Aircraft Encounters with Mountain Wave-Induced Clear Air Turbulence: Hindcasts and Operational Forecasts Using an Improved Global Model
Abstract
Mountain waves are important dynamical processes that require global modeling and forecasting. Variable distributions of mountain wave-induced drag and diffusion modify both the fine-scale and synoptic-scale circulations of the atmosphere. Global numerical weather prediction (NWP) models cannot resolve mountain waves and so must parameterize mountain wave effects globally to improve both their climatologies and forecast skill (Palmer et al. 1986; Zhou et al. 1996). Breaking mountain waves can also generate severe clear-air turbulence, thereby endangering aviation (Lilly 1978; Ralph et al. 1997). Mountain waves are particularly important in the stratosphere and mesosphere. Breaking waves drive global circulation patterns at these heights (Norton and Thuburn 1999), while the perturbations dominate the mesoscale stratospheric dynamics around undular terrain (Eckermann and Preusse 1999; Whiteway 1999), triggering stratosphere-troposphere exchange [Lamarque et al., 1996] and formation of ozone destroying polar stratospheric clouds [Carslaw et al.,1999]. Thus, global models of their effects are needed not just within the troposphere, but up to mesospheric heights of ~100 km. This work focuses on one such model, known as the Mountain Wave Forecast Model (MWFM), which we have developed and extended recently. We focus here on some recent applications of the model in forecasting mountain wave-induced turbulence for aviation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2000
- Accession Number
- ADA527188
Entities
People
- Dave Broutman
- Julio T. Bacmeister
- Stephen D. Eckermann
Organizations
- United States Naval Research Laboratory