Several people have noted the apparent mis-match between the NCDC report of all-time record warmth of global average sea surface temperatures in August, and the satellite tropospheric temperatures which are nowhere near a record.

But, as I have cautioned, there tends to be a time lag between SST warming and atmospheric warming…typically 1 month during non-ENSO conditions, and 2-3 months during ENSO. Furthermore, tropospheric temperature variations are somewhat larger than the SST variations that drive them, making direct comparison of the numbers more difficult.

You can get around both of these problems by plotting one versus the other on a graph to see if the latest behavior departs from the normal relationship previously displayed by the two variables (ocean surface temperature and oceanic lower tropospheric temperature).

If you also “connect the dots”, you get what’s called a phase space diagram. If we make such a plot for the 1997-98 super-El Nino, the 2009-10 El Nino, and the current (still weak) El Nino, it looks like this:

Phase space plot of monthly sea surface temperature versus tropospheric temperature anomalies for three El Nino events (all begin in January, anomalies are relative to 1981-2010 averages).

The time lag of tropospheric temperature behind ocean surface temperature causes a curved trajectory in the data, as I’ve indicated with the light gray line.

What is interesting is that the “record warm” SST month of August, 2014 seems to be an outlier, with the SSTs being too warm (or the tropospheric temperatures too cool) compared to the usual behavior.

Barring some mistake in data processing, the only explanation I have for this is the possibility I blogged about yesterday, that near-record low ocean winds are allowing excessive surface warming while transferring less energy through convection to warm the troposphere. As I also mentioned yesterday, such an excursion would be due to natural variability…not due to “extra” carbon dioxide in the atmosphere, which basically remains unchanged from one month to the next.