Post on 19-Dec-2015
transcript
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
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