As for sea temperatures, they are less significant for analyzing «global warming» than estimated total ocean heat content. (climatedepot.com)
I'd just assumed that: man's path = total ocean heat content leash length = bounds on energy transfers dog jiggles driven by ocean oscillations, solar jiggles, volcanoes... (realclimate.org)
One very important consideration to think about is that while surface temperature has a very high degree of variability, you do expect total ocean heat content to vary a great deal less in response to a constant forcing. (skepticalscience.com)