ESS220
Prof. Jin-Yi Yu
Ozone Hole
Depletion
qLong Antarctic winter (May
through September)
èThe stratosphere is cold
enough to form PSCs
èPSCs deplete odd nitrogen
(NO)
èHelp convert
unreactive forms of chlorine (ClONO2 and HCl) into more reactive
forms (such as Cl2).
èThe reactive chlorine remains
bound to the surface of clouds particles.
èSunlight returns in
springtime (September)
èThe sunlight releases
reactive chlorine from the particle surface.
èThe chlorine destroy ozone in
October.
èOzone hole appears.
èAt the end of winter, the
polar vortex breaks down.
èAllow fresh ozone
and odd nitrogen to be brought in from low latitudes.
èThe ozone hole recovers
(disappears) until next October.