The Azimuth Project
Is there an exact biannual global temperature oscillation?


Is there an exact biannual global temperature oscillation? refers to an observation in the context of the investigation Does global warming lag or lead a rise in greenhouse gas concentration? in which the visualization suggests an exact biannual temperature oscillation. This page documents a discussion about the corresponding findings.


The image in which it looks as if in odd years temperature anomalies rise is the following:

randform plot of global temperature anomalies

(please add 58 to the year count).

Light-brown bars are referring to El Nino’s and light-blue bars to El Nina’s according to this image by NOAA, where it should be pointed out that there is a little controversy about single events.

The exact biannuity might eventually be also inherent in the QBO oscillation. The QBO oscillation is usually attributed to belong not to 24 months but to a longer period (like Wikipedia currently speaks of 28 to 29 months), which is probably due to investigations with Fourier transformations. However in the image:

QBO from Tropospheric Torrent

which was posted by Paul Pukite in a comment on the Azimuth forum and which is from the blog post Prolonged negative QBO by OKpowdah on the blog Tropospheric Torrent, it looks as if this QBO oscillation might also be exact-biannual with some irregularities, like -as written in this comment:

like a signal thats sometimes “out of sync” with a biannual forcing. Where a rather likely forcing would be temperature (via radiation). (If we assume that the temperature data is not yet rotten enough for showing complete bogus). Moreover it looks to me as if there is also an annual oscillation contained in the signal, like there seems to be always a little “bump” on the downslide between peaks. This bump is sometimes rather high (“a small peak”, an “extrasystole”) and seems to lead in that case to a lagging behind of the biannual signal peak. This happens slightly before the year 63 (almost nonvisible) , before 65 the “extrasystole” is comparibly big leading to the lag between 65 and 67 the small peak behind 67 would have been the original 67 peak if there wouldn’t have been the lagging, in 69 the signal is again in sync, before 77 an extrasystole is again leading to a lagging, again before 79, leading to a lagging, the small peak at 81 would again be the peak at 81 if not for the lagging, here the signal has now a 90 degrees phaseshift, i.e. the beat is quite out of sync, it catches though up again in 85, in 87 small extrasystole with small lagging, in 89 big extrasystole, signal again out quite out of sync, catches up in 97, extrasystole before 01, 03 and 05, out of sync until it “catches up again” in 2013. If there is no extrasystole in 2014 I conjecture that the QBO index will peak again in summer 2015.

A discussion about possible causal mechanisms for this biannuity is also in this forum. Thus the annual travel of the earth through the heliospheric current sheet eventually together with some period doubling phenomenom was sofar briefly mentioned as a vague possibility.

However recently part of the temperature data itself was critically assessed, i.e. a problem with the temperature data can’t be excluded, likewise the QBO diagram still needs to be checked.