Evaluation of climate simulations produced with the Brazilian global atmospheric model version 1.2
Evaluation of climate simulations produced with the Brazilian global atmospheric model version 1.2
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DOI：
10.1007/s00382-020-05508-8
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发表时间：
2020-10
期刊：
影响因子：
4.6
通讯作者：
Caio A. S. Coelho;D. C. de Souza;P. Kubota;S. S. Costa-S.;Layrson Menezes;B. S. Guimarães;S. Figueroa;J. P. Bonatti;I. F. Cavalcanti;G. Sampaio;N. Klingaman;J. Baker
中科院分区：
文献类型：
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作者：
Caio A. S. Coelho;D. C. de Souza;P. Kubota;S. S. Costa-S.;Layrson Menezes;B. S. Guimarães;S. Figueroa;J. P. Bonatti;I. F. Cavalcanti;G. Sampaio;N. Klingaman;J. Baker
本文介绍了对天气预报和气候研究中心（CPTEC）的巴西全球大气模式1.2版（BAM-1.2）产生的气候模拟的评估。该模式在1975-2017年期间以两种空间分辨率运行，分别对应~ 180和~ 100 km，均有42个垂直高度，遵循大部分大气模式比对项目（AMIP）协议。在这个方案中，观测到的海面温度（SSTs）被用作大气模式的边界条件。这两项决议各有四名成员参加。计算了一系列诊断结果，以评估该模式对大气顶辐射、大气温度、环流和降水气候特征的表征能力。对降水年际变率、El Niño-Southern涛动（ENSO）降水遥相关、Madden和Julian涛动（MJO）和日降水特征进行了评价。该模型在两种分辨率下重现了许多观测到的温度、大气环流和降水气候特征，尽管存在一些已确定的偏差。模型大气被发现比观测结果更透明，导致云-辐射相互作用的错误描述。该模式很好地反映了对TOA期全球平均气候产生冷却效应的净云辐射强迫。发现这是由于模式中较弱的长波云辐射强迫（LWCRF）和短波云辐射强迫（SWCRF）之间的补偿。发现模式在两种分辨率下表示年际降水变率的能力与ENSO遥相关的充分表示有关。然而，该模式产生的对流活动弱于观测到的与MJO相关的对流活动。结果表明，模式对南美洲东南部及其他气候相似地区的日降水量估计过高，而对日降水量估计过低。提高空间分辨率有助于略微减少一些诊断偏差。执行的评估确定了需要改进的模型方面。这些特征包括极地大陆表面和海冰反照率、平流层臭氧、低空海洋云和日降水特征，这些特征被发现比观测到的特征更大，持续时间更长。
This paper presents an evaluation of climate simulations produced by the Brazilian Global Atmospheric Model version 1.2 (BAM-1.2) of the Center for Weather Forecast and Climate Studies (CPTEC). The model was run over the 1975–2017 period at two spatial resolutions, corresponding to ~ 180 and ~ 100 km, both with 42 vertical levels, following most of the Atmospheric Model Intercomparison Project (AMIP) protocol. In this protocol, observed sea surface temperatures (SSTs) are used as boundary conditions for the atmospheric model. Four ensemble members were run for each of the two resolutions. A series of diagnostics was computed for assessing the model’s ability to represent the top of the atmosphere (TOA) radiation, atmospheric temperature, circulation and precipitation climatological features. The representation of precipitation interannual variability, El Niño-Southern Oscillation (ENSO) precipitation teleconnections, the Madden and Julian Oscillation (MJO) and daily precipitation characteristics was also assessed. The model at both resolutions reproduced many observed temperature, atmospheric circulation and precipitation climatological features, despite several identified biases. The model atmosphere was found to be more transparent than the observations, leading to misrepresentation of cloud-radiation interactions. The net cloud radiative forcing, which produces a cooling effect on the global mean climate at the TOA, was well represented by the model. This was found to be due to the compensation between both weaker longwave cloud radiative forcing (LWCRF) and shortwave cloud radiative forcing (SWCRF) in the model compared to the observations. The model capability to represent inter-annual precipitation variability at both resolutions was found to be linked to the adequate representation of ENSO teleconnections. However, the model produced weaker than observed convective activity associated with the MJO. Light daily precipitation over the southeast of South America and other climatologically similar regions was diagnosed to be overestimated, and heavy daily precipitation underestimated by the model. Increasing spatial resolution helped to slightly reduce some of the diagnosed biases. The performed evaluation identified model aspects that need to be improved. These include the representation of polar continental surface and sea ice albedo, stratospheric ozone, low marine clouds, and daily precipitation features, which were found to be larger and last longer than the observed features.