August 2009
The 13th August event was part of a long-term disturbance dating back to at least the 10th of August. It was caused by an intrusion of a tropospheric anti-cyclone which caused upper level divergence (ozone advected away locally out f the column) and increases in tropopause height (cooling). The event is relatively small scale but slow moving and quasi-stationary over Europe (still detectable on the 15th August).
Figure A: Ozone anomaly map on the 12th August showing low event over Reading.
The 13th August event was part of a long-term disturbance dating back to at least the 10th of August. It was caused by an intrusion of a tropospheric anti-cyclone which caused upper level divergence (ozone advected away locally out f the column) and increases in tropopause height (cooling). The event is relatively small scale but slow moving and quasi-stationary over Europe (still detectable on the 15th August).
Figure A: Ozone anomaly map on the 12th August showing low event over Reading.