Strommen K, Mavilia I, Corti S, Matsueda M, Davini P, von Hardenberg J, Vidale P-L, Mizuta R
Department of Physics University of Oxford Oxford UK.
Istitutio di Scienze dell'Atmosfera e del Clima Consiglio Nazionale delle Richerche Rome Italy.
Geophys Res Lett. 2019 Jul 16;46(13):7810-7818. doi: 10.1029/2019GL082843. Epub 2019 Jul 9.
There is growing evidence that the atmospheric dynamics of the Euro-Atlantic sector during winter is driven in part by the presence of quasi-persistent regimes. However, general circulation models typically struggle to simulate these with, for example, an overly weakly persistent blocking regime. Previous studies have showed that increased horizontal resolution can improve the regime structure of a model but have so far only considered a single model with only one ensemble member at each resolution, leaving open the possibility that this may be either coincidental or model dependent. We show that the improvement in regime structure due to increased resolution is robust across multiple models with multiple ensemble members. However, while the high-resolution models have notably more tightly clustered data, other aspects of the regimes may not necessarily improve and are also subject to a large amount of sampling variability that typically requires at least three ensemble members to surmount.
越来越多的证据表明，冬季欧洲 - 大西洋地区的大气动力学部分是由准持续性天气形势驱动的。然而，一般环流模型通常难以模拟这些天气形势，例如，阻塞形势的持续性过弱。先前的研究表明，提高水平分辨率可以改善模型的天气形势结构，但迄今为止只考虑了一个模型，且每个分辨率下只有一个集合成员，这就留下了一种可能性，即这种改善可能是巧合或依赖于特定模型。我们表明，分辨率提高带来的天气形势结构改善在多个模型和多个集合成员中都是稳健的。然而，虽然高分辨率模型的数据聚类明显更紧密，但天气形势的其他方面不一定会改善，并且还受到大量抽样变异性的影响，通常需要至少三个集合成员才能克服。
