Comparative wind measurements in the lower thermosphere using rocket trail and meteor radar techniques

Abstract

In September 1973 a comparison of neutral wind measuring techniques for the lower thermosphere was made from the Western Isles off the West coast of Scotland using a mobile meteor radar system situated at Stornoway, Lewis, and two Petrel rockets, carrying Tri-methyl-aluminium (TMA) trail experiments, launched from the Royal Artillery Range at South Uist. The two sets of wind measurements are, in general, strongly correlated (0.5 < r < 0.8), especially between about 85 and 105 km. However, possibly due to differences between the statistical approach of volume sampling of the meteor method and the tracer technique of the TMA chemical release method, there were much poorer correlations between the TMA data and meteor data acquired some distance (> 100 km) and some time (> 15 min) from the TMA trail. Some of the apparent temporal and spatial structure may be inferred to be due to internal atmospheric gravity waves; however, the scale sizes necessary to explain the discrepancies are much smaller (100 km, 15 min) than those inferred independently from meteor radar or chemical release measurements (1000 km, 1–2 hr).