SUMMARY 
Background. Interactions between climate and the ocean are believed to be important on 
all climate time scales. Recently it has become increasingly clear that the ocean may play a 
major role in determining climate trends on decade to century time scales. 
The effect of ocean heat capacity as a thermal buffer on climate has been emphasized by 
Charney (1979) and others. Recent empirical paleoclimate evidence, especially the ice core data 
of Dansgaard, Oeschger and their colleagues, indicates that climate and perhaps also atmospheric 
carbon dioxide have undergone large fluctuations on time scales of 10-100 years (see, for 
example, Dansgaard et al., 1984; Oeschger et al., 1984). Although the explanation for the 
paleoclimate fluctuations may be complex, their existence indicates that we can not assume that 
ocean circulation and mixing will operate in a fixed way over decadal time scales. 
On the basis of considerations such as the large magnitude of climate fluctuations in the 
North Atlantic region, the unique role of North Atlantic deep water in the world ocean cir- 
culation, and evidence from oceanographic measurements and ocean tracer data that the deep 
water formation process is highly episodic, we chose to focus this workshop on the question: 
What controls the rate of deep water formation in the North Atlantic Ocean and what reper- 
cussions would there be from changes in this rate? 
Presentations. Presentations were organized in three half-day sessions on oceanography, 
paleoclimate and modeling. Extended abstracts and key figures from each of these presentations 
are included in the next section, as the bulk of this report. 
Recommendations. Strategies for improving our understanding of deep water formation 
were discussed in the final half-day session. Recommendations are presented in the final sec- 
tion below, the principal aspects being the need for the following studies: 
Oceanographic measurements: 
1) Hydrographic cruises each spring into the Norwegian, Greenland and Labrador Seas to deter- 
mine the amount and properties of NADW formed each winter for a 10 year period. 
2) Monitoring of the meteorological conditions before and during deep water formation to allow 
investigation of air-sea interaction events, such as the role of cyclogenesis in deep water for- 
mation, and monitoring of the sea ice distribution. 
3) Monitoring over the 10 year period of the currents and T/S properties of the outflows across 
the Greenland-Iceland-Faeroes-Scotland ridges into the North Atlantic Ocean. 
4) It is also desirable to monitor over this 10 year period currents and T/S properties of the 
inflows of source waters to the deep water formation regions from the Arctic, the subtropical 
gyre, and intermediate waters from the Labrador, Irminger and Mediterranean Seas. An alter- 
native is to define a sampling strategy for transient tracers and nutrients with a frequency ade- 
quate to define the contributions from different source waters. 
5) Development of the required improved capabilities for moored and drifting buoys, which can 
communicate results via satellite. 
6) Release of a network of XBTs into regions of developing deep convection. 
Paleoclimate data: 
1) Exploration for marshes and lakes with pollen records extending back at least 40,000 years, 
and detailed studies of such records. 
2) Retrieval and study of ocean cores from areas of high deposition rate (i.e., >6 cm/103 years) 
in the North Atlantic. 
3) Retrieval and study of ice cores from the Crete site in Greenland (site chosen by NSF for 
the next drilling effort). 
4) Extension of the tree ring record to all geographical regions around the North Atlantic basin. 
