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The Australian Wind Profiler Network
Bronwyn Dolman1,2, Iain Reid1,2, Chris Tingwell3 and Tom Kane3
1ATRAD Pty Ltd20 Phillips St Thebarton
South Australiawww.atrad.com.au
2University of Adelaide, Australia
3Australian Government Bureau of Meteorology
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Australian Profiler Network
Ceduna
Tennant Creek
Buckland Park
Carnarvon
Davis Station
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Australian Profiler Network
Weather Radar
Meteorological InstrumentationRemote Balloon Launcher
Wind Profiling Radar
Tennant Creek
• Complement existing meteorological technology providing continuous profiles of the atmosphere in the vertical column above the instrument
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Australian Profiler Network
• Currently all VHF systems (55 MHz)– Boundary Layer Profiler (BLP) 8 km coverage– Stratospheric Tropospheric Profiler (STP) 20 km coverage– System design is modularwith most components shared
Power Amplifiers 80 kW STP
Transceiver / signal
processing
Beam Steering
Combiner
Antennas
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Boundary Layer Profilers
• Spaced Antenna– Full Correlation Analysis– 27 Yagi antennas arranged in 3 groups of 9– 0.7 spacing
BLP
Frequency 55 MHz (range 30 ‐ 64 MHz)
Power 12 kW (3 4 kW modules)
Receiver 3 coherent (complex) channels
Acquisition Virtex‐4 FPGA
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Boundary Layer Profilers
• Spaced Antenna– Full Correlation Analysis– 27 Yagi antennas arranged in 3 groups of 9– 0.7 spacing
Low High
Pulse Width 100 m 500 m
PRF 20 000 Hz 10 000 Hz
Range 0 – 7 km 0 – 14 km
Sampling Interval 100 m 250 m
Dwell Time 55 s 55 s
Coherent Integrations 1000 500
Spectral Points 1100 1100
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Stratospheric Tropospheric Profilers
• Doppler Beam Steering Analysis– 144 Yagi antennas arranged on a 12 x 12 square grid– 0.7 spacing– Phase delays to steer beam
STP
Frequency 55 MHz (range 30 – 64 MHz)
Power 80 kW (24 4 kWmodules)
Receiver 3 coherent (complex) channels (1 used)
Acquisition Virtex‐4 FPGA
atrad.com.au
Stratospheric Tropospheric Profilers
• Doppler Beam Steering Analysis– 144 Yagi antennas arranged on a 12 x 12 square grid– 0.7 spacing– Phase delays to steer beam
Low High
Pulse Width 250 m 1000 m
PRF 14 000 Hz 6000 Hz
Range 0 – 8 km 1 – 20 km
Sampling Interval 100 m 200 m
Dwell Time 55 s (per beam) 55 s (per beam)
Coherent Integrations 700 150
Spectral Points 1100 2200
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Wind Measurements
Doppler
FCA X 15
Averaging interval: 30 mins
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Wind Measurements
Doppler
FCA
QualityControl
QualityControl
X 15
Averaging interval: 30 mins
atrad.com.au
Wind Measurements
Doppler
FCA
QualityControl
QualityControl
X 15
Wind Estimate
Wind Estimate
Averaging interval: 30 mins
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Wind Measurements
Doppler
FCA
QualityControl
QualityControl
X 15
Wind Estimate
Wind Estimate
BUFR
BUFR
Averaging interval: 30 mins
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Wind Measurements
Doppler
FCA
QualityControl
QualityControl
X 15
Wind Estimate
Wind Estimate
BUFR
BUFR
Output to user
Averaging interval: 30 mins
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Wind Measurements
• Verified at each site against sondes
Sonde magnitude against profilerZonal and meridional comparison
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Forecasters
• 30 minute average data available to Australian forecasters– Gradient and steering winds, jet onset time and duration– Aviation forecasts– Fire weather
20 km Tennant Creek 80 kW STP high mode
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Global data use
• Most BoM profilers now available on EUMETNET
http://eumetnet.eu/radar‐wind‐profilers
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ACCESS NWP
• Based on Met Office Unified Model and 4D‐Var data assimilation
• Provides the BoM with operational forecasts
Global and RegionalACCESS systems assimilate a wide range of meteorological observations in six‐hour cycles
Courtesy of Chris TingwellBoM
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ACCESS Forecast Sensitivity to ObservationsSignificant new technique in which the forecast error reduction in a 24 hour forecast due to data assimilation can be split up and attributed to each individual assimilated observation.
Forecast error is measured by a global energy norm (in J/kg).
Over several weeks, the reduction of forecast error due to observing systems, instruments, groups of observations etc. can be aggregated and compared.
Data Assimilation4D‐Var
Observations
ForecastT + 24h
ForecastT + 30h
ForecasterrorT + 24h
ForecasterrorT + 30h
Analysis
Change in forecast error
Change in forecast error due to analysis
Change in forecast error due to each observation
Adjoint PF model
model
model
Adjoint VAR
Courtesy of Chris TingwellBoM
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Australian Upper Air Observing Network
Halls CreekWINPRO & PILOT
WilliamtownSydney
TEMP: radiosonde observations of temperature, moisture, wind (once/twice per day)PILOT: tracked balloon flights – wind only (once/twice per day)WINPRO: wind profilers (hourly)
Labelled stations used for comparisons here
Courtesy of Chris TingwellBoM
atrad.com.au
Australian Upper Air Observing Network24 hour forecast error reduction in the global ACCESS system due to observations in the Australian Upper Air network aggregated over 10 weeks (more negative means more forecast error reduction).
Wind profilers contribute less than the impact of the radiosonde "TEMP" observations, but rather more than the "PILOT" wind observations.
WINPRO observation impacts are less on a per observation basis (2ndpanel) but this is counter‐balanced by their being much more frequent.
Forecast Impact/day (J/kg)
Forecast Impact/observation (J/kg)
Courtesy of Chris TingwellBoM
atrad.com.au
Australian Upper Air Observing NetworkTemp impacts greatest as include measurements of temperature, humidtyand wind reported at many observation levels. Also assigned a smaller observation error in the assimilation and is thus assigned more weighting.
Per observation refers to, say, a single zonal wind measurement at a particular height at a particular time.
Density and timing of observation must be considered here. The profilers are typically located at Bureau sites and thus amidst other observations. The sondes are at a lower temporal resolution and thus add information to a region of the model which hasn’t seen an observation for up to 24 hours.
Forecast Impact/day (J/kg)
Forecast Impact/observation (J/kg)
Courtesy of Chris TingwellBoM
atrad.com.au
Australian Upper Air Observing NetworkWilliamtown v. Sydney
Comparison of impacts from nearby radiosonde "TEMP" (Williamtown) and Wind profiler (Sydney) observations.
The greatest impact/observation is from the Williamtown temperature & moisture measurements, but the aggregated forecast impact from the Sydney wind profiler is almost as much as from the Williamtown radiosonde flights.
Forecast Impact/day (J/kg)
Forecast Impact/observation (J/kg)
Courtesy of Chris TingwellBoM
atrad.com.au
Australian Upper Air Observing NetworkHalls Creek
Co‐located wind profiler and PILOT observations
PROFILER: hourly observations throughout day.PILOT balloon flights: twice a day at 00 UTC & 06 UTC.
WINPRO observations have greater integrated forecast impact because of much greater numbers, although the impact per observation is less.
Forecast Impact/day (J/kg)
Forecast Impact/observation (J/kg)
Courtesy of Chris TingwellBoM
atrad.com.au
Current Developments
• Examining dwell time with an aim to reduce it• Turbulence estimates• Tropopause detection• Developing real‐time automatic peak detection routines– Automatically identify
and where possible or problematic, remove interference
– Trigger additional analysis such as precipitation retrievals
Alexander, S. P., Murphy, D. J. and Klekociuk, A. J., “High resolution VHF radar measurements of tropopause structure and variability at Davis , Antarctica (69o S, 78o E)”, Atmos. Chem. Phys., 13, 3121,‐3132, 2013
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Interference Removal
Aircraft interferenceCourtesy of Baden GilbertUoA
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Interference Removal
Aircraft interferenceCourtesy of Baden GilbertUoA
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Real Time Retrievals
Precipitation
Rainfall Clear air
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Real Time Retrievals
Drop Size Distribution
Precipitation
Rainfall Clear air
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Real Time Retrievals
Drop Size Distribution
Rain Rate Retrieval
Rainfall Clear air
Precipitation
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Conclusion
• Australian wind profiler network consists of 18 instruments across Australia and Antarctica– 11 assimilated profilers make a significant contribution to improving the forecast skill of ACCESS
• Current effort geared towards providing the best possible product for the user, and utilising data for more than wind estimates