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Implementation of One High Density XBT Line with TSG and IMET Instrumentation in the Tropical Atlantic

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July 1, 2004 through June 30, 2005

Dr. Robert A. Weller
Principal Investigator
Field Operations: Mr. Frank Bahr
Engineering Support: Mr. David S. Hosom
Physical Oceanography Department
Woods Hole Oceanographic Institution

Program Manager: Dr. Michael Johnson NOAA/OGP

Related NOAA Strategic Plan Goal:
Goal 2. Understand climate variability and change to enhance society’s ability to plan and respond.

Central to present efforts to improve the predictability of climate is the need to understand the physics of how the atmosphere and ocean exchange heat, freshwater, and momentum and, in turn, to accurately represent that understanding in the models to be used to make predictions. At present, over much of the globe, our quantitative maps of these air-sea exchanges, derived either from ship reports, numerical model analyses or satellites, have errors that are large compared to the size of climatically significant signals. Observations made using the IMET technology on the Volunteer Observing Ships on long routes that span the ocean basins are essential to providing the accurate, in-situ observations needed to:

1) identify errors in existing climatological, model-based, and remotely-sensed surface meteorological and air-sea flux fields,
2) to provide the motivation for improvements to existing parameterizations and algorithms,
3) to provide the data needed to correct existing climatologies,
4) and to validate new model codes and remote sensing methods.

AutoIMET was developed by the Woods Hole Oceanographic Institution to meet the need for improved marine weather and climate forecasting. It is a wireless, climate quality, high time resolution system for making systematic upper ocean and atmospheric measurements. This interfaces to the NOAA SEAS 2000 (Shipboard Environmental (Data) Acquisition System) that automatically receives meteorological data (from the AutoIMET) and sends in automated one hour satellite reports via Inmarsat C. This system will document heat uptake, transport, and release by the ocean as well as the air-sea exchange of water and the ocean’s overturning circulation.

Ship selection and interface to the NOAA SEAS system is via AOML. There is ongoing cooperation with Scripps via the CORCIII program as well as Southampton Oceanography Centre (SOC) of Southampton UK on Computer Flow Dynamics (CFD) for evaluation of the flow turbulence around the ship and its effect on the sensor placement. Some logistic support is provided by the Southern California Marine Institute on ship turnarounds. There is ongoing cooperation with the Atlantic Marine Ocean and Atmosphere Laboratory (AOML) in Miami on the Atlantic VOS program. There is also ongoing cooperation with many sensor manufacturers and the VOS people at the German Weather Service (Deutscher Wetter Dienst) in Hamburg Germany.

This project is managed in accordance with the Ten Climate Monitoring Principles.

Note that descriptions, technical information and data from the several VOS being serviced is posted on the site: Data (plots) are available for all ship sets.

Data (numbers) are available via anonymous ftp for the last data set only: If data from previous times are desired please contact
Frank Bahr at:

There is a link to the site: where there is detailed information on the AutoIMET and ASIMET modules. Instrument design questions can be addressed to Dave Hosom at:

The following list starts in March of 2005 rather than in July to include events that were not listed in last year’s report due to the early submission of that report.

- February ’05; Newark, NJ: meet the SeaLand Express to remove the AutoIMET installation, after we had learned, on short notice, that the ship had been sold and
was going to changed routes.
- April ’05: present a poster on the annual NOAA meeting in Silver Springs that included data products from the SeaLand Express.
- April ’05: meet Steve Cook in Newark, NJ, to visit a new VOS candidate M/V Merkur. However, problems related to a crew change prevented us from boarding the
- May ’05; Houston, TX: together with Steve Cook, visit M/V Merkur in preparation for a new AutoIMET installation. Meet with the ship’s captain and electrician to
identify cable penetrations on the bridge and to the ship’s bow thruster chamber.
- July ’05; Newark, NJ: visit M/V Merkur to install a new system. Carrie Wolfe had met the ship just a few days prior in Houston to installing the SEAS2000 computer
on the bridge. She also started “our” portion of the installation by mounting the radio link antenna onto the wheel house and running the cable to the SEAS2000
computer. Unfortunately, because the ship was a week behind schedule, the Newark port stop was shortened to just one night, and we did not finish.
- September ‘05: Houston, TX: meet the M/V Merkur to complete the installation. However, two of the sensors (wind and sea surface temperature) did not start. I
followed the ship to the next port stop in Savannah, GA, to fix the two sensors. The repairs were successful for the wind sensor, but not for SST. Will meet the ship again on its next cycle with additional trouble-shooting tools.
- October ’05: Savannah, GA: meet MV Merkur to repair SST. I had to swap both the power supply box and the logger before getting SST transmitted to the bridge and out via SEAS2000. I suspect that an electrical (wiring?) problem in the power box caused damage to the SST circuitry in the logger. All systems are running now.
- February ’06, Houston, TX: Meet the M/V Merkur in Houston to take down the AutoIMET system. This was planned as a normal sensor calibration exchange visit,
but we had received notice just a few days prior to the trip that the ship had been sold and was not going to return to U.S. ports in the future.
- May ’06: present a poster at the GOSUD/SAMOS meeting in Boulder, and at the annual NOAA meeting in Silver Springs, describing initial results from a comparison
of VOS data from the SeaLand Express and the Merkur to the Ocean Monitoring Station in the equatorial North Atlantic (“NTAS buoy”).

The Climate Observation Program Workshop in Silver spring, MD was attended by Dr. Robert Weller. The GOSUD/SAMOS meeting in Boulder CO was attended by Mr. Frank Bahr. A poster presentation on VOS was made at both meetings.

Last updated: August 19, 2008

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