Some Characteristics of the Mesosphere and Lower Thermosphere (MLT) as Observed by the High Resolution Doppler Imager (HRDI) on UARS

The HRDI instrument measured the winds, temperature, and molecular oxygen A band volume emission rate from November, 1991 until September, 2001. The altitudes examined were typically 65-115 km. The precession rate of UARS allowed complete local time coverage at mid and low latitudes to be sampled in about a month. This paper examines features found in nearly 10 years of MLT data collected by HRDI. This length of time has covered about 20 semi-annual cycles, 10 annual cycles, 4 QBO cycles, and almost an entire solar cycle. The response of the wind and temperature fields to these phenomena are examined