A new depth-time equation for Sippican or TSK T-7, T-6 and T-4 expendable bathythermographs (XBT)

Hanawa, Kimio; Rual, Pierre; Bailey, R.; Sy, Alexander; Szabados, M.

doi:10.1016/0967-0637(95)97154-z

Cited by 148 publications

(121 citation statements)

References 11 publications

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“…These bias corrections were used in addition to the common bias correction (Hanawa et al 1995) which is not time-varying. XBT biases are one of major sources of uncertainty in OHC estimation (Lyman et al 2010;Boyer et al 2016).…”

Section: Uncertainties In Global Mean Temperaturesmentioning

confidence: 99%

Accuracy of Global Upper Ocean Heat Content Estimation Expected from Present Observational Data Sets

Ishii¹,

Fukuda

Hirahara

et al. 2017

SOLA

145

153

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The simplest global mapping method and dense data coverage for the global oceans by the latest observation network ensure an estimate of global ocean heat content (OHC) within a satisfactory uncertainty for the last 60 years. The observational database conditionally presented a level high enough for practical use for the global OHC estimation when applying bias corrections of expendable bathythermograph, assuming that the other severe observational biases are not included in the database. Uncertainties in annual global mean temperatures averaged vertically from the surface to 1,500 m are within 0.01 K for the period from 1955 onward, when only sampling errors are taken into account. Those in annual mean global OHC of an improved objective analysis for 0−1,500 m depth is 16ZJ on average throughout the period. Compared to previous studies, the new objective analysis provides a higher estimation of the global 0−1,500 m OHC trend for a longer period from 1955 to 2015, which is an increase of 350 ± 57ZJ with a 95% confidence interval.(Citation: Ishii, M., Y. Fukuda, H. Hirahara, S. Yasui, T. Suzuki, and K. Sato, 2017: Accuracy of global upper ocean heat content estimation expected from present observational data sets.

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Section: Uncertainties In Global Mean Temperaturesmentioning

confidence: 99%

Accuracy of Global Upper Ocean Heat Content Estimation Expected from Present Observational Data Sets

Ishii¹,

Fukuda

Hirahara

et al. 2017

SOLA

145

153

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“…A study of Hanawa et al (1995), based on comparisons with CTDs, proposed a new fall-rate equation for some types of XBTs (T-4, T-6, T-7 and Deep Blue models). In 1995-1996 Sippican and TSK manufacturers implemented this new fall-rate equation.…”

Section: Xbt Bias Correctionsmentioning

confidence: 99%

The CORA dataset: validation and diagnostics of in-situ ocean temperature and salinity measurements

et al. 2013

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Abstract. The French program Coriolis, as part of the French operational oceanographic system, produces the COriolis dataset for Re-Analysis (CORA) on a yearly basis. This dataset contains in-situ temperature and salinity profiles from different data types. The latest release CORA3 covers the period 1990 to 2010. Several tests have been developed to ensure a homogeneous quality control of the dataset and to meet the requirements of the physical ocean reanalysis activities (assimilation and validation). Improved tests include some simple tests based on comparison with climatology and a model background check based on a global ocean reanalysis. Visual quality control is performed on all suspicious temperature and salinity profiles identified by the tests, and quality flags are modified in the dataset if necessary. In addition, improved diagnostic tools have been developed -including global ocean indicators -which give information on the quality of the CORA3 dataset and its potential applications. CORA3 is available on request through the MyOcean Service Desk (http://www.myocean.eu/).

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“…However, it is observed that the depth deduction from the fall rate has significant error ($25 m at a depth of 800 m). Hanawa et al (1995), herein after referred as HN-95, critically examined the XBT depth errors of T5, T6 and T7 probes based on a large set of simultaneous XBT-CTD data from different oceanic regions of the world. They proposed a common depth-time equation for T5, T6 and T7 probes that reduces the mean error to less than 1 m in the depth range of 0-800 m. Since the HN-95 data set was not having any representation from Indian Ocean, Thadathil et al (1998), using the controlled XBT-CTD data set, considered the use of HN-95 equation for XBT data from Indian Ocean.…”

Section: Fall Ratementioning

confidence: 99%

“…Curve with ' * ' represents depth error existing in XBT data. Whereas curve with open circle represents residual depth error after correction using fall rate equation of Thadathil et al, 1998, filled circle represents same for fall rate equation of Hanawa et al, 1995. The value of element is missing.…”

Section: Data Query and Visualizationmentioning

confidence: 99%

“…The XBT specific errors are: (a) Surface temperature error caused by start up transient in the digitizer electronics (Roemmich and Cornuelle, 1987). (b) Depth error caused by improper fall rate equation supplied by the manufacturer (Hanawa et al, 1995;Thadathil et al, 1999). (c) Unrealistic inversion like feature in surface layer temperature caused by wire stretch/pull or pinhole leak.…”

Section: Introductionmentioning

confidence: 99%

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An interactive graphical system for XBT data quality control and visualization

Pankajakshan

Ghosh

Sarupria

et al. 2001

Computers & Geosciences

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A PC-based system has been developed for quality control and visualization of expendable bathy thermograph (XBT) data archived at the Indian Oceanographic Data Centre. The system, coded in Visual C++, is user interactive and runs on Windows-95 platform. Quality control module of the system incorporates various quality norms/checks and has two levels; inventory and data levels. Inventory level checks are applied for land-sea position, speed of the vessel, invalid date/time, duplicates and station sounding. Station sounding check is performed based on the ETOPO bathymetry file having 5 0 Â 5 0 spatial resolution. Although the QCS is developed for quality control and visualization of the XBT data, it could be used for inventory level quality checks of any general oceanographic data. Data quality module involves tests for XBT-specific errors such as surface transient, temperature inversions, fall rate and depth reversal. This level also involves visual inspection of the profiles for identifying and correcting/flagging of features caused by wire stretch, wire break, bowing and nub in the mixed layer. Provision is given to compare individual XBT profiles with neighboring stations and also with 18 Â 18 monthly climatologies. Quality flags are assigned for each inventory and depth fields. Since data exchange (national and international), under the IODE system, stipulates standard quality flags, the Integrated Global Ocean Observing System recommended flags are applied in the system. Station having data with erroneous or doubtful flags are sent to error bin, which can be accessed by privileged users for possible correction and subsequent modifications in the data base. The data visualization module has options for data queries, selection and graphical presentations, like vertical and horizontal distribution of temperature. #

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A new depth-time equation for Sippican or TSK T-7, T-6 and T-4 expendable bathythermographs (XBT)

Cited by 148 publications

References 11 publications

Accuracy of Global Upper Ocean Heat Content Estimation Expected from Present Observational Data Sets

Accuracy of Global Upper Ocean Heat Content Estimation Expected from Present Observational Data Sets

The CORA dataset: validation and diagnostics of in-situ ocean temperature and salinity measurements

An interactive graphical system for XBT data quality control and visualization

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