Two decades of operations and performance for the MAESTRO instrument are reviewed. Topics addressed include: (a) occultation measurement schemes, (b) MAESTRO's field of view (FOV) on the Sun, (c) FOV changes on the solar disk during occultations and their impact on calculated transmittances, (d) the relation between the MAESTRO and ACE-FTS FOVs, (e) verification of wavelength assignment, and how it has been affected by thermal environment changes, and (f) the determination of MAESTRO tangent heights.

We developed a new photoreactor to study how organic compounds react in water under atmospheric-relevant conditions. Experiments were performed on smoke-related chemicals under controlled light, temperature, and humidity mimicking cloud and haze environments. Our results showed that saltier water speeds particle formation and changes their composition, providing new insights into atmospheric aerosol chemistry.