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emissions from the IEA model. GISS outputs are estimates of 

 ocean temperature increases on a five year basis. 



The use of diffusivity coefficients as a surrogate for all 

 circulation processes that transport heat may fail to describe 

 the time paths well, with the downward heat transport in the 

 latter period probably being overestimated because of increasing 

 oceanic stability. Nevertheless this method simplified the 

 problem substantially and a range of different possible coeffi- 

 cients was used to investigate the sensitivity of the overall 

 estimate to the rate of downward heat transport. 

 These coefficients are: 



High: = 1.9 cm 2 /sec 

 Low: = 1.18 cm2/sec 

 Special Scenarios: = 0.2 cm 2 /sec (minimum) 



= 4.0 cm 2 /sec (maximum) 



The range of coefficients used, 1.18 to 1.9 cm 2 /sec 



is representative of mean oceanwide mixing rates as determined 



by the NSF-sponsored transient tracer experiment and others. 



Variation in estimates of the exact value of the data depend 



on the tracer used and the statistical method of computing 



the global mean. We tested 0.2 and 4.0 cm 2 /sec to account 



for the possibility of dramatic changes in ocean transports due 



to deglaciation and climate change. 



