1
COASTAL OCEANCOASTAL OCEAN
• We will start with chapter 11 first, then chapter 10
Coastal ocean
• Shallow ocean area over continental shelf
• Complex shorelines
• Currents are more or less parallel to the shoreline
– 1. tides and winds have strong influence
– 2. affected by river discharge
3 estuarine circulation prevails (will see this later)
–
3
.
estuarine
circulation
prevails
(will
see
this
later)
–4. Davidson coastal: geostrophic currents (arises
from a balance between the down-slope component
of the gravitational force and the Coriolis effect
that deflects it) that parallel the coast (Fig 11.4 p
333)
Currents are more or less parallel to the shoreline
cont.
– 5. seasonal change - summer wind diminish or
little river discharge, and weaken coastal currents -
winter storms - coastal currents are re-established
Example
• surface waters can be blown toward shore and
held there by winds, depressing the pycnocline
(where water density changes markedly with depth
- changes in either temperature, salinity or both,
can cause the marked change in density). A
sloping sea surface results creating geostrophic
sloping
sea
surface
results
,
creating
geostrophic
currents that parallel the coast. Because of this
parallel flow transfer of freshwater across the
coastal ocean is slow - residence time of
freshwater is long, 1/2 year to 2+ years
