Modeling of climate tendencies in Arctic seas based on atmospheric forcing EOF decomposition

• Published in: Ocean dynamics 2019-06, Vol.69 (6), p.747-767
• Main Authors: Platov, Gennady A., Golubeva, Elena N., Kraineva, Marina V., Malakhova, Valentina V.
• Format: Article
• Language: English
• Subjects: 28 May to 1 June 2018; Air temperature; Arctic climates; Arctic ice; Arctic Oscillation; Atmospheric forcing; Atmospheric models; Atmospheric processes; Atmospheric Sciences; Belgium; Climate models; Climatic data; Computer simulation; Decomposition; Earth and Environmental Science; Earth Sciences; Fluid- and Aerodynamics; Geophysics/Geodesy; Ice; Ice formation; Ice volume; Liège; Marginal seas; Modelling; Modes; Monitoring/Environmental Analysis; Oceanography; Oscillations; Sea level; Sea level pressure; Seasonal variation; Sensitivity analysis; State vectors; Surface temperature; Surface wind; Surface-air temperature relationships; Topical Collection on the 50th International Liège Colloquium on Ocean Dynamics; Trends
• ISSN: 1616-7341; 1616-7228
• DOI: 10.1007/s10236-019-01259-1

The article analyzes the results of the EOF decomposition of climatic data and assesses the role of its components in the formation of climatic ice tendencies of recent decades. The analysis considers a state vector, which includes sea level pressure, surface air temperature, and surface wind, scaled accordingly. The seasonal cycle variations were also considered. An assessment of the ocean-ice system sensitivity to the time scales of atmospheric processes, based on the SibCIOM model, showed that the rate of decline of the annual ice minimum volume decreases by 2/3 when atmospheric forcing contains no variations of the 8–30-day scale, that is, if the formation of atmospheric blockings is excluded. Applying trend elimination for each of the EOF modes, comparing the results of the simulation with the base experiment which includes all trends, it was possible to estimate the role of each mode in shaping the trend of Arctic ice volume decline. The comparison shows that the first mode, representing the seasonal cycle, forms an integral tendency of ice volume decline by 96% of the original trend. Among other modes, the strongest influence on this trend shows second mode, representing Arctic Oscillations; it forms trend by 17%, and third mode, resulting from inclusion of the surface air temperature into the state vector, by 18%. In the marginal seas, the role of higher modes becomes not so small in comparison with the first mode.