The effect of ZRA and ZRAH on the growth rate of ice crystals along the <i>a</i>-axis.

<p>The X-axis represents the temperature below T_m. The Y-axis represents the rate of growth of the radius of the ice crystal. Each point represents the average of at least 3 measurements. (B) A magnified view of the area enclosed by the black rectangle in A. The horizontal dash-dot line indicates a growth rate of 0.02 µm/sec, which is the threshold value used to define the TH gap. The arrows indicate the semi-TH activity according to this modified definition. Note that according to the old threshold definition (0.2 µm/sec) the TH activity in the <i>a</i>-axis direction would be >0. 1°C.