32 research outputs found

    Improving the simulation of landfast ice by combining tensile strength and a parameterization for grounded ridges

    Get PDF
    ABSTRACT: In some coastal regions of the Arctic Ocean, grounded ice ridges contribute to stabilizing andmaintaining a landfast ice cover. Recently, a grounding scheme representing this effect on sea ice dynamicswas introduced and tested in a viscous-plastic sea ice model. This grounding scheme, based on a basalstress parameterization, improves the simulation of landfast ice in many regions such as in the East SiberianSea, the Laptev Sea, and along the coast of Alaska. Nevertheless, in some regions like the Kara Sea, the areaof landfast ice is systematically underestimated. This indicates that another mechanism such as ice archingis at play for maintaining the ice cover fast. To address this problem, the combination of the basal stressparameterization and tensile strength is investigated using a 0.258Pan-Arctic CICE-NEMO configuration.Both uniaxial and isotropic tensile strengths notably improve the simulation of landfast ice in the Kara Seabut also in the Laptev Sea. However, the simulated landfast ice season for the Kara Sea is too short com-pared to observations. This is especially obvious for the onset of the landfast ice season which systematical-ly occurs later in the model and with a slower build up. This suggests that improvements to the sea icethermodynamics could reduce these discrepancies with the data. Key Points - A grounding scheme is not enough to simulate landfast ice in Pan-Arctic simulations; - Both uniaxial and isotropic tensile strengths notably improve the simulation of landfast ice in deep coastal regions; - Simulated landfast ice season in the Kara Sea is still too short suggesting that thermodynamics should be improved

    High Energy QCD: Stringy Picture from Hidden Integrability

    Get PDF
    We discuss the stringy properties of high-energy QCD using its hidden integrability in the Regge limit and on the light-cone. It is shown that multi-colour QCD in the Regge limit belongs to the same universality class as superconformal N\cal{N}=2 SUSY YM with Nf=2NcN_f=2N_c at the strong coupling orbifold point. The analogy with integrable structure governing the low energy sector of N\cal{N}=2 SUSY gauge theories is used to develop the brane picture for the Regge limit. In this picture the scattering process is described by a single M2 brane wrapped around the spectral curve of the integrable spin chain and unifying hadrons and reggeized gluons involved in the process. New quasiclassical quantization conditions for the complex higher integrals of motion are suggested which are consistent with the S−S-duality of the multi-reggeon spectrum. The derivation of the anomalous dimensions of the lowest twist operators is formulated in terms of the Riemann surfacesComment: 37 pages, 3 figure
    corecore