Journal of Geophysical Research: Atmospheres A global ground truth view of the lunar air pressure tide L 2
Journal of Geophysical Research: Atmospheres A global ground truth view of the lunar air pressure tide L 2
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地球物理研究杂志：大气 月球气压潮 L 2 的全球地面实况视图
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通讯作者：
A. Saifuddin
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作者：
S. Redla;T. Sikdar;A. Saifuddin
根据陆地气压计和系泊浮标的2315个地面实况估计，建立了月球气压潮汐L2的综合模型。区域尺度的潮汐及其季节调制的特点，很好地解决了原位散射和网格化的2 × 10 - 4网格，通过多重二次插值。由此产生的气候作为一个独立的标准，以验证月球半日潮汐信号，是目前在ERA中期再分析产品，尽管没有L2相关的重力强迫机制，在规定的模型物理。气压计月潮的再分析解与其经验解之间的差异通常很小，但当对1979-2010年期间进行平均时，ERA-Interim将热带地区100 μ bar的开阔海洋潮汐振幅低估了20 μ bar，并产生了早于10个月球分钟的峰值压力时间。美国东部阿拉斯加海岸再分析潮的大振幅特征，和英国显然是虚假的，引入到分析系统的同化海洋压力数据在一个不变的参考表面，而不是适当占垂直传感器运动与M2海潮。此外，为20世纪世纪ERA-20 C飞行员再分析提供了可靠的L2信号。该模型仅依赖于地表观测的输入数据，这一事实清楚地表明，大气分析系统中的月球潮汐振荡与台站和海洋物体的常规压力测量值的同化密切相关。
A comprehensive model of the lunar air pressure tide L 2 is developed on the basis of 2315 ground truth estimates from land barometers and moored buoys. Regional-scale features of the tide and its seasonal modulations are well resolved by the in situ scatter and gridded to a 2 ∘ mesh through multiquadric interpolation. The resulting climatologies serve as an independent standard to validate the lunar semidiurnal tidal signal that is present in ERA-Interim reanalysis products despite the absence of L 2 -related gravitational forcing mechanisms in the prescribed model physics. Inconsistencies between the reanalysis solution of the barometric lunar tide and its empirical account are generally small, yet when averaged over the period 1979–2010, ERA-Interim underestimates the 100 μ bar open ocean tidal amplitude in the Tropics by up to 20 μ bar and produces times of peak pressure that are too early by 10 lunar minutes. Large-amplitude features of the reanalysis tide off the coast of Alaska, the eastern U.S., and Great Britain are evidently spurious, introduced to the analysis system by assimilating marine pressure data at an invariant reference surface instead of properly accounting for vertical sensor movements associated with the M 2 ocean tide. Additionally, a credible L 2 signal is documented for the ERA-20C pilot reanalysis of the twentieth century. The fact that this model rests upon input data from mere surface observations provides an unambiguous indication that the lunar tidal oscillation in atmospheric analysis systems is closely tied to the assimilation of conventional pressure measurements from stations and marine objects.