CLIMBER-2: a climate system model of intermediate complexity. Part I: model description and performance for present climate

Petoukhov, Vladimir; Ganopolski, Andrey; Brovkin, Victor; Claußen, Martin; Елисеев, А. В.; Kubatzki, Claudia; Rahmstorf, Stefan

doi:10.1007/pl00007919

Cited by 431 publications

(420 citation statements)

References 51 publications

Supporting

Mentioning

408

Contrasting

Unclassified

Order By: Relevance

“…Consistent with reanalysis data (Fig. 4) and theoretical considerations (36,39), continental rainfall is assumed to be proportional to the mean specific humidity within the atmospheric column…”

Section: Resultsmentioning

confidence: 77%

See 1 more Smart Citation

Basic mechanism for abrupt monsoon transitions

Levermann

Schewe

Petoukhov

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

129

124

View full text Add to dashboard Cite

Monsoon systems influence the livelihood of hundreds of millions of people. During the Holocene and last glacial period, rainfall in India and China has undergone strong and abrupt changes. Though details of monsoon circulations are complicated, observations reveal a defining moisture-advection feedback that dominates the seasonal heat balance and might act as an internal amplifier, leading to abrupt changes in response to relatively weak external perturbations. Here we present a minimal conceptual model capturing this positive feedback. The basic equations, motivated by observed relations, yield a threshold behavior, robust with respect to addition of other physical processes. Below this threshold in net radiative influx, R c , no conventional monsoon can develop; above R c , two stable regimes exist. We identify a nondimensional parameter l that defines the threshold and makes monsoon systems comparable with respect to the character of their abrupt transition. This dynamic similitude may be helpful in understanding past and future variations in monsoon circulation. Within the restrictions of the model, we compute R c for current monsoon systems in India, China, the Bay of Bengal, West Africa, North America, and Australia, where moisture advection is the main driver of the circulation.Earth system | tipping element | abrupt climate change | atmospheric circulation | nonlinear dynamics M onsoon rainfall shapes regional culture and the livelihoods of hundreds of millions of people (e.g., 1, 2). The future evolution of monsoon rainfall under increasing levels of atmospheric CO 2 and aerosol pollution is highly uncertain (3). Although greenhouse gas abundance tends to increase monsoon rainfall strength (4-6), the situation is more complex with changing aerosol distribution (7,8). Given this large uncertainty in the future forcing of monsoons, it is crucial to understand internal monsoon dynamics, especially with respect to self-amplifying feedbacks, which might result in potentially strong responses to small perturbations. Zickfeld et al. (2005) found two stable states in a simple model of the Indian summer monsoon, which in principle allows for rapid transition between radically different monsoon circulations (9, 10) and thereby identified the Indian monsoon as a potential tipping element of the climate system (11). Evidence for such behavior is found in paleodata that show rapid and strong variations in Indian and East Asian monsoon rainfall (12, 13). These abrupt changes have been linked to climatic events in the North Atlantic for the last glacial period (14, 15) as well as for the Holocene (16,17). Though a physical mechanism for this teleconnection has been suggested (18), relevant climatic signals of the North Atlantic events in Asia (such as temperature and moisture anomalies) are very small (19) indicating that internal feedbacks in monsoon dynamics may have amplified the weak external forcing.Both spatial patterns and temporal evolution of monsoon rainfall are influenced by a number of physical processes ...

show abstract

Section: Resultsmentioning

confidence: 77%

“…Note that l is scaling like q O α/β where α and β have clear-cut physical meaning (39). planetary boundary layer (PBL).…”

Section: Resultsmentioning

confidence: 99%

Basic mechanism for abrupt monsoon transitions

Levermann

Schewe

Petoukhov

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

129

124

View full text Add to dashboard Cite

show abstract

“…Second, we assume that changes over Greenland do not affect the climate outside it, i.e., we consider only uni-directional interaction. Third, vertical temperature and humidity profiles are assumed to have a universal structure (e.g., Petoukhov et al, 2000). Finally, the heat capacity of the active soil or snow/ice layer is neglected, as well as changes in cloud cover.…”

Section: Regional Energy-moisture Balance Modelmentioning

confidence: 99%

An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change

2010

Self Cite

View full text Add to dashboard Cite

Abstract. In order to explore the response of the Greenland ice sheet (GIS) to climate change on long (centennial to multi-millennial) time scales, a regional energy-moisture balance model has been developed. This model simulates seasonal variations of temperature and precipitation over Greenland and explicitly accounts for elevation and albedo feedbacks. From these fields, the annual mean surface temperature and surface mass balance can be determined and used to force an ice sheet model. The melt component of the surface mass balance is computed here using both a positive degree day approach and a more physically-based alternative that includes insolation and albedo explicitly. As a validation of the climate model, we first simulated temperature and precipitation over Greenland for the prescribed, present-day topography. Our simulated climatology compares well to observations and does not differ significantly from that of a simple parameterization used in many previous simulations. Furthermore, the calculated surface mass balance using both melt schemes falls within the range of recent regional climate model results. For a prescribed, ice-free state, the differences in simulated climatology between the regional energy-moisture balance model and the simple parameterization become significant, with our model showing much stronger summer warming. When coupled to a threedimensional ice sheet model and initialized with present-day conditions, the two melt schemes both allow realistic simulations of the present-day GIS.

show abstract

“…We use the climate-carbon coupled model CLIMBER-2 (Petoukhov et al, 2000;Brovkin et al, 2002Brovkin et al, , 2007. CLIMBER-2 is a model of intermediate complexity fast enough to run numerous long simulations.…”

Section: Climber-2 Climate-carbon Modelmentioning

confidence: 99%

Systematic study of the impact of fresh water fluxes on the glacial carbon cycle

2012

View full text Add to dashboard Cite

Abstract. During glacial periods, atmospheric CO 2 concentration increases and decreases by around 15 ppm. At the same time, the climate changes gradually in Antarctica. Such climate changes can be simulated in models when the AMOC (Atlantic Meridional Oceanic Circulation) is weakened by adding fresh water to the North Atlantic. The impact on the carbon cycle is less straightforward, and previous studies give opposite results. Because the models and the fresh water fluxes were different in these studies, it prevents any direct comparison and hinders finding whether the discrepancies arise from using different models or different fresh water fluxes.In this study we use the CLIMBER-2 coupled climate carbon model to explore the impact of different fresh water fluxes. In both preindustrial and glacial states, the addition of fresh water and the resulting slow-down of the AMOC lead to an uptake of carbon by the ocean and a release by the terrestrial biosphere. The duration, shape and amplitude of the fresh water flux all have an impact on the change of atmospheric CO 2 because they modulate the change of the AMOC. The maximum CO 2 change linearly depends on the time integral of the AMOC change. The different duration, amplitude, and shape of the fresh water flux cannot explain the opposite evolution of ocean and vegetation carbon inventory in different models. The different CO 2 evolution thus depends on the AMOC response to the addition of fresh water and the resulting climatic change, which are both model dependent. In CLIMBER-2, the rise of CO 2 recorded in ice cores during abrupt events can be simulated under glacial conditions, especially when the sinking of brines in the Southern Ocean is taken into account. The addition of fresh water in the Southern Hemisphere leads to a decline of CO 2 , contrary to the addition of fresh water in the Northern Hemisphere.

show abstract

CLIMBER-2: a climate system model of intermediate complexity. Part I: model description and performance for present climate

Cited by 431 publications

References 51 publications

Basic mechanism for abrupt monsoon transitions

Basic mechanism for abrupt monsoon transitions

An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change

Systematic study of the impact of fresh water fluxes on the glacial carbon cycle

Contact Info

Product

Resources

About