Intense winds and shears in the equatorial lower thermosphere measured by high-resolution nonspecular meteor radar

Abstract

Large horizontal winds and wind shears have been measured in the lower thermosphere by rockets, lidars, and nonspecular meteor radars. This paper describes a detailed analysis of three multihour nonspecular meteor radar data sets collected at the Jicamarca Radio Observatory. This provides some of the highest-resolution sustained measurements in this part of the atmosphere. These show (1) intense wind speeds, maintaining 180-m/s for half an hour and 160-m/s for another half an hour; (2) winds structured in layers that move up or, more commonly, down in the predawn hours at rates of a few kilometers per hour; (3) intense wind shears that typically persist at around 50-m/s/km but, in one instance, sustains values approaching 100-m/s/km for a few hours. Key Points Very high resolution measurements of LT winds Winds sustained at 180-m/s for extended period Highest sustained wind shears ever observed ©2014. American Geophysical Union. All Rights Reserved.