1997-3 -- FOR IMMEDIATE RELEASE: January 12, 1997
P.O. Box 3000
Boulder, CO 80307-3000
Telephone: (303) 497-8611
Fax: (303) 497-8610
The project is called the Fronts and Atlantic Storm Track Experiment (FASTEX). Operations began on January 6 and will continue through February. The findings should lead to better forecasts for the west coasts of both Europe and North America, as well as a better understanding of how oceanic winter storms affect world climate.
Scientists from the United States, Canada, Iceland, Ireland, the United Kingdom (U.K.), Denmark, Norway, France, Portugal, Spain, and the Ukraine are involved in FASTEX. The key U.S. scientific participants include the National Oceanic and Atmospheric Administration (NOAA), the U.S. Navy, the National Center for Atmospheric Research (NCAR), and university researchers supported by the National Science Foundation. The University Corporation for Atmospheric Research (UCAR), which operates NCAR under sponsorship of NSF, is providing logistical support.
Forecasting the development of oceanic storms is still a challenge, largely because there are fewer weather observations at sea than over land. Cyclones (low-pressure centers) that rake Europe tend to develop along slow-moving cold fronts that extend across the Atlantic. The cyclones often develop midway between North America and Europe and reach their peak strength a day or two later near the British Isles.
Even if a cold front is well forecast, the smaller cyclones that focus wind and rain along it are harder to predict. The researchers of FASTEX are hoping to identify precursors that may trigger cyclones once the precursors overtake the cold front. These precursors could include jet streaks (regions of higher wind speed inside the jet stream) and pockets of air that descend from the stratosphere. If such precursors can be located as they reach the North Atlantic, the cyclones they later generate might be better forecast up to two or three days in advance.
To follow the life cycles of precursors and cyclones, a wide array of observational tools stretches from continent to continent and extends from midlatitudes to polar regions.
The airborne Doppler radars aboard the NSF/NCAR and NOAA turboprop aircraft are being used to analyze mature cyclones at altitudes near or below 10,000 feet (3 kilometers). One of the flight plans, called a "lawnmower" pattern, crisscrosses a cyclone to analyze the frontal rainbands that produce much of a cyclone's heavy precipitation. The rapid-scanning abilities of the NCAR/NSF Electra Doppler radar are helping to document the turbulent ascent and descent of air in shallow rain showers behind a cyclone's cold front.
Although the geography of the Pacific Ocean differs from that of the Atlantic, some insights from FASTEX will be applicable to both. For instance, precursors exiting Asia are likely responsible for some cyclones that reach the U.S. West Coast several days later. Techniques developed in FASTEX for identifying precursors and targeting observations could help to improve forecasts for both North America and Europe. A follow-up field experiment is being considered for the North Pacific.
The main operations center for FASTEX is located at a newly constructed extension of the Shannon, Ireland, airport, where three of the five aircraft are based. The Lear jet will fly from an auxiliary control center at St. Johns, Newfoundland, and the U.K. C-130 from Brize Norton and Lyneham, both in England. The control center is being managed by French, British, and U.S. support staff, with logistics help from UCAR's Joint Office for Science Support (JOSS) and NCAR's Atmospheric Technology Division. Forecasters from France, United Kingdom, Ireland, and Canada are directing the experiment and providing computer-model guidance. A variety of specially generated weather products from the United States and elsewhere is being provided via five high-speed data lines.
The FASTEX field catalog is available on the World Wide Web.
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