Collaborative Research: EAGER--Novel Sampling and Isotopic Characterization of Upper Strato- to Mesospheric Photochemistry

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Isotopes in the atmosphere, such as 17O, 18O and others, can be used as tracers to track the movement of the atmosphere and understand the chemical reactions producing them. Obtaining measurements of such isotopes is difficult in the mesosphere which is too high to be reached by balloons. This project will experiment with a novel rocket technology to obtain air samples in the mesosphere and use state of the art mass spectrometers to analyze isotopes in the samples. The team plans to deploy a novel, zero-carbon emission rocket that will enable atmospheric sample collection at 37 km and 70 km altitude in the atmosphere. This will provide proof-of-concept for a clean, inexpensive, and efficient rocket sampler capable of atmospheric exploration well beyond the current altitude limit of conventional balloons (30 km). This rocket technology and platform will facilitate direct sampling of the upper atmosphere, especially the mesosphere on a scale that is currently economically and environmentally infeasible. Four atmospheric samples (2 launches at 37 km, 2 at 70 km) will be isotopically characterized using state of the art mass spectrometers at both UCSD and Harvard. The target atmospheric gasses are O2, CO2 and N2, which have either never been, or are severely under-sampled at these altitudes, limiting our understanding of mesospheric contributions to the stratosphere and troposphere. Isotopic analyses will also extend to the trace oxygen isotope – 17O – and isotopic ‘clumping’ in both O2 and CO2. The measurements will be compared to new laboratory experiments on the CO2-O2-O3 photochemical system, which aim to better constrain the characteristic isotope effects and physical chemistry of Mesosphere/Stratosphere O3 photolysis. This new rocket borne sampling technology is more flexible in terms of altitude targets, cheap relative to other sampling platforms, and environmentally responsible. It will open up new opportunities for sampling the atmosphere, most notably the mesosphere, and enable direct insight into atmospheric photochemistry, specially that related to ozone cycle, and better insight into this chemistry in situ and as it relates to airmasses being delivered to the strato- and troposphere 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.