• Development and application of isotope techniques to investigate physics and chemistry of the atmosphere 
• Global trace gas budgets 
• Impact of anthropogenic activities on the atmosphere. 
• Stratosphere-Troposphere exchange 
• Stratospheric water vapor 
• Development of air sampling devices for atmospheric trace gases (e.g. high altitude research aircraft "Geophysica", stratospheric balloon experiments). 
• Investigation of kinetic isotope effects in laboratory experiments 
• Investigation and application of mass independent isotope effects
• Reconstruction of the paleo-atmosphere using air samples from Arctic and Antarctic ice and firn

Member of the Netherlands Earth System Science Center consortium