Upper-Atmosphere Zonal Winds from Satellite Orbit Analysis.
Abstract
We review and interpret the values of upper-atmosphere rotation rate (zonal winds) obtained by analysing satellite orbits determined from observations. The history of the method are answered, and three examples are given. Existing analyses of the atmospheric rotation rate, Lambda, are critically reviewed, and, after rejecting some and revising others, we are left with 85 values. These are divided according to local time and season, to give the variation of Lambda with height in nine situations: morning, evening and average local time, for summer, winter and average season. These observational results indicate that the value of (in rev/day), averaged over both local time and season, increases from 1.0 at 125 km to 1.22 at 325 km and then decreases to 1.0 at 430 km and 0.82 at 600 km. The value of Lambda is higher in the evening (18-24 h), with a maximum value (near 1.4) corresponding to a west-to-east wind of 150 m/s at heights near 300 km. The value of Lambda is lower in the morning (06-12 h), with east-to-west winds of order 50 m/s at heights of 200-400 km. There is also a consistent seasonal variation, the values of Lambda being on average 0.15 higher in winter and 0.1 lower in summer than the average seasonal value. No significant variation with solar activity is found, but there is a slight tendency for a greater rotation rate at lower latitudes for heights above 300 km.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1982
- Accession Number
- ADA130311
Entities
People
- Desmond King-Hele
- Doreen Walker
Organizations
- Royal Aircraft Establishment