Global observations and modeling of nonmigrating diurnal tides generated by tide‐planetary wave interactions
Global observations and modeling of nonmigrating diurnal tides generated by tide‐planetary wave interactions
复制标题
潮汐-行星波相互作用产生的非迁移日潮的全球观测和建模
DOI：
10.1002/2015jd023739
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
D. Siskind
中科院分区：
文献类型：
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作者：
R. Lieberman;D. Riggin;D. Ortland;J. Oberheide;D. Siskind
对流过程耦合行星波与潮汐长期以来一直被认为是非迁移的周日潮汐的来源。本文报道了非迁移潮汐全球观测中的短期变率观测结果，这些观测结果预计是由迁移日潮（DW1）与准定常行星波1（PW1）的相互作用引起的。PW1和潮汐定义是从卫星温度和高空气象分析中提取的。在冬季，纬向波数为2（DW2）的向西行日潮的演变通常跟踪平流层强振幅PW1的演变。DW1和PW1谱用于计算平流引起的非线性潮汐强迫项。然后，我们研究了原始方程模型对基于观测的非线性强迫的响应。模式试验表明，DW1对PW1纬向动量的纬向平流是低热层DW2的重要来源。模拟DW2振幅与观测DW2振幅时，平流层PW1穿透赤道纬度是非常一致的。模型实验还表明，这种相互作用可以在夏季半球和低热层的DW2上留下与冬季PW1相关的短期变率。
Advective processes that couple planetary waves with tides have long been proposed as sources of nonmigrating diurnal tides. This paper reports observations of short‐term variability in global observations of nonmigrating tides predicted to arise from the interaction of the migrating diurnal tide (DW1) with a quasi‐stationary planetary wave number one (PW1). PW1 and tidal definitions are extracted from satellite temperatures and high‐altitude meteorological analyses. During winter months, the evolution of westward traveling diurnal tides with zonal wave number 2 (DW2) generally tracks that of strong‐amplitude stratospheric PW1. DW1 and PW1 spectra are used to compute nonlinear tidal forcing terms arising from advection. We then examine the response of a primitive equation model to the observation‐based nonlinear forcing. The model experiments indicate that meridional advection of PW1 zonal momentum by DW1 is a significant source of lower thermospheric DW2. Modeled DW2 amplitudes are very consistent with observed DW2 amplitudes when stratospheric PW1 penetrates to equatorial latitudes. The model experiments also indicate that the interaction can imprint short‐term variability associated with wintertime PW1 upon DW2 in the summer hemisphere and the lower thermosphere.