II. Critical Needs of the Core Program 



Besides the critical needs common to all the programs described in Section 1 1. A, certain elements 

 of the core Chemical Oceanography Program, as well as the Open Ocean Fluxes program, need 

 special support in order to exploit current developments in the field. This is particularly true 

 of accelerator mass spectrometry, which will also be vital to the WOCE program and the Marine 

 Geology and Geophysics Program. 



Accelerator Mass Spectrometry Facilities. Recent achievements in accelerator mass 

 spectrometry (AMS) have convinced a wide spectrum of environmental scientists to assign an 

 extremely high priority to developing a dedicated Ocean Sciences AMS facility in the U.S. The 

 AMS technique combines conventional methods of mass spectrometry (ionization and mass 

 discrimination by magnetic and electrostatic fields) with acceleration through high potentials of 

 1-15 MV to achieve spectacular increases in analytical sensitivity. Because AMS lowers 

 previously attainable detection limits by several orders of magnitude, it opens up a wide range 

 of very significant scientific opportunities and brings a previously difficult span of earth 

 history within reach of quantitative interpretation. 



The achievements referred to above include use of ^^C to reconstruct ocean ventilation rates, 

 direct confirmation of the plate tectonic cycle of subduction-melting-volcanic eruption with 

 ^°Be tracer, and the first-ever determination of the rate of groundwater flow through a major 

 aquifer using "^^Cl dating. Use of AMS has also made major contributions to studies of such 

 diverse problems as ocean circulation, soil and rock erosion rates, dating ice cores and cave 

 deposits, climate variations, origins of meteorites, atmospheric chemistry, waste containment 

 in geologic repositories, hydrothermal and ore-forming fluid circulation patterns, and direct 

 dating of petroleum fluids. 



The wide potential of AMS makes it imperative that we begin planning immediately to develop an 

 AMS capability in the U.S. One possibility is for an AMS facility to be developed around a new 

 Tandetron accelerator or its equivalent. This facility would respond to the rapidly growing needs 

 of ocean scientists for precise ^^C analysis. Establishment costs for this facility are estimated 

 at $5M, including capital construction, with $1 M operating funds for FY 1 989 and beyond. 

 These funds are incorporated in the facilities budget of the Global Ocean Studies because of the 

 wide utility of this facility. 



III. Chemical Components of the Global Program 



Global initiatives will involve the Chemical Program in a variety of areas, particularly in the 

 context of global ocean flux studies, which are sub-divided here into open ocean and coastal 

 components. 



1. Open Ocean Fluxes. A major goal for ocean sciences over the next decade will be to 

 determine the biogeochemical cycles and budgets in ocean basins over long time scales. The 

 physical dynamics (steady state and first order variability) essential to meeting this goal will 

 be obtained through research programs such as WOCE and the continuation of tracer studies. A 

 determination of the character and primary productivity of the sea surface will also be 

 available globally and synoptically from satellite and airborne sensors. Finally, the very 

 important lateral flux from the coastal boundary zone will be available from studies conducted 

 in that region. 



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