The Drift Function For The Monthly Global Land Anomaly Appears To Be Stable

  To determine the drift function for the monthly global land anomaly the interval from -2 degrees to 2 degrees was divided up into 20 parts then the anomaly values were scanned to determine the intervals they fell in and the interval of the following anomaly. The result of the scan was a 20 x 20 matrix in which the columns represented the sub-interval, x, the first anomaly fell into and the rows, x', that of the next anomaly. Next an expected value was computed for each column to determine the most likely value of x' given that of x. Finally the expected change, Δx = x' - x, was computed for each value of x. The results are plotted below along with a least squares polynomial fit.

The anomaly data indicates that at higher anomaly values the anomaly is likely to decrease and at lower values it is likely to increase while remaining relatively stationary near the center. This indicates that the anomaly fluctuates about a stable point.