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

大气中的同位素，如17 O、18 O等，可以作为示踪剂来跟踪大气的运动，并了解产生它们的化学反应。 在中间层中很难获得此类同位素的测量值，因为中间层太高，气球无法到达。 该项目将试验一种新的火箭技术，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，以实现在大气层37公里和70公里高度收集大气样本。这将为清洁、廉价和高效的火箭取样器提供概念验证，该火箭取样器能够进行远超过传统气球目前高度限制（30公里）的大气探测。这一火箭技术和平台将有助于对高层大气，特别是中间层进行直接取样，其规模目前在经济和环境上都不可行。将在加州大学圣地亚哥分校和哈佛大学使用最先进的质谱仪对四个大气样品（两次在37公里处发射，两次在70公里处发射）进行同位素鉴定。目标大气气体是O2，CO2和N2，在这些高度上从未进行过或严重欠采样，限制了我们对平流层和对流层的中间层贡献的理解。同位素分析还将扩展到痕量氧同位素-17 O-和O2和CO2中的同位素“聚集”。这些测量结果将与关于CO2-O2-O3光化学系统的新的实验室实验进行比较，这些实验旨在更好地限制中间层/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加灵活，相对于其他采样平台便宜，并且对环境负责。 它将为大气层，特别是中间层的取样提供新的机会，并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光化学，更好地了解这种化学反应，因为它与输送到平流层的气团有关，该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持和更广泛的影响审查标准。

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.