Gravity waves resolved in Numerical Weather Prediction products / Cornelia Strube. Jülich : Forschungszentrum Jülich, Zentralbibliothek, [2021]
Inhalt
- Introduction
- Gravity wave theory
- Perturbation effects
- Phase speed and group velocity
- Polarisation relations
- Interaction with the background flow and momentum flux
- Sources
- Propagation of gravity waves
- Propagation, refraction and amplitude calculation using ray tracing
- Data
- An analysis setup for resolved gravity waves in ECMWF products
- Gravity wave characterisation: S3D method
- Requirements to the method
- Description of the algorithm
- Inferred wave parameters
- Implementation of the method for various data sets
- Gravity wave propagation model: GROGRAT raytracer
- Background removal
- Spectral filtering methods
- Data for comparison
- Horizontal vs. vertical filtering
- When is the background removed?
- Minimum appropriate filter cutoff for vertical and horizontal background removals
- A compromise between removing inertial instability remnants and preserving gravity wave signals in ERA5 temperatures
- Effects for gravity wave climatologies
- Horizontal and vertical filtering on a one-year time series of SABER measurements
- Conclusion
- Case study: Waves at the southern hemisphere winter polar vortex
- Gravity wave characterization in the stratosphere
- Backward ray-tracing
- Categorisation of the backtraced rays
- Dependency of lateral propagation on wind and wave direction
- The relation of ground-based phase speeds and gravity wave sources
- Angle of the waves relative to the ground and to the wind
- Origin areas of non-orographic rays
- Conclusion
- Summary and outlook
- List of figures
- List of tables
- List of acronyms
- List of symbols
- Bibliography