The first multi-model ensemble of regional climate simulations at kilometer-scale resolution, part I: evaluation of precipitation
The first multi-model ensemble of regional climate simulations at kilometer-scale resolution, part I: evaluation of precipitation
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DOI：
10.1007/s00382-021-05708-w
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发表时间：
2021-04-09
期刊：
影响因子：
4.6
通讯作者：
Zander, Mar Janne
中科院分区：
文献类型：
--
作者：
Ban, Nikolina;Caillaud, Cecile;Zander, Mar Janne
在这里，我们提出了第一个多模式集合的区域气候模拟在更大尺度的水平网格间距超过十年之久。共有23个模拟运行的水平网格间距类似于3公里，驱动的ERA中期再分析，并进行了22个欧洲研究小组进行了分析。六个不同的区域气候模式（RCMs）代表在合奏。将模拟与可用的高分辨率降水观测值和具有参数化对流的粗分辨率（类似于12公里）RCM进行比较。模式的模拟和观测结果进行了比较，就平均降水，降水强度和频率，以及强降水的日和小时的时间尺度在不同的季节。结果表明，大尺度模式产生更真实的降水比粗分辨率的RCMs的代表。最显着的改善被发现在夏季的强降水和降水频率的每日和每小时的时间尺度。一般来说，与粗分辨率模式相比，大尺度模式往往产生更强烈的降水和减少湿小时频率。平均而言，多模式的平均值显示出减少的偏差，从类似的-40%在12公里到类似的-3%在3公里的每小时降水在夏季。此外，不确定性范围，即湿小时频率的模型之间的变异性减少了一半，使用更大规模的模型。尽管大尺度模式模拟结果与观测结果之间仍存在差异，但这些模拟结果在代表当今气候的降水方面明显上级粗分辨率RCM模拟结果，从而为研究局地到区域尺度的气候和气候变化提供了一条有前途的途径。
Here we present the first multi-model ensemble of regional climate simulations at kilometer-scale horizontal grid spacing over a decade long period. A total of 23 simulations run with a horizontal grid spacing of similar to 3 km, driven by ERA-Interim reanalysis, and performed by 22 European research groups are analysed. Six different regional climate models ( RCMs) are represented in the ensemble. The simulations are compared against available high-resolution precipitation observations and coarse resolution (similar to 12 km) RCMs with parameterized convection. The model simulations and observations are compared with respect to mean precipitation, precipitation intensity and frequency, and heavy precipitation on daily and hourly timescales in different seasons. The results show that kilometer-scale models produce a more realistic representation of precipitation than the coarse resolution RCMs. The most significant improvements are found for heavy precipitation and precipitation frequency on both daily and hourly time scales in the summer season. In general, kilometer-scale models tend to produce more intense precipitation and reduced wet-hour frequency compared to coarse resolution models. On average, the multi-model mean shows a reduction of bias from similar to -40% at 12 km to similar to -3% at 3 km for heavy hourly precipitation in summer. Furthermore, the uncertainty ranges i.e. the variability between the models for wet hour frequency is reduced by half with the use of kilometer-scale models. Although differences between the model simulations at the kilometer-scale and observations still exist, it is evident that these simulations are superior to the coarse-resolution RCM simulations in the representing precipitation in the present-day climate, and thus offer a promising way forward for investigations of climate and climate change at local to regional scales.