Continental-scale river flow in climate models

Abstract

In this paper a river routing model is developed to use with grid box climate models for the whole earth. The routing model needs an algorithm for the river mass flow and a river direction file, which has been compiled for 4° × 5° and 2° × 2.5° resolutions. River basins are defined by the direction files. The river flow leaving each grid box depends on river and lake mass, downstream distance, and an effective flow speed that depends on topography. As input the routing model uses monthly land source runoff from a 5-yr simulation of the NASA/GISS atmospheric climate model (Hansen et al.). The land source runoff from the 4° × 5° resolution model is quartered onto a 2° × 2.5° grid, and the effect of grid resolution is examined. -from Authors