Mesospheric temperature soundings with the new, daylight-capable IAP RMR lidar

Abstract

Abstract. Temperature measurements by lidar are an important tool for the understanding of the mean state of the atmosphere as well as the propagation of gravity waves and thermal tides. Though, mesospheric lidar soundings are often limited to nighttime conditions (e.g., solar zenith angle > 96 • ) due to the low signal-to-noise ratio during the day. By this, examination of long-period gravity waves and tides is inhibited, as well as soundings in summer at polar latitudes. We developed a new daylight-capable RayleighMie-Raman (RMR) lidar at our site in Kühlungsborn, Germany (54 • N, 12 • E), that is in routine operation since 2010 for temperature soundings up to 90 km or ∼ 75 km (night or day) and soundings of noctilucent clouds. Here we describe the setup of the system with special emphasis on the daylight suppression methods like spatial and spectral filtering. The small bandwidth of the Fabry-Pérot etalons for spectral filtering of the received signal induces an altitude-dependent transmission of the detector. As a result, the signal is no longer proportional to the air density and the hydrostatic integration of the profile results in systematic temperature errors of up to 4 K. We demonstrate a correction method and the validity of correction by comparison with data obtained by our co-located, nighttime-only RMR lidar where no etalon is installed. As a further example a time series of temperature profiles between 20 and 80 km is presented for day and night of 9-10 March 2014. Together with the other data of March 2014 these profiles are used to calculate tidal amplitudes. It is found that tidal amplitudes vary between ∼ 1 and 5 K depending on altitude.

Lidar Soundings of the Mesospheric Nickel Layer Using Ni(3F) and Ni(3D) Transitions

“…The signal level decreased in some nights by a factor of 100, while the simultaneous soundings of the RMR lidar at 532 nm (Gerding et al, 2016) essentially showed no change. This configuration was in fact similar to the setup used by CLM2015.…”

“…We noted a large variability of the Rayleigh signal level during the first trials, presumably due to changing atmospheric humidity that affects the aerosol properties, that is, visibility in the UV. The signal level decreased in some nights by a factor of 100, while the simultaneous soundings of the RMR lidar at 532 nm (Gerding et al, 2016) essentially showed no change. During the nights of normal signal level we detected the Rayleigh signal well into the altitude of the metal layer (cf.…”

Estimates of the Size Distribution of Meteoric Smoke Particles From Rocket‐Borne Impact Probes

“…Two triplets of MUDD probes were launched from Andøya Space Center (69.29°N, 16.02°E) at 09:43 UT on 30 June 2016 and 13:01 UT on 8 July 2016, respectively, on the MXD‐1 and MXD‐1B sounding rocket payloads. MXD‐1 was launched through a relatively broad NLC, reaching from ∼80 to 86 km, as detected by the RMR‐lidar at the ALOMAR observatory (see Gerding et al, ; Von Zahn et al, for technical details). This NLC had a strong volume backscatter coefficient from 80 to 82 km and a more diffuse appearance in the upper part.…”

On the evaluation of the phase relation between temperature and wind tides based on ground-based measurements and reanalysis data in the middle atmosphere

“…Especially such waves driven by the absorption of solar radiation are one of the strongest perturbations in the middle atmosphere. These so-called thermal tides are globalscale waves with periods of 1 solar day and the subharmonics of that day (24, 12 and 8 h; e.g., Chapman and Lindzen, 1970;Forbes, 1984;Hagan and Forbes, 2002). If tides propagate synchronously to the Sun (westward) around the globe they are usually called migrating, while tides are called nonmigrating when the horizontal propagation is in the opposite direction (eastward) or stationary.…”