Effect of horizontal resolution on ECHAM6-AMIP performance
Effect of horizontal resolution on ECHAM6-AMIP performance
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DOI：
10.1007/s00382-014-2396-x
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发表时间：
2015-07-01
期刊：
影响因子：
4.6
通讯作者：
Krismer, Thomas
中科院分区：
文献类型：
--
作者：
Hertwig, Eileen;von Storch, Jin-Song;Krismer, Thomas
本文分析了大气模式ECHAM6中水平分辨率的增加对模拟的平均气候状态和气候变率的影响。为此，将分辨率分别为T63L95、T127L95和T255L95的三种amip风格模拟与再分析数据和观测结果进行了比较。分别分析了大气场的偏置以及对流层和平流层的偏置。除了气候状态和方差的平均误差外，还研究了在三种水平分辨率下不同时间尺度的大气现象：瞬变涡动能、风暴路径、大气遥相关、麦登-朱立安振荡（MJO）和准两年一次振荡（QBO）。总的来说，当考虑平均状态和方差时，模拟气候的偏差随着分辨率的增加而减小。在热带外的对流层比在热带对流层有更大的改善。平流层的误差一般较大，但增加分辨率的相对效益大于对流层，我们发现平流层现象，如QBO，对水平分辨率很敏感。在全球范围内，平均状态的偏差提高了19%，而变异的偏差提高了15%（从T63到T255）。主要的挑战仍然是模拟降水和气候特征，如MJO，这可能需要一个耦合的大气-海洋模型。
This study analyzes the effect of increasing horizontal resolution in the atmospheric model ECHAM6 on the simulated mean climate state and climate variability. For that purpose three AMIP-style simulations with the resolutions T63L95, T127L95, and T255L95 are compared to reanalysis data and observations. Biases in atmospheric fields as well as tropospheric and stratospheric biases individually are analyzed. Besides mean errors of the climate state and the variance, some atmospheric phenomena with different time scales are studied at the three horizontal resolutions: the transient eddy kinetic energy, storm tracks, atmospheric teleconnections, the Madden-Julian-Oscillation (MJO), and the Quasi-Biennial Oscillation (QBO). The main result is that, overall, the bias of the simulated climate is reduced with increasing resolution when considering the mean state and the variance. A greater improvement takes place in the extra-tropical than in the tropical troposphere. The errors in the stratosphere are generally larger but the relative benefit of increasing resolution is greater than in the troposphere and we find that stratospheric phenomena, like the QBO, are sensitive to horizontal resolution. Globally, the bias of the mean state improves by 19 %, while the bias of the variability improves by 15 % (from T63 to T255). Major challenges remain the simulation of the precipitation and climate features like the MJO, which might require a coupled atmosphere-ocean model.