Bathythermograph


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bathythermograph

[¦bath·ə′thər·mə‚graf]
(engineering)
A device for obtaining a record of temperature against depth (actually, pressure) in the ocean from a ship underway. Abbreviated BT. Also known as bathythermosphere.

Bathythermograph

 

an instrument lowered from a ship in motion for measuring the distribution of the temperature of water relative to depth. The body of a bathythermograph has a streamlined shape and is equipped with tail fins for stabilizing the instrument’s attitude when it is lowered into the water; the instrument is lowered by means of a steel cable.

The temperature sensor is a hot-wire anemometer, consisting of a long copper capillary tube mounted on the tail fins. One end of the capillary tube is sealed and the other is connected to the fixed end of a manometric coil spring. The capillary and spring are filled with toluene. When the temperature changes, the volume of toluene and, consequently, the pressure within the manometric system change. With an increase in temperature the free end of the manometric spring is untwisted at an angle proportional to the amount of temperature change, and it is twisted with a decrease in temperature. The pointer attached to the free end of the manometric spring records the temperature on a smoked-glass plate, which is shifted by a hydrostatic depth sensor as the instrument is lowered in the water. Hermetically sealed Sylphons function as the depth sensors. Modern bathythermographs record water temperature with a minimum accuracy of 0.1°C. They are used in oceanographic research and on fishing survey vessels.

REFERENCES

Rukovodstvo po gidrologicheskim rabotam v okeanakh i moriakh. Leningrad, 1967.
Deriugin, K. K., and I. A. Stepaniuk. Morskaia gidrometriia. Leningrad, 1974.
References in periodicals archive ?
Wijffels, 2014: Time, probe type and temperature variable bias corrections to historical expendable bathythermograph observations.
Liu, 2011: A new method to estimate the systematical biases of expendable bathythermograph.
Kizu, 2013: Biases in expendable bathythermograph data: A new view based on historical side-by-side comparisons.
Seidel, 2010: Impact of bathythermograph temperature bias models on an ocean reanalysis.
At 35[degrees]S in the South Atlantic, MHT has been estimated using a combination of expendable bathythermograph (XBT) data and Argo profiling floats (Garzoli et al.
Water column data were collected with conductivity-temperature-depth (CTD) profilers 1 h before sunrise and 1 h after sunset on each survey day and with expendable bathythermographs (XBTs) during daylight hours at intervals of ~55 km.
The P-3 also carried a downward-looking ocean wave radar, a downward-looking W-band Doppler cloud radar, and airborne expendable bathythermographs (AXBTs) from the navy to measure the ocean mixed layer.
Site Equipment Lead/POC 2009 Central Sierra-- Aerosol, meteorological AW, KP X Sugar Pine Southern Sierra-- Aerosol, meteorological AW, KP Mariposa Central Valley-- ARO AW Sloughhouse Central Valley-- Scanning radar, radiosondes DK Lincoln Carquinez Strait-- ARO AW Concord HMT network-- Meteorological--in situ, radar AW X Many sites BBY ARO, aerosol AW, KP, AM DOEG-I Aerosol chemistry, RL, KP microphysics DOEAMF2 Suite RL NOAA G-IV Dropsondes, radar AW, RS, J1 RVB AMF2, aerosol, air-sea fluxes, CF, RL, PD expendable bathythermographs, conductivity-temperature- depths NOAA P-3 Dropsondes, Doppler radar, RS, DK etc.
Water temperature and depth profiles were collected at each station by using bathythermographs attached to the headrope of the bottom trawl net (expendable models before 1993 and microbathythermographs in later years).
For the period in question, the in situ observations are mainly ship based: temperatures from expendable bathythermographs (XBTs) corrected for fall rate (Wijffels et al.
2007), measured surface wind and rainfall; and airborne expendable bathythermographs (AXBTs) measured the ocean temperature in the upper 500-800 m.