ICE-IMPACT: International Consortium for the Exploitation of Infrared Measurements of PolAr ClimaTe

ICE-IMPACT：国际极地气候红外测量开发联盟

• 批准号: NE/N01376X/1
• 负责人: Helen Brindley
• 金额: $ 15.46万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN01376X%2F1
• 关键词: ICE; IMPACT; International; Consortium; Exploitation; ICE; IMPACT; International; Consortium; Exploitation

The Far infra red (FIR) is defined as the region of electromagnetic spectrum found at wavelengths greater than 15 microns. FIR radiation plays a major role in the Earth's energy balance, accounting for approximately half of the emission to space from the Earth and its atmosphere in the global mean. Fundamental physics implies that FIR radiation will play an even more important role in influencing climate variability and change in the fragile polar regions. The very cold surface temperatures found in these locations means that a greater fraction of the emitted surface energy is found at longer wavelengths. Moreover, the associated very low water vapour concentrations typically found in polar regimes effectively open up 'windows' in the FIR, making it possible to see further into the atmosphere from the ground than would normally be possible at these wavelengths. By the same argument, more of the surface energy emitted at these wavelengths is able to escape to space.Recent work has suggested that assumptions about FIR surface characteristics made in many of the most advanced models that we use to predict climate - termed Earth-system models - mean that they may be missing an important polar climate feedback process. This could lead to an additional Arctic surface warming of up to 2 K by the 2030s which would be expected to affect the rate of ice-melt and sea-level rise. Termed the 'ice-emissivity' feedback, the mechanism depends on the fact that snow and ice emit more energy at FIR wavelengths than sea-water at the same temperature. Current Earth-system models typically assume that all surfaces have the same emissivity in the FIR and so do not include this feedback process. These same models also struggle to match surface observations of the downwelling radiation emitted by the atmosphere in polar regions, a shortcoming that is believed to be principally due to inadequacies in the representation of polar clouds. However, up to now a detailed evaluation of the polar radiation budget has been hampered by a lack of dedicated observations spanning the entire infrared, including the FIR. This project seeks to address this deficiency by bringing together a team of international experts in FIR research and climate modelling to develop a suite of observationally based tools which will be used to assess model performance and drive future improvements. In the course of this work we will derive the first ever assessment of FIR surface emissivity from in-situ airborne observations over the Greenland plateau; characterise the infrared surface radiation budget over Antarctica and assess the meteorological processes driving variability there over a range of time-scales; evaluate approaches used to derive synthetic FIR measurements from space-based observations; and begin the process of quantifying the ice-emissivity feedback in two leading Earth-system models.

远红色（FIR）定义为在大于15微米的波长处发现的电磁光谱区域。 FIR辐射在地球的能量平衡中起着重要作用，约占从地球上排出空间的一半及其在全球平均值中的大气。基本物理学意味着，FIR辐射将在影响脆弱的极地区域的气候变异性和变化中发挥更重要的作用。在这些位置发现的非常冷的表面温度意味着在更长的波长下发现了较大的发射表面能。此外，相关的非常低的水蒸气浓度通常在极地状态下有效地打开FIR中的“窗户”，这使得从地面进一步看到大气比通常在这些波长下可能会有可能。通过同一论点，在这些波长下发出的更多表面能够逃到空间上。续签工作表明，关于我们用来预测气候 - 称为气候的地球系统模型的许多最先进模型中的FIR表面特征的假设 - 意味着它们可能缺少重要的重要极性气候反馈过程。到2030年代，这可能会导致高达2 K的额外北极表面变暖，预计会影响冰融化和海平面上升的速度。该机制被称为“冰出发性”反馈，取决于以下事实：雪和冰比在同一温度下的海水在FIR波长处发出的能量更多。当前的地球系统模型通常假定所有表面在FIR中具有相同的发射率，因此不包括此反馈过程。这些相同的模型也很难匹配极地区域大气发出的下降辐射的表面观测，这一缺点被认为主要是由于极地云的表示不足所致。但是，到目前为止，由于缺乏跨越整个红外线（包括FIR）的专用观察结果，对极地辐射预算进行了详细评估。该项目旨在通过将FIR研究和气候建模的国际专家团队汇集在一起​​，以开发一套基于观察的工具，以评估模型性能并推动未来的改进。在这项工作的过程中，我们将获得有史以来第一次评估FIR表面发射率，从格陵兰高原上的原位空降观察结果。表征南极的红外表面辐射预算，并评估在多个时间尺度上推动其变异性的气象过程；评估用于从空间观测中得出合成FIR测量的方法；并开始在两个领先的地球系统模型中量化冰出率反馈的过程。