The quasi‐biennial oscillation (QBO), a ubiquitous feature of the zonal mean zonal winds in the equatorial lower stratosphere, is forced by selective dissipation of atmospheric waves that range in periods from days to hours. However, QBO circulations in numerical models tend to be weak compared with observations, probably because of limited vertical resolution that cannot adequately resolve gravity waves and the height range over which they dissipate. Observations are required to help quantify wave effects. The passage of a superpressure balloon (SPB) near a radiosonde launch site in the equatorial Western Pacific during the transition from the eastward to westward phase of the QBO at 20 km permits a coordinated study of the intrinsic frequencies and vertical structures of two inertia‐gravity wave packets with periods near 1 day and 3 days, respectively. Both waves have large horizontal wavelengths of about 970 and 5,500 km. The complementary nature of the observations provided information on their momentum fluxes and the evolution of the waves in the vertical. The near 1 day westward propagating wave has a critical level near 20 km, while the eastward propagating 3‐day wave is able to propagate through to heights near 30 km before dissipation. Estimates of the forcing provided by the momentum flux convergence, taking into account the duration and scale of the forcing, suggests zonal force of about 0.3–0.4 m s⁻¹ day⁻¹ for the 1‐day wave and about 0.4–0.6 m s⁻¹ day⁻¹ for the 3‐day wave, which acts for several days.

中文翻译：

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短垂直波长重力波的气球-波恩观测及其与QBO风的相互作用

准两年一次振荡（QBO）是赤道下平流层中纬向平均纬向风的普遍特征，它是由选择性地驱散从几天到几小时不等的大气波强迫的。但是，与观测值相比，数值模型中的QBO环流往往较弱，这可能是因为垂直分辨率有限，无法充分解决重力波及其消散的高度范围。需要进行观察以帮助量化波浪效应。在QBO从东向西过渡20 km期间，赤道西太平洋无线电探空仪发射场附近超压气球（SPB）的通过允许对两个惯性重力的固有频率和垂直结构进行协调研究。波浪包，其周期接近1天和3天，分别。两个波都有大约970和5500 km的大水平波长。观测的互补性质提供了有关其动量通量和垂直波的演变的信息。近1天的向西传播波在20 km附近具有临界水平，而东传播的3天的波能够传播到消散前30 km附近的高度。考虑到强迫的持续时间和规模，由动量通量收敛提供的强迫估计表明区域力约为0.3-0.4 m s 近1天的向西传播波在20 km附近具有临界水平，而东传播的3天的波能够传播到消散前30 km附近的高度。考虑到强迫的持续时间和规模，由动量通量收敛提供的强迫估计表明，区域力约为0.3–0.4 m s 近1天的向西传播波在20 km附近具有临界水平，而东传播的3天的波能够传播到消散前30 km附近的高度。考虑到强迫的持续时间和规模，由动量通量收敛提供的强迫估计表明区域力约为0.3-0.4 m s^-1 天^-1为1天的波和大约0.4-0.6米每秒^-1 天^-1为3天的波，其作用数天。