The best guess for the moment is that the gravitational forces at work between the three stars could serve to dampen the oscillations at HD181068's surface.
These short-term global fluctuations are associated principally with natural oscillations of tropical Pacific sea surface temperatures summarized in the Nino index in the lower part of the figure. 2012 is nominally the 9th warmest year, but it is indistinguishable in rank with several other years, as shown by the error estimate for comparing nearby years.