The XBT/CTD pairs dataset (Version 1), used to calculate the historical XBT fall rate and temperature corrections presented in Cowley et al (2013), has been made publicly availble through the following DOI permanent link: http://dx.doi.org/10.4225/08/52AE99A4663B1. Each dataset contains the scientifically quality controlled version and the original data, when available. The publication of this dataset provides new ground for additional research on the XBT biases, in support of improvements on the XBT technology.
In a recent paper (Abraham et al. 2013), scientists assessed the evolution of ocean temperature measurement systems focusing on the development and accuracy of two critical devices in use today (expendable bathythermographs and CTDs – conductivity-temperature-depth instruments used on Argo floats). A detailed discussion of the accuracy of these devices and a projection of the future of ocean temperature measurements are provided. The accuracy of ocean temperature measurements is discussed in detail in the context of ocean heat content, Earth’s energy imbalance, and thermosteric sea level rise. The latest data for thermal expansion sea-level rise are included and analyzed.
With the collaboration of the Servicio de Hidrografia Naval (Argentinean Coast Guard) an AX18 cruise from Argentina to South Africa was conducted during the month of August, 2013. This was the 35th realization of this transect that has been continuously occupied since 2002. The XBT data collected along this transect is used to monitor the meridional mass and heat transport in the upper 800m along 30°S. XBT are mostly deployed from cargo vessels with the help of shipping companies that voluntarily participate in the Ship Of Opportunity Program. The recent AX18 cruise was carried out on board the MOL's Onix Ace.