Simulations with XBeach in 2DH show that the alongshore current
and its interaction with the cross-shore processes lead to significantly more dune erosion, and that the coastal orientation with respect to the wave angle also plays an important role.
They found that while sea level shows a seasonal variability, the alongshore current
shows no clear seasonal cycle but is dominated by intraseasonal (55-110 day) fluctuations.
In addition to these orbital velocities, the inshore transport of momentum by surface waves under certain conditions drives an alongshore current that can reach velocities in excess of 1 m/s in the surf zone.
Larvae released at the shoreline, in addition to being carried downstream by the alongshore current, can be mixed into and out of these embayments.
He attributed this phenomenon to the decrease in the clastic material supply from the northerly situated provenances combined with the development of a complicated current system, including alongshore currents
, in the sea.
By remaining close to shore, within the coastal boundary layer, larvae would be subjected to alongshore currents
with reduced velocities and, with changes in the wind direction, alternating directions (Largier, 2003).
The alongshore currents
have the greatest effects on the sediment redistribution of this littoral.
The region along the shelf break and over the upper slope has high primary productivity that may be driven by shelf-break fronts, seasonal upwelling, strong alongshore currents
, and tidal mixing (Parsons, 1986).
Martha's Vineyard and the Elizabeth Islands protect Woods Hole and make it a safe harbor, but they also block scientists from immediate access to undisturbed ocean waves and alongshore currents