International Research Centre for Telecommunications and Radar

High resolution atmospheric profiling with the S-band Doppler polarimetric radar TARA

Christine Unal, Marta Girame Ibanez, Yann Dufournet and Herman Russchenberg

Delft University of Technology, The Netherlands

TARA type of measurement Near vertical wind profiling mode First comparisons of TARA wind profiling with radiosondes

International Research Centre for Telecommunications and Radar

Hornisgrinde (site H)

TARA (Transportable Atmospheric Radar)

wavelength = 9.1 cm

1 s < time resolution < 10 s

3 m< height resolution< 30 m

can simultaneously measure

dynamics (wind profiling with 3 beams)

microphysics (polarimetry)

of precipitation, ice clouds, mixed-phased clouds and clear air scattering

4.5 Tb of raw data

International Research Centre for Telecommunications and Radar

Measurement configuration

3 beams 3 mean Doppler velocities

horizontal wind + vertical wind

MB

VV HV HH OB1 OB2

measurement sequence

time

International Research Centre for Telecommunications and Radar

Radiosondes comparison

Sites H and M

About 30 mn time difference

2.5 m/s

1.3 m/s

6.5 deg.

17.6 deg.

International Research Centre for Telecommunications and Radar

IOP-5a: reflectivity and horizontal wind

International Research Centre for Telecommunications and Radar

Comparison of TARA horizontal wind with radiosonde H

Standard deviation (radar measurement of 3 mn)

Wind speed: from 1 m/s (cloud) to 2 m/s (rain)

Wind direction: from 2 deg. (cloud) to 5 deg. (rain)

Differences of the order of 5 m/s and 25 deg. between TARA and radiosonde H

International Research Centre for Telecommunications and Radar

IOP-5a: horizontal wind and vertical velocity (zoom on 6 mn)

heterogeneity

International Research Centre for Telecommunications and Radar

IOP-8b: reflectivity and 3D wind

International Research Centre for Telecommunications and Radar

Comparison of TARA horizontal wind with radiosondes

Compared to precipitation, clear air scattering has a low signal-to-noise ratio and less data for the averaging period

Differences of the order of 5 m/s and 90 deg. between TARA and radiosonde H

International Research Centre for Telecommunications and Radar

IOP-8b: 3D wind (zoom on 30 mn)

turbulence

International Research Centre for Telecommunications and Radar

Status

atmosphere dynamics evaluation of TARA wind estimates - different meteorological conditions - accuracy - COPS user needs

atmosphere microphysics research on mixed-phased clouds (Yann Dufournet)

problems with TARA during COPS data quality ok (raw data) but a part of the processing is thus not automatic study cases will be selected

International Research Centre for Telecommunications and Radar

IOP-5a: 3 time series of mean Doppler velocities

International Research Centre for Telecommunications and Radar

IOP-8b: 3 time series of mean Doppler velocities