1998 Year of the Ocean Impacts of Global Climate Change 



climate variability on human activity and economic potential, and improving public education so 

 climate forecasts are understood and used. 



Societies from around the world could benefit by participating in a shared multinational 

 mechanism to maintain and enhance predictability, and learn how to incorporate the information 

 into decision making for broad based environmental and economic gain. Note that on a basic 

 level, activities such as agriculture, fishing, water management, and fuel distribution must take 

 into account the climatological mean annual cycle — crops are planted in anticipation of the 

 optimal growing season, fishing vessels in Peru and Oregon are readied for the seasons when 

 wind-driven upwelling provides nutrients for the food chain; reservoir levels are lowered in 

 anticipation of spring flooding; fiiel oil is distributed in anticipation of wintertime heating needs. 



Options for Consideration 



The best understood and strongest interannual air-sea climate signal comes from ENSO 

 which originates in the tropical Pacific and leads to changes in the atmospheric circulation well 

 beyond the tropical Pacific. ENSO episodes can now be predicted to a level of skill and with 

 enough lead time that hundreds of millions of dollars a year can be saved both in the U.S. 

 economy and abroad. 



NOAA currently provides operational seasonal forecasts based on a combination of 

 dynamical model and statistical predictions for the U.S. An International Research Institute has 

 been established to provide forecasts to other nations. For these efforts to succeed, it is necessary 

 to continue to invest in process and modeling research and to enhance the global observing and 

 data processing systems. It is also necessary to continue to study other interannual signals in the 

 tropics and in higher latitudes. In addition, institutionalized systems, such as the International 

 Research Institute, must continue to be supported so that national and international forecasts, as 

 well as other climate services, can be continued and expanded as predictability of ENSO and 

 other interannual signals improves. The development of new forecasting products that can be 

 used for economic, disaster preparedness, and other planning purposes would also be very 

 beneficial to the nation. 



DECADAL TO CENTENNIAL CLIMATE IMPACTS 



Introductory Considerations 



Both the atmosphere and the ocean act together as a giant heat engine with the ocean also 

 playing the role of a flywheel in the system. It takes approximately 4 years for the surface 

 currents of the world's ocean bodies to circulate around the globe. As they do so, they give up 

 their heat to their surroundings and cool. These relatively warm currents also tend to have a 

 slightly higher salt content than the waters they circulate through. This is due to increased 

 evaporation at low latitudes resulting in a small increase in the concentration of salt. In certain 



G-17 



