one in May 1999 and the second in January 2000 will sample upper
ocean and atmospheric boundary layer variability in the Japan/East
Sea. The spring cruise will focus on studying frontal dynamics,
characterizing bio-optical variability associated with the spring
phytoplankton bloom and documenting the location, range and properties
of water masses formed at the subpolar front during the preceding
winter. The wintertime cruise will focus on documenting the upper
ocean response to cold air outbreaks with particular attention to
processes associated with water mass formation and subduction at
the subpolar front. Both cruises will employ a towed, undulating
profiler (SeaSoar) to make highly-resolved observations of the upper
ocean. We will use real-time remotely sensed sea surface temperature
and ocean color images (R. Arnone, NRL and scientists from the Korean
Ocean Research and Development Institute, KORDI) to determine the
location of the subpolar front and to select intensive survey locations.
Real-time access to remotely sensed imagery will allow us to modify
our sampling in response to changes in the front. Repeated intensive
grid surveys will provide approximately synoptic, three-dimensional
coverage while a sequence of longer sections will document oceanic
and atmospheric boundary layer variability away from the front.
In addition to the suite of physical and bio-optical sensors carried
by SeaSoar, we will use a shipboard Acoustic Doppler Current Profiler
(ADCP) and GPS navigation to measure upper ocean currents. We will
also perform a limited number of hydrographic and bio-optical stations
off the Korean coast and across the subpolar front. Professor S.
Yang (Kwangju University) will perform additional biological and
bio-optical sampling (e.g. nutrient analysis, primary production,
vertical profiles from the surface to 350 m towing at 8 knots.
horizontal resolution of 3 km.
- Dual Seabird
temperature and conductivity sensors
- Light transmission
available radiation (PAR)
absorption and attenuation (Wetlabs HiStar, 100 bands at 3.3 nm
(Hobilabs HiStar, 6 wavelength bands)
salinity, chlorophyll fluorescence, light transmission, PAR, dissolved
oxygen, nutrients, pigment concentrations, primary production
absorption and attenuation (Wetlabs HiStar and AC-9), upwelling
and downwelling irradiance (Satlantic), PAR.
- 150 khz narrowband
ADCP (velocity to 350 m)
doppler sonar system (January 2000 only, velocity to 1500 m)
- P-code GPS
- GPS heading
system with near-surface temperature, conductivity and spectral
absorption and attenuation (Wetlabs AC-9).
Improved Meteorology Sensors (IMET) 15 m above the sea surface
measuring wind velocity, air temperature, sea surface temperature,
relative humidity, air pressure, short- and long-wave radiation
wind velocity, air temperature, relative humidity and air pressure
sensors at 10.8 m, 8.4 m and 22.7 m above the sea surface.
- Sonic anemometers
for boundary layer turbulence.
soundings using GPS sondes. Vertical profiles of temperature,
humidity, pressure and wind velocity.
thermal and ocean color imagery.
absorption, scattering and attenuation measurements.