Stronger Variability in the Arctic Ocean Induced by Sea Ice Decline in a Warming Climate: Freshwater Storage, Dynamic Sea Level and Surface Circulation
Arctic liquid freshwater content (FWC) influences both regional and large-scale ocean dynamics and climate. In this study the responses of Arctic FWC, sea surface height (SSH) and surface circulation to different atmospheric circulation modes and the impact of sea ice decline on these responses are investigated by using wind perturbation simulations. The responses are intensified by sea ice decline through its resulting enhancement in ocean surface stress, indicating stronger decadal variability in the Arctic liquid FWC, SSH and ocean circulation in a warming climate. The Arctic Oscillation (AO) and Beaufort High (BH) wind forcing can significantly change Arctic regional and total FWC. Compared to the sea ice condition in the 1980s, the amplitudes of the ocean responses to the same AO forcing are much larger under the sea ice condition in the 2010s for both Arctic total FWC (by up to 50%) and regional SSH and velocity (doubled in some places). Sea ice decline intensifies ocean responses to the BH forcing in the Canada Basin with a similar strength. The Arctic Dipole Anomaly (DA) causes opposite changes in FWC between the Eurasian and Amerasian sectors in the cold decade, with the impact through changing sea ice thermodynamics being nonnegligible compared with that through changing ocean surface stress. Sea ice decline makes the ocean response to DA forcing less regular spatially. This study indicates an increasing vulnerability of the Arctic Ocean to winds in a warming world, which implies that extreme marine events may occur more often in the future.
Helmholtz Research Programs > CHANGING EARTH (2021-2027) > PT2:Ocean and Cryosphere in Climate > ST2.2: Variability and Extremes
Helmholtz Research Programs > CHANGING EARTH (2021-2027) > PT2:Ocean and Cryosphere in Climate > ST2.3: Sea Level Change