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so that they would begin transmission only when they were actually on the surface. Packages 
surfacing under ice could remain silent until they eventually surface in a lead between floes. 
In a few areas such as the center of the Greenland Sea and the Labrador and Irminger 
Seas, satellite drifting buoys with long (<2000m) T or T/S chains might remain quasistationary 
for periods of months and thus provide oceanographic time series on the evolution of water 
masses in these basins. Such time series will be a valuable addition to the few oceanographic 
series still being collected by weatherships. 
Studies of the Labrador Sea (Clarke and Gascard, 1983) have shown the importance of epi- 
sodic events in deep water formation, with the occurrence of deep water formation apparently 
dependent on the presence of sea ice and strong cooling winds in the appropriate regions. 
There is a need to develop a better understanding of such air-sea interaction events, including 
the role of cyclogenesis processes. This will require data on synoptic scale atmospheric beha- 
vior, wind stress and sea ice. Appropriate monitoring appears to be possible with the com- 
bination of existing weather stations and planned satellite measurements (see below). 
Analysis of convective events and their dependence on large scale atmosphere and ocean 
conditions would be aided greatly by focused observations of specific events. This could be 
accomplished by having equipment on the ready and, when available data suggested initiation of an 
event, sending a plane to release expendable bathythermographs (XBTs) into the indicated 
region. We understand that a proposal to NSF for such an undertaking is in preparation. 
The oceanographic measurement program should be coordinated through the Inter- 
governmental Council for the Exploration of Sea Ice (ICES) hydrographic committee. Many 
European nations already have regular oceanographic cruises in these waters for fisheries 
investigations. Hardware support in the form of high precision CTD systems and technical sup- 
port for standardization would allow hydrographic data of the required precision to be collected. 
ICES Service Headquarters may also agree to serve as a data center, and simple mooring packa- 
ges could be deployed by such fisheries research vessels. The initial need is for the design 
and package development programs, so that such an oceanographic measurement program can be 
started in the late 1980s. 
In summary, the needed oceanographic studies are: 
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. 
Paleoclimatic Research 
Climatic records for the North Atlantic and its adjacent lands are to be found in marine 
sediments, the Greenland ice cap, in marsh and lake sediments and in trees. Each type of 
record has its peculiar advantages and disadvantages. 
The most dramatic changes seen in the ocean, ice and pollen records for this region are 
pronounced warm events which punctuated glacial time. Oeschger associates these changes with 
flips between quasi-stable modes of operation of the climatic system. Broecker et al. (1984) 
extend this idea and associate the rapid warmings with brief reinitiations of the glacially dormant 
deep water production in the North Atlantic. Much could be done to improve the data base. 
Regional information exists to date for only the last of these events (i.e., the so called 
