The interaction of seasonality and lowfrequencies in a stochastic Arctic sea ice model
Abstract
The stochastic Arctic sea ice model described as a single periodic nonautonomous stochastic ordinary differential equation (ODE) is useful in explaining the seasonal variability of Arctic sea ice. However, to be nearer to realistic approximations we consider the inclusion of longterm forcing implying the effect of slowlyvarying ocean or atmospheric lowfrequencies. In this research, we rely on the equivalent FokkerPlanck equation instead of the stochastic ODE owing to the advantages of the FokkerPlanck equation in dealing with higher moments calculations. We include simple longterm forcing into the FokkerPlanck equation and then seek approximate stochastic solutions. The formalism based on the FokkerPlanck equation with a singular perturbation method is flexible with regard to accommodating further complexity that arises due to the inclusion of longterm forcing. These solutions are then applied to the stochastic Arctic sea ice model with longterm forcing. Strong seasonality in the Arctic sea ice model combined with longterm forcing, changes the seasonal variability depending on the phase of the longterm forcing. The change includes the shift of mean and the increase or decrease of variance and skewness. Stochastic realisations show that the change of the statistical moments due to longterm forcing is realised by unusual fluctuations particularly concentrated at a specific time of a year.
 Publication:

arXiv eprints
 Pub Date:
 October 2016
 arXiv:
 arXiv:1611.00268
 Bibcode:
 2016arXiv161100268M
 Keywords:

 Physics  Atmospheric and Oceanic Physics;
 Mathematics  Probability;
 Nonlinear Sciences  Chaotic Dynamics