HR: 11:20h
AN: AE31B-04 INVITED     [PDF]
TI: Developing Oceanic Convective Products to Mitigate the Impact of Weather Hazards on Transoceanic Flights
AU: * Nierow, A
EM: alan.nierow@faa.gov
AB: Transoceanic flights will increase significantly in the next decade. To manage this increased demand for capacity, while maintaining safety, the Federal Aviation Administration (FAA) is exploring whether the separation minima normally used between aircraft crossing oceanic regions can be reduced both horizontally and vertically. However, before reducing separation standards, the increased hazard of encountering convective weather over oceanic routes must be considered. New evidence has shown that roughly half of the turbulence encounters over oceanic regions were likely associated with convective activity. This phenomenon, Convectively-Induced Turbulence (CIT), can occur several kilometers from convective cores. Operational decision-makers need to detect turbulence associated with oceanic convective activity to route or reroute aircraft safely. However, the only weather data consistently available is from satellite imagery, which can reveal potential areas of convection, but can't unambiguously isolate the hazardous regions from the benign regions. Being able to do this would improve routing and rerouting decisions. The FAA and other agencies are collaborating to develop oceanic convective products. The National Weather Service's Aviation Weather Center created a product that identifies thunderstorms by using the output from different satellite imagers. The technique exploits the difference between the 11-micron infrared (IR) channel and the 6.7-micron water vapor channel. The National Center for Atmospheric Research has developed a new product that maps cloud top temperatures drawn from IR satellite imagery and converts them to aircraft flight levels. In addition, the Naval Research Lab in Monterey, CA is developing cloud classification algorithms that will distinguish between cirrus and convective clouds. We have compared these new convective diagnostic techniques to long-range ground base lightning data and lightning data from the National Aeronautics and Space Administration (NASA) Tropical Rainfall Measuring Mission (TRMM) satellite. We will present the results of the comparison at the meeting. Developing oceanic convective and turbulence nowcasting and short-term forecasting products would have a significant positive impact on flight operations since they would show possible locations of turbulence and wind shear associated with convection. These products would also increase airspace capacity by enabling the FAA to decrease oceanic aircraft separation standards while preserving safety. We wish to reduce the incidence of noncoordinated deviations (because of unexpected encounters with turbulence associated with convection), through greater situational awareness and more time for coordination. By helping pilots avoid areas of convective activity and associated turbulence over oceanic regions, these products have the potential to improve safety of flight and increase efficiency (e.g., facilitate routing and rerouting resulting in smaller flight track deviations and reduced fuel costs).
DE: 3324 Lightning
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 3360 Remote sensing
DE: 3364 Synoptic-scale meteorology
DE: 3379 Turbulence
SC: Atmospheric and Space Electricity [AE]
MN: 2003 Fall Meeting