Airborne measurements of oxygen concentration from the surface to the lower stratosphere and pole to pole
Airborne measurements of oxygen concentration from the surface to the lower stratosphere and pole to pole
复制标题
从地表到平流层下部以及从极到极的氧气浓度的机载测量
DOI：
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发表时间：
2020
影响因子：
3.8
通讯作者：
B. Daube
中科院分区：
文献类型：
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作者：
B. Stephens;E. Morgan;J. Bent;R. Keeling;A. Watt;S. Shertz;B. Daube
抽象的。我们已经开发了现场和烧瓶采样系统，用于在百万分之几的水平上对O2/N2比率的变化进行空中测量。
我们已经在一系列的飞机活动中部署了这些仪器，以测量从0-14 公里和87∘ N到86∘ 的大气O2在整个季节周期中的分布。
美国国家大气研究中心(NCAR)的机载氧气仪(AO2)使用真空紫外线(VUV)吸收氧气的探测器，还包括一个红外二氧化碳传感器。
真空紫外探测器的精度在5 S为±1.25每兆克(1σ)δ(O2/N_2))，但当在飞行中采样环境空气时，热分馏和运动效应将其提高到每兆克±2.5-4.0。
NCAR/Scripps气载烧瓶采样器(Medusa)在主动控制的流量和压力条件下，每一次飞行收集32个低温干燥的空气样本。
对于现场或烧瓶氧气测量，在要求较高的相对精度时，分馏和表面效应可能是重要的。
我们描述了我们的采样和测量技术，以及为减少潜在偏差所做的努力。
我们还提供了一系列的观测结果，突出了单个和组合仪器的性能。
其中包括垂直剖面、O2：CO2相关性和反映陆地光合作用、大气-海洋气体交换、各种燃料燃烧和平流层动态的不同影响的纬度横截面。
当存在时，我们已经校正了烧瓶δ(O2/N2)测量，以便在采样或分析期间使用并发的δ(Ar/N2)测量进行分馏。
我们还对进气分馏和湿度影响的现场δ(O2/N2)测量进行了修正，并与修正后的烧瓶值进行了比较。
经Ar/N_2校正的水母烧瓶δ(O2/N_2)测量结果与斯克里普斯O2计划地区观测站观测结果的比较表明，在最近的10次活动中没有系统性偏差(每兆克+0.2%±8.2%，平均偏差和标准偏差，n=86)。
对于二氧化氧，在解决了样品干燥和入口分馏偏差之前约为每兆克10-100后，最近六次活动的独立氧气δ(O2/N_2)测量结果与水母烧瓶测量结果相差-0.3%±7.2%(平均和标准偏差，n=1361)，特定活动的平均值范围为每兆克−5至+5。
Abstract. We have developed in situ and flask sampling systems for airborne measurements of variations in the O2/N2 ratio at the part per million level.
We have deployed these instruments on a series of aircraft campaigns to measure the distribution of atmospheric O2 from 0–14 km and 87∘ N to 86∘ S throughout the seasonal cycle.
The National Center for Atmospheric Research (NCAR) airborne oxygen instrument (AO2) uses a vacuum ultraviolet (VUV) absorption detector for O2 and also includes an infrared CO2 sensor.
The VUV detector has a precision in 5 s of ±1.25 per meg (1σ) δ(O2/N2), but thermal fractionation and motion effects increase this to ±2.5–4.0 per meg when sampling ambient air in flight.
The NCAR/Scripps airborne flask sampler (Medusa) collects 32 cryogenically dried air samples per flight under actively controlled flow and pressure conditions.
For in situ or flask O2 measurements, fractionation and surface effects can be important at the required high levels of relative precision.
We describe our sampling and measurement techniques and efforts to reduce potential biases.
We also present a selection of observational results highlighting the individual and combined instrument performance.
These include vertical profiles, O2:CO2 correlations, and latitudinal cross sections reflecting the distinct influences of terrestrial photosynthesis, air–sea gas exchange, burning of various fuels, and stratospheric dynamics.
When present, we have corrected the flask δ(O2/N2) measurements for fractionation during sampling or analysis with the use of the concurrent δ(Ar/N2) measurements.
We have also corrected the in situ δ(O2/N2) measurements for inlet fractionation and humidity effects by comparison to the corrected flask values.
A comparison of Ar/N2-corrected Medusa flask δ(O2/N2) measurements to regional Scripps O2 Program station observations shows no systematic biases over 10 recent campaigns (+0.2±8.2 per meg, mean and standard deviation, n=86).
For AO2, after resolving sample drying and inlet fractionation biases previously on the order of 10–100 per meg, independent AO2 δ(O2/N2) measurements over six more recent campaigns differ from coincident Medusa flask measurements by -0.3±7.2 per meg (mean and standard deviation, n=1361) with campaign-specific means ranging from −5 to +5 per meg.
DOI：
10.5194/acp-2020-95
发表时间：
2020
期刊：
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影响因子：
--
作者：
Birner B
通讯作者：
Birner B
用于绘制化学示踪剂和计算大气库存的质量加权等熵坐标
影响因子：
6.3
作者：
Jin, Yuming;Keeling, Ralph F.;Morgan, Eric J.;Ray, Eric;Parazoo, Nicholas C.;Stephens, Britton B.
通讯作者：
Stephens, Britton B.