March 19, 2014

Novel Airborne GPS Technology Could Revolutionize Weather Models And Hurricane Forecasting

April Flowers for - Your Universe Online

GPS technology has had a profound effect on the world by advancing science and society's ability to pinpoint precise information, from driving directions to tracking ground motions during earthquakes. A new study from the Scripps Institution of Oceanography demonstrates a novel technique that stands to improve weather models and hurricane forecasting by detecting precise conditions in the atmosphere through a new GPS system onboard airplanes. The findings, published in Geophysical Research Letters, show how the project's leaders are pushing towards a goal of broadly implementing the technology in the near future on commercial aircraft.

Current weather measurement systems that use GPS satellite signals as a source to probe the atmosphere rely on one of two methods: GPS receivers that are fixed to the ground which can't measure over the ocean, or GPS receivers on satellites that are expensive to launch and measure regions near storms only intermittently. Jennifer Haase of Scripps Institution of Oceanography geophysicist led the research team to design a new system that captures detailed meteorological readings at different elevations at targeted areas of interest, such as over the Atlantic Ocean in regions where hurricanes might develop.

“This field campaign demonstrated the potential for creating an entirely new operational atmospheric observing system for precise moisture profiling from commercial aircraft,” said Haase, an associate researcher with the Cecil H. and Ida M. Green Institute of Physics and Planetary Physics (IGPP) at Scripps. “Having dense, detailed information about the vertical moisture distribution close to the storms is an important advancement, so if you put this information into a weather model it will actually have an impact and improve the forecast.”

“These are exciting results, especially given the complications involved in working from an airplane,” says Eric DeWeaver, program director in the National Science Foundation’s (NSF) Division of Atmospheric and Geospace Sciences, which funded the research. “Satellite-based measurements are now regularly used for weather forecasting and have a big impact, but airplanes can go beyond satellites in making observations that are targeted right where you want them.”

The team conducted a flight campaign in 2010 aboard NSF aircraft, then analyzed the data that demonstrated that atmospheric data could be captured by airborne GPS devices. This is the first time such a determination has been made. The instrumentation, named GNSS (Global Navigation Satellite System) Instrument System for Multistatic and Occultation Sensing (GISMOS), increased the number of atmospheric profiles available for studying the evolution of tropical storms by more than 50 percent.

“We’re looking at how moisture evolves so when we see tropical waves moving across the Atlantic, we can learn more about which one is going to turn into a hurricane,” said Haase. “So being able to look at what happens in these events at the early stages will give us a lot longer lead time for hurricane warnings.”

“This is another case where the effective use of GPS has the potential to improve the forecast and therefore save lives,” said Richard Anthes, president emeritus of the University Corporation for Atmospheric Research, which currently runs the satellite based GPS measurements system called COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate).

GISMOS is currently the size of a refrigerator. Haase and her colleagues, however, are working to miniaturize the technology to more of a shoe box size. At that size, the system can more feasibly fit onto a commercial aircraft. The hundreds of daily flights would provide a potential flood of new atmospheric data to greatly improve hurricane forecasting and weather models.

The researchers believe that their technology could also improve interpretations of long-term climate models by advancing our understanding of factors that are favorable for hurricane development, such as moisture conditions.