ETL Conducting East Pacific Marine Stratocumulus Study

Contact: Chris Fairall

ETL will be joining the Woods Hole Oceanographic Institution (WHOI) in a cruise aboard the R/V Roger Revelle as part NOAA's Climate Variability (CLIVAR) PACS and Climate Observations (CO) Programs. The principal goal of the CLIVAR PACS is to extend the scope and improve the skill of operational seasonal-to-interdecadal climate prediction over the Americas. The Climate Observation program supports ocean and atmospheric projects designed to contribute to the implementation of the global climate observing system that is needed to satisfy the long-term requirements of the operational forecast centers, international research programs, and the major scientific assessments.

The primary purpose of this cruise is to recover and then re-deploy a well-instrumented WHOI surface mooring under the stratocumulus clouds found off Chile and Peru in the vicinity of 20S, 85W. The mooring is being maintained at that site as a long-term Surface Reference site, part of the Global Ocean Observing System. This project will also collect underway oceanographic and meteorological data including aerosol data (Jason Tomlinson, Texas Ai&M) and atmospheric profiles, turbulent fluxes, and cloud radar data (Chris Fairall, ETL). Extensive comparison of the shipboard sensors will be made with the existing buoy prior to recovery and the new buoy after deployment. During the 16 days at sea, atmospheric and oceanographic observations will be carried out to add to our understanding of the stratus clouds. In addition, the cruise will host two teachers in the NOAA teacher at sea program, Deb Brice from San Marcos, California, and Viviana Zamorano from Arica, Chile. The ship will depart Manta, Ecuador, on November 10, and conclude at Arica, Chile, on November 26, 2003.

The science objectives of the long-term mooring program off northern Chile are to observe the surface meteorology and air-sea exchanges of heat, freshwater, and momentum, to observe the temporal evolution of the vertical structure of the upper 500 m of the ocean, and to document and quantify the local coupling of the atmosphere and ocean in this region. Air-sea coupling under the stratus clouds is not well understood, and numerical models show broad scale sensitivity over the Pacific to parameterizations of clouds and air-sea interaction.

ETL contributes to PACS and CO through regular studies of the regional atmosphere-ocean dynamics from ship and satellite based instruments. Shipboard instrumentation for this cruise includes:

• Surface flux system (temperature, moisture and solar fluxes),
• 35 GHz Doppler cloud radar and microwave water vapor/cloud liquid radiometer,
• S-band precipitation Radar and lidar cloud base ceilometer,
• Rawinsonde upper-air system.

Data from this cruise will be analyzed in conjunction with data collected during a previous cruise (EPIC 2001) and future annual cruises to this site.

More Informations

• PACS
  
• EPIC
  
• Climate Observations (CO) Programs