Abstract
Seasonal and inter-annual variability of transport in the Strait of
Belle Isle (SBI) were examined using 14 years of moored ADCP data. Tidal
currents were largely along strait and homogeneous with depth.
Transports were inwards on average, lowest (−1.0±0.8 dSv) from April to
July, and highest (−4.1±1.1 dSv) from September to January. Monthly
scale outflow towards the Labrador Shelf was more than twice as common
between April and August than between September and March. Averaged
seasonal transports were generally lower but within one standard
deviation of previously published modelled values. The volume of winter
Labrador Shelf water (LShW) entering the Gulf of St. Lawrence (GSL) was
computed by transport integration and compares well with integrated
volumes that meet LShW temperature-salinity criteria during an annual
March survey of the GSL. Integrating over the whole year showed that on
average 590±351 km3 enters the GSL after the March surveys are
conducted, or 36±19% of the total LShW volume. Annual volumes of LShW
calculated from transport suggest that inflow through the SBI accounts
for 12–18% of the GSL winter surface mixed layer. Cross-strait current
shear may have affected transport integration values, but SST data
suggests this bias was limited to the summer. Corrections were
empirically derived to account for cross strait shear in our transport
calculation. The corrected time series suggests dominant summer
transport may have been flowing towards the Labrador Shelf (0.4 ± 0.6
dSv).