Peak height of OH airglow derived from simultaneous observations a Fabry‐Perot interferometer and a meteor radar

A new method for estimating daily averaged peak height of the OH airglow layer from a ground-based Meteor Radar (MR) and a Fabry-Perot Interferometer (FPI) is presented. The first results are derived from four-year simultaneous measurements of winds by a MR and a FPI at two adjacent stations over center China, and are compared with observations from the TIMED/SABER instrument. The OH airglow peak heights, which are derived by using correlation analysis between winds of the FPI and MR, are found to generally peak at an altitude of 87 km, and frequently varied between 80 km to 90 km day to day. In comparison with SABER OH 1.6 µm observations, reasonable similarity of airglow peak heights is found, and rapid day-to-day variations are also pronounced. Lomb-Scargle analysis is used to determine cycles of temporal variations of airglow peak heights, and there are obvious periodic variations both in our airglow peak heights and in the satellite observations. In addition to the annual, semi-annual, monthly and three monthly variations, the shorter time variations, e.g. day-to-day and several days’ variations are also conspicuous. The day-to-day variations of airglow height obviously could reduce observation accuracy and lead to some deviations in FPI measurements. These FPI wind deviations arising from airglow height variations are also estimated to be about 3 - 5 m/s from 2011 to 2015, with strong positive correlation with airglow peak height variation. More attention should be paid to the wind deviations associated with airglow height variation when using and interpreting winds measured by FPI.