Long Term Evolution and Coupling of the Boundary Layers in the Stratus Deck Regions of the Eastern Pacific: Mooring Deployment Cruise October 2001
Long Term Evolution and Coupling of the Boundary Layers in the
Stratus Deck Regions of the Eastern Pacific: Mooring Deployment
Cruise October 2001
|
PI's: |
Robert A. Weller and Steven P. Anderson |
|
Contact: |
Robert A. Weller |
|
Ship: |
R/V Melville |
|
Dates: |
October 2, 2000 depart Arica, Chile; |
|
Cruise track: |
From Arica to vicinity of 20S, 85W and back |
Overview:
The purpose of this cruise is to deploy a well-instrumented surface mooring under the stratocumulus deck, in the vicinity of either 18S, 85W or 20S, 85W. The mooring will be maintained at that site for 3 years, with cruises to come in October 2001, October 2002, and October 2003. The science objectives are, over several annual cycles, to observe the surface forcing, 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 models show broad scale sensitivity over the Pacific to how the clouds and air-sea interaction and this region are parameterized.
The approach taken to meet these objectives is to establish and maintain a well-instrumented surface mooring for three years under the stratus deck and to seek cooperative participation by other investigators to make additional oceanographic and meteorological observations at the site and to use the in-situ data sets to investigate how well oceanic, atmospheric, and coupled models perform in this region. The buoy will carry two redundant sets of meteorological sensors (wind speed and direction, air and sea surface temperature, barometric pressure, relative humidity, incoming shortwave radiation, incoming longwave radiation, and precipitation). In the mooring line, temperature recorders, temperature/conductivity recorders, 4 current meters, and an Acoustic Doppler Current Profiler will be deployed to observe temperature, salinity, and velocity in the upper 500 m. Two acoustic rain gauges will be placed on the mooring by Jeff Nyusten (U. W. APL).
Using ship's equipment and upon obtaining clearance from Chile, we would continuously sample surface meteorology, sea surface temperature and salinity, upper ocean currents using the ship's ADCP, bottom topography (using the ship's SeaBeam). As time permits, we would use our own CTD to make stations along the line of the transit and at the mooring site. We would, as time permits, and in collaboration with other groups, make additional meteorological and oceanographic measurements during the transits to and from the mooring site.
Preliminary science party roster:
Robert A. Weller, WHOI, Chief Scientist
James M. Dunn, WHOI
Albert S. Fischer, WHOI
Erica A. Greeley, WHOI
William M. Ostrom, WHOI
George H. Tupper, WHOI
Rochelle A. Ugstad, WHOI
TBD, Research Associate, WHOI
TBD, Chilean scientists
Planned measurements:
Surface meteorology, underway and on station, starting and stopping in Arica if permission is obtained to sample in Chilean waters, using the ship's IMET system.
Surface sea temperature and salinity, underway and on station, starting and stopping in Arica if permission is obtained to sample in Chilean waters, using the ship's thermosalinograph system.
Mapping the seafloor underway and while surveying the site for the mooring, starting and stopping in Arica if permission is obtained to sample in Chilean waters, using the ships Seabeam system.
CTD stations, taking temperature, salinity, depth profiles using WHOI internally recording CTD on ship's winch with hydro wire. Stations spaced along ship's track as time permits and at mooring site.
Upper ocean currents, underway and on station, starting and stopping in Arica if permission is obtained to sample in Chilean waters, using the ship's ADCP system.
Radiosonde balloon launches to obtain atmospheric profiles, underway and on station, starting and stopping in Arica if permission is obtained to sample in Chilean waters, using radiosonde system brought on board by Chilean investigators.
Ships equipment required:
Crane, A-frame, deck gear for mooring deployment and recovery
IMET meteorological system
Thermosalinograph
12KHz depth sounder
Seabeam with tech support to produce bottom topography maps in real time
XBT for Seabeam calibration
ADCP
P-code GPS
Hydrowinch
Electrical connections for mooring winch which WHOI will provide
Air connections for tuggers which WHOI will provide