1998 Year of the Ocean Impacts of Global Climate Change 



changes in the storage and fluxes of heat and freshwater; and (3) provide data for model 

 vahdation studies. 



Upper layer temperature data are collected, in part, by a global Volunteer Observing Ship 

 network. This network provides over 100 years of surface data including SST and about 30 years 

 of subsurface temperature data. Analysis of these data provided the characteristics of many of the 

 decadal signals described above. There are, however, large areas, particularly in the central and 

 eastern northern oceans and all of the southern oceans, where little or no data are available. Data 

 sparsity in the northern hemisphere precludes validation of several of the theories described 

 above. In the southern hemisphere, variability in water properties as large as those associated 

 with the PNA pattern and NAO have been observed. Possible aliasing and other problems 

 resulting from the sparse sampling in the region has made establishing dynamical mechanisms 

 and air-sea feedback difficult. Trade-offs between in situ and remote sampling of upper layer 

 characteristics in data poor regions must be evaluated to develop cost-effective network designs. 

 Combinations of modeling and empirical network design efforts are an integral part of 

 developing detection/attribution capabilities. 



NOAA/OAR/ERL (Environmental Research Laboratories) are active in long term climate 

 research ranging from data collection to data synthesis, and from model development to model 

 validation. For example, the Atlantic Oceanographic and Meteorological Laboratory and the 

 Pacific Marine Environmental Laboratory) are engaged in completing the global carbon survey 

 directed at obtaining an accurate benchmark inventory of CO . anthropogenic CO and other 



properties. In addition, the Atlantic Oceanographic and Meteorological Laboratory, the Climate 

 Diagnostics Center, and the Pacific Marine Environmental Laboratory are involved in the 

 Atlantic Climate Change Experiment, the last field phase of the World Ocean Circulation 

 Experiment. This NSF/NOAA program is concerned with increased understanding of the role of 

 the Atlantic Ocean in global atmospheric climate. ERL scientists are also involved in the 

 synthesis of these data, bringing the diverse World Ocean Circulation Experiment and other data- 

 sets into a comprehensive picture of the present state of the ocean. Attention is directed at air-sea 

 and meridional ocean fluxes of carbon, heat, and freshwater, and the amount of anthropogenic 

 CO sequestered in the ocean. 



GFDL scientists are constantly improving coupled GCMs to study natural decadal to 

 centennial climate variability and the effects of different CO, scenarios. Recent activities have 

 included: (1) The development of coupled models with higher computational resolution, leading 

 to substantial improvements in the simulation of interannual to decadal climate variability; (2) 

 fundamental improvements in the representation of sub-grid scale processes in ocean models; 

 and (3) the simulation of the climate response to estimates of the time-varying radiative forcing 

 of the Earth over the last 200 years. GFDL model results and results from other modeling centers 

 are being compared to observations by all four ERL groups. The model-data comparisons are not 

 only leading to GCM improvements but also to increased understanding of both the coupled air- 

 sea system and the predictability of this system. 



G-22 



