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Abstract The Oleander project, a program to monitor upper ocean currents between Bermuda and New Jersey, started in fall 1992, at about the same time modern satellite altimetry began. This study has two purposes. First, it revisits earlier work that compared Oleander estimates of sea level with altimetry. They agree well with respect to mean surface transport, but the Oleander velocity data exhibit significant temporal variability principally due to a varying Ekman layer. Second, we compare Oleander and altimetry‐derived transport estimates with a set of oceanographic products (OSCAR, GLORYS12, GREPV2, ARMOR3D) as well as with transport estimates from hydrography. All agree with respect to surface transport reflecting the dominant influence of altimetry. Upper ocean (0–1,000 m) transports agree poorly except for acoustic Doppler current profiler estimates, and dynamic height. The analysis products give completely different results with respect to total (surface to bottom) transport. 

Abstract Past studies of dispersion with float‐pairs have indicated that they may remain close together for much longer when they equilibrate on the same isopycnal, presumably due to the reduced influence of vertical shear. To examine this question more closely, we use a set of 13 and 15 float pair combinations that equilibrated within 0.1 °C (∼σ_θ = 0.01 kg m⁻³) of each other on two density surfaces in the main thermocline in a Lagrangian dispersion study. Their average rate of separation after launch was 0.0021 ± 0.0014 ms⁻¹(∼5.5 km after 30 days). Relative dispersion is accurately expressed by <D²> = 4•10⁶exp (t/10.8) m²from start to about 30 days. Relative diffusivity (K) versus separation dropped well below the classical 4/3rds power law settling out at about 2–3 m²s⁻¹for separations less than ∼6 km, far lower than results from other float studies, but in accord with dye dispersion estimates. 

Abstract The flow of warm water into the Nordic Seas plays an important role for the mild climate of central and northern Europe. Here we estimate the stability of this flow thanks to the extensive hydrographic record that dates back to the early 1900s. Using all casts in two areas with little mean flow just south and north of the Greenland‐Scotland Ridge that bracket the two main inflow branches, we find a well‐defined approximately ±0.5 Sv volume transport (and a corresponding ±30 TW heat flux) variation in synchrony with the Atlantic multidecadal variability that peaked most recently around 2010 and is now trending down. No evidence is found for a long‐term trend in transport over the last 70 to 100 years.