A coordinated study of 1 h mesoscale gravity waves propagating from Logan to Boulder with CRRL Na Doppler lidars and temperature mapper

Abstract

We present the first coordinated study using two lidars at two separate locations to characterize a 1 h mesoscale gravity wave event in the mesopause region. The simultaneous observations were made with the Student Training and Atmospheric Research (STAR) Na Doppler lidar at Boulder, CO, and the Utah State University Na Doppler lidar and temperature mapper at Logan, UT, on 27 November 2013. The high precision possessed by the STAR lidar enabled these waves to be detected in vertical wind. The mean wave amplitudes are ~0.44 m/s in vertical wind and ~1% in relative temperature at altitudes of 82–107 km. Those in the zonal and meridional winds are 6.1 and 5.2 m/s averaged from 84 to 99 km. The horizontal and vertical wavelengths inferred from the mapper and lidars are ~219 ± 4 and 16.0 ± 0.3 km, respectively. The intrinsic period is ~1.3 h for the airglow layer, Doppler shifted by a mean wind of ~17 m/s. The wave packet propagates from Logan to Boulder with an azimuth angle of ~135° clockwise from north and an elevation angle of ~ 3° from the horizon. The observed phase difference between the two locations can be explained by the traveling time of the 1 h wave from Logan to Boulder, which is about ~2.4 h. The wave polarization relations are examined through the simultaneous quantifications of the three wind components and temperature. This study has developed a systematic methodology for fully characterizing mesoscale gravity waves, inspecting their intrinsic properties and validating the derivation of horizontal wave structures by applying multiple instruments from coordinated stations.

Validation of SABER v2.0 Operational Temperature Data With Ground‐Based Lidars in the Mesosphere‐Lower Thermosphere Region (75–105 km)

“…Second, strong temporal and spatial variability exists in the vertical temperature profile (with short‐term variability primarily due to small‐scale gravity waves and tides; e.g., see Chen et al, ; Dalin et al, ; Fritts & Alexander, ; Kutepov et al, ; Lu, Chen, et al, ; Lu, Chu, et al, ; Lu et al, ; Lübken et al, ; Mertens et al, ; Rapp et al, ; Stevens et al, ; Zhao et al, ): Unless the satellite and lidar instruments are perfectly collocated, there are likely to be substantial differences in the resulting temperature profiles as a result of this natural variability. Figure illustrates the nature of the short‐term variability in the vertical temperature profile, with all available nighttime profiles at the Arecibo lidar low‐latitude location shown for 19 December 2003.…”

Lidar observations of persistent gravity waves with periods of 3–10 h in the Antarctic middle and upper atmosphere at McMurdo (77.83°S, 166.67°E)

“…By decomposing the time series into time‐frequency space, wavelet analysis allows us to determine not only the dominant modes of variability but also how those modes evolve with time [ Torrence and Compo , ]. Many studies on gravity waves have used this technique to determine the locations of wave events [e.g., Sato and Yamada , ; Zhang et al , ; Wang et al , ; Lu et al , ] and to extract monochromatic wave packets [e.g., Zink and Vincent , , ; Werner et al , ; Murphy et al , ]. The ability to analyze nonstationary signals gives the wavelet technique advantages over traditional Fourier spectrum analysis, which assumes constant amplitudes of oscillation over the data series.…”

Does Strong Tropospheric Forcing Cause Large‐Amplitude Mesospheric Gravity Waves? A DEEPWAVE Case Study

“…For example, investigations of the evolution and propagation of GWs in the stratosphere were conducted based on, for example, aircraft measurements (e.g., Bougeault et al, ; Lilly & Kennedy, ; Smith et al, ; Woods & Smith, ) and radiosondes (e.g., Geller et al, ; Sato & Dunkerton, ). In the middle atmosphere, the evolution of GWs can be studied with all‐sky imagers using the airglow of different molecules (e.g., Smith et al, ; Taylor et al, ; Wrasse et al, ) and lidars (e.g., Bossert et al, ; Kaifler, Kaifler, et al, ; Kaifler, Lübken, et al, ; Lu et al, ) and in situ measurements on sounding rockets (e.g., Rapp et al, ). These studies face the challenge that the observations are limited to specific regions that do not cover the complete vertical column from the troposphere to the middle or upper atmosphere.…”