Global wave activity from upper stratosphere to lower thermosphere: A new turbopause concept
Global wave activity from upper stratosphere to lower thermosphere: A new turbopause concept
复制标题
从平流层上层到热层下层的全球波浪活动：新的涡轮顶概念
DOI：
10.1016/j.jastp.2006.01.013
复制
发表时间：
2006
影响因子：
1.9
通讯作者：
M. Mlynczak
中科院分区：
文献类型：
--
作者：
D. Offermann;M. Jarisch;J. Oberheide;O. Gusev;I. Wohltmann;J. Russell;M. Mlynczak
全球温度测量可从CRISTA（低温红外光谱仪和大气望远镜）和SABER（使用宽带发射辐射测量法的大气探测）获得，最高可达110公里。纬向平均温度的标准偏差被用作波活动指标（代理）。这些标准差σ或方差σ 2的高度/纬度图显示了一种依赖于季节的结构。此外，还存在显著的区域不对称性。通过σ场的垂直切割显示了90和100 km之间的显著过渡：100 km以上的线性拟合曲线具有类似于自由（向上）传播波的振幅增加的梯度。90 km以下的相应梯度要平坦得多，因此表明波浪阻尼相当大。这两条拟合曲线的交点在这里被称为“波-湍流层顶”，并且被认为靠近湍流层顶或传输湍流层顶。CRISTA-1、CRISTA-2和SABER的波涡层顶位于90- 95 km附近。它是比较相应的冷点中层顶和等值线的估计潜在的涡度显示与对流层顶的相似之处。波涡层顶的高度取决于纬度。它也有相当大的季节变化，这在高纬度和低纬度是非常不同的。
Global temperature measurements are available from CRISTA (CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere) and from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) up to 110km. Standard deviation from zonal mean temperature is used as a wave activity indicator (proxy). Altitude/latitude plots of these standard deviations σ or variances σ2show a structure that is dependent on the season. There is also substantial zonal asymmetry. Vertical cuts through the σ-field show a remarkable transition between 90 and 100km: linear fit curves above 100km have a gradient similar to the amplitude increase of freely (upward) propagating waves. The corresponding gradients below 90km are much flatter and thus indicate considerable wave damping. The intersection of the two fit curves is dubbed the “wave-turbopause” here, and is believed to be near the turbulent or transport turbopause. This wave-turbopause is found in the vicinity of 90–95km for CRISTA-1, CRISTA-2, and SABER. It is compared to the corresponding cold point mesopause and to the isolines of estimated potential vorticities to show similarities with the tropopause. The height of the wave-turbopause depends on latitude. It also has considerable seasonal variation, which is very different at high and low latitudes.