The Ocean Reference Station at 20°S, 85°W under the stratus clouds west of northern Chile is
being maintained to provide ongoing climate-quality records of surface meteorology; air-sea
fluxes of heat, freshwater, and momentum; and of upper ocean temperature, salinity, and velocity
variability. The Stratus Ocean Reference Station (ORS Stratus) is supported by the National
Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. It is
recovered and redeployed annually, with cruises that have come between October and December.
During the 2008 cruise on the NOAA ship Ronald H. Brown to the ORS Stratus site, the primary
activities were recovery of the Stratus 8 WHOI surface mooring that had been deployed in
October 2007, deployment of a new (Stratus 9) WHOI surface mooring at that site; in-situ
calibration of the buoy meteorological sensors by comparison with instrumentation put on board
by staff of the NOAA Earth System Research Laboratory (ESRL); and observations of the stratus
clouds and lower atmosphere by NOAA ESRL. A buoy for the Pacific tsunami warning system
was also serviced in collaboration with the Hydrographic and Oceanographic Service of the
Chilean Navy (SHOA). The DART (Deep-Ocean Assessment and Reporting of Tsunami) carries
IMET sensors and subsurface oceanographic instruments. A DART II buoy was deployed north
of the STRATUS buoy, by personnel from the National Data Buoy Center (NDBC)
Argo floats and drifters were launched, and CTD casts carried out during the cruise.
The ORS Stratus buoys are equipped with two Improved Meteorological (IMET) systems, which
provide surface wind speed and direction, air temperature, relative humidity, barometric
pressure, incoming shortwave radiation, incoming longwave radiation, precipitation rate, and sea
surface temperature. Additionally, the Stratus 8 buoy received a partial CO2 detector from the
Pacific Marine Environmental Laboratory (PMEL). IMET data are made available in near real
time using satellite telemetry. The mooring line carries instruments to measure ocean salinity,
temperature, and currents.
The ESRL instrumentation used during the 2008 cruise included cloud radar, radiosonde
balloons, and sensors for mean and turbulent surface meteorology.
Finally, the cruise hosted a teacher participating in NOAA’s Teacher at Sea Program.