First page Back Continue Last page Overview Graphics

Medium Term Auto Correlation

Notes:

This plot shows the auto correlation results after 6000 year smoothing. The first peak at 22K years is somewhat obscured by overlapping the anti correlation peak of a 41K year periodic influence. The 22K year peak corresponds to the periodic relationship between the perihelion of the Earths orbit and the month of the year. Today, perihelion is in January. Each year it moves a little bit earlier and in about 11K years, it will be in July.

The global yearly average temperature is the coolest when perihelion occurs during the northern hemisphere late spring and early summer. It's at this time that the northern hemisphere winter snow pack can reflect the most energy. The warmest yearly global average temperatures occur when perihelion is at the peak of the southern hemisphere summer, when the southern oceans can absorb the maximum amount of solar energy. This is where we are today.