Long–term evolution and coupling of the boundary layers in the Stratus Deck Regions of the eastern Pacific (STRATUS) data report

Abstract

The surface mooring component of the CLIVAR Long Term Evolution and Coupling of the Boundary Layers in the Stratus Deck Regions study (STRATUS) took place from October 2000 in the eastern tropical Pacific. As part of the Eastern Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC), STRATUS is a CLIVAR study with the goal of investigating links between sea surface temperature variability in the eastern tropical Pacific and climate over the American continents. This study started a three-year occupation off Chili in order to collect accurate time series of surface forcing and upper ocean variability. The Upper Ocean Processes (UOP) Group at WHOI deployed one fully instrumented surface mooring near 20°S 85°W in October 2000, at the western edge of the stratocumulus cloud deck found west of Peru and Chile, to achieve a good understanding of the role of clouds in the eastern Pacific in modulating atmosphere-ocean coupling. Data from the moorings will improve our understanding of the air-sea fluxes and be used to examine the processes that control sea surface temperature in the cold tongue/intertropical convergence zone (ITCZ) and in the stratus deck region. The first surface mooring (STRATUS 1) was deployed in October 2000 by the UOP group and replaced by a second mooring one year later with almost identical instrumentation (STRATUS 2). STRATUS 1 was equipped with meteorological instrumentation, including two Improved METeorological (IMET) systems. The mooring also carried Vector Measuring Current Meters (VMCMs), single point temperature, salinity and conductivity recorders, and an acoustic Doppler Current Profiler (ADCP) to monitor the upper 500m of the ocean. In addition to the traditional instruments, several other experimental instruments were deployed with limited success on the mooring line including an acoustic current meter, bio-optical instrumentation packages, and an acoustic rain gauge. This report describes the instrumentation deployed on the first STRATUS surface mooring (STRATUS 1 mooring) from October 2000 to October 2001, along with information on the processing and quality control of the returned data. It presents a detailed overview of the meteorological and physical oceanographic data including time series plots, statistics and spectra of key parameters. It also presents the estimated air-sea heat, moisture and momentum fluxes.