Vertical diffusion transport of atomic oxygen in the mesopause region consistent with chemical losses and continuity: Global mean and inter-annual variability
Vertical diffusion transport of atomic oxygen in the mesopause region consistent with chemical losses and continuity: Global mean and inter-annual variability
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DOI：
10.1016/j.jastp.2018.05.014
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发表时间：
2018-10
影响因子：
1.9
通讯作者：
G. Swenson;Y. Yee;F. Vargas;A. Liu
中科院分区：
文献类型：
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作者：
G. Swenson;Y. Yee;F. Vargas;A. Liu
本研究描述了 SABER 对中层 [O] 的气候测量得出的垂直扩散速度和涡流传输系数平均值。五十年前，科尔格罗夫等人。 (1967) 描述了使用传输和连续性方程以及一维成分分布在大气两个区域之间转变的过程。本研究的两个部分是使用 SABER 得出的 O 密度计算向下的 O 扩散速度和涡流扩散系数：1）全球平均值（±55°）和 2）全球和赤道年平均 O 密度的年际变化。导出的传输扩散速度在 95-83km 范围内为 ∼1 到 4cms−1，kzz 在相同高度范围内变化为 ∼9.0–5.0×105cm2s−1。这里在 80-100km 区域导出的 kzz 值在 98km 处比 Salinas 等人计算的值大。 (2016) 使用 SABRE CO2 测量，比Qian 等人少约 0.5 倍。 （2009、2013 和 TIEGCM 模型）源自热层 O/N2 测量研究。考虑中间层的 kzzaltitude 剖面，Salinas 等人的平均值。 （2016）这项研究是〜7。 E+05 cm2s-1。 kzz（和向下传输速度）的年际变化与全球平均 O 剖面的标准偏差 <5%。赤道处的偏差稍大（7.4%），在 88 公里处注意到 QBO 趋势，尽管还没有大到足以在中层 O 柱密度的时间历史中检测到。每个太阳黑子的中间层（80-100km）中O的全球平均柱密度有0.30%的变化。我们建议模型研究可能需要考虑 100-110km 区域的更高湍流（和 kzz），以满足中层和热层组成。
This study describes the vertical diffusion velocity and eddy transport coefficient means derived from the climatological measurements of mesospheric [O] by SABER. Fifty years ago, Colegrove et al. (1967) described a process to transition between the two regions of the atmosphere using transport and continuity equations along with a 1-D composition profile. The two parts of this study are calculations of the downward O diffusion velocities and eddy diffusion coefficients using O densities derived from SABER for: 1) the global mean (±55°) and 2) the inter-annual variation of global and equatorial annual mean O densities. The derived transport diffusion velocities range from ∼1 to 4 cm s−1at 95-83 km, and kzzvaries between ∼9.0–5.0 × 105cm2s−1over the same altitude range. The values of kzzderived here in the 80–100 km region are larger at 98 km than those calculated by Salinas et al. (2016) using SABER CO2measurements and ∼0.5 times less than Qian et al. (2009, 2013 and TIEGCM model) which were derived from studies of thermospheric O/N2measurements. Consideration of the kzzaltitude profiles in the mesosphere, the mean values for both Salinas et al. (2016) and this study is ∼7. E+05 cm2s-1. The standard deviation of the inter-annual variability in kzz(and downward transport velocities) from globally averaged O profiles is <5%. The deviation is slightly larger (7.4%) at the equator, where a QBO trend is noted at 88 km, although not sufficiently large to be detected in the time history of the mesospheric O column density. The global average column density of O in the mesosphere (80–100 km) had a 0.30% change per sunspot. We suggest that model studies may need to consider higher turbulence (and kzz) in the 100–110 km region in order to satisfy both mesospheric and thermospheric composition.