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

大气中的同位素，如17O、18O等，可以作为示踪剂来追踪大气的运动，并了解产生它们的化学反应。在大气层中测量这些同位素是很困难的，因为大气层太高，气球无法到达。该项目将试验一种新型火箭技术，以获取中间层的空气样本，并使用最先进的质谱仪分析样本中的同位素。该团队计划部署一种新型的零碳排放火箭，可以在37公里和70公里高度的大气中收集大气样本。这将为一种清洁、廉价和高效的火箭采样器提供概念证明，这种采样器能够进行大气探测，远远超出目前传统气球的高度限制（30公里）。这种火箭技术和平台将促进高层大气，特别是中间层的直接采样，目前在经济和环境上都是不可行的。四个大气样本（2个在37公里处发射，2个在70公里处发射）将使用加州大学圣地亚哥分校和哈佛大学最先进的质谱仪进行同位素表征。目标大气气体是O2、CO2和N2，在这些高度，它们要么从未被采样过，要么严重采样不足，这限制了我们对中间层对平流层和对流层的贡献的理解。同位素分析也将扩展到微量氧同位素- 17O -和同位素在O2和CO2中的“聚集”。这些测量结果将与新的CO2-O2-O3光化学系统的实验室实验进行比较，旨在更好地约束中间层/平流层O3光解的特征同位素效应和物理化学。这种新的火箭载采样技术在高度目标方面更灵活，相对于其他采样平台便宜，并且对环境负责。它将为大气采样，尤其是中间层采样开辟新的机会，使人们能够直接了解大气光化学，特别是与臭氧循环有关的大气光化学，并更好地了解这种原位化学，因为它与输送到平流层和对流层的气团有关。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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 troposphereThis 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.