180°. The 100,000-meter squares from 80° to 84° are
used only in the south polar region.
Because there are no column numbers in the grid
Within the full and partial 100,000-meter squares,
subdivisions into 10,000-meter squares, 1,000-meter
squares, and smaller squares are the same as in the UTM
zone reference, complete grid locations appear slightly
different, such as ZBM 40170.
Figure 4-7.Meteorological chart projections.