Airborne Wind Lidar Measurements of Vertical and Horizontal Winds for the Investigation of Orographically Induced Gravity Waves

Witschas, Benjamin; Rahm, Stephan; Dörnbrack, Andreas; Wagner, Jochen; Rapp, Markus

doi:10.1175/jtech-d-17-0021.1

Cited by 67 publications

(124 citation statements)

References 39 publications

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“…Here the observed steep phase lines in the troposphere clearly document that these waves are indeed penetrating the whole troposphere. These findings are in agreement with recent DWL observations over Northern Scandinavia by Wagner et al () and Witschas et al ().…”

Section: Resultssupporting

confidence: 94%

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

et al. 2017

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On 4 July 2014, during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), strong low‐level horizontal winds of up to 35 m s−1 over the Southern Alps, New Zealand, caused the excitation of gravity waves having the largest vertical energy fluxes of the whole campaign (38 W m−2). At the same time, large‐amplitude mesospheric gravity waves were detected by the Temperature Lidar for Middle Atmospheric Research (TELMA) located at Lauder (45.0°S, 169.7°E), New Zealand. The coincidence of these two events leads to the question of whether the mesospheric gravity waves were generated by the strong tropospheric forcing. To answer this, an extensive data set is analyzed, comprising TELMA, in situ aircraft measurements, radiosondes, wind lidar measurements aboard the DLR Falcon as well as Rayleigh lidar and advanced mesospheric temperature mapper measurements aboard the National Science Foundation/National Center for Atmospheric Research Gulfstream V. These measurements are further complemented by limited area simulations using a numerical weather prediction model. This unique data set confirms that strong tropospheric forcing can cause large‐amplitude gravity waves in the mesosphere, and that three essential ingredients are required to achieve this: first, nearly linear propagation across the tropopause; second, leakage through the stratospheric wind minimum; and third, amplification in the polar night jet. Stationary gravity waves were detected in all atmospheric layers up to the mesosphere with horizontal wavelengths between 20 and 100 km. The complete coverage of our data set from troposphere to mesosphere proved to be valuable to identify the processes involved in deep gravity wave propagation.

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Section: Resultssupporting

confidence: 94%

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

et al. 2017

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“…Afterwards, wind observations performed with the A2D during the two above-mentioned NAWDEX flights are presented, demonstrating the ability of the lidar system to provide wind profiles with broad data coverage under various atmospheric conditions. Evaluation of the data accuracy and precision is conducted by comparing the measured wind speeds with those obtained by DLR's coherent wind lidar system (Weissmann et al, 2005;Witschas et al, 2017), which was operated in parallel from the same aircraft as a reference system. Finally, ZWC based on the refined ground detection scheme is shown to provide a significant reduction of the systematic wind error for the second flight.…”

Section: O Lux Et Al: Airborne Wind Lidar Observations Over the Normentioning

confidence: 99%

Airborne wind lidar observations over the North Atlantic in 2016 for the pre-launch validation of the satellite mission Aeolus

et al. 2018

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Abstract. In preparation of the satellite mission Aeolus carried out by the European Space Agency, airborne wind lidar observations have been performed in the frame of the North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX), employing the prototype of the satellite instrument, the ALADIN Airborne Demonstrator (A2D). The direct-detection Doppler wind lidar system is composed of a frequency-stabilized Nd:YAG laser operating at 355 nm, a Cassegrain telescope and a dual-channel receiver. The latter incorporates a Fizeau interferometer and two sequential Fabry-Pérot interferometers to measure line-of-sight (LOS) wind speeds by analysing both Mie and Rayleigh backscatter signals. The benefit of the complementary design is demonstrated by airborne observations of strong wind shear related to the jet stream over the North Atlantic on 27 September and 4 October 2016, yielding high data coverage in diverse atmospheric conditions. The paper also highlights the relevance of accurate ground detection for the Rayleigh and Mie response calibration and wind retrieval. Using a detection scheme developed for the NAWDEX campaign, the obtained ground return signals are exploited for the correction of systematic wind errors. Validation of the instrument performance and retrieval algorithms was conducted by comparison with DLR's coherent wind lidar which was operated in parallel, showing a systematic error of the A2D LOS winds of less than 0.5 m s −1 and random errors from 1.5 (Mie) to 2.7 m s −1 (Rayleigh).

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“…Evaluation of the data accuracy and precision is conducted by comparing the measured wind speeds with those obtained by DLR's coherent wind lidar system (Weissmann et al, 2005;Witschas et al, 2017) which was operated in parallel from the same aircraft as a reference system. Finally, ZWC based on the refined ground detection scheme is shown to provide a significant reduction of the systematic wind error for the second flight.…”

Section: Introductionmentioning

confidence: 99%

Airborne wind lidar observations over the North Atlantic in 2016 for the pre-launch validation of the satellite mission Aeolus

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Lemmerz²,

Weiler³

et al. 2018

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The paper also highlights the relevance of accurate ground detection for the Rayleigh and Mie response calibration and wind retrieval. Using a detection scheme developed for the NAWDEX campaign, the obtained ground return signals are exploited for the correction of systematic wind errors. Validation of the instrument performance and retrieval algorithms was conducted by comparison with DLR's coherent wind lidar which was operated in parallel, showing a systematic error of the A2D LOS winds of less than 0.5 m·s -1 and random errors from 1.5 m·s -1 (Mie) to 2.7 m·s -1 (Rayleigh). 20

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Airborne Wind Lidar Measurements of Vertical and Horizontal Winds for the Investigation of Orographically Induced Gravity Waves

Cited by 67 publications

References 39 publications

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

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

Airborne wind lidar observations over the North Atlantic in 2016 for the pre-launch validation of the satellite mission Aeolus

Airborne wind lidar observations over the North Atlantic in 2016 for the pre-launch validation of the satellite mission Aeolus

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