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4th Symposium on Lidar Atmospheric Applications

4th Symposium on Lidar Atmospheric Applications. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Institute for Meteorology and Climate Research, KIT Karlsruhe, Germany.

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4th Symposium on Lidar Atmospheric Applications

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  1. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier 4th Symposium on Lidar Atmospheric Applications 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Institute for Meteorology and Climate Research, KITKarlsruhe, Germany

  2. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Contents Horizontal wind • complementary profiles and • identification of measurement errors Vertical wind • in different atmospheric situations • a new approach estimating rain-drop size-distributions • complementary profiles of vertical velocity variance

  3. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Instrumental and experimental setup 2 µm Doppler lidar 35.5 GHz cloud radar Collocated on Hornisgrinde mountain (Black Forest) and performing a coordinated scan strategy from June to August 2007, COPS campaign

  4. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Horizontal wind Hypothesis: aerosol drifts with horizontal wind independent of it’s size simultaneous measurements deliver same results lidar radar

  5. Horizontal wind Hypothesis: aerosol drifts with horizontal wind independent of it’s size simultaneous measurements deliver same results Increase of available information from 32% using only lidar to 51% using the combination. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier

  6. Horizontal wind Hypothesis: aerosol drifts with horizontal wind independent of it’s size simultaneous measurements deliver same results velocities differ by 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier

  7. Horizontal wind Hypothesis: aerosol drifts with horizontal wind independent of it’s size simultaneous measurements deliver same results Ground clutter problem velocities differ by 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier

  8. involving ground clutter ground clutter corrected velocities differ by Horizontal wind Hypothesis: aerosol drifts with horizontal wind independent of it’s size simultaneous measurements deliver same results Ground clutter problem 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier

  9. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind Hypothesis: size dependent fall velocity of the larger aerosols and droplets simultaneously measurements deliver different results due to different wavelengths of the instruments and so different scatter mechanism

  10. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind Hypothesis: size dependent fall velocity of the larger aerosols and droplets simultaneously measurements deliver different results due to different wavelengths of the instruments and so different scatter mechanism Clear air day 82.1% agree better than 0.5 ms-1

  11. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind Hypothesis: size dependent fall velocity of the larger aerosols and droplets simultaneously measurements deliver different results due to different wavelengths of the instruments and so different scatter mechanism During rain Mean difference of 3 ms-1

  12. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind during rain Lidar double peaks

  13. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind during rain Lidar double peaks

  14. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind during rain Lidar double peaks

  15. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Vertical wind during rain Idea: Estimating rain drop size distribution from velocity difference Radar Rayleigh scattering reflectivity proportional D6 Lidar optical scattering backscatter proportional D2 lidar radar Size dependent terminal fall velocity and γdistribution of rain-drop-size

  16. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Power spectra and vertical wind variance Is vertical velocity variance influenced by the differences of measured vertical velocity? Clear air conditions Light rain conditions lidar radar Clouds ?

  17. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Conclusions • Increase of valid horizontal wind information • Little redundant measurements • Potential to detect measurement errors • Differences in vertical wind velocity due to terminal size dependent fall velocities of scatterers • New approach to estimate rain drop size distribution from different measured velocities • Clear air power spectra behave quite similar, potential to extend profiles of vertical velocity variance into clouds Measurement combination of a cloud radar and a Doppler lidar allows new measurement approaches.

  18. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Thanks Thanks for attention. For details please see manuscript.

  19. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Additionally information

  20. Instrument specifications Cloud radar Wind lidar wavelength 8.44 mm 2023 nm Pulse width 200 ns 425 ns Pulse repetition frequency 5 kHz 500 Hz Unambiguous velocity ± 10.6 ms-1 ± 20 ms-1 Sampling rate 50 MHz 100 MHz Peak power 30 kW 4.5 kW Range gates 512 100 Lowest range gate 150 m 350 m Spatial resolution 30 m 72 m Azimuth angle -3 … 363° 0 … 360° Elevation angle 45 … 135° -5 … 185° Scan velocity Up to 10° s-1 0.1 … 25° s-1 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier

  21. 5.3 Advantages of a coordinated scanning Doppler lidar and cloud radar system for wind measurements K. Träumner, J. Handwerker, A. Wieser, J. Grenzhäuser and C. Kottmeier Effect ground clutter correction

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