What is happening in the lagoon? Are we expecting
an air attack? The answer is NO. The mini Barrage
Balloon
you may have seen on the MCU Pinnace is, in fact,
a Kytoon(?) which is being used as a sky-hook for
a Radar
Reflector. Why does the Pinnace need to fly a radar
reflector? The short answer to that is - the Equatorial
Undercurrent Project.
It has been discovered in recent years that in all
oceans along the equator, at depths of between 150
and
600 feet, and between 2 deg. North and 2 deg. South
there is a strong eastward flowing current. In the
Atlantic
and Pacific Oceans the current is fairly steady as
are the winds near the Equator (Trade Winds) and so
it is
suspected that the winds are the main driving force
for the sea currents.
In the Indian Ocean however, the winds change in a
regular cycle, blowing from the southwest from May
to
September and changing to northeast for the rest Of
the year. What is not known is how much this change
in
wind affects the sea current. Only a very few observations
have been made in the Indian Ocean and these tend
to
show that in the southwest wind the current is absent
altogether, or at best very variable. An attempt therefore
is
now being made to establish what really happens in
the yearly cycle.
Once a week the Pinnace will take out to sea an Aanderaa
Current Meter to alternate positions 15 miles north
of Bushey and 15 miles south of Gan Channel. The meter
is lowered into the water and allowed to sink slowly
through the current layers. The meter has sensors
which tell the temperature of the water, the salinity
md the
speed of the water past the current meter. There is
also a compass to check the direction of the current
and
a pressure sensitive device to tell the depth of the
meter. The information from all these sensors is recorded
on
a tape recorder built into the meter and when the
meter is recovered, the tape is removed and sent off
to the
Woods Hole Oceanographic Institute in America where
it is fed into a computer for analysis.
This brings us back to the mini Barrage Balloon. By
following the Pinnace on the Met Office radar its
exact
position can be plotted and its rate of drift worked
out so that this drift can be added to or subtracted
from
the meter readings in order to find out the exact
speed of the current in relation to the Ocean bed. The
project
is expected to last for a year, so the next time you
see a Barrage Balloon don't dive into the nearest air-raid shelter |