I am currently a Stanford Science Fellow doing postdoctoral research in the Doerr School of Sustainability and in the Department of Physics. My research focuses on understanding the ultimate fate of methane and other carbon species in the atmosphere. To do this, I apply remote sensing, data assimulation, and numerical models to improve the way we detect, quantify, and trace carbon with satellites and ground-based sensors. I earned my PhD in Environmental Science and Engineering at Caltech in 2023. I am also an avid marathon runner, and proud to be representing Rabbit as a member of their 2024 Elite Team!

Stanford Advisors

Lab Affiliations

All Publications

  • Precision Doppler shift measurements with a frequency comb calibrated laser heterodyne radiometer. Optics letters Cole, R. K., Fredrick, C., Nguyen, N. H., Diddams, S. A. 2023; 48 (20): 5185-5188


    We report precision atmospheric spectroscopy of CO2 using a laser heterodyne radiometer (LHR) calibrated with an optical frequency comb. Using the comb calibrated LHR, we record spectra of atmospheric CO2 near 1572.33 nm with a spectral resolution of 200 MHz, using sunlight as a light source. The measured CO2 spectra exhibit frequency shifts by approximately 11 MHz over the course of the 5-h measurement, and we show that these shifts are caused by Doppler effects due to wind along the spectrometer line of sight. The measured frequency shifts are in excellent agreement with an atmospheric model, and we show that our measurements track the wind-induced Doppler shifts with a relative frequency precision of 2 MHz (3 m·s-1) for a single 10 s measurement, improving to 100 kHz (15 cm·s-1) after averaging (equivalent to a fractional precision of a few parts in 1010). These results demonstrate that frequency comb calibrated LHR enables precision velocimetry that can be of use in applications ranging from climate science to astronomy.

    View details for DOI 10.1364/OL.500652

    View details for PubMedID 37831823

  • Effects of Chemical Feedbacks on Decadal Methane Emissions Estimates GEOPHYSICAL RESEARCH LETTERS Nguyen, N. H., Turner, A. J., Yin, Y., Prather, M. J., Frankenberg, C. 2020; 47 (3)
  • Large regional shortwave forcing by anthropogenic methane informed by Jovian observations. Science advances Collins, W. D., Feldman, D. R., Kuo, C., Nguyen, N. H. 2018; 4 (9): eaas9593


    Recently, it was recognized that widely used calculations of methane radiative forcing systematically underestimated its global value by 15% by omitting its shortwave effects. We show that shortwave forcing by methane can be accurately calculated despite considerable uncertainty and large gaps in its shortwave spectroscopy. We demonstrate that the forcing is insensitive, even when confronted with much more complete methane absorption spectra extending to violet light wavelengths derived from observations of methane-rich Jovian planets. We undertake the first spatially resolved global calculations of this forcing and find that it is dependent on bright surface features and clouds. Localized annual mean forcing from preindustrial to present-day methane increases approaches +0.25 W/m2, 10 times the global annualized shortwave forcing and 43% of the total direct CH4 forcing. Shortwave forcing by anthropogenic methane is sufficiently large and accurate to warrant its inclusion in historical analyses, projections, and mitigation strategies for climate change.

    View details for DOI 10.1126/sciadv.aas9593

    View details for PubMedID 30263955

    View details for PubMedCentralID PMC6157968