Are Global Mean Temperatures Significantly Affected by Long-Term Lunar Atmospheric Tides?

Wilson and Sidorenkov find that there are four extended pressure features in the summer (DJF) mean sea-level pressure (MSLP) anomaly maps that are centred between 30 and 50° S and separated from each other by approximately 90° in longitude. In addition, they show that, over the period from 1947 to 1994, these patterns drift westward in longitude at rates that produce circumnavigation times that match the 18.6 year lunar Draconic cycle. These type of pressure anomaly pattern naturally produce large extended regions of abnormal atmospheric pressure that pass over the semi-permanent South Pacific sub-tropical high roughly once every ∼ 4.5 years. These moving regions of higher/lower than normal atmospheric pressure increase/decrease the MSLP of the semi-permanent high pressure system, temporarily increasing/reducing the strength of the East-Pacific trade winds. This leads to conditions that preferentially favor the onset of La Niña /El Niño events that last for approximately 30 years. Wilson and Sidorenkov find that the pressure of the moving anomaly pattern changes in such a way as to favor La Niña over El Niño events between 1947 and 1970 and favor El Niño over La Niña events between 1971 and 1994. This is in agreement with the observed evolution of the El Niño/ La Niña events during the latter part of the 20 th century. They speculate that the transition of the pattern from a positive to a negative pressure anomaly follows a 31/62/93/186 year lunar tidal cycle that results from the long-term interaction between the Perigee-Syzygy and Draconic lunar tidal cycles. Hence, the IPCC needs to take into consideration the possibility that long term Lunar atmospheric tides could be acting as a trigger to favor either El Niño or La Niña conditions and that these changes in the relative frequency of these two type of events could be responsible for much of the observed changes in the world mean temperature during the 20 th century.