The following is a note from Bob Tisdale discussing this error:
After I posted the above, I found that Dr. Geert Jan van Oldenborgh had emailed me to notify me of the correction. I have received his permission to reproduce his email:
Dear Bob Tisdale,
please note that NODC discovered that they had accidentally posted the wrong version of their last file (apr-jun2009), a preliminary version with most data still missing had somehow made it to their web site. A quick look at the map for that quarter showed that there were hardly any anomalies visible and big anomalies in the North Atlantic and Pacific did not persist from the previous quarter, so the data were clearly suspicious. This mix-up has been fixed tonight (Dutch time) at NODC and in the Climate Explorer. A corrected version of the average heat content is attached, the value of apr-jun2009 is now more in line with the values of previous quarters.
Greetings from chilly Holland,
The revised chart can be seen here