64 
Allerod-Younger Dryas oscillation). It appears in the Greenland ice cap, in high deposition deep 
sea sediments from the Northern Atlantic, and in marsh and lake sediments from Nova Scotia and 
western Europe. It is absent in the eastern United States. Similar studies are needed for the 
events in the 20,000 to 40,000 year time period where several such "Oeschger events" are found 
in the Greenland ice record. 
The Greenland ice cap record shows that these Oeschger events are found not only in the 
6180 (i.e., air temperature record) but also in the dust, l9Be chemistry and CU, records. The 
cause of these changes must be explored. The validity of the ice core CO g results as indicators 
of atmospheric change must be tested through studies of ice cores from Antarctica. While the 
changes in other properties may prove to be regional, any CO») changes must be global. 
Trees offer a year by year record of tree growth which extends back several hundred 
years. To date, few attempts have been made to tie ring thickness fluctuations to historic cli- 
mate records for Iceland and Scandanavia or to fluctuations in ice accumulation or 6180 variation 
in the Greenland and Iceland ice caps. Such studies must be conducted to see if any regional 
signal can be found which might be related to variations in the intensity of deep water for- 
mation. 
Unfortunately, our knowledge of historic changes in deep water formation is virtually 
nonexistent. This makes the job of connecting climate change and deep water production changes 
very difficult. Nevertheless, a joint study of historic climate, tree ring, and ice cap data 
should be conducted. In order to do this, the tree ring data especially will have to be 
augmented. 
In summary, the needed paleoclimatic studies are: 
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 em/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. 
Satellite Data 
Satellites measurements have the potential of assuming several key roles in the develop- 
ment of an understanding of deep water formation. Some of these measurements are already 
planned, but others must still be developed. 
In situ oceanographic measurements, of the type discussed above and in proposed 'cage' 
studies (Dobson et al., 1982), will provide the most precise measurements of ocean heat 
transport. However, an additional useful estimate of ocean heat transports can be inferred from 
the combination of radiation budget measurements at the top of the atmosphere and meteorological 
measurements of atmospheric heat transports. This procedure has been used for estimating the 
zonal mean heat transport by the ocean. It is practical to obtain very accurate local radiation 
budget measurements from satellites with a resolution of about 1000 km. If these were combined 
with meteorological measurements of winds and temperatures at a comparable resolution, it would 
be possible to infer the divergence of heat in the ocean at 1000 km resolution. The Earth 
Radiation Budget Experiment should allow a first attempt at this kind of analysis. It may be 
possible to also extend the results to a much finer horizontal resolution by combining high reso- 
lution satellite visible and infrared imaging with the spectrally more complete and accurate 
radiation budget data. 
Fluxes of momentum and moisture at the ocean surface, in addition to heat discussed 
above, drive the ocean circulation, including deep water formation. Satellites offer the only 
possibility for measuring these quantities on a global or oceanwide basis. Measurements of sur- 
face wind may be possible with a 'scatterometer', an instrument which has been shown to have 
promise for this purpose. Techniques for obtaining rainfall rates from microwave measurements 
are being developed, and it has recently been proposed (Liu, 1984) that evaporation could also 
be inferred from microwave measurements. A program to fully exploit the satellite capabilities 
should have high priority. Of course it is important to maintain the weather station network in 
and around the North Atlantic Ocean, because its data is needed to infer the energy divergence 
in the ocean and for spot checks of satellite measurements. 
