Tropospheric Chemistry: VOC Instruments
Volatile organic compounds (VOCs) are emitted to the atmosphere from a wide variety of sources, both natural and man-made. In the atmosphere, VOCs have lifetimes varying from minutes to years. Sinks include chemical reactions with OH, ozone and nitrate radicals, and deposition at the Earth's surface either directly, or indirectly after uptake by aerosols or cloud droplets. The chemical transformation of VOCs in polluted air leads to the production of ozone, a harmful gas when present in the air we breathe. In addition, processed VOCs can condense onto aerosols and add to their mass loading. Aerosols in themselves are harmful, since they are small enough to penetrate deep into our lungs. Also, aerosols play an important role in the Earth's radiation balance, and thus the climate, either directly by the scattering and absorption of radiation or indirectly by acting as cloud-condensation nuclei.
Our VOC research uses state-of-the-art instruments to measure VOCs in the atmosphere. We do this mostly during large-scale field missions, which also determine many of the other atmospheric constituents. From the results we hope to understand quantitatively the emissions, chemical transformations and ultimate loss processes of VOCs, and how these processes contribute to the formation of ozone and aerosol in the atmosphere.
We also study how VOC emissions may change in a future atmosphere: our sources of energy are rapidly changing and will continue to change in the future atmosphere. As a result, the emissions of VOCs will change as well as the effects they have on ozone and aerosol formation. This research is done in close connection with the University of Colorado Boulder (CU) Cooperative Institute for Research in Environmental Sciences (CIRES) Energy & Environment Initiative (E&E).
- Proton-Transfer Reaction Time-of-Flight Chemical Ionization Mass Spectrometry (PTR-ToF-CIMS)
- Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)
- Airborne Chromatograph for Hydrocarbons (TACOH)
Decommissioned VOC instruments:
- Laser Photo-Acoustic Spectroscopy (LPAS), decommissioned
- Organic Acid - Chemical Ionization Mass Spectrometer (Acid CIMS), decommissioned
- Proton-Transfer Ion-Trap Mass Spectrometry (PIT-MS), decommissioned