for different ζ
, ∂w/∂z , or ∂2
. Histograms of in the TIL in the regions of either (a) ζ
TP<0 and ζ
TP≥0, (b) ∂ w/∂ z<0 and ∂ w/∂ z≥0, or (c) ∂2
w/∂ z2<0 and ∂2
w/∂ z2≥0. Computed from hourly outputs from t=24 to 36 h. The ∂ w/∂ z and ∂2
w/∂ z2 are computed at the same level as . Each histogram is normalized by its sample size. Values on the top left are significance levels for the differences in mean by the moving block bootstrap method with block sizes of (from top to bottom) 10×10×5, 20×20×10, and 40×40×10 grid points (or, equivalently 200 km × 200 km × 5 h, 400 km × 400 km × 10 h, and 800 km × 800 km × 10 h) in the x, y, and t directions.