The distribution of 85Kr in the air over the North and South Pacific Ocean

The north-south section of the atmospheric concentration of ^(Kr) over the Pacific is first reported. The most striking feature of the section is a large concentration difference at the geographical position of the intertropical convergence. The ^(Kr) concentration in the air over the North Pacific ranged from 22 to 23pCi m^ and in the South Pacific 16pCi m^. The concentration differences between two hemispheres is about 6pCi m^. Five year records from land stations in Japan indicate that the annual increase is about 1pCi m^y^. It seems that the amount of the southward transport of ^(Kr) from the northern hemisphere is nearly equilibrated with that of radioactive disintegration and/or dissolution of ^(Kr) into the ocean in the southern hemisphere