The Infrared Radiative Impact of Antarctic Clouds

尽管它们对辐射传输很重要，但极地云中过冷液态水的数量可能是不确定的。这种低估反过来导致地表和TOA（大气顶部）的显著辐射偏差，以及对极地气溶胶-云相互作用的错误描述。最近的工作涉及调整气候模式以使混合相云分布与观测相匹配，结果导致南极洲上空的净云辐射效应增加。因此，了解南极气候的一个关键组成部分是更准确地表示云中过冷液体的丰度以及相应的云-辐射相互作用。利用先前在南极站（2000年）、Dome C站（2003年）和麦克默多站（计划于2015年11月- 11月）用FT-IR仪器（大气发射辐射干涉仪；AERIs）收集的下井辐射测量数据。（2016）将用于评估云特性的季节性依赖以及云对当地地表辐射收支的影响。本文将考虑两种假设：1)南极辐射收支对云的性质，特别是热力学阶段高度敏感。2)南极云层中过冷液体的辐射影响受到水复折射率（CRI）的温度依赖性的显著影响。

Despite their importance to radiative transfer, the amount of supercooled liquid water in polar clouds may be uncertain. This underestimation in turn results in significant radiation biases at the surface and TOA (top of the atmosphere) and misrepresentation of polar aerosol-cloud interactions. Recent work involving tuning a climate model to match mixed phase cloud distributions with observations resulted in an increase in net cloud radiative effects over Antarctica. A crucial component of understanding Antarctic climate, therefore, is a more accurate representation of the abundance of supercooled liquid in clouds and of corresponding cloud-radiative interactions.Leveraging down-welling radiance measurement data previously collected with FT-IR instruments (Atmospheric Emitted Radiance Interferometers; AERIs) at South Pole Station - (2000) , Dome C - (2003) and to be made at McMurdo Station (planned for Nov. 2015-Nov. 2016) will be used to assess the seasonal dependence of cloud properties and cloud impacts on the local surface radiative budget. Two hypotheses will be considered:1) The Antarctic radiation budget is highly sensitive to cloud properties, particularly thermodynamic phase.2) The radiative impact of supercooled liquid in Antarctic clouds is significantly influenced by the temperature dependence of the complex refractive index of water (CRI)