A Dynamical Stabilizer in the Climate System: A Mechanism Suggested by a Simple Model and Supported by GCM Experiments and an Observational Data Study

Abstract The changes in model ENSO behavior due to an increase in greenhouse gases, according to the Intergovernmental Panel on Climate Change (IPCC) Business-As-Usual scenario, are investigated using a 62-member ensemble 140-yr simulation (1940–2080) with the National Center for Atmospheric Research Community Climate System Model (CCSM; version 1.4). Although the global mean surface temperature increases by about 1.2 K over the period 2000–80, there are no significant changes in the ENSO period, amplitude, and spatial patterns. To explain this behavior, an analysis of the simulation results is combined with results from intermediate complexity coupled ocean–atmosphere models. It is shown that this version of the CCSM is incapable of simulating a correct meridional extension of the equatorial wind stress response to equatorial SST anomalies. The wind response pattern is too narrow and its strength is insensitive to background SST. This leads to a more stable Pacific climate system, a shorter ENSO period, and a reduced sensitivity of ENSO to global warming.

Download Full-text

What we know about the Climate System? A brief review of current research

Global Climate ◽

10.1007/978-3-662-05285-3_1 ◽

2003 ◽

pp. 3-24 ◽

Cited By ~ 1

Author(s):

Francisco A. Comín ◽

Miguel Angel Rodríguez-Arias

Keyword(s):

Climate System ◽

System A

Download Full-text

Evaluation of a very simple model for predicting the moisture content of eucalypt litter

International Journal of Wildland Fire ◽

10.1071/wf11006 ◽

2011 ◽

Vol 20 (8) ◽

pp. 1000 ◽

Cited By ~ 15

Author(s):

Jason J. Sharples ◽

Richard H. D. McRae

Keyword(s):

Simple Model ◽

Moisture Content ◽

Observational Data ◽

Short Note ◽

Fuel Moisture ◽

Computational Power ◽

Complex Process ◽

Fuel Moisture Content ◽

Better Than

Operational prediction of wildfire behaviour requires assessment of dead fuel moisture content to an acceptable degree of accuracy. Ideally, the methods of assessment should be simple enough to implement in most operational settings, including those where computational power is a constraining factor. In this short note, we describe a very simple model for estimating dead fine fuel moisture content and compare its predictions with several fuel moisture observations and the predictions of a complex process-based model and two of its simplifications. Remarkably, the very simple model is shown to fit the observational data just as well, if not slightly better, than the more sophisticated models. The result highlights the issues of engineering and parsimony of models for dead fuel moisture content. These issues are briefly discussed.

Download Full-text

Interactions of the carbon cycle, human activity, and the climate system: a research portfolio

Current Opinion in Environmental Sustainability ◽

10.1016/j.cosust.2010.08.003 ◽

2010 ◽

Vol 2 (4) ◽

pp. 301-311 ◽

Cited By ~ 42

Author(s):

Josep G Canadell ◽

Philippe Ciais ◽

Shobhakar Dhakal ◽

Han Dolman ◽

Pierre Friedlingstein ◽

...

Keyword(s):

Carbon Cycle ◽

Human Activity ◽

Climate System ◽

System A

Download Full-text

On the Milankovitch sensitivity of the Quaternary deep-sea record

Climate of the Past Discussions ◽

10.5194/cpd-9-1237-2013 ◽

2013 ◽

Vol 9 (2) ◽

pp. 1237-1257

Author(s):

W. H. Berger

Keyword(s):

Climate Change ◽

Global Warming ◽

Climate Variability ◽

Deep Sea ◽

Climate System ◽

Ice Age ◽

External Forcing ◽

Orbital Forcing ◽

Early Pliocene ◽

System A

Abstract. The response of the climate system to external forcing has become an item of prime interest in the context of global warming, especially with respect to the rate of melting land-based ice masses. The deep-sea record of ice-age climate change has been useful in assessing the sensitivity of the climate system to such forcing, notably to orbital forcing, which is well-known for the last several million years. When comparing response and forcing, one finds that sensitivity varies greatly through time, apparently in dependence on the state of the system. The changing stability of ice masses presumably is the underlying cause for the changing state of the system. A buildup of vulnerable ice masses within the latest Tertiary, when going into the ice ages, is conjectured to cause a stepwise increase of climate variability since the early Pliocene.

Download Full-text

On the Milankovitch sensitivity of the Quaternary deep-sea record

Climate of the Past ◽

10.5194/cp-9-2003-2013 ◽

2013 ◽

Vol 9 (4) ◽

pp. 2003-2011 ◽

Cited By ~ 9

Author(s):

W. H. Berger

Keyword(s):

Climate Change ◽

Global Warming ◽

Climate Variability ◽

Deep Sea ◽

Climate System ◽

Ice Age ◽

External Forcing ◽

Orbital Forcing ◽

System A ◽

Yield Information

Abstract. The response of the climate system to external forcing (that is, global warming) has become an item of prime interest, especially with respect to the rate of melting of land-based ice masses. The deep-sea record of ice-age climate change has been useful in assessing the sensitivity of the climate system to a different type of forcing; that is, to orbital forcing, which is well known for the last several million years. The expectation is that the response to one type of forcing will yield information about the likely response to other types of forcing. When comparing response and orbital forcing, one finds that sensitivity to this type of forcing varies greatly through time, evidently in dependence on the state of the system and the associated readiness of the system for change. The changing stability of ice masses is here presumed to be the chief underlying cause for the changing state of the system. A buildup of vulnerable ice masses within the latest Tertiary, when going into the ice ages, is thus here conjectured to cause a stepwise increase of climate variability since the early Pliocene.

Download Full-text