1. Günther Haase Tomas Landelius Daniel Michelson Generation of superobservations (WP2)

2. Günther HaaseColchester, 9 January 20032 Objectives While reflectivity data are regularly used in operational forecasting procedure much efforts should be devoted to improve the use of Doppler data. This WP seeks to increase the exploitation of these information following two complementary strategies. On one hand Doppler data will be processed in order to be use in NWP models (i.e. define a super- observation product), on the other extraction of information from Doppler data (VAD or multiple Doppler wind retrieving) will improve the understanding of weather phenomena and will give a detailed wind field to be compared with NWP models output and meso-scale analysis. Identify the limitations for improving clear air retrievals of wind and boundary layer processes at the operational weather radar frequencies used in Europe.

3. Günther HaaseColchester, 9 January 20033 Radar radial wind measurements (volume data) Quality control (dealiasing) Generation of superobservations Overview

4. Günther HaaseColchester, 9 January 20034 Radial wind measurements Finnish radar network: 10 elevation angles (≥ 0.5°) 360 azimuth gates per scan 500 range gates per scan 500 m range bin spacing 0.9° vertical beamwidth volume data every 15 min. ±7.8 m/s unamb. vel. int.

5. Günther HaaseColchester, 9 January 20035 Dealiasing of a synthetic measurement

6. Günther HaaseColchester, 9 January 20036 Parametric curve in cylinder coordinates (ignore z-axis): Tangent to T (first component):

7. Günther HaaseColchester, 9 January 20037 Numerical estimation of the tangent (least square approach) to get a first guess wind field (u,v)

8. Günther HaaseColchester, 9 January 20038 Dealiasing

9. Superobservations 1.horizontal length is used as a search radius in the interpolation 2.vertical length is used to select non-overlapping scans and to describe the atmospheric depth sampled by the radar D. B. Michelson, 2002 0.9° elevation angle 105 azimuth gates per scan 10 km range bin spacing 0.9° vertical beamwidth Averaging lengths

10. Günther HaaseColchester, 9 January 200310 Horizontal averaging in polar volumes D. B. Michelson, 2002 Radar Karlskrona 3 December 1999, 18:30 UTC

11. Longitude, latitude and altitude of the radar antenna Elevation angle of the given scan Halfpower beamwidth Azimuth angle between successive azimuth gates of the output superob geometry Range bin spacing of the output superob geometry Longitude, latitude, altitude, azimuth and slant range of the centre of the output polar bin Horizontal and vertical averaging length Radial wind velocity, reflectivity factor and spectral width (average, variance and sample size) Available superob information

12. Günther HaaseColchester, 9 January 200312 Deliverable 2.1 Superobservation dataset 1-10 December 1999 1-14 June 1999 1-31 July 2000