Download - Heat flow , q (mW/m 2 )
Sediment Sediment below icebelow ice
TemperatureTemperaturesensorssensors
qq = - = -kk dTdT//dzdz
kk = thermal conductivity = thermal conductivity
dTdT//dzdz = thermal gradient = thermal gradient
Te
mp
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ture
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mp
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TimeTime
each sensor...each sensor...
Heat flowHeat flow, q (mW/m, q (mW/m22))
Bottom Bottom waterwater
Pen
etra
tion
Pen
etra
tion
Partial Partial equilibrationequilibration
ProbeProbeextractionextraction
WISSARDWISSARDheat flowheat flow probe probe
Weight standWeight stand
LanceLance
MasterMastermachinistmachinist
Key features:Key features:• • Stainless steel construction Stainless steel construction
(except for two brass rings)(except for two brass rings)• • Max. diameter = 25 cmMax. diameter = 25 cm• • Length, ~2.5–3 m Length, ~2.5–3 m (2 or 3 sensors on lance)(2 or 3 sensors on lance)• • Adjustable weight, ~200-450 kgAdjustable weight, ~200-450 kg• • Autonomous outrigger probesAutonomous outrigger probes• • Bottom water and tilt sensorsBottom water and tilt sensors• • Shipping crate with integrated Shipping crate with integrated
cradle for servicing, launch, cradle for servicing, launch, recoveryrecovery
Weight stand featuresWeight stand features
Stabilizing ringStabilizing ring(holds lance)(holds lance)
Tapered Tapered upsetupset
6 U-channels6 U-channels(hold weights)(hold weights)
FrontFront
RearRear
Tapered Tapered upsetupset
WeightWeightclampclamp
Oceanographic-grade swivelOceanographic-grade swivel
Limited travel on pinLimited travel on pin
7 klb strength7 klb strengthNo greaseNo grease
Outrigger mountOutrigger mount
Autonomous outrigger probesAutonomous outrigger probes
Deck boxDeck box(program, download)(program, download)
Clamshell protects loggerClamshell protects logger
Bolted on lanceBolted on lance
Electronics and batteryElectronics and battery
Pressure casePressure case
Short tip version (for bottom water)Short tip version (for bottom water)
16-bit A/D16-bit A/D1 mK resolution1 mK resolutionCalibrated (NIST-traceable) to ± 2 mKCalibrated (NIST-traceable) to ± 2 mKThrough-case serial Through-case serial
communicationcommunication
Thermistor in long probeThermistor in long probeDelrin outriggerDelrin outrigger
Thermal conductivity system, data processingThermal conductivity system, data processingThermal conductivityThermal conductivity• • Needle probe methodNeedle probe method• • Constant heatingConstant heating• • Custom software for Custom software for
acquisition and processingacquisition and processing
Heat flow processingHeat flow processing• • Extrapolation of 6-7 minutes of Extrapolation of 6-7 minutes of
subsurface datasubsurface data• • Multiple probes --> gradientMultiple probes --> gradient• • Combine with thermal Combine with thermal
conductivity --> heat flowconductivity --> heat flow• • Monte Carlo analysis of Monte Carlo analysis of
uncertaintiesuncertainties