ESRL Quarterly Newsletter - Winter 2011

Now Boarding...Weather!

ESRL scientists seek to improve aviation efficiency by developing highly accurate and timely weather information for integration into air traffic management operations

Managing commercial air traffic is difficult enough without having to worry about weather. To keep increasing numbers of airplanes away from one another and on track, most air traffic controllers and managers rely on technologies, some of which are significantly less powerful than their own smart phones, said ESRL’s Lynn Sherretz (Global Systems Division, GSD).

Add weather to the system, and air traffic management becomes an even greater challenge. If a thunderstorm threatens, for example, air traffic managers usually stop using computerized tools that normally help them efficiently line airplanes up for landing.

“That system would produce solutions that could put planes right into storms,” Sherretz said. “This is an example of why weather needs to be integrated into these tools.”

So Sherretz and colleagues throughout GSD are helping to develop and test weather-related concepts for the Next Generation Air Transportation System (NextGen). NextGen is an executive and Congressionally mandated effort to significantly improve efficiency and safety in the skies by 2025, when air traffic is expected to at least double . ESRL’s work is in collaboration with many other organizations and federal agencies, from NASA and the National Center for Atmospheric Research to NOAA’s National Weather Service, the U.S. Department of Transportation, and the Massachusetts Institute of Technology’s Lincoln Laboratory.

GSD’s role

GSD’s responsibilities within NextGen revolve around weather information research and development, said Sherretz, the division’s NextGen program manager. This includes developing and testing concepts for producing, displaying, and verifying meteorological observations and forecasts, and tools for standardizing and quickly sharing such data through Internet technologies.

The overall goal, he said, is to deliver timely and accurate weather information, whenever and wherever needed, to those managing the U.S. airspace, to improve efficiency and absorb predicted increases in traffic. More reliable or consistent forecasts, for example, might prevent an airline from unnecessarily loading airplanes with enough extra fuel to get to an alternative destination—a costly precaution that’s mandated if visibility at the destination terminal is predicted to be poor.

Right now, weather information is widely distributed, not standardized for accessibility, often not detailed enough to be useful, and sometimes even contradictory. In part, that’s because various weather products were developed for different users (e.g., public and aviation operations), or because regulations have led to diverse weather products that are not always consistent.

“At any given time, several different organizations may be all putting out information on the same weather event,” said GSD’s Darien Davis, NOAA’s Research and Development Coordinator for NexGen. “There are warning products, meteorological impact statements, the collaborative convective forecast… ” Davis said. “And guess what: What comes out of one office isn’t always the same as what comes out of another. So that leaves folks in aviation wondering what to believe.”

That lack of consistency is a major problem for air traffic managers, who must often act upon the most conservative forecasts—the ones most likely to cause delays.

A single, authoritative source

A major part of the NextGen weather effort, therefore, is to produce what has been termed the “Single Authoritative Source,” or SAS, Davis and Sherretz said. The SAS is envisioned as the single best forecast at any given place and time for any given aviation operation. A policy has already been established that the Federal Aviation Administration must use the SAS; other aviation operators may use it if they choose.

This could mean, for example, the best forecast for enroute airspace, complete with statistical information about the likelihood of certain events, say icing or hail formation. Or it might be real-time information about turbulence, relayed by aircraft in the sky.

Either way, observations and forecasts must be conveyed along networks in accessible formats, so they can be quickly ingested by many different systems, including decision support tools used in air traffic management. Those data will also find a home in a virtual repository that includes access tools—the so-called “4-D Weather Cube” (three dimensions of space plus time).

The NWS plans to release a request for proposals, for companies interested in building the Cube (also known as the Weather Information Database), Sherretz said. The contractor will be responsible for the hardware and software involved in data services and management, and with the NWS, GSD will work closely with the contractor, testing architecture, speed, accuracy, and other components.

Early testing and data

Weather data and predictions are so critical to aviation operations that some of NextGen’s first tasks deal with weather data exchange. A key initial goal is for NOAA and FAA to exchange meteorological observations and forecasts using standard data services and standard product formats.

Last fall, an experiment run from the FAA’s William J. Hughes Technical Center (WJHTC) in Atlantic City, NJ, showed early success. NOAA and the FAA ran a “capability evaluation,” demonstrating they could share meteorological data in standard formats along secured networks.

GSD researchers are also working on verification systems, to understand the skill of various types of forecasts and tools, including the value added by human forecasters. Understanding skill and accuracy will be critical for helping NextGen managers decide what forecast models, data, and data assimilation systems should be part of the future aviation weather system.

“GSD researchers are excited about contributing advanced weather-related capabilities to enhance the efficiency of tomorrow’s national airspace system,” Sherretz said.

Last year, a series of severe winter storms walloped the Eastern Seaboard, paralyzing air travel in the region, Davis said.

“Those storms were very well predicted, and many airports even closed down ahead of time,” she said “That’s because we were all spot on and we were all consistent… That’s how it should work, but it’s not always the case.” NextGen, she and her colleagues said, should make such successes increasingly common.