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 between October and December.
During the October 2007 cruise on the NOAA ship Ronald H. Brown to the ORS Stratus site, the
primary activities were recovery of the Stratus 7 WHOI surface mooring that had been deployed
in October 2006, deployment of a new (Stratus 8) WHOI surface mooring at that site; in-situ
calibration of the buoy meteorological sensors by comparison with instrumentation put on board
the ship by staff of the NOAA Earth System Research Laboratory (ESRL); and observations of
the stratus clouds and lower atmosphere by NOAA ESRL. Meteorological sensors on a buoy for
the Pacific tsunami warning system were 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
new 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 pressure of 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 2007 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.