Investigating the impact of Land-use and land-cover change on Aerosol-Cloud-precipitation interactions Using Polarimetric Radar retrievals (ILACPR)

ILACPR项目有助于优先方案的目标之一--利用雷达偏振测量进行定量过程和模型评估，并就人为土地利用和土地覆盖变化对云微物理和宏观物理(动力学)机制的影响提供了新的见解。对具有大尺度气溶胶扰动和地表变化的夏季对流风暴的初步数值模拟研究表明，地面降水系统对强迫的响应较弱。然而，作为强迫变化的缓冲系统的微物理/宏观物理路径是不同的。极化雷达测量与这种数值模式情景相结合，可以调查陆地、气溶胶、云和降水过程之间相互作用产生的缓冲机制。旋光法使我们能够研究模拟和观测的降水云的微物理和宏观物理过程的演变。偏振指纹方面的修正降水产生过程的示意图使我们能够验证数值模式情景的结果，并表示地面通量分配和气溶胶-云相互作用之间的反馈过程。陆地系统模拟平台(TerrSysMP)将用于调查土地利用/土地覆盖变化对气溶胶分布和陆地-气溶胶-云-降水相互作用的影响。虽然TerrSysMP中的大气模式目前忽略了土地覆盖、大气化学和气溶胶的可变性和反馈，但该模式将得到一个化学输送模式(CTM)的扩展，以允许对陆地-气溶胶-云-降水相互作用进行定量研究。TerrSysMP和TerrSysMP-CTM将在德国西北部与荷兰、比利时、卢森堡和法国接壤的地区进行不同气象条件下的日尺度多重集合模拟。对观测到的和合成的(模型生成的)微物理和宏观物理过程的极化指纹的共同分析，如蒸发、环流/聚集和上升气流-下沉气流强度，基于有和没有CTM的不同模式情景，是了解人为土地利用和土地覆盖变化对降水产生系统演变的影响的一种新的有希望的战略。

Project ILACPR contributes to objective one of a priority programme, the exploitation of radar polarimetry for quantitative process and model evaluation, and provides new insights on the impact of anthropogenic land-use and land-cover changes on cloud microphysical and macrophysical (dynamical) mechanisms. Preliminary numerical modeling study of summertime convective storm with large-scale perturbation of aerosols and change in land-cover suggests that the response of the system in terms of surface precipitation to the forcing is weak. However, the microphysical/macrophysical pathways acting as a buffered system to the changes in forcing, differs. Polarimetric radar measurements in combination with such numerical model scenarios allow investigation of the buffering mechanisms, arising from interactions between land, aerosols, clouds and precipitation processes. Polarimetry enables us to study the evolution of the microphysical and macrophysical processes for simulated as well as observed precipitating clouds. The sketches of modified precipitation generating processes in terms of polarimetric fingerprints enables us to validate the results from the numerical model scenarios and represent the feedback processes between the surface flux partitioning and aerosol-cloud interactions. The Terrestrial Systems Modeling Platform (TerrSysMP) will be used to investigate the impact of land-use/land-cover change on aerosol distributions and land-aerosol-cloud-precipitation interactions. While the atmospheric model in TerrSysMP currently ignores the variability and feedbacks of land-cover, atmospheric chemistry and aerosols, the model will be extended with a chemical transport model (CTM) to allow for the quantitative investigation of land-aerosol-cloud-precipitation interaction.Multiple ensemble simulations over diurnal scales with different meteorological settings will be conducted with TerrSysMP and TerrSyMP-CTM over the northwestern part of Germany, bordering Netherlands, Belgium, Luxemburg and France. The common analysis of observed and synthetic (model generated) polarimetric fingerprints for microphysical and macrophysical processes, like evaporation, riming / aggregations, and updraft-downdraft intensities based on different model scenarios with and without CTM represents a new promising strategy to understand the impact of anthropogenic land-use and land-cover changes on the evolution of precipitation generating systems.