Net total amount 5.63×10^20: free oxygen in the atmosphere 3.75×10^19: dissolved oxygen in the oceans 3.1×10^17: (the remainder stored in a large number of oxidized terrestrial and oceanic compounds) mol
||Duursma EK, Boisson MPRM, Global oceanic and atmospheric oxygen stability considered in relation to the carbon-cycle and to different time scales. Oceanologica Acta (0399-1784) (Gauthier-Villars), 1994 , Vol. 17 , N. 2 , P. 117-141 link p.117 2nd paragraph
||P.117 2nd paragraph: "Atmospheric oxygen production began some 3.2 billion years ago, and has resulted in a net total amount of 5.63×10^20 mol (1.8×10^22 g) of oxygen, of which 3.75×10^19 mol is present as free oxygen in the atmosphere and 3.1×10^17 mol as dissolved oxygen in the oceans, the remainder being stored in a large number of oxidized terrestrial and oceanic compounds. For the past 600 million years, atmospheric oxygen has been modelled as ranging between 7 and 30 O2 vol % (one model even proposes up to 35 O2 vol%)."