Importance of instantaneous radiative forcing for rapid tropospheric adjustment
Importance of instantaneous radiative forcing for rapid tropospheric adjustment
复制标题
瞬时辐射强迫对于对流层快速调整的重要性
DOI：
10.1007/s00382-013-1955-x
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发表时间：
2014
期刊：
影响因子：
4.6
通讯作者：
Miho Sekiguchi
中科院分区：
文献类型：
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作者：
Tomoo Ogura;Mark J. Webb;Masahiro Watanabe;Hugo Lambert;Yoko Tsushima;Miho Sekiguchi
为了更好地理解CFMIP/CMIP对CO2增加的快速低云响应的模型间差异及其相关的有效辐射强迫，我们研究了三个大气环流模式(GCM)中对流层下部稳定性(LTS)的对流层调节：HadGEM2-A、MIROC3.2 MEDRES和MIROC5。与其他两个模型相比，MIROC3.2 MEDES显示副热带海洋上空的LTS减少。这种减少与对流层中层温度的下降是一致的。温度下降主要是由二氧化碳增加引起的瞬时辐射强迫(RF)驱动的。云层造成的辐射和潜热以及绝热和平流加热的减少也是温度下降的原因之一。MIROC3.2 MEDES的对流层中层瞬时射频与逐线计算的结果不一致，因此被认为是有问题的。这些结果说明了用LBL计算评估瞬时RF垂直廓线的重要性；未来模式在这方面的改进应该有助于增加我们对GCM对流层调整的信心。
To better understand CFMIP/CMIP inter-model differences in rapid low cloud responses to CO2increases and their associated effective radiative forcings, we examined the tropospheric adjustment of the lower tropospheric stability (LTS) in three general circulation models (GCMs): HadGEM2-A, MIROC3.2 medres, and MIROC5. MIROC3.2 medres showed a reduction in LTS over the sub-tropical ocean, in contrast to the other two models. This reduction was consistent with a temperature decrease in the mid-troposphere. The temperature decrease was mainly driven by instantaneous radiative forcing (RF) caused by an increase in CO2. Reductions in radiative and latent heating, due to clouds, and in adiabatic and advective heating, also contribute to the temperature decrease. The instantaneous RF in the mid-troposphere in MIROC3.2 medres is inconsistent with the results of line-by-line (LBL) calculations, and thus it is considered questionable. These results illustrate the importance of evaluating the vertical profile of instantaneous RF with LBL calculations; improved future model performance in this regard should help to increase our confidence in the tropospheric adjustment in GCMs.