Use the very simple two-band parameterization of the ECHAM4 climate model, described in (); this is probably only meaningful if you want to compare your results with ECHAM4, the two bands are 0.2 - 0.68 micrometer and 0.68 - 4.0 micrometer; within these bands, the optical properties are assumed constant.



Jonas Kylling 2010-03-06