The Earth System is changing and humans are involved in many ways. The current geological era has therefore been named 'The Antropocene' instead of 'The Holocene'. Climate change, global-scale air pollution, and ozone layer depletion are the most pressing environmental issues directly related to the rapid changes in global atmospheric composition which are caused by unsustainable human activities. Just a thought...

My research topics center around 'chemistry-climate interactions' with a focus on the parameters that determine the oxidising ('cleansing') capacity of the atmosphere: methane, tropospheric ozone, nitrogen oxides, carbon monoxide, non-methane hydrocarbons and formaldehyde, the hydroxyl radical (OH), UV radiation (via photolysis) and water vapour.

Two returning activities in my work are:

(1) Contributions to the long-term monitoring of the global distributions of atmospheric trace gases and UV radiation by means of satellite observations.

(2) The interpretation of observations (satellite / airborne / ground-based) with chemistry transport models such as TM5 that describe emission, transport, chemical transformation and deposition, of trace gases and aerosols, as well as the UV radiation intensities in the Earth's atmosphere.

I am member of the ESA Mission Advisory Group for the ESA candidate satellite mission PREMIER (PRocess Exploration through Measurements of Infrared and millimetre-wave Emitted Radiation) to investigate the impacts of composition variations in the upper troposphere and lower stratosphere on surface climate via general circulation changes and in general to improve our understanding of processes coupling atmospheric composition changes to the physical climate.

I contribute to TM5 model improvements. TM5 is the global chemistry module of the Earth System model EC Earth. Coupling TM5 with the physical climate is needed to improve climate modelling w.r.t. chemistry-climate interactions in relation to air pollution (aerosol, tropospheric ozone, methane lifetime), stratospheric ozone (in interaction with the general circulation and modulating solar and volcanic forcings in the stratosphere) and climate-biosphere couplings (e.g. methane natural emissions in response to changes in climate parameters and land-use).

UV information

I give support to the TEMIS UV monitoring products. See the 2008 Supremacy project report and 2010 GRL paper below

• UV index
Forecast UV index based on assimilated ozone from SCIAMACHY
• UV dose
Analysed UV daily dose based on SCIAMACHY and Meteosat
• TEMIS
  Tropospheric Emission Monitoring Internet Service
• Supremacy report 2008 (pdf)
  Final report of the NIVR project Surface Solar and UV products for Europe by combination of MSG and SCIAMACHY (SUPREMACY)
• Extreme Sunbathing (pdf)
  Extreme UV index values over Patagonia

Other information

• Eyjafjallajokull
TM4 analysis of the spread of the Iceland Eyjafjallajokull volcanic plume (14 - 23 April 2010)
• Upper Tropsopheric Methane Variability (pdf)
  van Weele, Michiel, Jason E. Williams, Peter F.J. van Velthoven, Tanja J. Schuck, and Carl A.M. Brenninkmeijer, 2011, Methane variability in the upper troposphere and lower stratosphere and their relevance for emission inversions constrained by satellite observations. Paper presented at the Sixth International Symposium on Non-CO2 Greenhouse Gases (NCGG-6); Amsterdam, The Netherlands, 2-4 November 2011.
• TM5 movie showing CH4 variability and transport in UTLS

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