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Spatial Patterns and Frequency of Unforced Decadal-Scale Changes in Global Mean Surface Temperature in Climate Models
- Source :
- Journal of Climate. 29:6245-6257
- Publication Year :
- 2016
- Publisher :
- American Meteorological Society, 2016.
-
Abstract
- The causes of decadal time-scale variations in global mean temperature are currently under debate. Proposed mechanisms include both processes internal to the climate system as well as external forcing. Here, the robustness of spatial and time scale characteristics of unforced (internal) decadal variability among phase 5 of the Coupled Model Intercomparison Project (CMIP5) preindustrial control runs is examined. It is found that almost all CMIP5 models produce an interdecadal Pacific oscillation–like pattern associated with decadal variability, but the frequency of decadal-scale change is model dependent. To assess the roles of atmosphere and ocean dynamics in producing decadal variability, two preindustrial control Community Climate System model (version 4) configurations are compared: one with an atmosphere coupled to a slab ocean and the other fully coupled to a dynamical ocean. Interactive ocean dynamics are not necessary to produce an IPO-like pattern but affect the magnitude and frequency of the decadal changes primarily by impacting the strength of El Niño–Southern Oscillation. However, low-frequency El Niño–Southern Oscillation variability and skewness explains up to only 54% of the spread in frequency of decadal swings in global mean temperature among CMIP5 models; there may be other internal mechanisms that can produce such diversity. The spatial pattern of decadal changes in surface temperature are robust and can be explained by atmospheric processes interacting with the upper ocean, while the frequency of these changes is not well constrained by models.
- Subjects :
- Atmospheric Science
Coupled model intercomparison project
010504 meteorology & atmospheric sciences
Forcing (mathematics)
010502 geochemistry & geophysics
Atmospheric sciences
01 natural sciences
Ocean dynamics
Atmosphere
Climatology
Spatial ecology
Environmental science
Community Climate System Model
Climate model
Pacific decadal oscillation
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 15200442 and 08948755
- Volume :
- 29
- Database :
- OpenAIRE
- Journal :
- Journal of Climate
- Accession number :
- edsair.doi...........b6adc9dd127c517bee4984c9ae74ad17