A Comparison of the Midlatitude Nickel and Sodium Layers in the Mesosphere: Observations and Modeling
A Comparison of the Midlatitude Nickel and Sodium Layers in the Mesosphere: Observations and Modeling
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DOI：
10.1029/2021ja030170
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
J. Jiao;W. Feng;Fang Wu;Fuju Wu;Haorang Zheng;Lifang Du;Guotao Yang;J. Plane
中科院分区：
文献类型：
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作者：
J. Jiao;W. Feng;Fang Wu;Fuju Wu;Haorang Zheng;Lifang Du;Guotao Yang;J. Plane
利用工作波长为341和589 nm的双波长共振荧光激光雷达对北京延庆站（40.41°N，116.01°E）高层大气中的Ni层和Na层进行了同步观测。从2019年4月至2020年3月和2021年4月至2021年8月，在126个夜晚（共1090小时）进行了激光雷达测量，从而首次观察到Ni层的完整季节循环。Ni层和Na层表现出相似的年周期，从仲夏最小值到仲冬最大值增加了10.3倍。Ni和Na的年平均柱密度分别为3.1 × 108和2.5 × 109 cm−2，平均Na：Ni比为8.1，明显大于它们的CI比1.2。这是因为宇宙尘埃粒子中Na的消融效率提高了3倍，而Na+在90至100公里之间的中和速度更快，测得的Na+：Ni+比仅为2.2。Ni层峰值出现在84km附近，比Na层峰值低8km。全大气群落气候模式（WACCM）对这些特征进行了令人满意的模拟，并通过两种金属在90公里以下的中性化学和90至100公里之间的离子分子化学的显着差异来解释。
A dual‐wavelength resonance fluorescence lidar facility, operating at 341 and 589 nm, was used to observe simultaneously the Ni and Na layers in the upper atmosphere over Yanqing station, Beijing (40.41°N, 116.01°E). Lidar measurements were performed on 126 nights (1090 hr in total) from April 2019 to March 2020 and April 2021 to August 2021, so that the full seasonal cycle of the Ni layer was observed for the first time. The Ni and Na layers exhibit a similar annual cycle, increasing by a factor of ∼3 from a mid‐summer minimum to a midwinter maximum. The annual mean column densities of Ni and Na are 3.1 × 108 and 2.5 × 109 cm−2, respectively, giving a mean Na:Ni ratio of 8.1, which is significantly larger than their CI chondritic ratio of 1.2. This is explained by the more efficient ablation of Na from cosmic dust particles by a factor of 3, and the more rapid neutralization of Na+ between 90 and 100 km, where the measured Na+:Ni+ ratio is only 2.2. The Ni layer peak occurs around 84 km, 8 km below that of Na. These features are simulated satisfactorily by the Whole Atmosphere Community Climate Model (WACCM) and are explained by significant differences in the neutral chemistry of the two metals below 90 km and their ion‐molecule chemistry between 90 and 100 km.