Horizontal transport processes in a changing climate and its impact on the ozone distribution in mid-latitudes
Abstract
The transport of tropical air masses to mid and high latitudes is characterised by high N2O and low ozone values compared to midlatitude values. Therefore this can reduce the ozone content in mid-latitudes. A meridional gradient criterion has been defined and applied to the N2O-distribution of a multi-year model simulation with the coupled chemistry-climate model ECHAM4.L39(DLR)/CHEM. The standard simulation representing "1990" conditions is compared to a climatology derived from the model KASIMA for the period between 1990 until 1999 by using the same counting algorithm. The temperature field in KASIMA is nudged to ECMWF analyses depending on height and horizontal scale. The annual and geographical variation is presented and the impact of streamers on the mid-latitude ozone distribution is investigated with the help of a sensitivity experiment employing ECHAM4.L39(DLR)/CHEM. The question whether streamer activity changes in a changing climate is examined with four different time slice experiments under "1960", "1980", "1990", and "2015" conditions.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....8680E