Two circulation regimes of the wind‐driven Arctic Ocean

Abstract

Abstract. The major goal of this paper is to demonstrate the existence in the Arctic Ocean of two regimes of wind-forced circulation. We simulated the vertically averaged currents, sea level heights, and ice drift in the Arctic Ocean from 1946 to 1993 using a two-dimensional, wind-forced, barotropic model that includes frictional coupling between the ocean and ice. The model has a spatial resolution of 55.5 km and is driven by winds, river runoff, and an imposed but realistic sea level slope between the Pacific and the Atlantic Oceans. There is a good agreement between velocities from observed buoy motions and velocities of modeled ice drift even though the model lacks ocean baroclinicity and ice thermodynamics. The results indicate that wind-driven motion in the central Arctic alternates between anticyclonic and cyclonic circulation, with each regime persisting for 5-7 years, based upon our analysis of the modeled sea level and ice motion. Anticyclonic wind-driven motion in the central Arctic appeared during 1946-1952, 1958-1963, 1972-1979, and 1984-1988, and cyclonic motion appeared during 1953-1957, 1964-1971, 1980-1983, and 1989-1993. Shifts from one regime to another are forced by changes in the location and intensity of the Icelandic low and the Siberian high. The two regimes may help explain the significant, basin-scale changes in the Arctic's temperature and salinity structure observed recently, the Great Salinity Anomaly, and the variability of ice conditions in the Arctic Ocean. A series of two-dimensional (2-D) numerical model results [Fel'zenbaum, 1958;Campbell, 1965;Galt, 1973;Hart, 1975 Introduction This paper examines the role of wind-driven variations in the

Relaxation of central Arctic Ocean hydrography to pre‐1990s climatology

“…The more cyclonic atmospheric circulation results in the shift in the Atlantic-Pacific upper-ocean front and more cyclonic ocean circulation. Several modeling studies support these ideas [e.g., Proshutinsky and Johnson, 1997;Zhang et al, 2000].…”

Simulated low‐frequency modes of circulation in the Arctic Ocean

“…The midlatitude North Atlantic surface temperatures associated with NAO displays a distinct variability at 12-14 year periods [Deser and Blackmon, 1993]. In the Arctic, a decadal cyclicity is found by Proshutinsky and Johnson [1997], who describe the ice drift and barotropic ocean current system as having 5-7 year regimes of anticyclonic and cyclonic rotation resulting from fluctuations of the strength between Icelandic low and Siberian high.…”

“…We apply principal component analysis to explore spatial and temporal variability in the high northern latitudes and thus offer a complementary perspective to the study by Proshutinsky and Johnson [1997]. Our study is a hindcast from 1946 to 1993 using Comprehensive Ocean and Atmosphere Data Set (COADS) anomalies [daSilva et al, 1994] added to a monthly climatology compiled from different sources.…”

Liquid export of Arctic freshwater components through the Fram Strait 1998–2011

“…The pathways of freshwater in the Arctic Ocean and their arrival in the Fram Strait are related to both the large-scale atmospheric circulation influencing upper ocean currents and hydrography (Proshutinksy and Johnson, 1997;Steele and Boyd, 1998;Zhang et al, 2003;Häkkinen and Proshutinsky, 2004;Dukhovskoy et al, 2006), and regional processes governing the storage and release of liquid freshwater.…”