Computational considerations
§Transport model runs to generate H:
§22 regions x 16 years x 12 months x 36 months = 152 K tracer-months (if using real winds)
§22 x 12 x 36 = 9.5 K tracer-months              (using climatological winds)
§Matrix inversion computations: O (N3)
§N = 22 regions x 16 years x 12 months = 4.4 K
§Matrix storage: O (N*M) --- 66 MB
§M = 78 sites x 16 years x 12 months = 15 K