Project Grant 2204474

This Project Grant from the National Science Foundation Division of Atmospheric and Geospace Sciences, under the Geosciences federal grant program (CFDA 47.050), provides $263,928 to fund collaborative research involving novel sampling and isotopic characterization of upper stratospheric to mesospheric photochemistry. Specifically, the award supports experimentation with a zero-carbon emission rocket to obtain air samples from the mesosphere at 37km and 70km altitudes. Four atmospheric samples will be collected over two launches at each altitude and isotopically analyzed using state-of-the-art mass spectrometers at the University of California, San Diego and Harvard University. Target gases include O2, CO2 and N2, which are under-sampled at these altitudes, limiting understanding of mesospheric contributions to the stratosphere and troposphere. Isotopic measurements will also examine the trace oxygen isotope 17O and isotopic "clumping" in both O2 and CO2. Results will be compared to new laboratory experiments on CO2-O2-O3 photochemistry to better constrain isotope effects and physical chemistry of mesosphere/stratosphere ozone photolysis. This novel rocket sampling opens new opportunities for flexible atmospheric sampling of the understudied mesosphere and insights into related atmospheric photochemistry and air mass transport.