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IES Calibration and Mapping Procedures.

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Title: IES Calibration and Mapping Procedures.
Authors: Tracey, Karen L., Howden, Stephan D., Watts, D. Randolph
Source: Journal of Atmospheric & Oceanic Technology. Dec97, Vol. 14 Issue 6, p1483. 11p.
Subjects: Ocean, Forecasting, Calibration, Gulf Stream
Abstract: The procedures used in the Synoptic Ocean Prediction experiment for calibration of inverted echo sounder (IES) travel time τ data have led to substantially improved accuracy. In previous work, τ was converted to main thermocline depth Z[subT] using point measurements of the 12°C depth from coincident expendable bathythermograph (XBT) casts. The new method presented in this study vertically integrates the XBT temperature to produce the quantity Q[subT], which is very tightly related to τ. The advantage of this method is that the calibration constants have roughly half the uncertainty obtained with the traditional method. Seasonal changes in τ determined from hydrographic data in the Gulf Stream region were found to vary with geographic region; near 68°W τ changed by 1.8 ms from March to September, whereas near Cape Hatteras the annual change was only 1.0 ms. The fully calibrated IES Z[sup*][subT] has an estimated error of 19 m (one standard deviation). An iterative optimal interpolation scheme is described, by which the Gulf Stream thermocline depth was mapped on a two-dimensional grid. Initially, daily maps were generated using established mapping techniques. Subsequently, these maps were averaged for 31-day periods and in turn used as the new 'mean fields' for the final maps. Verification of the mapped fields against independent XBT data gives rms differences of 31-46 m, which is only 3%-5% of the 900-m range of the observed... [ABSTRACT FROM AUTHOR]
Copyright of Journal of Atmospheric & Oceanic Technology is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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DbLabel: Engineering Source
An: 5648028
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  Data: IES Calibration and Mapping Procedures.
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  Data: <searchLink fieldCode="AR" term="%22Tracey%2C+Karen+L%2E%22">Tracey, Karen L.</searchLink><br /><searchLink fieldCode="AR" term="%22Howden%2C+Stephan+D%2E%22">Howden, Stephan D.</searchLink><br /><searchLink fieldCode="AR" term="%22Watts%2C+D%2E+Randolph%22">Watts, D. Randolph</searchLink>
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  Data: <searchLink fieldCode="JN" term="%22Journal+of+Atmospheric+%26+Oceanic+Technology%22">Journal of Atmospheric & Oceanic Technology</searchLink>. Dec97, Vol. 14 Issue 6, p1483. 11p.
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  Data: <searchLink fieldCode="DE" term="%22Ocean%22">Ocean</searchLink><br /><searchLink fieldCode="DE" term="%22Forecasting%22">Forecasting</searchLink><br /><searchLink fieldCode="DE" term="%22Calibration%22">Calibration</searchLink><br /><searchLink fieldCode="DE" term="%22Gulf+Stream%22">Gulf Stream</searchLink>
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  Label: Abstract
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  Data: The procedures used in the Synoptic Ocean Prediction experiment for calibration of inverted echo sounder (IES) travel time τ data have led to substantially improved accuracy. In previous work, τ was converted to main thermocline depth Z[subT] using point measurements of the 12°C depth from coincident expendable bathythermograph (XBT) casts. The new method presented in this study vertically integrates the XBT temperature to produce the quantity Q[subT], which is very tightly related to τ. The advantage of this method is that the calibration constants have roughly half the uncertainty obtained with the traditional method. Seasonal changes in τ determined from hydrographic data in the Gulf Stream region were found to vary with geographic region; near 68°W τ changed by 1.8 ms from March to September, whereas near Cape Hatteras the annual change was only 1.0 ms. The fully calibrated IES Z[sup*][subT] has an estimated error of 19 m (one standard deviation). An iterative optimal interpolation scheme is described, by which the Gulf Stream thermocline depth was mapped on a two-dimensional grid. Initially, daily maps were generated using established mapping techniques. Subsequently, these maps were averaged for 31-day periods and in turn used as the new 'mean fields' for the final maps. Verification of the mapped fields against independent XBT data gives rms differences of 31-46 m, which is only 3%-5% of the 900-m range of the observed... [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Atmospheric & Oceanic Technology is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
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      – Type: doi
        Value: 10.1175/1520-0426(1997)014<1483:ICAMP>2.0.CO;2
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 11
        StartPage: 1483
    Subjects:
      – SubjectFull: Ocean
        Type: general
      – SubjectFull: Forecasting
        Type: general
      – SubjectFull: Calibration
        Type: general
      – SubjectFull: Gulf Stream
        Type: general
    Titles:
      – TitleFull: IES Calibration and Mapping Procedures.
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            NameFull: Tracey, Karen L.
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            NameFull: Howden, Stephan D.
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            NameFull: Watts, D. Randolph
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            – D: 01
              M: 12
              Text: Dec97
              Type: published
              Y: 1997
          Identifiers:
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              Value: 07390572
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              Value: 14
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              Value: 6
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            – TitleFull: Journal of Atmospheric & Oceanic Technology
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