Long‐term variability and tendencies in migrating diurnal tide (DW1) are investigated for the first time using a three‐member ensemble of historical simulations by NCAR's Whole Atmosphere Community Climate Model, latest Version 6 (WACCM6) for 1850–2014 (165 years). The model reproduces the climatological features of the tide in temperature (T), zonal wind (U), and meridional wind (V). The amplitudes peak in the upper mesosphere and lower thermosphere (above ~0.001 hPa) at the equator for T (~10 K) and over 20–30°N and S latitudes for U (~15 m/s) and V (~25 m/s). The contributions of solar cycle (SC), quasi biennial oscillation (QBO) at 10 and 30 hPa, El Niño–Southern Oscillation (ENSO), ozone depleting substances (ODS), carbon dioxide (CO₂), and stratospheric sulfate aerosols (volcanic eruptions) to change in annual mean amplitudes are analyzed using multiple linear regression. The tidal amplitudes in three components show a long‐term increase in the upper stratosphere (0.95–10.7 hPa) and the upper mesosphere (0.0001–0.01 hPa), predominantly due to increasing CO₂ with a smaller contribution from the trend in ENSO. Interestingly, the global mean tidal amplitude in T decreases sharply after 1950–1960 until 1995 and then increases in association with changes in ODSs. The seasonal differences in tidal responses to the above indices can be as large as the overall signals. All the responses are stronger in the upper mesosphere; however, there is also a pronounced negative response of temperature tide to ODSs over middle to high latitudes around the stratopause (~1 hPa) during all seasons.

中文翻译：

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1850-2014年期间从WACCM6模拟中迁移日潮的长期变化和趋势

NCAR的整个大气社区气候模型最新版本6（WACCM6）的1850-2014年（165年）的历史模拟由三人组成的合奏首次调查了日潮（DW1）的长期变化和趋势。 。该模型再现了潮汐的温度（T），纬向风（U）和子午风（V）的气候特征。对于T（〜10 K），在20-30°N和U（〜15 m / s）和V（〜25）的北纬，赤道上层中层和下层热层（〜0.001 hPa以上）的振幅峰值多发性硬化症）。太阳周期（SC），10 hPa和30 hPa的准两年期振荡（QBO），厄尔尼诺-南端振荡（ENSO），臭氧消耗物质（ODS），二氧化碳（CO ₂），并使用多元线性回归分析平流层硫酸盐气溶胶（火山爆发）年平均振幅的变化。三个分量的潮汐振幅显示平流层上部（0.95 hPa – 10.7 hPa）和中层上部层（0.0001 hPa – 0.01 hPa）长期增加，主要是由于CO ₂增加在ENSO趋势中贡献较小。有趣的是，T的全球平均潮汐振幅在1950-1960年之后一直急剧下降，直到1995年，然后随着ODS的变化而增加。潮汐对上述指标的季节性差异可能与总体信号一样大。在中层上层，所有反应都较强；然而，在所有季节中，层状顶（〜1 hPa）周围的中高纬度地区的ODS对潮汐都有明显的负响应。