Improved estimates for neutral air temperatures at 90 km and 78°N using satellite and meteor radar data

A technique for using satellite‐derived temperatures to calibrate initial estimates of 90 km temperatures measured by meteor wind radar is presented. Temperatures derived from the Nippon/Norway Svalbard Meteor Radar, situated on Svalbard at 78°N, 16°E, are calibrated using data from the Aura spacecraft's Microwave Limb Sounder (MLS) experiment. The calibration was performed in a two‐step process: after an initial calibration of first‐guess temperatures, results were used to adjust the MLS values to reflect daily means rather than the 0200–1100 UT observation period of the satellite instrument; thereafter the calibration was repeated with the revised MLS temperatures. The resulting temperature time series represents a marked improvement on earlier results calibrated using hydroxyl emission and potassium/K‐Lidar observations, as the uncertainty is reduced from 17 to 7 K. These latest results represent a new step toward reliable and continual monitoring of upper mesosphere/lower thermosphere temperature.