Abstract: The ocean is the primary reservoir of thermal energy in the earth system. As greenhouse gasses affect the planetary energy balance, key ways to track and predict energy variability are ocean observations and modeling. However, to go beyond rough trend estimates, there are major challenges in observation, understanding, modeling, and prediction to be overcome. This talk will describe and quantify some of the challenges, processes, and observational analyses involved.
An interesting aspect on which I will focus is the role of variability in the deep ocean, below the pycnocline and in "very old" water assets--those which have been out of direct contact with the atmosphere for a long time as indicated by radiocarbon dating and other tracer-based analyses. What kinds of variability can occur in these watermasses? How does it affect our understanding of the Earth's energy budget? On what timescales do deep waters vary, and on what timescales do they affect the energy budget? What do observational records and paleo-proxies tell us about deep variability on short timescales? I will reflect on my developing thoughts and framing of problems on these fronts, and present some results from recent collaborations.