Source: Journal of Geophysical Research: Atmospheres
In a new study, Ma et al.  find that the Arctic Sea ice concentration is crucial for the prediction of strong and long-lasting Ural blocking formation. The authors adopt a conditional nonlinear optimal perturbation method to explore the influence of Arctic Sea ice on Ural blocking prediction.
Numerical results show that sea ice concentration in the Greenland, Barents, and Okhotsk seas is crucial for 4-pentad prediction of these Ural blockings. Further diagnoses reveal that sea ice perturbations in these areas first influence the local temperature through the diabatic heating process and further affect the temperature in the Ural sector mainly by advection and convection processes. Moreover, zonal winds in the Ural sector are adjusted by the thermal wind balance, thus affecting Ural blocking formation.
The local characteristics of the Arctic Sea ice concentration indicate that the Greenland, Barents and Okhotsk seas may be sensitive areas in regard to 4-pentad prediction of strong and long-lasting Ural blocking formations. These results provide scientific supports for future target observations and ensemble subseasonal forecast.
Citation: Ma, X., Mu, M., Dai, G., Han, Z., Li, C., & Jiang, Z. (2022). Influence of Arctic sea ice concentration on extended-range prediction of strong and long-lasting Ural blocking events in winter. Journal of Geophysical Research: Atmospheres, 127, e2021JD036282. https://doi.org/10.1029/2021JD036282
—Yimin Liu, Associate Editor, Journal of Geophysical Research: Atmospheres