Open AccessModel study of a stratospheric intrusion event at lower midlatitudes associated with the development of a cutoff low
Author(s) -
Kentarchos A. S.,
Roelofs G. J.,
Lelieveld J.
Publication year - 1999
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1998jd100051
Subject(s) - troposphere , tropopause , stratosphere , atmospheric sciences , climatology , potential vorticity , environmental science , middle latitudes , geopotential height , ozone , extratropical cyclone , synoptic scale meteorology , forcing (mathematics) , data assimilation , anticyclone , geopotential , meteorology , vorticity , geology , physics , precipitation , vortex
A tropopause folding event associated with the development of a cutoff low over southeastern Europe at the end of March 1995 enhanced the ozone concentrations in the upper troposphere. The episode has been simulated using a coupled chemistry‐general circulation model that has been “nudged” toward actual meteorology using a simple four‐dimensional assimilation technique based on European Centre for Medium‐Range Weather Forecasts data. Model results are compared with ozone observations and analyzed meteorological data. In particular, simulated geopotential heights show a realistic representation of the synoptic development of the cutoff low system. The model also succesfully reproduces the space‐time evolution of potential vorticity and specific humidity fields associated with the tropopause fold. Furthermore, modeled ozone concentrations during that period show a pronounced increase in the upper troposphere associated with downward fluxes from the stratosphere. The total amount of stratospheric ozone transferred into the troposphere during the event is estimated at 6.4 × 10 8 kg. The results of the present simulation indicate that the model provides a useful tool to simulate stratosphere‐troposphere exchange and its effect on global tropospheric ozone, and that the model representation of the large‐scale wave forcing is more important than the fine details of tropopause foldings.