Reassessing the Effect of Cloud Type on Earth’s Energy Balance in the Age of Active Spaceborne Observations. Part I: Top of Atmosphere and Surface
Reassessing the Effect of Cloud Type on Earth’s Energy Balance in the Age of Active Spaceborne Observations. Part I: Top of Atmosphere and Surface
复制标题
重新评估活跃星载观测时代云类型对地球能量平衡的影响第一部分：大气层和地表顶部。
作者：
T. L’Ecuyer;Yun Hang;A. Matus;Zhien Wang
这项研究重新审视了星载主动观测时代量化独特云类型辐射效应的经典问题。九种云类型的辐射效应根据 CloudSat 和 CALIPSO 观测定义的垂直结构进行区分，并在大气顶部和表面进行评估。单云和多层云的贡献得到明确诊断。由于-44.2 ± 2 W m−2 的短波冷却和27.1 ± 3.7 W m−2 的长波加热，大气顶部的全球年平均净云辐射效应为-17.1 ± 4.2 W m−2 。利用明确的云底和垂直结构信息，我们进一步估计地表的年平均净云辐射效应为−24.8±8.7Wm−2（短波中为−51.1±7.8Wm−2，长波中为26.3±3.8Wm−2）。人们发现多层云对大气层顶部能量平衡的影响最大。然而，半球之间净云辐射冷却的强烈不对称性（8.6 W m−2）主要是由南部海洋上空层积云的增强冷却决定的。研究发现，由于冬季南大洋云长波发射增强，地表不存在相应的不对称性，这抵消了夏季对太阳吸收的很大一部分影响。因此，云辐射效应的不对称性完全是由于半球之间的大气加热不平衡而实现的。
This study revisits the classical problem of quantifying the radiative effects of unique cloud types in the era of spaceborne active observations. The radiative effects of nine cloud types, distinguished based on their vertical structure defined by CloudSat and CALIPSO observations, are assessed at both the top of the atmosphere and the surface. The contributions from single- and multilayered clouds are explicitly diagnosed. The global, annual mean net cloud radiative effect at the top of the atmosphere is found to be −17.1 ± 4.2 W m−2 owing to −44.2 ± 2 W m−2 of shortwave cooling and 27.1 ± 3.7 W m−2 of longwave heating. Leveraging explicit cloud base and vertical structure information, we further estimate the annual mean net cloud radiative effect at the surface to be −24.8 ± 8.7 W m−2 (−51.1 ± 7.8 W m−2 in the shortwave and 26.3 ± 3.8 W m−2 in the longwave). Multilayered clouds are found to exert the strongest influence on the top-of-atmosphere energy balance. However, a strong asymmetry in net cloud radiative cooling between the hemispheres (8.6 W m−2) is dominated by enhanced cooling from stratocumulus over the southern oceans. It is found that there is no corresponding asymmetry at the surface owing to enhanced longwave emission by southern ocean clouds in winter, which offsets a substantial fraction of their impact on solar absorption in summer. Thus the asymmetry in cloud radiative effects is entirely realized as an atmosphere heating imbalance between the hemispheres.
气候模型中水平和垂直云结构改进表示的影响
影响因子：
4.6
作者：
Shonk J
通讯作者：
Shonk J
地球水和能量平衡的半球对称性的奇妙本质
影响因子：
9.5
作者：
Stephens, GL;Hakuba, M.Z.;Hawcroft, MJ;Haywood, JM;Behrangi, AS;Kay, JE;Webster, PJ
通讯作者：
Webster, PJ