Aerodyne C-ToF AMS (Compact Time-of-Flight AMS)

First version of the C-ToF in two aircraft racks (2008). Picture: J. Schneider, MPIC.

First version of the C-ToF in two aircraft racks (2008). Picture: J. Schneider, MPIC.

In 2007 we upgraded our Q-AMS to a C-ToF-AMS in order to gain sensitivity and mass resolution. The gain in sensitivity is especially important for mobile measurements (aircraft, mobile laboratory), because here a high time resolution is desired. The C-ToF-AMS was integrated into the two DLR Falcon racks that carried the Q-AMS and was operated on two aircraft missions in 2008 (POLARCAT with the ATR-42 and CONCERT with the Falcon). After that it was used in numerous ground based missions (see Projects).

C-ToF-AMS in HALO rack during EMeRGe (2017). Picture: J. Schneider, MPIC.

C-ToF-AMS in HALO rack during EMeRGe (2017). Picture: J. Schneider, MPIC.

It can also be equipped with a light scattering probe (LSP) that enables single particle analysis. The light scattering probe was first used during the MEGAPOLI 2009 summer campaign and was after used during several following projects.

In December 2012 we integrated the instrument into one HALO rack. The first ground based mission in the new one-rack configuration was the INUIT-JFJ campaign in Jan/Feb 2013. The first HALO mission for the C-ToF-AMS was ACRIDICON-CHUVA which took place in August-September 2014. For the aircraft campaign DACCIWA in July 2016, the C-ToF-AMS was re-fitted into two Falcon racks. After that, the C-ToF-AMS was rebuilt into the HALO rack and was used on the HALO missions EMeRGe-EU (2017), EMeRGe-Asia (2018), and CAFE-Africa (2018). The next upcoming mission will be CAFE-Brazil in April-May 2020.

Selected references:

Basic instrument description:
Drewnick, Frank, Silke S. Hings, Peter DeCarlo, John T. Jayne, Marc Gonin, Katrin Fuhrer, Silke Weimer, Jose L. Jimenez, Kenneth L. Demerjian, Stephan Borrmann, Douglas R. Worsnop: A new Time-of-Flight Aerosol Mass Spectrometer (TOF-AMS) : Instrument Description and First Field Deployment, Aerosol Science & Technology 39, 637-658, doi:10.1080/02786820500182040, 2005.

Aircraft application:
Schmale, J., J. Schneider, T. Jurkat, C. Voigt, H. Kalesse, M. Rautenhaus, M. Lichtenstern, H. Schlager, G. Ancellet, F. Arnold, M. Gerding, I. Mattis, M. Wendisch, and S. Borrmann, Aerosol layers from the 2008 eruptions of Mt. Okmok and Mt. Kasatochi: In-situ UT/LS measurements of sulfate and organics over Europe, J. Geophys. Res., 115, D00L07, doi:10.1029/2009JD013628, 2010.

Schmale, J., Schneider, J., Ancellet, G., Quennehen, B., Stohl, A., Sodemann, H., Burkhart, J., Hamburger, T., Arnold, S. R., Schwarzenboeck, A., Borrmann, S., and Law, K. S.: Source identification and airborne chemical characterisation of aerosol pollution from long-range transport over Greenland during POLARCAT summer campaign 2008, Atmos. Chem. Phys., 11, 10097-10123, doi:10.5194/acp-11-10097-2011, 2011.

Schulz, C., Schneider, J., Amorim Holanda, B., Appel, O., Costa, A., de Sá, S. S., Dreiling, V., Fütterer, D., Jurkat-Witschas, T., Klimach, T., Knote, C., Krämer, M., Martin, S. T., Mertes, S., Pöhlker, M. L., Sauer, D., Voigt, C., Walser, A., Weinzierl, B., Ziereis, H., Zöger, M., Andreae, M. O., Artaxo, P., Machado, L. A. T., Pöschl, U., Wendisch, M., and Borrmann, S.: Aircraft-based observations of isoprene-epoxydiol-derived secondary organic aerosol (IEPOX-SOA) in the tropical upper troposphere over the Amazon region, Atmos. Chem. Phys., 18, 14979-15001, https://doi.org/10.5194/acp-18-14979-2018, 2018.

Light scattering probe:
Freutel, F., Drewnick, F., Schneider, J., Klimach, T., and Borrmann, S.: Quantitative single particle analysis with the Aerodyne aerosol mass spectrometer: development of a new classification algorithm and its application to field data, Atmos. Meas. Tech., 6, 3131-3145, doi:10.5194/amt-6-3131-2013, 2013.

Ground based cloud residual analysis:
Schneider, J., Mertes, S., van Pinxteren, D., Herrmann, H., and Borrmann, S.: Uptake of nitric acid, ammonia, and organics in orographic clouds: mass spectrometric analyses of droplet residual and interstitial aerosol particles, Atmos. Chem. Phys., 17, 1571-1593, doi:10.5194/acp-17-1571-2017, 2017.