Saturday, March 3, 2012

The Open Atmospheric Science Journal, 2012, 6, 49-60

Lunar Tides and the Long-Term Variation of the Peak Latitude Anomaly of the Summer Sub-Tropical High Pressure Ridge over Eastern Australia

by Ian R.G. Wilson

Abstract: This study looks for evidence of a correlation between long-term changes in the lunar tidal forces and the interannual to decadal variability of the peak latitude anomaly of the summer (DJF) subtropical high pressure ridge over Eastern Australia (LSA) between 1860 and 2010. A simple "resonance" model is proposed that assumes that if lunar tides play a role in influencing LSA, it is most likely one where the tidal forces act in "resonance" with the changes caused by the far more dominant solar-driven seasonal cycles. With this type of model, it is not so much in what years do the lunar tides reach their maximum strength, but whether or not there are peaks in the strength of the lunar tides that re-occur at the same time within the annual seasonal cycle. The “resonance” model predicts that if the seasonal peak lunar tides have a measurable effect upon LSA then there should be significant oscillatory signals in LSA that vary in-phase with the 9.31 year draconic spring tides, the 8.85 year perigean spring tides, and the 3.80 year peak spring tides. This study identifies significant peaks in the spectrum of LSA at 9.4 (+0.4/-0.3) and 3.78 (± 0.06) tropical years. In addition, it shows that the 9.4 year signal is in-phase with the draconic spring tidal cycle, while the phase of the 3.8 year signal is retarded by one year compared to the 3.8 year peak spring tidal cycle. Thus, this paper supports the conclusion that long-term changes in the lunar tides, in combination with the more dominant solar-driven seasonal cycles, play an important role in determining the observed inter-annual to decadal variations of LSA.

Important blog sites that are discussing this paper.

The above graph shows that there is actually quite a good match between the number of days the nearest Full/New moon is from perihelion and the peaks in LSA (see the diagram below). In fact, the correspondence between the peaks in the data sets are (generally) so good, that it is possible identify peaks in LSA that are caused by large Plinarian [> 4] volcanic eruptions to the near north of Australia. (i.e. in the Indonesian Archipelago (e.g. Krakatoa in 1883) and New Britain).

A recently published paper that supports the assertion that atmospheric tides can have an influence upon regional weather patterns on times scales of ~ two weeks. 

Monthly lunar declination extremes’ influence on tropospheric circulation patterns

Daniel S. Krahenbuhl,1 Matthew B. Pace,1 Randall S. Cerveny,1 and Robert C. Balling Jr.1

Received 22 July 2011; revised 13 October 2011; accepted 13 October 2011; published 15 December 2011.

Short‐term tidal variations occurring every 27.3 days from southern (negative) to northern (positive) maximum lunar declinations (MLDs), and back to southern declination of the moon have been overlooked in weather studies. These short‐term MLD variations’ significance is that when lunar declination is greatest, tidal forces operating on the high latitudes of both hemispheres are maximized. We find that such tidal forces deform the high latitude Rossby longwaves. Using the NCEP/NCAR reanalysis data set, we identify that the 27.3 day MLD cycle’s influence on circulation is greatest in the upper troposphere of both hemispheres’ high latitudes. The effect is distinctly regional with high impact over central North America and the British Isles. Through this lunar variation, mid-latitude weather forecasting for two‐week forecast
periods may be significantly improved.

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