Low-cost Approaches for Atmospheric Sensing

The atmosphere is a complex mixture of gases and aerosols that range in concentration from the sub-part-per-billion level up to many percent, and which vary with both time and space.  There are numerous analytical challenges associated with study of the atmosphere, and studies focused on understanding atmospheric chemistry have traditionally required numerous expensive, often custom-built instruments that are cost-prohibitive for many researchers.  Over the past decade, advances in consumer electronics and low-cost sensors have enabled a new generation of low-cost chemical instrumentation; while such instrumentation may have inherent drawbacks in terms of sensitivity, accuracy, and/or precision compared to research-grade equipment, its low-cost and accessibility make it valuable nevertheless.  Moreover, modern computational methods (i.e. “machine learning”) have expanded our ability to draw relevant conclusions from the often noisy data produced by low-cost instruments.  Here, a suite of low-cost tools for the study atmospheric chemistry will be discussed, including a low-cost photoacoustic spectrometer for measuring absorption by atmospheric trace gases and aerosols, a low-cost cavity enhanced spectrometer for measurement of extinction by atmospheric trace gases and aerosols, and machine learning approaches that make use of free, publicly available data and data generated by low-cost instrumentation.