Temperature profiling of the atmospheric boundary layer with rotational Raman lidar during the HD(CP)<sup>2</sup> Observational Prototype Experiment

Abstract

Abstract. The temperature measurements of the rotational Raman lidar of the University of Hohenheim (UHOH RRL) during the High Definition of Clouds and Precipitation for advancing Climate Prediction (HD(CP) 2 ) Observation Prototype Experiment (HOPE) in April and May 2013 are discussed. The lidar consists of a frequency-tripled Nd:YAG laser at 355 nm with 10 W average power at 50 Hz, a twomirror scanner, a 40 cm receiving telescope, and a highly efficient polychromator with cascading interference filters for separating four signals: the elastic backscatter signal, two rotational Raman signals with different temperature dependence, and the vibrational Raman signal of water vapor. The main measurement variable of the UHOH RRL is temperature. For the HOPE campaign, the lidar receiver was optimized for high and low background levels, with a novel switch for the passband of the second rotational Raman channel. The instrument delivers atmospheric profiles of water vapor mixing ratio as well as particle backscatter coefficient and particle extinction coefficient as further products. As examples for the measurement performance, measurements of the temperature gradient and water vapor mixing ratio revealing the development of the atmospheric boundary layer within 25 h are presented. As expected from simulations, a reduction of the measurement uncertainty of 70 % during nighttime was achieved with the new low-background setting. A two-mirror scanner allows for measurements in different directions. When pointing the scanner to low elevation, measurements close to the ground become possible which are otherwise impossible due to the non-total overlap of laser beam and receiving telescope field of view in the near range.An example of a low-level temperature measurement is presented which resolves the temperature gradient at the top of the stable nighttime boundary layer 100 m above the ground.

Profiles of second- to fourth-order moments of turbulent temperature fluctuations in the convective boundary layer: first measurements with rotational Raman lidar

“…In Sect. 2, the setup of the UHOH RRL is described briefly; more details can be found in Hammann et al (2015). The meteorological background and turbulence measurements are presented in Sect.…”

“…This setting allows for high reflectivity of the signals of the channels following in the chain (Behrendt and Reichardt, 2000;Behrendt et al, 2002Behrendt et al, , 2004. The filter passbands were optimized within detailed performance simulations for measurements in the CBL in daytime (Behrendt, 2005; Radlach et al, Hammann et al, 2015). The new daytime/nighttime switch for the second rotational Raman channels (Hammann et al, 2015) was set to daytime optimizing the signal-to-noise ratio of the RR2 channel for high-background conditions.…”

“…The filter passbands were optimized within detailed performance simulations for measurements in the CBL in daytime (Behrendt, 2005; Radlach et al, Hammann et al, 2015). The new daytime/nighttime switch for the second rotational Raman channels (Hammann et al, 2015) was set to daytime optimizing the signal-to-noise ratio of the RR2 channel for high-background conditions. Further details on the receiver setup and the filter passbands can be found in Hammann et al (2015).…”

“…The new daytime/nighttime switch for the second rotational Raman channels (Hammann et al, 2015) was set to daytime optimizing the signal-to-noise ratio of the RR2 channel for high-background conditions. Further details on the receiver setup and the filter passbands can be found in Hammann et al (2015).…”

Development and application of a backscatter lidar forward operator for quantitative validation of aerosol dispersion models and future data assimilation

“…Using ground-based DIAL (differential absorption lidar; Weitkamp, 2008;Späth et al, 2016) water-vapor can be measured, which can even be combined with backscatter measurements to derive more details of aerosol particle properties (Wulfmeyer and Feingold, 2000). Lidar techniques based on the vibrational and rotational Raman effect, like RRL (rotational Raman lidar) allow for the measurement of trace gas profiles (Whiteman et al, 1992;Turner et al, 2002;Wulfmeyer et al, 2010;Haarig et al, 2016) as well as profiles of atmospheric temperature, particle backscatter cross section, particle extinction cross section, and particle depolarization properties (Behrendt et al, 2002;Hammann et al, 2015;Radlach et al, 2008). High-spectral-resolution lidar (HSRL) systems furthermore allow for cloud and particle characterization (Shipley et al, 1983).…”