Using the
global map of rank of observation, R (l, m), the rank histogram, h (i) is the histogram of the ranks, weighted by the fractional area of each grid box (the average weight will be 1 / n grid, where n grid is number of grid point), over the
whole grid.
Setting the radius at 250 km., and taking the first decade of Bart's graph, 1880 - 1890, the
map reveals «
global» mean temperature perforce excluded the
whole of Central America, virtually all of South America and Africa, all of Thailand, Vietnam, Cambodia, Malaysia, Indonesia, and almost all of China.