Global Warming and Continental Hydrology
Syukuro Manabe
Frontier Research System for Global Change (FRSGC)
Tokyo, Japan
Richard T. Wetherald
Geophysical Fluid Dynamics Laboratory/NOAA
Princeton, NJ, USA
This presentation explores the future change of climate based upon the results from a coupled atmosphere-ocean-land surface model with improved computational resolution (grid size: about 250 km). It describes the changes in surface temperature, river runoff and soil moisture, which may be realized by the second half of the 21st century.
In general, global mean rates of both precipitation and evaporation are expected to increase by several percents. The increase in the rate of river runoff is particularly large over Canada and Siberia. Runoff also increases substantially in some tropical rivers such as Ganges and Amazon.
In middle and high latitudes, soil moisture is usually reduced in summer, but increases in winter. It decreases during most of a year in many semi-arid regions of the world such as the southwestern portion of North America, Mediterranean coast of Europe, northeastern portion of China, and grasslands of Africa, Australia and South America.
Finally, the strategy for reducing the large uncertainty in the projection of global warming is discussed.
