The Brewer-Dobson circulation and total ozone from seasonal to decadal time scales
The Brewer-Dobson circulation and total ozone from seasonal to decadal time scales
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DOI：
10.5194/acp-11-11221-2011
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发表时间：
2011-11
影响因子：
6.3
通讯作者：
M. Weber;S. Dikty;J. Burrows;H. Garny;M. Dameris;A. Kubin;J. Abalichin;U. Langematz
中科院分区：
文献类型：
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作者：
M. Weber;S. Dikty;J. Burrows;H. Garny;M. Dameris;A. Kubin;J. Abalichin;U. Langematz
抽象的。利用来自合并的 GOME/SCIAMACHY/GOME-2 (GSG) 数据集 (1995-2010) 的卫星总臭氧数据以及两个化学气候模型 (CCM)、FUB-EMAC 和 DLR-E39C-A 模型的输出，研究了冬季布鲁尔-多布森环流 (BDC) 对两个半球总臭氧的季节和年代际演变的影响。结合两个半球的数据，冬季平均温带 100 hPa 涡流热通量与臭氧相对于秋季臭氧水平的比率之间存在线性关系，并且对于热带和极地臭氧来说具有统计显着性。高纬度地区的高相关性一直持续到夏季，直到下一个冬季开始。然而，随着极地涡旋的侵蚀，累积涡热通量与热带臭氧比率的反相关性在春季被打破，并转变为类似于高纬度地区观察到的弱正相关性。因此，冬季、春季和夏季各半球臭氧的年际变化和年代际演变是由前一冬季经向环流的累积效应驱动的。在本研究中使用的两种 CCM 中也发现了这种紧凑的线性关系，表明当前模型真实地描述了平流层环流的变化及其对臭氧总量的影响。两个模型都显示，直到 2050 年，两个半球的冬季平均涡热通量（和冬季 BDC 强度）都呈正趋势，但年际变化（峰到峰）比 1960 年至 2050 年之间的平均变化大两到三倍。尽管如此，还是有可能检测到与平流层卤素负荷过去和未来变化相关的这种紧凑线性关系的变化。使用SBUV/TOMS/OMI (MOD V8)合并数据集(1980-2010)可以看出，从1990-1999年到2000-2010年，这种线性关系保持不变(平流层卤素负荷转变前后)，而1980-1989年(平流层卤素负荷上升趋势)和20 世纪 90 年代，这是一个明显的迹象，表明尽管极地臭氧变化很大，但可以检测到恢复的开始。由于BDC环流每年都有很大的变化，在未来几十年内，在BDC较弱和极地平流层温度非常低的某些冬季，仍可能发生大量的极地臭氧消耗。
Abstract. The effect of the winter Brewer-Dobson circulation (BDC) on the seasonal and decadal evolution of total ozone in both hemispheres is investigated using satellite total ozone data from the merged GOME/SCIAMACHY/GOME-2 (GSG) data set (1995–2010) and outputs from two chemistry-climate models (CCM), the FUB-EMAC and DLR-E39C-A models. Combining data from both hemispheres a linear relationship between the winter average extratropical 100 hPa eddy heat flux and the ozone ratio with respect to fall ozone levels exists and is statistically significant for tropical as well as polar ozone. The high correlation at high latitudes persists well into the summer months until the onset of the next winter season. The anti-correlation of the cumulative eddy heat flux with tropical ozone ratios, however, breaks down in spring as the polar vortex erodes and changes to a weak positive correlation similar to that observed at high latitudes. The inter-annual variability and decadal evolution of ozone in each hemisphere in winter, spring, and summer are therefore driven by the cumulative effect of the previous winter's meridional circulation. This compact linear relationship is also found in both CCMs used in this study indicating that current models realistically describe the variability in stratospheric circulation and its effect on total ozone. Both models show a positive trend in the winter mean eddy heat flux (and winter BDC strength) in both hemispheres until year 2050, however the inter-annual variability (peak-to-peak) is two to three times larger than the mean change between 1960 and 2050. It is, nevertheless, possible to detect a shift in this compact linear relationship related to past and future changes in the stratospheric halogen load. Using the SBUV/TOMS/OMI (MOD V8) merged data set (1980–2010), it can be shown that from the decade 1990–1999 to 2000–2010 this linear relationship remained unchanged (before and after the turnaround in the stratospheric halogen load), while a shift is evident between 1980–1989 (upward trend in stratospheric halogen) and the 1990s, which is a clear sign that an onset of recovery is detectable despite the large variability in polar ozone. Because of the large variability from year to year in the BDC circulation substantial polar ozone depletion may still occur in coming decades in selected winters with weak BDC and very low polar stratospheric temperatures.