Research Topics

Research Interests (also see https://you.stonybrook.edu/johnmak/mak-lab/)

We are currently working on atmospheric chemistry projects in the New York City region. Among the most recent topics is the impact of the statewide shutdown during the COVID-19 pandemic (NYS PAUSE) on regional chemistry using observations of volatile organic compounds from a high resolution proton transfer time of flight mass spectrometer (Cao et al., ES&T, in press), where we observer both a significant reduction and a significant subsequent increase in VOC emissions driven by reductions in anthropogenic emissions and an abnormal increase in biogenic emissions, respectively, during and immediately after the regional economic shutdown in 2020. These data are now being compared to observations made at the Flax Pond Marine Laboratory, on the north shore of Long Island about 60 miles east of New York City, using the same instrumentation (Cao et al., in prep). This work has been supported by New York State’s Department of Environmental Conservation (NYSDEC), the Northeast States for Coordinated Air Use Management (NESCAUM), and the National Science Foundation (NSF).

This line of research will be continuing in the summer of 2023 and beyond, with GOTHAAM (Greater New York Trace Gas, Halogen, and Aerosol Airborne Mission) having been postponed to the summer of 2024 (www.gothaam.science; https://you.stonybrook.edu/johnmak/mak-lab/). Mak is lead PI of this NSF funded highly collaborative project with the University of California Irvine (Carlton), the University of Washington (Thornton and Jaegle), the University of Colorado (Mauldin and Cantrell), Colorado State University (Farmer), the University of Maryland (Rheem), NASA (Wolfe), the University of Michigan (Pratt), Purdue University (Laskin), and colleagues at Stony Brook (Shepson and Knopf). Check out this highlight video from NCAR and visit the GOTHAAM website to learn more.

Along with Prof Greg Henkes in Earth and Space Sciences at SBU, I am working on the quantification of the multiply substituted isotopologue (clumped isotope) of atmospheric carbon monoxide. Because of the unique fractionation during the CO+OH reaction, it is hypothesized that atmospheric CO has a 13C18O abundance that significantly deviates from the thermodynamic equilibrium value. We show this is in a recent paper (Henkes et al., in review). This work is supported by the National Science Foundation.

In the future we will be focusing our attention on mineral dust/sea salt aerosol (MDSA) mechanisms for the catalytic removal of atmospheric methane. A recent paper (van Herpen et al., PNAS, in press) has illustrated that observations made by Mak et al. (2003) can now be explained by an as-yet unobserved process that may be significant for the removal of atmospheric methane in the remote tropical troposphere.

Previous work
In 2010 we published a paper that indicated the contribution of biomass burning to the Southern Hemisphere was much more variable in past centuries than previously supposed (Z. Wang*, J. Chappellaz, K.H. Park*, and J.E. Mak, Large Variations in Southern Hemisphere Biomass Burning During the Last 650 Years, Science, 30, 1663-1666, 2010) and Additional PDF. As a followup to this work we are analyzing samples for ¹³C and ¹⁸O in CO from the Vostok ice core and from WAIS Divide. In 2015 we were funded by NSF to analyze samples from the recently drilled South Pole Ice Core (SPICECORE.ORG) to extend the paleo-CO record to the last glacial maximum (LGM). In addition to this work, we are developing a new analytical technique to measure ¹⁷O in CO from ice cores. C¹⁷O has been shown to be an effective proxy of OH abundance, thus measuring ¹⁷CO from ice cores will allow us to constrain OH in the paleo atmosphere.

In 2013 we were funded by the US EPA (along with co-PIs Alex Guenther, UC Irvine, and Allen Goldstein, UC Berkeley) to participate in the SAS (Southeast Atmosphere Study). During the summer of 2013 my team of 6 spent 6 weeks in Alabama quantifying the emissions and chemistry of select OVOC’s including acetaldehyde, acetone, methyl butenol, and select terpenes from our own aircraft and a forest tower using our high resolution time of flight proton transfer mass spectrometer (PTR-TOFMS). Senior PhD candidate Luping Su has been working on the quantification of OVOCs (oxygenated volatile organic compounds) for eddy covariance studies using the PTR-TOFMS data (see Su et al., ACP, doi:10.5194/acp-16-7725-2016). He is currently using three different boundary layer models to help interpret our observations.

We also develop instrumentation for research aircraft, including the WASP (Whole Air Sample Profiler) system that was deployed in the summer of 2013 in Alabama. In 2016 we were part of a team that published a cover article in BAMS showing unique and novel airborne observations of boundary layer turbulence (http://dx.doi.org/10.1175/BAMS-D-14-00253.1).

News related to the Mak Lab

In 2020, our latest project was funded by the National Science Foundation; GOTHAAM (GreaterNY Oxidant, Trace gas, Halogen and Aerosol Airborne Mission). This highly collaborative project will utilize NSF’s Hercules C-130 research aircraft, which is operated by the Environmental Observations Laboratory (EOL) of the National Center for Atmospheric Research (NCAR). SOMAS at Stony Brook is the lead institution (Mak is the lead PI), and will be joined by colleagues from the University of Washington, University of California at Irvine, Colorado State University, University of Colorado, University of Michigan, and University of Maryland. This project was originally scheduled for the summer of 2021, however because of the pandemic, the project now will be postponed until the summer of 2023.

• What Can Ice Reveal About Fire? from NSF (2010)
• Research Highlight: Dr. John Mak’s Research on the Use of Isotopes as Tracers of the Chemistry, Origin and Transport in Atmospheric and Marine Environments (2011)
• Stony Brook Professor John Mak Flies into New Research Territory
• Research Highlight: SoMAS Leading IMPOWR Field Study to Improve Offshore Wind Mapping and Forecasting