Shipboard Investigation of Air-sea Interaction and Cloud Processes in the VOCALS Stratocumulus Region (VOCALS Submission)

NOAA ETL, University of Miami, and Brookhaven National Laboratory have cooperated with the Woods Hole Oceanographic Institution (WHOI) for two research cruises to the stratocumulus region of Peru/Chile as part of NOAA's PACS/EPIC program. Ship-based measurements have taken in October of 2001, November 2003, and December 2004 at the WHOI ocean reference buoy at 20 S 85 W during the annual cruise to service the buoy. The goal of this work is to improve understanding of coupled air-sea processes in subtropical stratocumulus regions and to gather statistics on flux, boundary layer, and cloud properties to promote the evaluation of models and satellite data products. Specific scientific objectives involve improved bulk cloud-radiative parameterizations, methods for retrieving cloud microphysical properties, and investigation of the relative roles of cloud-top entrainment and drizzle production on the dynamics of stratocumulus. The measurements provide a more detailed context for measurements made on the WHOI buoy over the annual cycle. This will be achieved through: $ Comprehensive characterization of clouds, surface fluxes, and PBL profiles using a variety of in situ and remote sensing systems $ Evaluation of various bulk models of stratocumulus cloud radiative transfer properties using resulting cloud microphysics (integrated liquid water, drop size and number concentration) determined with ship-board remote sensors

In this paper we will present the results from the three cruises emphasizing then diurnal cycle of cloud properties and comparing the seasonal differences.