1. REanalysis of the TROpospheric chemical
composition during the last 40 years
Introduction
In order to better understand the reasons behind the observed concentration trends of tropospheric ozone, NOx, CO, and other air pollutants, we have undertaken a 40-year reanalysis using a set of global models driven by reanalysed meteorological data from ECMWF.
The project has generated new data sets of anthropogenic and wildland fire emissions. Simulations performed in RETRO contributed to multi-model assessment studies, and policy scenarios may help to elucidate the effectiveness of emission control regulations.
The project has ended in the summer of A draft final report is available at ftp://ftp.retro.enes.org/pub/documents/reports.
Emissions
Long-term model simulations require accurate estimates of precursor emissions from anthropogenic and natural sources. New global inventories for “anthropogenic” and “fire” emissions were generated and are made available to the community. As an example, the figure below shows the annual total direct carbon emissions from forest and savanna fires and their variability.
Trend Analysis
Three global models of atmospheric chemistry and transport simulated the complete 41-year ERA-40 period with well constrained boundary conditions. The models often show good consistency in terms of patterns and trends, but they sometimes disagree in terms of absolute concentrations.
Monthly mean summertime boundary layer (0-1 km) ozone concentrations
as simulated by the three RETRO long-term reanalysis simulations
Policy Scenarios
The RETRO models were used to estimate the effects of different policy options. Here, we show the impacts on surface NOx and ozone concentrations over Europe from a scenario where all cars in the OECD countries adhere to EURO V standards.
UiO
TM4
LMDz
MOZECH
NOx reduction
Ozone change
Web site:
Emissions data: ftp://ftp.retro.enes.org/pub/emissions
Model data: ftp://ftp.retro.enes.org/pub/model_results
Web display of model results:
Project reports, poster, etc.: ftp://ftp.retro.enes.org/pub/documents
M. G. Schultz1, S. Rast2, S. Dalsøren3, D. Hauglustaine4, S. Szopa4, T. van Noije5 and the RETRO team (contact:
1) Max Planck Institute for Meteorology, Hamburg, Germany, now at Forschungszentrum Jülich, Germany
2) Max Planck Institute for Meteorology, Hamburg, Germany
3) University of Oslo, Oslo, Norway
4) Laboratoire des Sciences du Climat et de L‘Environment, CEA-CNRS Orme des Merisiers, Gif-sur-Yvette cedex, France
5) Royal Netherlands Meteorological Institute, De Bilt, The Netherlands
The European Commission is kindly acknowledged for funding RETRO as project EVK2-CT