Submitting Campus

Prescott

Department

Applied Aviation Sciences

Document Type

Article

Publication/Presentation Date

5-2026

Abstract/Description

Clear‑air turbulence (CAT) is a major aviation hazard that occurs near airline cruising altitudes in both cloud and cloud‑free environments. Its lack of a distinct visual signature makes detection and avoidance difficult. CAT is associated with wind shear near jet streams, gravity waves, and Kelvin–Helmholtz instability and may be further enhanced by climate change. This study examines the climatology, spatial distribution, seasonal variability, and trends of CAT over the contiguous United States.

Pilot Reports (PIREPs) from 2001–2025 between 100 and 400 hPa are analyzed alongside jet stream, shear, and stability diagnostics derived from NCEP–NCAR Reanalysis data. Proxies such as inverse Richardson number are used to diagnose shear-driven turbulence and evaluate possible trends. Results show a pronounced winter maximum in CAT, with persistent hotspots to the lee of Rocky Mountains, the Midwestern, and the northeastern United States, consistent with jet streak structure and enhanced shear in these regions. Although average reported turbulence intensity shows a slight decreasing trend, this could possibly reflect improved avoidance procedures. Environmental diagnostics from the proxy turbulence estimates indicate a modest increase in CAT‑favorable conditions, emphasizing the need for integrated observational and diagnostic assessments of evolving turbulence risk.

Location

Prescott, AZ

Number of Pages

21

Additional Information

Senior Thesis

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