As shown in Fig. 9, the seasonal variations of daily mean tilt angles μ and θ and number of storms exhibit nearly same semiannual patterns.
For quantitative analysis of tilt, we have used Hough space to measure the absolute mean tilt angles of the mortar cues in the edge map of the Café Wall pattern at multiple scales [48, 49, 50]. Figure 5 shows the tilt analysis results of a crop section of a Café Wall pattern.
The mean cane tilt angle, sweeping angle, and grip rotation deviation were measured.
That means the tilt angle above is not the actual angle but the apparent angle.
To test its model, the team predicted values for the mean and tilt angles for two species of the Geraniaceae family one commonly known as stork's bill (Erodium cicutarium, pictured) and the other as cranesbill (Geranium pusillum)—that would produce the observed coiling.
They described these helices with two parameters, the so-called mean angle and tilt angle of the fibers, and found that if these didn't change as the cell shrunk due to lowering humidity, the cell would have to respond by taking on its own spiral shape.
That means the actual tilt angle should be smaller than 31°.
The semiannual variations observed also in the mean energy input during MP obtained from Dst are consistent with the variations of the daily mean Earth's dipole tilt angle µ involved in the equinoctial hypothesis and θ involved in the RM effect.
