The CU AMAX-DOAS instrument was deployed onboard the NSF / NCAR Gulfstream V to measure iodine monoxide (IO) and ozone (O3) in the upper troposphere and lower stratosphere (UTLS).


Text from NSF Award #2027252:

"This field campaign includes test flights to certify instrumentation not previously flown on the NSF/NCAR Gulfstream V research aircraft. It also includes flights to address several scientific hypotheses, including the investigation of ozone loss in the upper troposphere and lower stratosphere (UTLS) due to iodine in the region. The research results from this novel collection of instrumentation flown in the UTLS is expected to significantly improve the scientific understanding of chemistry in the region.

This project will test advanced instrumentation and a newly designed laminar flow inlet suitable for measuring condensable vapors and ambient ions on the GV research aircraft to achieve the following objectives: (1) The aircraft payload has been developed to experimentally constrain 90% of total iodine in the stratosphere by attempting the first simultaneous aircraft measurements of gas- and particle iodine; (2) Iodic acid (HIO3), a widespread condensable vapor that grows nanoparticles and drives changes in gas-particle partitioning of iodine, will be measured for the first time in the UTLS by aircraft; (3) Simultaneous measurements of ambient ions (number & chemical composition) will identify those condensable vapors that participate in ion-induced nucleation in the UTLS.

Initial test flights will be conducted in Colorado, after which a limited number of (~3-6) exploratory science flights are planned from Kona Hawaii to demonstrate the science readiness of the aircraft payload, evaluate instrument performance, and to inform long-term measurements at Mauna Loa Observatory (MLO) in preparation for future campaigns. Aircraft measurements made above MLO, along with iodine oxide (IO) radical measurements from a MAX-DOAS instrument at MLO, will enable the characterization of the nature and shape of the vertical profile of IO above MLO.

This project includes collaboration with scientists from three U.S. National Laboratories, one foreign university, and 5 foreign National Laboratories. Four graduate students and three postdocs will interact with scientists at eleven different institutions in the U.S., Germany, Belgium, Russia, and Spain, and gain experience with sophisticated instrumentation, computational fluid dynamics simulations, data interpretation, forecasting, and global modeling."