Dynamic-chemical coupling of the upper troposphere and lower stratosphere region.

Journal Article (Journal Article)

The importance of the interaction between chemistry and dynamics in the upper troposphere and lower stratosphere for chemical species like ozone is investigated using two chemistry-climate models and a Lagrangian trajectory model. Air parcels from the upper troposphere, i.e. regions of lightning and aircraft emissions, are able to be transported into the lowermost stratosphere (LMS). Trajectory calculations suggest that the main transport pathway runs via the inter tropical convergence zone, across the tropical tropopause and then to higher latitudes, i.e. into the LMS. NOx from aircraft emissions at mid-latitudes are unlikely to perturb the LMS since they are washed-out while still in the troposphere. In contrast, NOx from tropical lightning has the chance to accumulate in the LMS. Because of the longer residence times of NOx in the LMS, compared to the upper troposphere, this excess NOx from lightning has the potential to form ozone in the LMS, which then is transported back to the troposphere at mid-latitudes. In the models, around 10% of the ozone concentration and 50% of the NOx concentration in the northern hemisphere LMS is produced by lightning NOx At least 5% of the ozone concentration and 35% the NOx concentration at 150 hPa at mid-latitudes originates from tropical lightning in the climate-chemistry simulations.

Full Text

Duke Authors

Cited Authors

  • Grewe, V; Reithmeier, C; Shindell, DT

Published Date

  • June 2002

Published In

Volume / Issue

  • 47 / 8

Start / End Page

  • 851 - 861

PubMed ID

  • 12079080

Electronic International Standard Serial Number (EISSN)

  • 1879-1298

International Standard Serial Number (ISSN)

  • 0045-6535

Digital Object Identifier (DOI)

  • 10.1016/s0045-6535(02)00038-3


  • eng