Grid Statistics - 2° Latitude by 2° Longitude Cells

The one-degree grid cell contour maps in the preceding section could be considered 'noisy' and some of the detail in the original grid analysis could be related to the small grid-size itself.  There is also the inherent limitation of using a grid based upon a fixed degree size in that the area of a grid cell changes as one moves from south to north.  Effectively, this means that a storm count further north is more significant than the same count further south.

Example:  1° x 1° degree cells at different latitudes:

  • Cell 1, 14° N–16° N, 47,773 km2
  • Cell 2, 40° N–42° N, 37,323 km2
  • Ratio of areas = 47,773 / 37,323 = 1.28

A storm count of 10 in each cell actually represents an
effective count of 10 * 1.28 = 12.8 over the northern cell.

It was decided to reanalyze the data based upon a 2° x 2° grid and to add additional charts that attempt to address the issue of the changing cell areas over the grid extent.  The 36 maps that follow attempt to provide a thorough review of this topic.  The maps are arranged as shown below:

1901 to 2000

All Intensities

  • Range Map   crossings/hits per cell   06°N to 72°N   10°E to 110°W
  • Contour Map   crossings/hits per cell 10°N to 60°N   40° to 100°W
  • Contour Map (zoom)   crossings/hits per cell 30°N to 60°N   40° to 80°W
  • Range Map   crossings/hits per 1000 km2   06°N to 72°N   10°E to 110°W
  • Contour Map   crossings/hits per 1000 km2  10°N to 60°N   40° to 100°W
  • Contour Map (zoom)   crossings/hits per 1000 km2 30°N to 60°N   40° to 80°W

Hurricane Force Storms (SS1-5)

  • Six charts above are repeated

Intense Hurricane Force Storms (SS3-5)

  • Six charts above are repeated

1951 to 2000

All Intensities

  • Six charts above are repeated

Hurricane Force Storms (SS1-5)

  • Six charts above are repeated

Intense Hurricane Force Storms (SS3-5)

  • Six charts above are repeated

Chapter Sections:
Grid Statistics - 2° Latitude by 2° Longitude Cells