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与云的相互作用产生的辐射强迫是量化当前气候变化强迫的主要不确定性。虽然对于主导短波（太阳）部分电磁波谱强迫的液态水云已经取得了一些进展，但对于长波（陆地）频谱的强迫，只有一般环流模式的粗略估计。在初步工作中，我们提出了一种建议，即如何利用主动卫星遥感来表征冰晶数浓度和共入射气溶胶浓度，从而可能对陆地光谱中的气溶胶强迫进行评估。然而，卫星遥感数据具有高度的不确定性，需要使用参考数据进行验证。在FLASH中，我们建议(i)利用HALO （ac<s:1> on, ML-CIRRUS）现有的大量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）利用HALO （NARVAL, NARVAL- ii， NAWDEX）机载激光雷达和雷达对机载检索进行验证，后者具有更好的时空分辨率。（iii）利用气候模式模拟来解释统计关系，以及（iv）对长波频谱上气溶胶辐射强迫的估计和不确定性特征进行研究。在SPP 1294中，FLASH计划利用现有的数据，并以综合的方式处理来自多个活动的即将获得的数据，以实现更好地量化气溶胶-气候强迫的目标，验证创新和关键的卫星检索，以及评估和改进气候模式中的基本参数化。

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.