research aircraft is deployed out of Monterey for 20 flights in SC. It carries a full complement of sensors to produce measurements related to those physical processes. Sensors include the UFT (Ultra-Fast Temperature probe), PVM (fast Particulate Volume Monitor), fast Lyman-alpha hygrometer, POI (Phased Doppler Interferometry Probe), other droplet probes, gust probe, solar and infrared radiometers, and the standard set of Twin Otter probes producing meteorology and aircraft operating properties. The aircraft is deployed primarily in fields of unbroken SC with a stress on porpoising maneuvers vertically about SC top to detect fine-scale behavior. Boundary layer profiles and near-surface horizontal legs are flown to deduce fluxes. NEXSAT and CLOUDSAT products are compared to aircraft measurements and used to help vector the aircraft to fields of SC. The analysis phase of the field study includes comparisons between the measured physical processes and the calculated cloud-top entrainment velocities with the purpose of clarifying the cause and effect for the latter.
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Publications Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal
Data Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal