As I've posted above we've seen decreases in the mass of ice at both poles via satellite measurements indicating melting. Melting requires energy. Energy that wouldn't be available if Argo was wrong and ocean temperature was decreasing.
It's likely that melting hasn't stopped since the Little Ice Age ended.
Example One - Glaciers Of Norway And Alaska Lost Half Their 'size' During The First Half Of The 20th Century
Example Two - Alaskas Most Famous Glacier Retreated Eight Feet Per Day Between 1794 And 1879
It's also likely that melting won't stop there, because
sea levels were higher during the Eemian. Thus we won't equal previous, natural, interglacial warming until much more ice has melted.
Thus what you describe is not unique to the 21st century, or CO2 induced warming. Also... Argo measures OHC, but you moved your argument out of ocean to discuss glacial mass loss? Or... if you're discussing sea ice, that's only the sea surface and then we need to start discussing weather anomalies which temporarily displace that energy for decades at a time.
Either way Ice is a messy subject, where our true observations are only as old at the satellite era. Unless you'd like to discuss the
USS Skate, which surfaced in open water near the pole in 58 or 59.
She also mentions that it may not make sense that warm water would be carried down...
I was interested in the error margin for Argo, for measuring OHC. Since we're talking two hundredths of a degree. It is interesting that it continues to rise, but such a small amount overall and only over an 11 year period. The "signal" in the Argo data is going to take time to mature and become convincing beyond doubt.