The FAA Aviation Weather Research Program’s In Situ Turbulence Measurement and Reporting System Larry Cornman NCAR/RAP

Current Observation System For Turbulence--Voice Pilot Reports Issues: Inadequate spatial and temporal accuracy Not all pilots report Lack of null reports Subjective measure Dissemination of turbulence information is poor

In situ turbulence measurement program Goal: To augment/replace subjective PIREPs with objective and precise turbulence measurements Features: Automatically computes turbulence intensities (median and peak) Aircraft independent (eddy dissipation rate, EDR) EDR can be scaled into aircraft-dependent metric (rms-g). Automatically downloads data periodically during flight using ACARS network Adopted as ICAO Standard

Uses for the in situ turbulence data: Provides near real-time state of the atmosphere for pilots, dispatchers, airline and aviation Met. Services. Provides quantitative database for the verification of turbulence forecasting algorithm (GTG) and WSR-88D turbulence detection algorithm (NTDA). Useful as an input into turbulence diagnostic algorithms. Useful in providing a climatology of turbulence.

Programmatic Status Continuing implementation. Performing verification with Pireps. Providing data to GTG and NTDA developers.

In Situ Implementation Status Algorithm loaded on 101 UAL 737-300s and 96 757s - currently receiving data from the 737s. Contract with Delta has been signed, first aircraft implementation in early CY05. Implementation on Southwest Airlines aircraft in CY05.

Case Study: Peak EDR’s, with lightning and Pirep’s 31 kft 33 kft 35 kft 37 kft

Case Study: Flight From Chicago to Salt Lake City Mean and Peak EDR’s with Lightning Notice 3 “hits”: Iowa into Nebraska