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

2. 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

4. 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

5. 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.

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

7. In Situ Implementation Status
Algorithm loaded on 101 UAL s and s - 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.

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

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