Mid-latitude ozone changes: studies with a 3-D CTM forced by ERA-40 analyses
Mid-latitude ozone changes: studies with a 3-D CTM forced by ERA-40 analyses
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中纬度地区臭氧变化：ERA-40 分析强制进行的 3-D CTM 研究
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发表时间：
2006
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通讯作者：
Philippe Ricaud
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作者：
Wuhu Feng;M. Chipperfield;M. Dorf;K. Pfeilsticker;Philippe Ricaud
我们使用离线三维（3- d）化学传输模型（CTM）来研究平流层臭氧的长期变化。该模型于1977-2004年运行，并由ECMWF ERA-40和业务分析进行了验证。进行了模型运行，以检查来自短寿命源气体的卤素和平流层溴的增加的影响。这些分析捕获了观测到的柱臭氧年际变化的大部分，但也有一些不现实的特征。特别是ERA-40分析在20世纪80年代后期引起了北半球（NH） O 3列的一个大的正异常。此外，在2002年初，从ERA-40到工作风的变化在一些模式场（如温度、臭氧）中引入了突变，影响了趋势分析。该模式再现了90年代中期以来观测到的北半球中纬度柱的增加。对固定卤素运行的分析表明，这种增加不是由于卤素引起的损失显著减少，即不是恢复的迹象。该模型预测，在1999年之后，卤素引起的损失只会略有减少。在平流层上层，尽管模拟了1999年前后氯的周转量，但由于ECMWF温度升高、该高度模拟的ch4降低以及ERA-40期末SH温度突变的影响，o3并没有增加。来自短命物种的平流层溴增加5 pptv的影响使中纬度O 3柱减少约10 DU。然而，除了在大火山负荷时期外，对模拟的相对o3异常的影响通常很小。
We have used an off-line three-dimensional (3-D) chemical transport model (CTM) to study long-term changes in stratospheric O 3 . The model was run from 1977–2004 and forced by ECMWF ERA-40 and operational analyses. Model runs were performed to examine the impact of increasing halogens and additional stratospheric bromine from short-lived source gases. The analyses capture much of the observed interannual variability in column ozone, but there are also unrealistic features. In particular the ERA-40 analyses cause a large positive anomaly in northern hemisphere (NH) column O 3 in the late 1980s. Also, the change from ERA-40 to operational winds at the start of 2002 introduces abrupt changes in some model fields (e.g. temperature, ozone) which affect analysis of trends. The model reproduces the observed column increase in NH mid-latitudes from the mid 1990s. Analysis of a run with fixed halogens shows that this increase is not due to a significant decrease in halogen-induced loss, i.e. is not an indication of recovery. The model predicts only a small decrease in halogen-induced loss after 1999. In the upper stratosphere, despite the modelled turnover of chlorine around 1999, O 3 does not increase because of the effects of increasing ECMWF temperatures, decreasing modelled CH 4 at this altitude, and abrupt changes in the SH temperatures at the end of the ERA-40 period. The impact of an additional 5 pptv stratospheric bromine from short-lived species decreases mid-latitude column O 3 by about 10 DU. However, the impact on the modelled relative O 3 anomaly is generally small except during periods of large volcanic loading.