The impact of resolution on the adjustment and decadal variability of the Atlantic meridional overturning circulation in a coupled climate model. Hodson, D.&nbsp;L.<nbsp>R. & Sutton, R.&nbsp;T. Climate Dynamics, 39:3057--3073, 2012.
doi  abstract   bibtex   
Variations in the Atlantic meridional overturning circulation (MOC) exert an important influence on climate, particularly on decadal time scales. Simulation of the MOC in coupled climate models is compromised, to a degree that is unknown, by their lack of fidelity in resolving some of the key processes involved. There is an overarching need to increase the resolution and fidelity of climate models, but also to assess how increases in resolution influence the simulation of key phenomena such as the MOC. In this study we investigate the impact of significantly increasing the (ocean and atmosphere) resolution of a coupled climate model on the simulation of MOC variability by comparing high and low resolution versions of the same model. In both versions, decadal variability of the MOC is closely linked to density anomalies that propagate from the Lab-rador Sea southward along the deep western boundary. We demonstrate that the MOC adjustment proceeds more rapidly in the higher resolution model due the increased speed of western boundary waves. However, the response of the Atlantic sea surface temperatures to MOC variations is relatively robust—in pattern if not in magnitude—across the two resolutions. The MOC also excites a coupled ocean-atmosphere response in the tropical Atlantic in both model versions. In the higher resolution model, but not the lower resolution model, there is evidence of a significant response in the extratropical atmosphere over the North Atlantic 6 years after a maximum in the MOC. In both models there is evidence of a weak negative feedback on deep density anomalies in the Labrador Sea, and hence on the MOC (with a time scale of approximately ten years). Our results highlight the need for further work to under-stand the decadal variability of the MOC and its simulation in climate models.
@article{ Hodson2012,
  author = {Hodson, Daniel L. R. and Sutton, Rowan T.},
  title = {{The impact of resolution on the adjustment and decadal variability
	of the Atlantic meridional overturning circulation in a coupled climate
	model}},
  journal = {Climate Dynamics},
  year = {2012},
  volume = {39},
  pages = {3057--3073},
  abstract = {Variations in the Atlantic meridional overturning circulation (MOC)
	exert an important influence on climate, particularly on decadal
	time scales. Simulation of the MOC in coupled climate models is compromised,
	to a degree that is unknown, by their lack of fidelity in resolving
	some of the key processes involved. There is an overarching need
	to increase the resolution and fidelity of climate models, but also
	to assess how increases in resolution influence the simulation of
	key phenomena such as the MOC. In this study we investigate the impact
	of significantly increasing the (ocean and atmosphere) resolution
	of a coupled climate model on the simulation of MOC variability by
	comparing high and low resolution versions of the same model. In
	both versions, decadal variability of the MOC is closely linked to
	density anomalies that propagate from the Lab-rador Sea southward
	along the deep western boundary. We demonstrate that the MOC adjustment
	proceeds more rapidly in the higher resolution model due the increased
	speed of western boundary waves. However, the response of the Atlantic
	sea surface temperatures to MOC variations is relatively robust—in
	pattern if not in magnitude—across the two resolutions. The MOC
	also excites a coupled ocean-atmosphere response in the tropical
	Atlantic in both model versions. In the higher resolution model,
	but not the lower resolution model, there is evidence of a significant
	response in the extratropical atmosphere over the North Atlantic
	6 years after a maximum in the MOC. In both models there is evidence
	of a weak negative feedback on deep density anomalies in the Labrador
	Sea, and hence on the MOC (with a time scale of approximately ten
	years). Our results highlight the need for further work to under-stand
	the decadal variability of the MOC and its simulation in climate
	models.},
  doi = {10.1007/s00382-012-1309-0},
  file = {:Users/reinhard/Documents/articles/mendeley//Hodson, Sutton. 2012. Climate Dynamics.pdf:pdf},
  isbn = {0930-7575},
  issn = {09307575},
  keywords = {Atlantic,Decadal,MOC}
}

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