Direct measurements of transport and water properties through the Bering Strait

Abstract

Four years of temperature, salinity, and velocity data enable a direct computation of volume transport and a temporal description of water properties exchanged through the Bering Strait. The mean volume transport over the 4‐year period (September 1990 through September 1994) is 0.83 Sv northward with a weekly standard deviation of 0.66 Sv. The maximum error in this mean estimate is 30%. Interannual variability in transport is typically 0.1 Sv but can, at times, reach nearly 50% of the mean. The transport of 1.14 Sv during the first 9 months of 1994 is the largest in the last 50 years. The rate of winter salinity increase is very similar from year to year, suggesting regional average ice formation of about 5 cm d−1. The amplitude of the annual salinity cycle is about 2 psu, with salinity reaching a maximum in early April. There can be large interannual variations in the salinity (about 1), particularly in winter. Background autumn salinities average 32.0 in the eastern and 32.6 in the western channel.

The Chukchi slope current

“…However, the data are largely anecdotal, and there are no published estimates of the transport of this shelfbreak flow. the mean volume flux of Pacific water to be 0.13 ± 0.08 Sv, which is only about 15% of the long-term transport through Bering Strait (0.83 Sv, Roach et al, 1995). Furthermore, while the northward volume flux through Bering Strait has increased in recent years to just over 1 Sv (Woodgate et al, 2012), the eastward transport of Pacific water in the Beaufort shelfbreak jet has decreased to 0.021-0.041 Sv (Brugler et al, 2014).…”

Atlantic Meridional Overturning Circulation at 14.5° N in 1989 and 2013 and 24.5° N in 1992 and 2015: volume, heat, and freshwater transports

“…For instance, using hydrographic section data obtained during the International Geophysical Year (IGY) and the World Ocean Circulation Experiment (WOCE), many studies focused on estimating the volume transport and heat and freshwater transports related to the AMOC (e.g., Roemmich and Wunsch, 1985;Macdonald, 1998;Ganachaud andWunsch, 2000, 2003;Lumpkin and Speer, 2003). These pioneer studies revealed a consistent picture of the AMOC in terms of largescale horizontal and overturning circulation.…”

The Barents and Chukchi Seas: Comparison of two Arctic shelf ecosystems

“…The Bering Strait volume transport averages about 0.8 Sv northwards over the year (Roach et al, 1995;Woodgate et al, 2006), being strongest in summer and weakest in winter. Occasionally, there are wind-driven reversals to southward transport between November and March (e.g., Woodgate et al, 2005b).…”