The first 80‐hour continuous lidar campaign for simultaneous observation of mesopause region temperature and wind

TLDR

The paper reports the initial results of the first April 2002 campaign, which collected 145 hours of simultaneous mesopause temperature and zonal wind data, including an 80‑hour continuous run. The upgraded Colorado State Sodium lidar, now a two‑beam system, enabled simultaneous day‑and‑night measurements of temperature and wind in the mesopause region. The continuous data show coherent upward‑propagating waves with day‑night wind differences up to 15.5 m s⁻¹ at 88 km and temperature differences of 10 K at 92 km, 10‑hour temperature and 16‑hour wind oscillations indicating nonlinear interactions, and diurnal tide amplitudes and phases that agree with GSWM00 predictions while being modulated by a significant upward‑propagating wave.

Abstract

The Colorado State Sodium lidar has been upgraded to a two‐beam system capable of simultaneous measurement of mesopause region temperature and winds, day and night, weather permitting. This paper reports the initial result of the first campaign, conducted in April 2002, with a total of 145 hours of observation including an 80‐hour continuous data acquisition of temperature and zonal wind. The contour plots of the continuous data set show considerable coherence and activities of upward propagating waves, with a maximum day‐night difference of 15.5 m/s in zonal wind at 88 km and of 10 K in temperature at 92 km. Oscillations at periods of 10‐hour in temperature and 16‐hour in zonal wind, implicating nonlinear interactions, can be identified. Decomposition of the time series into tidal periods, resulted in very good agreement with the GSWM00 predictions of diurnal tide. The observed altitude dependence in diurnal amplitudes and phases is consistent with the presence of a significant upward propagating wave, accompanying and modulating the main diurnal tide.