Thermal Inertia of Conductivity Cells: Observations with a Sea-Bird Cell

Lueck, Rolf G.; Picklo, James J.

doi:10.1175/1520-0426(1990)007<0756:tiocco>2.0.co;2

Cited by 93 publications

(81 citation statements)

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“…8 of UH2014). The thermal mass correction was performed following the algorithm of Lueck and Picklo (1990) and using the mean values of error magnitude and time constant from UH2014 (cf . Table 1 of UH2014).…”

Section: Ctd and Uctd Measurementsmentioning

confidence: 99%

On the meridional ageostrophic transport in the tropical Atlantic

Karstensen

Brandt

2017

Ocean Sci.

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Abstract. The meridional Ekman volume, heat, and salt transport across two trans-Atlantic sections near 14.5 • N and 11 • S were estimated using in situ observations, wind products, and model data. A meridional ageostrophic velocity was obtained as the difference between the directly measured total velocity and the geostrophic velocity derived from observations. Interpreting the section mean ageostrophy to be the result of an Ekman balance, the meridional Ekman transport of 6.2±2.3 Sv northward at 14.5 • N and 11.7±2.1 Sv southward at 11 • S is estimated. The integration uses the top of the pycnocline as an approximation for the Ekman depth, which is on average about 20 m deeper than the mixed layer depth. The Ekman transport estimated based on the velocity observations agrees well with the predictions from in situ wind stress data of 6.7 ± 3.5 Sv at 14.5 • N and 13.6 ± 3.3 Sv at 11 • S. The meridional Ekman heat and salt fluxes calculated from sea surface temperature and salinity data or from highresolution temperature and salinity profile data differ only marginally. The errors in the Ekman heat and salt flux calculation were dominated by the uncertainty of the Ekman volume transport estimates.

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Section: Ctd and Uctd Measurementsmentioning

confidence: 99%

On the meridional ageostrophic transport in the tropical Atlantic

Karstensen

Brandt

2017

Ocean Sci.

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“…These biases are due to thermal inertia of the sensors, and mostly occur between the lowering and rising of the device, which result in a delay between the conductivity and temperature measurements (see Barth et al, 1996). These errors are corrected by applying a couple of coefficients, a first one correcting the amplitude of the signals between the rising and the lowering of the SeaSoar, and a second coefficient correcting the time delay (see Lueck andPicklo, 1990 andMensah et al, 2008). Once corrected, the SeaSoar measurements 2 CTD for conductivity, temperature, depth 3 ADCP for acoustic Doppler current profiler 4 XBT and XCTD for expendable bathythermograph and CTD 5 VM-ADCP for vessel-mounted acoustic Doppler current profiler are validated against CTD station or XCTD cast data (such stations or casts were achieved along the SeaSoar transects).…”

Section: The Phys-indien 2011 Measurementsmentioning

confidence: 99%

Mesoscale eddies and submesoscale structures of Persian Gulf Water off the Omani coast in spring 2011

et al. 2016

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“…As Lueck and Picklo (1990) discovered, a thermohaline staircase is an ideal place to test the dynamic response of CTD systems. The characteristic mixed layers with near uniform properties separated by thin interfaces with strong gradients approximates ideal step changes in T and S with depth.…”

Section: The Double-diffusive Interface Tank a Double-diffusive Theorymentioning

confidence: 99%

“…Effects due to the thermal mass of the conductivity cell appear as a delayed conductivity response as high T, C values in the lower layer are approached. Lueck (1990) and Lueck and Picklo (1990) describe the thermal mass effect of conductivity cells. Because of the heat capacity of the cell, the temperature and thus the conductivity of the fluid in the measurement volume is altered by the presence of the cell.…”

Section: Application Of Sensor Response Correctionmentioning

confidence: 99%

“…However, these tests failed to detect the substantial thermal mass problems of one conductivity cell (Lueck and Picklo, 1990;Lueck, 1990), since there was little or no temperature difference across the salt interface in most of the trials. Others have used quickly removed barriers between different water types to generate a step change in properties (Fozdar et al, 1985), but the set-up required limits the ease of repeat measurements.…”

Section: Introductionmentioning

confidence: 99%

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A double-diffusive interface tank for dynamic-response studies

Schmitt¹,

Millard²,

Toole³

et al. 2005

J Mar Res

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A large tank capable of long-term maintenance of a sharp temperature-salinity interface has been developed and applied to measurements of the dynamical response of oceanographic sensors. A two-layer salt-stratified system is heated from below and cooled from above to provide two convectively mixed layers with a thin double-diffusive interface separating them. A temperature jump exceeding 10°C can be maintained over 1-2 cm (a vertical temperature gradient of order 10 3°C /m) for several weeks. A variable speed-lowering system allows testing of the dynamic response of conductivity and temperature sensors in full-size oceanographic instruments. An acoustic echo sounder and shadowgraph system provide nondisruptive monitoring of the interface and layer microstructure. Tests of several sensor systems show how data from the facility is used to determine sensor response times using several fitting techniques and the speed dependence of thermometer time constants is illustrated. The linearity of the conductivity-temperature relationship across the interface is proposed as a figure of merit for design of lag-correction filters to accurately match temperature and conductivity sensors for the computation of salinity. The effects of finite interface thickness, slow sensor sampling rates and the thermal mass of the conductivity cell are treated. Sensor response characterization is especially important for autonomous instruments where data processing and compression must be performed in-situ, but is also helpful in the development of new sensors and in assuring accurate salinity records from traditional wire-lowered and towed systems.

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Thermal Inertia of Conductivity Cells: Observations with a Sea-Bird Cell

Cited by 93 publications

References 0 publications

On the meridional ageostrophic transport in the tropical Atlantic

On the meridional ageostrophic transport in the tropical Atlantic

Mesoscale eddies and submesoscale structures of Persian Gulf Water off the Omani coast in spring 2011

A double-diffusive interface tank for dynamic-response studies

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