Earth's albedo and its symmetry
Earth's albedo and its symmetry
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地球的反照率及其对称性
DOI：
10.1002/essoar.10506526.1
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发表时间：
2021
影响因子：
5.2
通讯作者：
B. Stevens
中科院分区：
文献类型：
--
作者：
George Datseris;B. Stevens
行星反射率（英语：Planetary radiation energy）是一个行星的固有属性，测量它反射回太空的入射辐射能（或日射）的比例。因此，它的补量，即余射量I，决定了剩余的太阳辐射量I中有多少部分用来加热地球。地球的几个组成部分以及它们之间的相互作用决定了地球的价值。对于地球来说，大气和云层是影响反照率的主要因素（Ramanathan，1987），其表面特性（土地比例、冰盖（Budyko，1969）甚至生物圈（Betts，2000））也是如此。尽管对南极洲各组成部分的贡献已经进行了非常详细的研究，但很少有人关注从太空以及从另一颗行星上观察南极洲的整体性质。摘要利用20年的天基云与地球辐射能系统能量平衡与充满积的测量结果，分析了地球辐射的性质及其对称性。尽管表面不对称，大气层顶部的时间和半球平均反射太阳辐照度R出现对称的北方/南半球。这是证实与使用代理时间序列，它提供的利润率为10.002 0.1 0.28Wm可能的半球差异支持云和地球的辐射系统的数据。R时间序列进一步分析分解成一个季节性（每年和半年）的周期和残差。反射太阳辐照度的变化几乎完全（99%）是由于季节性变化，主要是由于日照的季节性变化。半球平均R的残差不仅很小，而且与噪声无法区分，因此在半球之间不相关。这使得年度和分年度的时间尺度不太可能作为对称建立机制的基础。然而，残差包含一个全球性的趋势，是大的，相比预期的反馈。它也是半球对称的，因此表明在更长的时间尺度上对称性强制机制的可能性。为了精确地确定地球系统的哪些部分建立了半球对称性，我们从数据中创建了一个能量一致的云场。我们表明，表面的不对称性是由云之间的不对称性补偿在热带外海洋，南半球的风暴轨迹比他们的北方半球同行多云11%。这再次表明，假设这种对称性不是偶然的结果，它的机制可能在大的时间和空间尺度上起作用。
The planetary albedo , an intrinsic property of a planet, measures the fraction of incident radiant energy (or insolation) that it reflects back to space. Its complement, the co-albedo (1 ) thus determines what fraction of that insolation, I , remains to heat the planet. Several components of the planet and interactions among them go into deciding the value of . For Earth, the atmosphere and clouds are major contributors to albedo (Ramanathan, 1987), as are its surface properties (the land fraction, ice cover (Budyko, 1969) and even the biosphere (Betts, 2000)). Whereas the contributions of the constituent parts of the albedo have been studied in great detail, little attention has been devoted to understanding the properties of the albedo as a whole, as seen from space, and as one might do for another planet. Abstract The properties of Earth's albedo and its symmetries are analyzed using twenty years of space-based Energy Balanced And Filled product of Clouds and the Earth's Radiant Energy System measurements. Despite surface asymmetries, top of the atmosphere temporally & hemispherically averaged reflected solar irradiance R appears symmetric over Northern/Southern hemispheres. This is confirmed with the use of surrogate time-series, which provides margins of 2 0.1 0.28Wm for possible hemispheric differences supported by Clouds and Earth's Radiant System data. R time-series are further analyzed by decomposition into a seasonal (yearly and half yearly) cycle and residuals. Variability in the reflected solar irradiance is almost entirely (99%) due to the seasonal variations, mostly due to seasonal variations in insolation. The residuals of hemispherically averaged R are not only small, but also indistinguishable from noise, and thus not correlated across hemispheres. This makes yearly and subyearly timescales unlikely as the basis for a symmetry-establishing mechanism. The residuals however contain a global trend that is large, as compared to expected albedo feedbacks. It is also hemispherically symmetric, and thus indicates the possibility of a symmetry enforcing mechanism at longer timescales. To pinpoint precisely which parts of the Earth system establish the hemispheric symmetry, we create an energetically consistent cloud-albedo field from the data. We show that the surface albedo asymmetry is compensated by asymmetries between clouds over extra-tropical oceans, with southern hemispheric storm-tracks being 11% cloudier than their northern hemisphere counterparts. This again indicates that, assuming the albedo symmetry is not a result of chance, its mechanism likely operates on large temporal and spatial scales.
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
通过推断的高反照率识别岩石系外行星上的大气
DOI：
10.3847/1538-4357/ab4c90
发表时间：
2019
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Mansfield, Megan;Kite, Edwin S.;Hu, Renyu;Koll, Daniel D.;Malik, Matej;Bean, Jacob L.;Kempton, Eliza M.-R.
通讯作者：
Kempton, Eliza M.-R.
影响因子：
5.2
作者：
Loeb, Norman G.;Wang, Hailan;Wyser, Klaus
通讯作者：
Wyser, Klaus