Final Report Summary - CLIMBAIR (Coupled model simulations of global climate, terrestrial biosphere and atmospheric composition focused on global and European air quality)
The CLIMBAIR project aims at quantifying potential effects of future climate change on global and European air quality.
Changes in future climate are expected to impact air pollution in different ways:
.Affecting meteorological variables to which pollutants are sensitive (temperature, humidity, solar irradiance, winds and precipitation).
.Affecting atmospheric circulation patterns that exchange pollutants and air masses between different atmospheric regions.
.Causing changes in natural emissions of pollutants and its precursors (e.g. from wildfires and forests)
The CLIMBAIR project adopts an Earth System model (ESM) approach, in which not only the free troposphere is considered, but also the effects from the upper atmosphere (stratosphere) and from the land surface/vegetation are considered. We have used the European Earth system model (EC-Earth) and two chemistry-transport models (TM5 and TOMCAT/SLIMCAT).
One of the main concerns for air quality is ground level ozone (tropospheric ozone). Part of the ozone in the troposphere comes from direct influx from the stratospheric ozone layer, via air circulation exchange between the different altitude regions. Quantifying how this influx will change under future climate conditions is essential, as changes in the contribution from the stratosphere will alter the background concentrations of tropospheric pollutants, requiring the adaptation of imposed limits to anthropogenic emissions.
Climate and air quality science is clearly at the interface of policy and decision making. That is why the project also aims at providing the Researcher with skills and opportunities to communicate science to policy makers.
* Summary of Specific Objectives:
-Understand how the exchange of air masses between the stratosphere and the troposphere will evolve under a warming climate.
-Quantify the impact of stratospheric ozone transport on surface air quality (AQ).
-Communicate project related science to policy makers and end users.
* Summary of Work Performed:
Trends in stratospheric circulation that affect the distribution and exchange with the troposphere of chemical species crucial for air quality (e.g. ozone and water vapour) have been identified. For this, several model runs (CTM runs and EC-Earth runs) have been performed and analysed.
Trends in stratospheric circulation diagnostics have been obtained from model results corresponding to the ‘recent past’ period (1980-2009). These trends are not homogeneous all throughout the stratosphere but show an heterogeneous structure depending on altitude and latitude. Results from the model simulations have been validated against the recent MIPAS satellite measurements of SF6, providing good agreement.
Such circulation trends in our model runs are in agreement with recent observational studies but do not fully agree with most previous climate model studies. Understanding this apparent discrepancy between models and observations is essential to estimate future levels of tropospheric pollutants, as well as to provide more reliable surface global warming projections. This has therefore become one of the main tasks of the project.
A significant part of the project has also consisted of development activities in complementary skills essential for the career development of the Researcher (from the advanced career stage at the start of the project towards research independency steps). For instance, the host institution, the Royal Netherlands Meteorological Institute (KNMI), has the adequate resources and experience to provide the Researcher with skills and opportunities to communicate science to policy makers. Two short articles have been written for a publication distributed to European politicians and policy makers (The Parliament Magazine).
* Summary of Main Results:
-Trends in stratospheric circulation diagnostics have been obtained from model results corresponding to the ‘recent past’ period (1980-2009). These trends are not homogeneous all throughout the stratosphere but show an heterogeneous structure depending on altitude and latitude.
-Results from the model simulations have been validated against the recent MIPAS satellite measurements of SF6, providing good agreement.
-On-going analyses for other periods are expected to disentangle the apparent discrepancy between previous climate models studies and observations, as well as to provide information on what processes are responsible for the detected trends.
-Preliminary results have been presented at international conference (European Geophysical Union Assembly, Vienna, 2012).
-These results have also prompted fruitful international collaborations (e.g. with the Karlsruhe Institute of Technology in Germany, and the Spanish Meteorological Agency).
-One scientific article is in preparation to be submitted to a high impact journal, submission is envisaged for early 2014.
* Summary of Impacts:
-Results obtained so far regarding atmospheric circulation trends have had a high impact within the research community (both the modelling and the observations communities), and have significantly contributed to the career development plan proposed for this fellowship:
-Results show the usefulness of a modelling approach that considers the stratosphere, for quantifications of links between climate change and air quality.
-The Researcher has been invited to give seminars at the University of Reading (United Kingdom, autumn 2013) and at the Karlsruhe Institute for Technology (Germany, spring 2014).
-The Researcher is, from December 2012, chapter leader in a major international project within the ‘Stratospheric Processes and their Role in Climate’ (SPARC) Programme.
-Two articles have been published for politicians, policy makers and the general public (The Parliament Magazine) to raise awareness on the links between climate change and air quality.
-Final results on stratospheric contribution to background ozone concentrations are expected to provide valuable information to optimise European policies to mitigate climate change impacts on air quality.
After the end of the project, the Researcher has joined the Research Department of the European Centre for Medium-Range Weather Forecasts (ECMWF), where she can be contacted at beatriz.monge-sanz@ecmwf.int