TOGA-HR-TOF: High Resolution Time-Of-Flight System
ACOM instrument samples wildfire smoke during FIREX-AQ
The TOGA-HR-TOF (Trace Organic Gas Analyzer High Resolution Time-of-Flight mass spectrometer) is flying on the NASA DC8 for the NASA/NOAA FIREX-AQ experiment! The most recent ACOM instrument, supported by NSF and developed by the ACOM VOC Measurements Group (Eric Apel, Alan Hills, and Rebecca Hornbrook) has been completed and is now collecting data on western wildfire smoke during August and prescribed burns in the Southeast U.S. during August and early September. The TOGA-HR-TOF high data acquisition rates is a great match for the TOGA platform that quickly measures a wide range of volatile organic compounds (VOCs), from species containing only one carbon atom to those containing 10 or more. For FIREX-AQ, the TOGA-TOF is measuring more than 100 VOC species (including oxygenates, biogenics, organic nitrates, nitriles, and halogenates) over an integrated sampling time of 33 seconds or less, and repeats the measurement every one minute and 45 seconds, with the ability to target narrow plumes on demand. The system is highly selective, in part because of the high resolution mass spectra capability, which is critical in analyzing complex VOC mixtures emanating from fires. Additionally, since the TOGA-HR-TOF does not require that compounds being analyzed have to be pre-selected, discovery and identification of new species that have not been specifically targeted for analysis is possible. These features are well suited to the study of fire emissions, which have a highly complex chemical make-up, and the chemical evolution of fire emissions as they age. We look forward to our collaborations with the rest of the FIREX-AQ science team and to the great science that will come from this experiment!