TAO/NOPP Mooring Overview
Monitoring the North Pacific for Improved Ocean, Weather, and Climate Forecasts
M. J. McPhaden, NOAA/Pacific Marine Environmental Laboratory
As part of the Nation Ocean Partnership Program (NOPP), PMEL has been funded during
1997-99 to develop and deploy moorings in the North Pacific in collaboration with
the University of Washington/Applied Physics Lab, Scripps Institution of Oceanography,
NOAA/NESDIS, and the Naval Research Lab. The first of these moorings was deployed
at Ocean Station PAPA (50N, 145W) from the NOAA Ship Ron Brown on 28 September
This mooring will be in place for one year, then recovered and redeployed
in late 1999. A second mooring site, nominally at 35N, 165W, will be occupied
in late 1999 with a similarly designed mooring. We have dubbed this second site
MOMMA (Mid-Ocean Moored Measurement Array). The two moorings will sample contrasting
climatic regimes of the subarctic gyre (PAPA) and subtropical gyre (MOMMA).
The PAPA mooring will extend the measurements at this site which began in 1956,
first as weather ship measurements (until 1981), then as cruises 3-4 times a
year along Line P conducted by the Institute of Ocean Sciences (IOS) in Sydney,
OBJECTIVES AND RATIONALE
The overall objectives of our multi-institutional NOPP study are:
The rationale for this project can be summarized as follows:
- To develop and deploy new, robust air-sea interaction moorings, one at
Station P, a second in the subtropical gyre.
- To deploy low cost acoustic receivers on PMEL moorings in order to expand
the Acoustic Thermometry of Ocean (ATOC) in the North Pacific.
- To combine these measurements and other data with eddy-resolving ocean circulation
models to produce optimal nowcasts and forecasts.
- To assess the present observing system of the North Pacific, and suggest
possible future systems that will improve climate forecasts.
- Substantial interannual to decadal variations in SST occur in the North
Pacific associated with El Nino/Southern Oscillation (ENSO) and the Pacific
Decadal Oscillation (PDO), but they are not well understood.
- Anomalous SSTs in the North Pacific are highly correlated with the Pacific
North American (PNA) surface atmospheric pressure pattern and with the climate
over North America.
- Variations in North Pacific SSTs are well correlated with various components
of the ocean's ecosystem, including plankton and top predators such as salmon.
- Progress in understanding and ultimately predicting these fluctuations is
hampered by lack of systematic time series observations in the upper ocean
of the North Pacific.
PMEL effort during the past year has been involved in mooring design, equipment
acquisition, fabrication, testing, software development, organization of and participation
in the deployment cruise, and interaction with the partners. A robust surface
buoy and mooring have been designed for the high latitude deployments with an
emphasis on stability and reliability to withstand the forces of typical winter
storms. Instrumentation to measure surface meteorology, subsurface temperature,
salinity and velocity has been integrated into a high capacity controller mounted
in an instrument well on the buoy. Real-time data telemetry will utilize the GOES
Data Collection System (DCS) with data retrieval via a 5-m antenna and a Direct
Readout Ground Station (DRGS) that was recently acquired at PMEL. A nearby ATOC
mooring communicates with the PAPA surface buoy via an acoustic modem, and a compressed
file of acoustic travel time information will be transmitted via GOES. In addition,
PMEL deployed an upward looking 153.6 kHz acoustic Doppler current profiler (ADCP)
at Station P.
Discussions with IOS/BC have been underway about coordinating field work and data
analyses from the vicinity of PAPA in view of 3-4 cruise per year along Line P
by the Canadian R/V Tully. We also are planning collaboration with the multi-discplinary
team of O-SCOPE investigators representing UC Santa Barbara, PMEL, AOML, and Monterey
Bay Acquarium Research Institute. This activity will involve engineering development
for nutrient, chemical, and bio-optical measurements on PAPA and possibly MOMMA,
as well as joint analyses of mooring data.
Funding for this NOPP study will expire near the end of FY 99. Continuation
of the PMEL mooring work is planned, though sponsorship and partners for this
continuation are not yet identified.
Dr. Michael J. McPhaden
NOAA/Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle, WA 98115