Probe use while upside down
David McJannet & Aaron Hawdon
CSIRO LAND AND WATER / WATER FOR A HEALTHY COUNTRY
CosmOz
Australian cosmic-ray soil moisture observing network
CosmOz - Australian cosmic-ray soil moisture
observing network
• CosmOz - funded in 2010 through internal CSIRO
budget
• 11 probes were purchased– last one installed
June 2011
• Developed collaborative network with Uni Tas,
Uni NSW, Monash Uni, Charles Darwin Uni
• Co-located with other measurements e.g. flux
towers, water balance, CalVal, crop growth
• Current funding: 0.75 full time person
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http://www.marsdaily.com
CosmOz monitoring locations
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Bit of geography...
• 80% live within 50 km (30 miles) of coast
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CosmOz setup
Satellite link
Rain gauge
Solar panel
Pressure sensor
(temperature &
humidity soon)
Small concrete
pad
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Data logger
Neutron tube
(moderated)
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The CosmOz network: Data delivery
http://cosmoz.csiro.au/cosmoz/
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Where are we up to?
• All probes installed
• Longest record – 2 yrs
• Shortest record – 1.25 yrs
• Very reliable - one cable failure and one probe
replaced
• Calibrations – Aiming for a wet and a dry
calibration per site (at least)
• 4 sites have 2+ calibrations
• 6 sites have dry calibrations
• Lattice water sampling currently underway
• Data processing approaches defined and being
implemented
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Observations and discussion points
Corrections
• Pressure
• Vapour
• Dosage
Calibrations
Surface runoff
Probe corrections and data smoothing
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Corrections – Vapour pressure
• Standard COSMOS correction applied
• Where possible we use local site data
• Plan to add Hydroinnova T & RH to each site
Weany Creek 2011 – Vapour Correction
10%
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Corrections – Atmospheric Pressure
• Inspired by Marek’s Hurricane Sandy slide - Cyclone Yasi
• Category 5 cyclone - 285 km/h (180 m/h)
Weany Creek Probe
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Dealing with the aftermath...
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Corrections – Atmospheric Pressure
• Corrections range by 20%
Weany Creek Probe
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Corrections – Cosmic-ray dose (discussion)
• CosmOz cut-off rigidity varies from 2 – 13
• Originally extracted site specific dosage (kspc22.unibe.ch) but
stopped in early 2012
• Moved to data from NMDB.eu using Swiss station but found some
issues after discussions with Marek...
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Corrections – Cosmic-ray dose
Solar
Flare
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Corrections – Cosmic-ray dose
• It does make some difference – which is more correct?
Up to 10% difference
Solar
Flare
• For now CosmOz sticking with nearest Rigidity NMDB.eu site
• Keep in mind this could be important when the world ends on 21st Dec!
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Calibration of CosmOz probes
• 24 sampling points – 8 points in
each of 3 concentric rings
• 3 depths at each point = 72
samples (0-5, 10-15, 25-30cm)
• Collect wet and dry soil
calibration points
• Standard calibration function
tuned to measurements using
one free parameter
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Calibration – Weany Creek
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Cosmic-ray probe and lattice water
• Lattice water samples being
prepared for ACTLABS
• For now using relationship
between lattice water and
clay content for Australian
soils
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Calibration – Weany Creek
Add in lattice water estimate
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Calibration – Tullochgorum
Add in lattice water estimate
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Calibration – Robson Creek
Add in lattice water
???
Is this a soil carbon effect?
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Calibration - Gnangara
• Soil almost pure silica sand
• Collected one wet calibration point (assume no lattice water)
• Applied calibration to whole time-series
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Calibration - Gnangara
-ve!
• Standard curve fit not applicable (<2%!)
• Empirical fit and more data points required
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Weany Creek -case study
Weany Creek
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Weany Cr - measurement depth and fluxes
Water flux (mm)
Infiltration
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Drainage and
evaporation
Discussion points – Probe corrections & Filtering
• At least 4 four probe types – is there a need for comparison of
‘standardised count’? i.e. San Pedro
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CosmOz future directions
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Future – South East Esk Sensor Web
• Smart irrigation project
• Balancing farmer, hydropower and environment
needs
• Measurements coupled with
flow/rain prediction (1km
grid, 6 hr)
• Near real-time decision
making
• 3 cosmic-ray probes
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Future – Potential adopters
• Apart from CSIRO and uni researchers the Bureau of
Meteorology is a potential adopter
• Bureau of Meteorology has interests in weather
prediction and water balance accounting
• Recent seminars given to demonstrate potential uses
of cosmic-ray probes
• Used combination of CosmOz and COSMOS progress
• Lots of interest in applications from various
groups...no commitments as yet...watch this space!
• Hopefully you will hear more about CosmOz at future
meetings
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David McJannet
Email
David.McJannet@csiro.au
CSIRO LAND AND WATER / WATER FOR A HEALTHY COUNTRY