Potential Predictability of Multidecadal Oscillations of Sea Surface Temperature in the Arctic and Their Sensitivity to External Forcings

Аннотация

The low-frequency variability of sea surface temperature and salinity in the Arctic is analyzed using the data of the 1200-year preindustrial experiment with the INM-CM5 climate model developed in the Marchuk Institute of Numerical Mathematics of Russian Academy of Sciences. It is shown that the leading variability pattern is a regular coupled oscillation of temperature and salinity with the period of about 50 years. The empirical method based on the fluctuation-dissipation theorem was applied to evaluate influence functions which provide the optimum excitation of this oscillation phases. It is demonstrated that salinity anomalies are the main driver of this variability. The time of potential predictability of sea surface temperature and salinity was determined using the analog method, it equals about six years for 15-year means. The main source of long-term predictability is the spatial pattern associated with the leading mode of low-frequency variability of the analyzed parameters in the Arctic.