Updated on June 3, 2003

NERI work examples

Boundary conditions for transient model experiment

One of the scientific objectives within the ORFOIS project, is to estimate the changes in the CO2 sea surface source/sink patterns and in the vertical redistribution of carbon during future climate change. For this purpose, a complete set of forcingdata has been prepared as boundary conditions for the models, such that the BOGCM's in the project can be integrated and studied for different climate change scenarios. The forcingdata are the output from the coupled atmosphere/ocean model ECHAM4/OPYC3 (Roeckner et al., J. Clim., 12, 3004-3032, 1999). The fields of temperature (see figure), precipitation, dew point temperature, solar radiation and wind stress from the coupled ECHAM4/OPYC3 experiment have been downloaded and are interpolated onto the model grid during the transient experiments.

Two climate change scenarios

Two scenarios have been prepared for the period 1860-2050. The GHG-experiment include the greenhouse gas forcng from the gases CO2, CH4, N2O and CFC's observed in the period 1860 - 1990, and then following the climate change scenario IS92a from 1990. The GSDIO-experiment include the same greenhouse gases as the GHG-experiment and in addition both the direct radiative effect from aerosols due to backscattering of the radiation and the indirect radiative effect associated with changes in cloud albedo are included in the experiment. The influence from the aerosols in the GSDIO-experiment causes a significantly lower temperature change during the integration period (see figure).

Figure 1: The annual average of 2m air temperature [K] for the year 1860 in the GSDIO-experiment.

Figure 2: The global annual averaged 2m air temperature change for the GSDIO and the GHG experiment for the period 1860 - 2050.