Forcing in the long-wave spectrum due to aerosol-cloud interactions: satellite and climate modelling vs. HALO (FLASH)

人为气溶胶通过气溶胶-云相互作用产生的辐射强迫是量化气候变化当前强迫的主要不确定性。虽然在电磁谱的短波(太阳)部分的强迫中占主导地位的液态水云已经取得了一些进展，但对于长波(地面)谱中的强迫，目前仅有来自大气环流模式的粗略估计。在初步工作中，我们提出了一项建议，即如何使用活跃的卫星遥感来描述冰晶数浓度和同入射气溶胶浓度，从而可以评估陆地光谱中的气溶胶强迫。然而，卫星遥感数据具有高度的不确定性，需要利用参考数据进行验证。在闪光方面，我们建议(I)利用HALO(ACRIDICON，ML-Cirrus)现有的大型统计数据验证卫星冰晶浓度及其对温度、垂直风、云况和气溶胶条件的敏感性，(Ii)使用具有更好时空分辨率的激光雷达和机载HALO(NARVAL，NARVAL-II，NAWDEX)用机载反演验证空间反演，(Iii)利用气候模式模拟来解释统计关系和(Iv)在长波光谱中对气溶胶辐射强迫的估计和不确定性特征。在SPP 1294范围内，全球气候变化监测系统打算利用现有数据，并以综合方式处理来自多个活动的即将到来的数据，以实现以下目标：更好地量化气溶胶-气候强迫、验证创新和关键的卫星反演，以及评估和改进气候模式中的基本参数。

The radiative forcing by anthropogenic aerosols via aerosol-cloud interactions is the main uncertainty in quantifying current forcing of climate change. While some progress has been achieved for liquid water clouds that dominate the forcing in the short-wave (solar) part of the electromagnetic spectrum, for the forcing in the long-wave (terrestrial) spectrum only crude estimates from general circulation models exist. In preliminary work, we have developed a suggestion how active satellite remote sensing might be used to characterise ice crystal number concentrations and co-incident aerosol concentrations, and thus might allow for an assessment of the aerosol forcing in the terrestrial spectrum. However, the satellite remote sensing data are highly uncertain and need to be validated using reference data. In FLASH, we propose to (i) validate the satellite ice crystal concentration and its sensitivity to temperature, vertical wind, cloud regime, and aerosol conditions using the large statistics now available from HALO (ACRIDICON, ML-CIRRUS), (ii) verify the spaceborne retrievals with airborne retrievals using the lidar and radar onboard HALO (NARVAL, NARVAL-II, NAWDEX) that have better spatiotemporal resolution, (iii) make use of climate model simulations for interpretation of the statistical relationships and (iv) work towards an estimate and uncertainty characterisation of the aerosol radiative forcing in the long-wave spectrum. Within SPP 1294, FLASH is intends to exploit the exiting data and work with upcoming data from multiple campaigns in an integrative way, towards the goals of achieving a better quantification of the aerosol-climate forcing, a validation of innovative and crucial satellite retrievals, as well as an evaluation and improvement of essential parameterisations in climate models.