Decadal
variability in surface heat fluxes can most clearly be seen from small
changes in temperature between sections taken during different epochs.
The ocean effectively integrates small changes in surface heat flux
that result in variability in sea surface temperature which become
subducted and overturned into the deeper waters. Repeat hydrographic
measurements taken at the same location through time can then be differenced
to get indicators of climate change.
During
the World Ocean Circulation Experiment (WOCE), a global occupation
of total water column transects were obtained. Several of the WOCE
sections, including the 24N section in the Atlantic, were also occupied
earlier, providing estimates of total water column changes over several
decades. The 24N section in the Atlantic provides a particularly unique
opportunity to examine total water column changes due to the 4 occupations
of the section: in 1957, 1981, 1992 and 1998
Location
of the stations for the 1998 (black and '+'s) and 1992 (red and triangles)
hydrographic stations. Note that the 1992 transect followed the path
of the original 1957 IGY section (blue and 'o'), while the 1998 section
follows more closely the path of the Atlantis 109 1981 section (green
and '+'). Within the Florida Straits (upper panel) the 1992 and earlier
data are from 26 N. The 1998 data are from 27 N. The more southerly
crossing misses any flow which may pass through the Northwest Providence
Channel.
T/S
changes along 24N
Figures:
grid50_theta_9892.jpg
and grid50_theta_9281.jpg,
![[Horizontal Rule]](../graphics3/hr.gif){kind=small}
