Pan-European climate at convection-permitting scale: a model intercomparison study
Pan-European climate at convection-permitting scale: a model intercomparison study
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DOI：
10.1007/s00382-018-4114-6
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发表时间：
2020-07-01
期刊：
影响因子：
4.6
通讯作者：
Fosser, Giorgia
中科院分区：
文献类型：
--
作者：
Berthou, Segolene;Kendon, Elizabeth J.;Fosser, Giorgia
我们调查的影响，使用对流允许模式（CPM）跨越泛欧域的降水分布在气候尺度上的代表性。特别是，我们比较了两个2.2公里的模型与两个12公里的模型运行的ETH苏黎世（ETH-12公里和ETH-2.2公里）和气象局（UKMO-12公里和UKMO-2.2公里）。尽管使用了不同的动力学核心和不同的参数化包，这两个CPM产生定性相似的差异，降水气候学相比，12公里的模式。定量分析证实，CPM给最大的差异相比，12公里的模型在每小时的降水分布的区域和季节，对流是一个关键的过程：在整个欧洲的夏季和秋季在地中海和沿海地区。平均降水量在高地形上增加，日变化幅度增大。我们强调，这两个CPM都显示出增加了数量的中度到强烈的短期持续事件和减少了数量的长期持续的低强度事件无处不在，纠正（往往是过度纠正）12公里模型的偏见。瑞士的整体小时分布和最强烈事件的强度有所改善，英国的改善程度较小，但在德国恶化。降水日周期峰值出现的时间得到改善。在每日时间尺度上，降水分布的差异不太明显，但大阿尔卑斯地区的差异最大。此外，地中海秋季强烈的事件更好地代表在日常的时间尺度在两个2.2公里的模式，由于改进的中尺度过程的代表性。
We investigate the effect of using convection-permitting models (CPMs) spanning a pan-European domain on the representation of precipitation distribution at a climatic scale. In particular we compare two 2.2 km models with two 12 km models run by ETH Zurich (ETH-12 km and ETH-2.2 km) and the Met-Office (UKMO-12 km and UKMO-2.2 km). The two CPMs yield qualitatively similar differences to the precipitation climatology compared to the 12 km models, despite using different dynamical cores and different parameterization packages. A quantitative analysis confirms that the CPMs give the largest differences compared to 12 km models in the hourly precipitation distribution in regions and seasons where convection is a key process: in summer across the whole of Europe and in autumn over the Mediterranean Sea and coasts. Mean precipitation is increased over high orography, with an increased amplitude of the diurnal cycle. We highlight that both CPMs show an increased number of moderate to intense short-lasting events and a decreased number of longer-lasting low-intensity events everywhere, correcting (and often over-correcting) biases in the 12 km models. The overall hourly distribution and the intensity of the most intense events is improved in Switzerland and to a lesser extent in the UK but deteriorates in Germany. The timing of the peak in the diurnal cycle of precipitation is improved. At the daily time-scale, differences in the precipitation distribution are less clear but the greater Alpine region stands out with the largest differences. Also, Mediterranean autumnal intense events are better represented at the daily time-scale in both 2.2 km models, due to improved representation of mesoscale processes.