Blame it on El Niño

by Tom Shepherd and Susan Cobb

When NSSL scientists first agreed to assist in project CALJET (CAlifornia Land-falling JETs), they thought they were just going to lend their expertise temporarily to Principal Investigator (PI) Marty Ralph (ETL) on his first aircraft project. But, as in everything else this year, El Niño changed that.

The project was initially awarded 80 flight hours on the NOAA P-3 aircraft to study the low-level jet associated with the frontal boundaries of Pacific storm systems. This jet often contains a great deal of moisture, causing extreme coastal rains when it hits the mountains along the west coast of the United States. While CALJET was not targeted as an EL Niño study specifically, the result of the record El Niño event was a greater-than-average number of storms than CALJET was designed to study.

The P-3 involvement in CALJET was scheduled to begin on January 16, 1998 and end on February 28, 1998. Before CALJET even started, an additional 100 flight hours were awarded due to the heightened interest in the continuing strong El Niño event. Mid-project, NOAA officials requested another extension-- the real-time information that was being provided by instrumentation onboard the aircraft was extremely valuable to the NWS meteorologists on the west coast. They found their forecasting efforts weregreatly enhanced by this real-time data that was being ingested into the latest model runs. More aircraft time was added, making a total of 235 flight hours in 26 aircraft missions. In terms of aircraft hours, this made CALJET the largest project to date since the aircraft became a part of the NOAA fleet. The last flight was March 24, 1998, and NSSL participated in CALJET throughout the extended time.

NOAA's P-3 research aircraft has been used in several NSSL research projects including VORTEX and FASTEX. NSSL's role in CALJET was to share our in-flight expertise. NSSL was represented in the project by 5 scientists. Diana Bartels was present the initial 2 weeks of the project as a crew member onboard the P-3. Her role was to train Naval Post Graduate School meteorologists in the use of the Airborne Vertical Air Profiling System (AVAPS). Dave Jorgensen and Brad Smull were part of CALJET for two separate 2-week intervals to provide scientific guidance. Tom Shepherd and John Daugherty were present for the entire project. Shepherd was the radar scientist onboard the P-3 who provided in-flight interpretation of the radar data, and flew on all but one of the 26 missions. John Daugherty was the data manager for the project. He flew on several of the missions as well as provided invaluable pre-flight and post-flight meteorological products to the aircraft PI's.

For more information contact Dave Jorgensen at: davej@mrd3.nssl.ucar.edu