This study compares the ozone valleys over the Tibetan Plateau (TP) and the Rocky Mountains (RM) using the ERA5 reanalysis data set. The dynamical transport of the ozone over these two regions is analyzed using the Lorenz circulation decomposition method. The ozone content valley over TP is observed around 200–50 hPa (upper troposphere and lower stratosphere, or UTLS), and that over RM is around 300–100 hPa. It is shown that the TP ozone content is smaller than that over RM. By analyzing the spatiotemporal distribution of the ozone content and the general circulation, the anticyclone over Southern Asian (SAH) plays a significant role in existence of the TP ozone valley, and the ozone content flux reaches its maximum in July. Large-scale terrain and related general circulation determine the ozone valley appearance. Further analysis suggests that stationary transport has a larger impact on the ozone valley formation than the transient transport. The transport by the zonal circulation nearly cancels out most of that by the meridional circulation, due to the fact that the zonal transport magnitude is nearly equal to the meridional transport. The transport center over the RM is much weaker than that over the TP. Furthermore, the contrasts between transient and stationary transports are less evident over RM than over TP. The eddy-driven stationary ozone transport flux significantly impacts the development of the two low ozone centers across these large terrains.

中文翻译：

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青藏高原与落基山脉臭氧谷气候特征比较

本研究使用 ERA5 再分析数据集比较了青藏高原 (TP) 和落基山脉 (RM) 的臭氧谷。使用洛伦兹循环分解方法分析了这两个区域的臭氧动态传输。 TP 上空的臭氧含量谷值约为 200-50 hPa（对流层上层和平流层下层，简称 UTLS），RM 上空的臭氧含量谷值约为 300-100 hPa。结果表明，TP 区臭氧含量小于 RM 区臭氧含量。通过分析臭氧含量时空分布和大气环流，发现南亚反气旋（SAH）对青藏高原臭氧谷的存在具有重要作用，臭氧含量通量在7月份达到最大。大范围的地形和相关的大气环流决定了臭氧谷的外观。进一步分析表明，静止传输对臭氧谷形成的影响比瞬态传输更大。由于纬向环流的输送量几乎等于经向输送量，因此纬向环流的输送量几乎抵消了大部分经向环流的输送量。高原上的交通中心比高原上的交通中心弱得多。此外，RM 上的瞬时传输和静态传输之间的对比不如 TP 上那么明显。涡流驱动的固定臭氧传输通量极大地影响了这些大地形上两个低臭氧中心的发展。