English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Sensitivity of tracer transport model resolutions, forcing data and tracer lifetime in the general circulation model ECHAM5

Aghedo, A. M., Rast, S., & Schultz, M. G. (2010). Sensitivity of tracer transport model resolutions, forcing data and tracer lifetime in the general circulation model ECHAM5. Atmospheric Chemistry and Physics, 10, 3385-3396. doi:10.5194/acp-10-3385-2010.

Item is

Files

show Files
hide Files
:
acp-10-3385-2010.pdf (Publisher version), 548KB
Name:
acp-10-3385-2010.pdf
Description:
-
OA-Status:
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Aghedo, Adetutu M.1, 2, Author           
Rast, Sebastian3, 4, Author           
Schultz, Martin G.3, Author           
Affiliations:
1The Ocean in the Earth System, MPI for Meteorology, Max Planck Society, ou_913552              
2IMPRS on Earth System Modelling, MPI for Meteorology, Max Planck Society, ou_913547              
3The Atmosphere in the Earth System, MPI for Meteorology, Max Planck Society, ou_913550              
4Middle and Upper Atmosphere, The Atmosphere in the Earth System, MPI for Meteorology, Max Planck Society, ou_913574              

Content

show
hide
Free keywords: -
 Abstract: Atmospheric transport of traces gases and aerosols plays an important role in the distribution of air pollutants and radiatively active compounds. For model simulations of chemistry-climate interactions it is important to know how the transport of tracers depends on the geographical resolution of the general circulation model. However, this aspect has been scarcely investigated until now. Here, we analyse tracer transport in the ECHAM5 general circulation model using 6 independent idealized tracers with constant lifetimes, which are released in two different altitudes at the surface and in the stratosphere, respectively. Model resolutions from T21L19 to T106L31 were tested by performing multi-annual simulations with prescribed sea surface temperatures and sea ice fields of the 1990s. The impacts of the tracer lifetime were investigated by varying the globally uniform exponential decay time between 0.5 and 50 months. We also tested the influence of using prescribed meteorological fields (ERA40) instead of climatological sea surface temperature and sea ice fields. Meridional transport of surface tracers decreases in the coarse resolution model due to enhanced vertical mixing, with the exception of the advection into the tropical region, which shows an inconsistent trend between the resolutions. Whereas, the meridional transport of tracers released in the stratosphere was enhanced with higher model resolutions, except in the transport from tropical stratosphere to the Southern Hemisphere, which exhibits an increase trend with increasing model resolution. The idealized tracers exhibit a seasonal cycle, which is modulated by the tracer lifetime. In comparison to the run with prescribed sea surface temperature and sea ice fields, the simulation with prescribed meteorological fields did not exhibit significant change in the meridional transport, except in the exchange of stratospheric tracers between both hemispheres, where it causes about 100% increase. The import of the surface tracers into the stratosphere is increased by up to a factor of 2.5, and the export from the stratosphere into the troposphere was increased by up to 60% when prescribed meteorological fields is used. The ERA40 simulation also showed larger interannual variability (up to 24% compared to 12% in the standard simulations). Using our surface tracers released in either the northern or Southern Hemisphere, respectively, we calculate inter-hemispheric transport times between 11 and 17 months, consistent with values reported in the literature. While this study cannot be used to relate differences in model results to specific changes in transport processes, it nevertheless provides some insight into the characteristics of tracer transport in the widely used ECHAM5 general circulation model.

Details

show
hide
Language(s): eng - English
 Dates: 2010
 Publication Status: Issued
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Atmospheric Chemistry and Physics
  Alternative Title : Atmos. Chem. Phys.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 10 Sequence Number: - Start / End Page: 3385 - 3396 Identifier: -