the whole of the South Atlantic between 20°S
and 25°S.
The concept of a quasi-steady mean circulation
also seems elusive. John Swallow’s failed attempt
to observe it off Bermuda during the Aries Expedition discovered, instead, the ocean mesoscale phenomenon. By choosing a location in the world’s
oceans where the mesoscale energy would be small,
DBE investigators seem, instead, to have found an
energetic, longer-period variability. As has been
discovered elsewhere in the very spotty holdings
that we have of long time series, the frequency
spectrum is generally red, a particularly good
example being the increasingly long time series
from ‘KIEL 276’, a mooring that has been maintained for 20 years in the eastern North Atlantic
(Müller and Siedler, 1992).
However, there are aspects of the deep circulation that are robust. Heat and mass transports
through deep passages are quite steady, in contrast
to those elsewhere along the boundaries. The consequent implications for upward diffusion of properties show mixing rates greater, indeed, in some
places much greater, than 1 cm
2 s
91
, in the deep
ocean wherever such estimates have been made.
Acknowledgements
Continued support from the National Science Foundation through grants OCE 90-04396, OCE 9004864 and OCE 94-15509 is much appreciated.
Comments from two reviewers and Mindy Hall
were very helpful. This is contribution number 9997
from the Woods Hole Oceanographic Institution.
SECTION 4 THE GLOBAL FLOW FIELD
270
and 25°S.
The concept of a quasi-steady mean circulation
also seems elusive. John Swallow’s failed attempt
to observe it off Bermuda during the Aries Expedition discovered, instead, the ocean mesoscale phenomenon. By choosing a location in the world’s
oceans where the mesoscale energy would be small,
DBE investigators seem, instead, to have found an
energetic, longer-period variability. As has been
discovered elsewhere in the very spotty holdings
that we have of long time series, the frequency
spectrum is generally red, a particularly good
example being the increasingly long time series
from ‘KIEL 276’, a mooring that has been maintained for 20 years in the eastern North Atlantic
(Müller and Siedler, 1992).
However, there are aspects of the deep circulation that are robust. Heat and mass transports
through deep passages are quite steady, in contrast
to those elsewhere along the boundaries. The consequent implications for upward diffusion of properties show mixing rates greater, indeed, in some
places much greater, than 1 cm
2 s
91
, in the deep
ocean wherever such estimates have been made.
Acknowledgements
Continued support from the National Science Foundation through grants OCE 90-04396, OCE 9004864 and OCE 94-15509 is much appreciated.
Comments from two reviewers and Mindy Hall
were very helpful. This is contribution number 9997
from the Woods Hole Oceanographic Institution.
SECTION 4 THE GLOBAL FLOW FIELD
270