Climate Variability & Change
Working Group CVCWG
CESM1 Indian Ocean Pacemaker Ensemble
A 10-member ensemble of CESM1 (1 degree spatial resolution) simulations in which time-evolving SST
anomalies in the tropical Indian Ocean (15oS-15oN, the African coast to 180W,
with a linearly tapering buffer zone that extends to 20S and 20N, are nudged to observations
(NOAA Extended Reconstruction Sea Surface Temperature version 3: ERSSTv3b) during 1920-2013 (extended through
September 2017). In this way, the observed evolution of tropical Indian Ocean and western Pacific
SST is maintained in each simulation, with the rest of the model's coupled climate system free to
evolve. Note that only the SST anomalies, not the total SST, are nudged to observations,
maintaining the model's mean state, including any model biases. All external forcings are
identical to the LENS, aside from stratospheric ozone. Further details are provided in the two papers below:
provided in the papers below:
- Yang D., J.M. Arblaster, G.A. Meehl, M.H. England, E.-P. Lim, S. Bates, N.
Rosenbloom, 2020, Role of tropical variability in driving decadal shifts in the Southern
Hemisphere summertime eddy-driven jet, J Climate, https://doi.org/10.1175/JCLI-D-19-0604.1
- Zhang, L., W. Han, K. B. Karnauskas, G. A. Meehl, A. Hu, N. Rosenbloom, and T. Shinoda, 2019:
Indian Ocean Warming Trend Reduces Pacific Warming Response to Anthropogenic Greenhouse Gases: An
Interbasin Thermostat Mechanism. Geophys. Res. Lett., 46 10882-90
We kindly ask that you reference one of these papers and acknowledge the CVCWG when
presenting results based on the CESM1 Pacemaker Ensemble in either oral and written form.
The CESM1 Indian Ocean Pacemaker 10-member ensemble is available from the Climate Data Gateway
Contact the CVCWG liaisons with questions. .