Deep convective clouds (DCCs) are crucial in the Earth's energy budget. Although the abundant DCC-generated ice-phase anvil and cirrus theoretically have a warming effect, the reported observations of their cloud radiative effect (CRE) by previous studies are unexpectedly negative. Here, we find that the apparent contradiction between theory and observations resulted from neglecting the radiative contribution of background underlying clouds based on the five-years active and passive satellite observations in global. The probability of underlying clouds below the anvils is up to 2/3. They can contribute up to 70 % of the observed total shortwave cooling effect when they fully overlap with anvils. After excluding the effect of underlying clouds, most of the anvil CRE changes sign from negative to positive, increasing by over +25 W/m2, especially over land. This revelation suggests a substantially underestimated warming effect of DCC anvils and cirrus in previous observations. Also, it may imply an underestimated aerosol-driven positive radiative forcing on DCC, which has been estimated as neutral previously.

中文翻译：

---

热带对流砧的大幅变暖被其底层云层所掩盖


深对流云 （DCC） 在地球的能量收支中至关重要。尽管丰富的 DCC 产生的冰相砧和卷云理论上具有变暖效应，但先前研究报道的对其云辐射效应 （CRE） 的观测结果出乎意料地是负面的。在这里，我们发现理论与观测之间的明显矛盾是由于忽略了基于全球五年主动和被动卫星观测的背景底层云的辐射贡献。铁砧下方底层云的概率高达 2/3。当它们与铁砧完全重叠时，它们可以贡献高达 70% 的观察到的总短波冷却效果。在排除底层云的影响后，大多数砧座 CRE 变化符号从负到正，增加了超过 +25 W/m2，尤其是在陆地上。这一发现表明，在之前的观测中，DCC 砧和卷云的变暖效应被大大低估了。此外，这可能意味着 DCC 上被低估的气溶胶驱动的正辐射强迫，而之前一直估计为中性。