ATTREX Global Hawk UAS Radiation Measurements

ATTREX-Aircraft_Radiation_Measurements are in-situ radiation measurements collected onboard the Global Hawk Uninhabited Aerial System (UAS) during the Airborne Tropical TRopopause EXperiment (ATTREX) campaign. This collection consists of in-situ radiation properties collected by the Solar Spectral Flux Radiometer (SSFR) during the 2011 and 2013 deployments over California, and 2014 deployment over Guam. Data collection is complete.

Even though it is typically found in low concentrations, stratospheric water vapor has large impacts on the Earth’s climate and energy budget. Studies have suggested that even relatively small changes in stratospheric humidity may have significant climate impacts and future changes in stratospheric humidity and ozone concentration in response to a changing climate are significant climate feedbacks. Tropospheric water vapor climate feedback is typically well represented in global models. However, predictions of future changes in stratospheric humidity are highly uncertain due to gaps in our understanding of physical processes occurring in the region of the atmosphere that controls the composition of the stratosphere, the Tropical Tropopause Layer (TTL, ~13-18 km). The ability to predict future changes in stratospheric ozone are also limited due to uncertainties in the chemical composition of the TTL. In order to address these uncertainties, the Airborne Tropical Tropopause Experiment (ATTREX) was completed. Instruments during ATTREX provided measurements to trace the movement of reactive halogen-containing compounds and other important chemical species, the size and shape of cirrus cloud particles, water vapor, and winds in three dimensions through the TTL. Bromine-containing gases were measured to improve understanding of stratospheric ozone. ATTREX consisted of four NASA Global Hawk Uninhabited Aerial System (UAS) campaigns deployed from NASA’s Armstrong Flight Research Center (formally Dryden Flight Research Center). Campaigns were deployed over Edwards, CA, Guam, Hawaii, and Darwin, Australia in Boreal summer, winter, fall, and summer, respectively.

ATTREX-机载辐射测量数据集，是在机载热带对流层顶实验（Airborne Tropical Tropopause EXperiment, ATTREX）期间，由全球鹰无人航空系统（UAS）搭载获取的原位辐射测量数据。该数据集包含由太阳光谱通量辐射计（Solar Spectral Flux Radiometer, SSFR）在2011年、2013年于加利福尼亚州上空，以及2014年于关岛上空的部署任务中采集的原位辐射特性数据，数据采集工作已全部完成。
尽管平流层水汽通常浓度极低，但其对地球气候与能量收支具有显著影响。已有研究表明，平流层湿度即便发生相对微小的变化，也可能对气候造成显著影响；而未来平流层湿度与臭氧浓度随气候变迁产生的变化，亦是重要的气候反馈过程。对流层水汽的气候反馈过程在全球气候模式中通常已有较好的表征，但由于我们对控制平流层成分的关键大气区域——热带对流层顶层（Tropical Tropopause Layer, TTL，约13-18公里）内发生的物理过程认知存在不足，未来平流层湿度变化的预测仍存在高度不确定性。由于热带对流层顶层化学成分存在不确定性，对未来平流层臭氧变化的预测能力同样受限。为解决这些认知不确定性，机载热带对流层顶实验（ATTREX）应运而生并顺利完成。本次实验搭载的仪器可通过三维观测，追踪活性含卤化合物与其他关键化学物质的运移路径，同时获取卷云粒子的尺寸与形态、水汽分布以及三维风场数据，覆盖整个热带对流层顶层区域。此外，实验还对含溴气体进行了测量，以加深对平流层臭氧相关过程的理解。ATTREX实验共包含四次由美国国家航空航天局（NASA）阿姆斯特朗飞行研究中心（原德莱顿飞行研究中心）部署的全球鹰无人航空系统（UAS）任务。四次任务的作业区域分别为加利福尼亚州爱德华兹、关岛、夏威夷以及澳大利亚达尔文，对应作业时段依次为北半球夏季、冬季、秋季与夏季。