756230.fig.0010a
(a)
756230.fig.0010b
(b)
Figure 10: Variations of vorticities ( ; ×10−5 sec−1) at 500 hPa level at (a) 09:00 LST October 27, 2003, and (b) 21:00 LST. Triangle in the center indicates Gangneung city. Colorful (white) area indicates positive (negative) vorticity, which implies the downward (upward) motion of air at the 500 hPa level and corresponds to negative (positive) geopotential tendency area. Upward motion of air at the 500 hPa level with negative vorticity of −2.5 × 10−5 sec−1 at 21:00 LST became weaker than one with negative vorticity of −4 × 10−5 sec−1 at 09:00 LST, resulting in shrunken atmospheric depth.