Report Concludes 449-MHz Wind Profiler Well Suited for Coastal Weather Applications


December 5, 2007

Time-height cross section of winds measured by the 1/4-scale 449-MHz wind profiler at La Jas, Puerto Rico More than half of the Nation's population lives along the coasts, yet none of NOAA's operational wind profilers are currently located in coastal regions. On November 15, 2007 the NOAA Earth System Research Laboratory (ESRL) released a report documenting the results of a year-long evaluation conducted along the coast of California to determine which current state-of-the-art profiler technology (915-MHz vs. 449-MHz) is best suited for coastal and marine weather applications. NOAA's Integrated Ocean Observing System (IOOS) and Coastal Storms Program (CSP) sponsored the study. NOAA's Weather and Water Science, Technology and Infusion Program has proposed to deploy coastal wind profiler networks to help improve coastal weather and air quality forecasts. 915-MHz wind profilers have a proven track record in coastal regions but they operate in an overcrowded frequency band that experiences significant interference, which limits data quality. 449-MHz wind profilers operate in a band specifically set aside for wind profilers, but it was not clear whether their performance in coastal regions was adequate for critical applications. The ESRL Physical Sciences Division has significant experience developing 449-MHz systems, and performed a side-by-side comparison with proven 915-MHz technology. The study determined that the 449-MHz technology was also well-suited to coastal applications, which opens the door for implementation of an operational coastal wind profiler network. (Figure–click image to enlarge: Time-height cross section of winds measured by the 1/4-scale 449-MHz wind profiler at La Jas, Puerto Rico)

Background:
For more than a decade, ESRL has operated boundary-layer, 915-MHz wind profilers in the West for winter weather and summer air quality research field campaigns. More recently, ESRL deployed a first-of-its-kind network of transportable 449-MHz wind profilers along the southern border of the U.S. for the U.S. Air Force. The report also summarizes feedback received from NOAAs Weather Forecast Offices and River Forecast Centers on how the 449-MHz wind profiler data and associated products developed by ESRL scientists were used in daily forecast operations. In addition to supporting the issuance or cancellation of official watches and warnings of hazardous weather, the data were used to support operational forecasts of fire weather, aviation weather, and air quality.

Significance:
Coastal and marine weather prediction suffers from a lack of available observations, especially of upstream weather conditions coming in from the Pacific. Coastal profiler networks would aid in reducing coastal storm disaster losses by providing the National Weather Service with measurements necessary for improving short-term wind, precipitation, and aviation forecasts. This study sponsored by IOOS and CSP supports NOAA's weather and water goal by providing a critical step towards finding a workable technology for coastal weather and air quality forecast improvements.

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