Abstract
AbstractUnderstanding the causes for discrepancies between modelled and observed regional climate trends is important for improving present-day climate simulation and reducing uncertainties in future climate projections. Here, we analyse the performance of coupled climate models in reproducing regional precipitation trends during the satellite era. We find statistically significant observed drying in southwestern North America and wetting in the Amazon during the period 1979–2014. Historical climate model simulations do not capture these observed precipitation trends. We trace this discrepancy to the inability of coupled simulations to capture the observed Pacific trade wind intensification over this period. A linear adjustment of free running historical simulations, based on the observed strengthening of the Pacific trade winds and modeled ENSO teleconnections, explains the discrepancy in precipitation trends. Furthermore, both the Pacific trade wind trends and regional precipitation trends are reproduced in climate simulations with prescribed observed sea surface temperatures (SST), underscoring the role of the tropical Pacific SST patterns.
Funder
China Scholarship Council
RCUK | Natural Environment Research Council
A.A.S was supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra.
A.S. was supported by the Earth System and Climate Change Hub of the Australian Government’s National Environment Science Program (NESP), and Centre for Southern Hemisphere Oceans Research (CSHOR).
Publisher
Springer Science and Business Media LLC