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，可以作为示踪剂来跟踪大气的运动并了解产生它们的化学反应。在气球无法到达的高度太高的中间层，测量这种同位素是很困难的。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，能够在37公里和70公里高度的大气层中采集大气样本。这将为清洁、廉价和高效的火箭采样器提供概念验证，该采样器能够远远超出目前常规气球的高度限制(30公里)进行大气探测。这一火箭技术和平台将促进对高层大气，特别是中间层的直接采样，其规模目前在经济上和环境上都是不可行的。四个大气样本(两次在37公里处发射，两次在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，它们要么从来没有，要么在这些高度严重采样不足，限制了我们对中间层对平流层和对流层的贡献的理解。同位素分析还将延伸到氧气和二氧化碳中的痕量氧同位素-17O-和同位素“聚集”。这些测量将与新的关于CO2-O2-O3光化学系统的实验室实验进行比较，该实验旨在更好地限制中间层/平流层O3光分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来说更便宜，而且对环境负责。它将为采样大气，尤其是中间层开辟新的机会，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大气光化学，并更好地深入了解这种化学，因为它与输送到海峡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智力优势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.