90% of the heat trapped on Earth by anthropogenic greenhouse gasses is absorbed by the ocean, with the unfortunate by-product of thermosteric sea level rise – as the ocean warms, it expands. Therefore, it is essential that we can accurately measure how much heat the ocean is absorbing over time. This is estimated from profiles of ocean temperature taken by research vessels and autonomous instruments, these point measurements are converted into global maps using a range of different techniques.
The research in this paper shows that the different mapping methods can lead to slightly different estimates of ocean heating, especially in highly energetic regions like the East Australian Current. This work will help scientists to home in on a more accurate estimate of how our planet is warming. It is important to note that the uncertainty range produced by the different mapping methods is very small compared to the vast amount of heating caused by human greenhouse gas emissions.
- Paper: Savita, A., Domingues, C.M., Boyer, T., Gouretski, V., Ishii, M., Johnson, G.C., Lyman, J.M., Willis, J.K., Marsland, S.J., Hobbs, W., Church, J.A., Monselesan, D.P., Dobrohotoff, P., Cowley, R., Wijffels, S.E., 2021. Quantifying spread in spatio-temporal changes of upper-ocean heat content estimates: an internationally coordinated comparison. Journal of Climate 1, 1–59. https://doi.org/10.1175/JCLI-D-20-0603.1