John Mak’s research group is primarily interested in the use of stable and radioisotopes as tracers of chemistry, origin, and/or transport in both the marine and atmospheric environments. We investigate problems in the atmospheric and marine sciences by using a combination of field and laboratory measurements, followed by (when appropriate) theoretical model simulations.
Phone: (631) 632-8673 | Fax: (631) 632-6251 | e-mail: email@example.com
We have in our lab a Finnegan 253 isotope ratio mass spectrometer with GC-combustion interface, a Finnegan Delta Plus IRMS with dual inlet and continuous flow GC interfaces, two standalone HP 6890 GCs, and a Pfeiffer quadrupole mass spectrometer. There is also an Ionicon high resolution proton transfer time of flight mass spectrometer (HR-PTRTOFMS) (shared with D. Knopf).
We have two cryogenic vacuum extraction lines for the separation and quantification of specific trace gases, such as isoprene, methanol, carbon monoxide and methane. We have developed our own preconcentration systems for the analysis of selective trace species via continuous flow isotope ratio mass spectrometry (IRMS); this allows us to quantify the isotopic composition of gases from ice core samples (e.g., Mak and Yang, 1998; Wang and Mak, 2010; Wang et al., 2010). We are currently funded to analyze the stable isotopic composition of CO from Antarctic Ice cores (e.g., SPICE), as well as Greenland ice.
We are also involved in the development and application of research instrumentation on small aircraft. We see the application of small aircraft as a bridge between larger platforms (e.g., the NSF C-130, the NOAA P-3) and small UAVs (drones). Under an NSF funded RAPID, we recently developed the WASP, Whole Air Sample Profiler, which can collect vertical profiles of air for subsequent analysis, from small aircraft. We have access to an experimental research airplane that is equipped with an Aventech AIMMS-20 meteorological measurement system that can measure winds in three dimensions at 20 Hz. The WASP system, along with the AIMMS-20, was successfully implemented during the 2011 BEACHON campaign in Colorado, and further refined and developed for successful deployment in the summer of 2013 during SOAS. That deployment was funded by the US EPA.