Embrace-AGS-growth: advancing temperature-dependent absorption models to support next-generation remote sensing

This Project Grant award from the National Science Foundation's Geosciences Program (CFDA 47.050) provides $399,934 to Bates College to develop a low-temperature spectroscopy facility. The goal is to improve spectroscopic models used in remote sensing instruments, which currently have biases that limit their ability to accurately measure atmospheric methane. The project will leverage specialized equipment at Bates College and the University of Colorado Boulder to conduct reference spectroscopy over a wide temperature range, generating new data on methane line shapes and their temperature dependence. This will help reduce biases between different monitoring instruments. The award also supports training for Bates students on advanced laboratory and field measurement techniques. This collaborative research effort is expected to run from March 2025 through February 2029.

Abstract

This embrace growth project will support the development of a low-temperature spectroscopy facility at bates college. Currently, biases between sensing instruments for certain compounds are too large for addressing critical uncertainties in global budgets. For instruments based on absorption spectroscopy, a primary source of these biases lies in inaccuracies in the spectroscopic models that convert atmospheric spectra to concentrations. Through a unique collaboration between bates college and the university of colorado, this low-temperature facility will combine dual frequency comb spectrometers and high-temperature test environments to enable broadband, high accuracy reference spectroscopy over a wide range of temperatures. This project will make important contributions toward addressing inaccuracies in spectroscopic models through careful laboratory reference spectroscopy and fundamental line shape studies that will disentangle near-infrared spectra. The method will be applied to measurements of atmospheric methane to reduce biases between monitoring instruments. The study will provide a significant amount of new data to the spectroscopic and remote sensing communities including advanced line shape parameters and their temperature dependence for methane transitions that have never been measured previously. This project forges a collaboration between researchers at university of colorado boulder and bates collage that will facilitate technical training for bates students on state-of-the-art, NSF-funded laboratory and field-measurement resources. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are planned for this award.