Parallel climate model (PCM) control and transient simulations

Download
Author
Semtner, A.J. Jr.
Washington, W.M.
Weatherly, J.W.
Meehl, G.A.
Bettge, T.W.
Craig, A.P.
Strand, W.G. Jr.
Arblaster, J.
Wayland, V.B.
James, R.
Zhang, Y.
Date
2000Metadata
Show full item recordAbstract
The Department of Energy (DOE) supported Parallel Climate Model (PCM) makes use of the NCAR Community Climate Model (CCM3) and Land Surface Model (LSM) for the atmospheric and land surface components, respectively, the DOE Los Alamos National Laboratory Parallel Ocean Program (POP) for the ocean component, and the Naval Postgraduate School sea-ice model. The PCM executes on several distributed and shared memory computer systems. The coupling method is similar to that used in the NCAR Climate System Model (CSM) in that a flux coupler ties the components together, with interpolations between the different grids of the component models. Flux adjustments are not used in the PCM. The ocean component has 2/3° average horizontal grid spacing with 32 vertical levels and a free surface that allows calculation of sea level changes. Near the equator, the grid spacing is approximately 1/2° in latitude to better capture the ocean equatorial dynamics. The North Pole is rotated over northern North America thus producing resolution smaller than 2/3° in the North Atlantic where the sinking part of the world conveyor circulation largely takes place. Because this ocean model component does not have a computational point at the North Pole, the Arctic Ocean circulation systems are more realistic and similar to the observed. The elastic viscous plastic sea ice model has a grid spacing of 27 km to represent small-scale features such as ice transport through the Canadian Archipelago and the East Greenland current region. Results from a 300 year present-day coupled climate control simulation are presented, as well as for a transient 1% per compound CO₂ increase experiment which shows a global warming of 1.27°C for a 10 year average at the doubling point of CO₂ and 2.89°C at the quadrupling point. There is a gradual warming beyond the doubling and quadrupling points with CO₂ held constant. Globally averaged sea level rise at the time of CO₂ doubling is approximately 7 cm and at the time of quadrupling it is 23 cm. Some of the regional sea level changes are larger and reflect the adjustments in the temperature, salinity, internal ocean dynamics, surface heat flux, and wind stress on the ocean. A 0.5% per year CO₂ increase experiment also was performed showing a global warming of 1.5°C around the time of CO₂ doubling and a similar warming pattern to the 1% CO₂ per year increase experiment. El Niño and La Niña events in the tropical Pacific show approximately the observed frequency distribution and amplitude, which leads to near observed levels of variability on interannual time scales.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.Collections
Related items
Showing items related by title, author, creator and subject.
-
Changes in the hydrography of Central California waters associated with the 1997-98 El Niño
Collins, C.A.; Castro, C.G.; Asanuma, H.; Rago, T.A.; Han, S.-K.; Durazo, R.; Chavez, F.P. (2002);Oceanographic conditions off Central California were monitored by means of a series of 13 hydrographic cruises between February 1997 and January 1999, which measured water properties along an oceanographic section ... -
Changes in the hydrography of Central California waters associated with the 1997-1998 El Niño
Asanuma, Hiromi (Monterey, California. Naval Postgraduate School, 1999-06-01); NPS-OC-99-01During 1997-1998, oceanographic conditions off Central California were monitored by means of a series of thirteen cruises which measured water properties along an oceanographic section perpendicular to the California Coast. ... -
The Response of the Polar Regions to Increased CO2 in a Global Climate Model with Elastic--Viscous--Plastic Sea Ice
Zhang, Yuxia; Weatherly, John W. (2001-02-01);A global atmosphere–ocean–sea ice general circulation model (GCM) is used in simulations of climate with present-day atmospheric CO2 concentrations, and with CO2 increasing to double the present-day values. The Parallel ...