Simulations of the Boreal Winter Upper Mesosphere and Lower Thermosphere With Meteorological Specifications in SD‐WACCM‐X
Simulations of the Boreal Winter Upper Mesosphere and Lower Thermosphere With Meteorological Specifications in SD‐WACCM‐X
复制标题
使用 SD-WACCM-X 中的气象规范模拟北方冬季上层中间层和下层热层
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
C. Randall
中科院分区：
文献类型：
--
作者：
F. Sassi;D. Siskind;J. Tate;Han L. Liu;C. Randall
我们研究了高空轻推在模拟北方冬季，特别是2009年1月平流层突然变暖前后，上层中间层和下层热层(UMLT)动力气象的结构和短期变化方面的益处。我们比较了使用指定的动力学，全大气社区气候模式，扩展版本，使用海军作战全球大气预测系统，高级物理高海拔生成的大气规范的NUMPED的模拟。进行了两组模拟：一组在0到90公里的垂直域上使用轻推；另一组在0到50公里的垂直域上使用轻推。动力行为是根据风、温度和纬向加速度的集合平均和标准差来诊断的，这是由于分解的和参数化波引起的。我们发现，在这两个实验中，UMLT的动力学行为有很大的不同，在成分输运的结构和可变性方面存在显著差异。我们将数值实验的结果与大气化学实验-傅里叶变换光谱仪对一氧化碳的观测结果进行了比较，结果表明高空轻推能够高保真地再现观测到的变率，行星波是动力学的重要组成部分。这项研究的结果表明，要捕捉影响UMLT短期变率(定义为平流层变暖后约10天内的大气行为)的关键物理过程，仅有平流层大气状态的规范是不够的，需要高层大气规范。
We investigate the benefit of high‐altitude nudging in simulations of the structure and short‐term variability of the upper mesosphere and lower thermosphere (UMLT) dynamical meteorology during boreal winter, specifically around the time of the January 2009 sudden stratospheric warming. We compare simulations using the Specified Dynamics, Whole Atmosphere Community Climate Model, extended version, nudged using atmospheric specifications generated by the Navy Operational Global Atmospheric Prediction System, Advanced Level Physics High Altitude. Two sets of simulations are carried out: one uses nudging over a vertical domain from 0 to 90 km; the other uses nudging over a vertical domain from 0 to 50 km. The dynamical behavior is diagnosed from ensemble mean and standard deviation of winds, temperature, and zonal accelerations due to resolved and parameterized waves. We show that the dynamical behavior of the UMLT is quite different in the two experiments, with prominent differences in the structure and variability of constituent transport. We compare the results of our numerical experiments to observations of carbon monoxide by the Atmospheric Chemistry Experiment‐Fourier Transform Spectrometer to show that the high‐altitude nudging is capable of reproducing with high fidelity the observed variability, and traveling planetary waves are a crucial component of the dynamics. The results of this study indicate that to capture the key physical processes that affect short‐term variability (defined as the atmospheric behavior within about 10 days of a stratospheric warming) in the UMLT, specification of the atmospheric state in the stratosphere alone is not sufficient, and upper atmospheric specifications are needed.