World Ocean Database XBT/MBT bias correction data
XBT/MBT data can be downloaded with depth/temperature biases corrected. Corrections are from the refereed scientific literature. As of yet, no correction algorithm has been chosen as the recommended correction by the international oceanographic community.
MBTs/XBTs downloaded will have second header 54 (systematic fix) set as follows:
- -1. insufficient depth equation information
- 0. no corrections
- needs Hanawa et al.; 1994 applied (XBT)
- needs Kizu et al.; 2005 applied (XBT)
- Hanawa et al.; 1994 applied (XBT)
- Kizu et al.; 2005 applied (XBT)
- Levitus et al.; 2009 applied (XBT/MBT)
- Wijffels et al.; 2008 Table 1 applied (XBT)
- Wijffels et al.; 2008 Table 2 applied (XBT)
- Ishii and Kimoto; 2009 applied (XBT/MBT)
- Gouretski and Reseghetti; 2010 applied (XBT/MBT)
- Good; 2011 applied (XBT)
- Hamon et al.; 2012 applied (XBT/MBT)
- Gourestki; 2012 applied (XBT)
*-1, insufficient depth equation information are for XBTs dropped after 1995 which do not contain information on which depth equation was used (before that time, only one choice was routinely used).
If correction 3 or 4 is requested, both corrections 3 and 4 are applied.
Note, that when corrections 3-12 are requested, for XBT data with insufficient depth equation information, the correction is applied after conversion to Hanawa depth equation for years 1996-1997 and directly for years 1998-present. This assumes that software with the Hanawa corrections was not widely used in the first two years of its availability, but was widely used afterwards. This is only an assumption, and we do not recommend using these data for climate studies. The data will be represented with a second header 54 with a negative value of the applied correction. For instance, if the Hamon et al correction is applied to an XBT cast with insufficient depth equation information, second header 54 will have a value of -11.
0, no corrections : this means no corrections are necessary (or the particular XBT type does not yet have correction information)
1,2 - for these values, no corrections are made, but it is recommended that the listed correction be made to use the data for climate study purposes.
For those corrections which split into shallow and deep (see bias page) but do not specify a correction for T5 XBTs, no correction is made to T5 data except Kizu et al. 2005.
For 7, Wijffels et al, Table 2, no correction is made prior to 1993.
For all correction algorithms, data from years beyond the last year listed in the tables on the bias page use the correction information from the last available year.
Data using all corrections are available for observed level data download only. Standard level data are available only with Levitus et al (5) corrections.
Data using all corrections are only available currently in native format and csv format. NetCDF format does not yet contain corrections.
As more corrections are published, they will be added to the list of correction choices.
