  From the Archean toward the Proterozoic, the Earth's atmosphere underwent a
major shift from anoxic to oxic conditions, around 2.4 to 2.1 Gyr, known as the
Great Oxidation Event (GOE). This rapid transition may be related to an
atmospheric instability caused by the formation of the ozone layer. Previous
works were all based on 1D photochemical models. Here, we revisit the GOE with
a 3D photochemical-climate model to investigate the possible impact of the
atmospheric circulation and the coupling between the climate and the dynamics
of the oxidation. We show that the diurnal, seasonal and transport variations
do not bring significant changes compared to 1D models. Nevertheless, we
highlight a temperature dependence for atmospheric photochemical losses. A
cooling during the late Archean could then have favored the triggering of the
oxygenation. In addition, we show that the Huronian glaciations, which took
place during the GOE, could have introduced a fluctuation in the evolution of
the oxygen level. Finally, we show that the oxygen overshoot which is expected
to have occurred just after the GOE, was likely accompanied by a methane
overshoot. Such high methane concentrations could have had climatic
consequences and could have played a role in the dynamics of the Huronian
glaciations.
