The Mid-Holocene Climate Simulated by a Grid-Point AGCM Coupled with a Biome Model

The climate simulation for the mid-Holocene about 6000 years before present (6 ka BP) is carried out with a grid-point atmospheric general circulation model (AGCM) coupled with a biome model. This coupled model simulation employs orbital parameters of 6 ka BP but present forcing conditions. Results show that large-scale climate differences between now and then are substantial in summer with dramatically strong African-Asian monsoon flow and precipitation during mid-Holocene. Although the results of this coupled model are qualitatively close to those of the AGCM, the coupled model shows a larger changes in both precipitation and temperature in summer over the North African monsoon area with weaker cooling in the Northern autumn.