NOAA 2000-079
FOR IMMEDIATE RELEASE
Contact: Barbara McGehan
11/20/00

NEW WIND SENSOR ABOARD NOAA SHIP WITHSTANDS STORMS, PROVIDES CURRENT WEATHER DATA

An impressive new instrument rigged to withstand high seas and ocean storms is sending back continuous wind data from its perch aboard the NOAA research vessel, Ronald H. Brown. Early reports indicate it's a huge success.

Developed at NOAA's Environmental Technology Laboratory in Boulder, Colo., the instrument is the first wind profiler to be permanently installed aboard a research ship to provide scientists with valuable weather and climate data.

"NOAA now has an important new wind sensor that will greatly aid the study of air-sea interactions at sea, and provide critically needed wind measurements off shore to improve NOAA forecasts of coastal severe weather," said M.J. Post, chief of ETL's technology transfer group.

The instrument, a 915-MHz radar wind profiler, underwent a major redesign to accommodate the unique conditions found on a ship. Usually installed on land, wind profilers are Doppler radars that are pointed upward and are used to measure winds and temperature up to heights of several kilometers. The data are used for weather forecasts, climate models, aviation weather and other meteorological needs. In this instance, the Brown profiler not only had to withstand rough seas, sea spray and extreme temperatures, but also had to overcome several technical problems.

"Previous designs were bulky, required moving parts to stabilize the antenna from ship motion, and displayed degraded performance due to extraneous signals from the sea surface," Post said. "Sea clutter was a significant problem, since it affected the scientific value of wind measurements in the lower atmosphere where important air-sea interactions, such as the recent El Niño and La Niña events, occur."

Engineers in Post's group came up with a bold new antenna design that dealt with many of the problems. Over the next two years an ETL team of experts developed a "next generation" wind profiler including electronic - not mechanical - motion compensation and new signal processing. In August, the team installed the instrument aboard the Brown in just five days, before it took off for Alaska. Engineers turned on the system during a stormy voyage in the Gulf of Alaska later that month and let it collect data unattended for three weeks. It was then tested during the Brown's voyage from Dutch Harbor, Alaska to San Diego during September and October.

It worked perfectly. "This significant leap in wind profiler technology has reached well beyond its deployment on the Ronald H. Brown and its ability to support all subsequent scientific missions on board. It opens doors for scientists to more accurately probe the atmosphere and detect its structure, both on land and at sea," said Post.

"Perhaps most importantly, it offers a compact, lightweight, resilient wind profiler for deployment on ships, buoys and other moving platforms like trailers and aircraft."

Post says a network of buoy-mounted off-shore wind profilers along the west coast would greatly improve forecasts for the entire western U.S.

The three-year old Brown is one of the most technologically advanced floating laboratories in the world, with the most impressive array of atmospheric and near-surface oceanographic sensors ever assembled on a ship. The ship carries a Doppler radar similar to those used by the National Weather Service on land, and also has the capability to take simultaneous ocean and atmospheric measurements essential to the study of sea-surface and atmospheric coupling and its effect on climate.The 274-ft. Brown is home ported in Charleston, S.C. and will be arriving in Charleston on Nov. 25

Photos of the profiler aboard the Brown can be found at:
http://www4.etl.noaa.gov/ronbrown/

For more information about NOAA Research, visit: http://www.oar.noaa.gov

For more information about the Ronald H. Brown, see the Office of Marine and Aviation Operations Web site at: http://www.nc.noaa.gov/dec99rhb.htm