Quasi-zero Wind Layer
Author: CislunarSpace
Site: https://cislunarspace.cn
Definition
The Quasi-zero Wind Layer (QZWL) refers to the atmospheric region at the bottom of the stratosphere (typically 18-25 km altitude) where wind speed is significantly lower than the layers above and below. This altitude layer provides a relatively stable station-keeping environment for stratospheric airships and is an important flight zone for high-altitude balloons and airships.
Altitude Range
| Name | Altitude Range | Typical Wind Speed |
|---|---|---|
| Tropopause | 10-18 km | Variable |
| Quasi-zero Wind Layer | 18-25 km | <10 m/s |
| Westerly Jet Stream | 25-35 km | 30-100 m/s |
| Middle Stratosphere | 35-50 km | 10-50 m/s |
Formation Mechanisms
Thermodynamic Causes
| Factor | Effect |
|---|---|
| Temperature gradient | Stratospheric inversion suppresses turbulent exchange |
| Ozone layer | Ozone absorbs UV forming stable stratification |
| Radiative balance | Small diurnal heating difference |
Applications in Stratospheric Airships
Altitude Selection Strategy
| Strategy | Advantage | Disadvantage |
|---|---|---|
| QZWL center (~21 km) | Minimum wind speed | Low pressure, reduced buoyancy |
| QZWL bottom (~18 km) | Sufficient buoyancy | Slightly higher wind speed |
| QZWL top (~25 km) | Balanced | Higher altitude control precision required |
Related Concepts
References
- Zhang L, et al. Quasi-zero Wind Layer Characteristics over East Asia[J]. Journal of Atmospheric Sciences, 2025.
- NOAA. US Standard Atmosphere 1976[M]. US Government Printing Office, 1976.