Ice NUcleation Process Investigation And Quantification

在这一提案中，我们正在寻求资金参与一项有国际参与者的实地活动，该活动是多学科的，将于2013年冬季在瑞士阿尔卑斯山的少女峰山研究气溶胶与云的相互作用。在之前NERC投资的基础上，这是一个具有成本效益和及时的项目。地球的辐射收支很大程度上受到云的影响，而人类引起的粒子负荷变化对云的影响被称为间接影响，这种变化很大，而且高度不确定。这种不确定性在很大程度上是由于对气溶胶和云的基本特性和过程缺乏了解，导致它们在当前科学水平的模型中表现不佳。事实上，IPCC没有对这一迹象进行任何评估，更不用说辐射强迫的不确定性了，这可归因于气溶胶对冰云的影响，因为他们认为目前的不确定性太大了。冰和混合相/液体云之间的快速转变是由于气溶胶与云的相互作用。在少女峰观测到的云层中冰晶的数量可以用在云层逆风处观测到的非均匀IN来解释。基于大气颗粒（如尘埃、生物颗粒、烟灰）的替代物，实验室推导出的冰核参数化足以解释云内的原始冰形成速率。NERC SIMPLEX项目（PI: Connolly）得出的冰-冰聚集率可以用来解释真实大气中的冰-冰聚集。5. 次级冰的增加对这些云中的冰有很大的贡献。我们建议进一步深入了解这些问题，并通过开展实地活动，然后进行广泛的数据分析和建模，来测试这些假设。野外战役将有几个新的方面：最先进的云微物理测量，包括2DS和CPI-3V.2。新测量生物、尘埃、黑碳、挥发性和总气溶胶，以及它们在现场冰粒中的富集程度。3 .使用IN计数器在现场（云内）和逆风地点测量冰核。与国际合作伙伴的有效合作，包括来自瑞士的科学家和德国的几个研究所。NCAS仪器科学家在将仪器部署到野外方面的专业知识。利用激光雷达在逆风地点测量气溶胶和湍流的剖面。为了解释测量结果，我们将使用一个详细的气溶胶-云和降水相互作用模型，该模型是由PI: Connolly在曼彻斯特开发的，作为评估研究计划的一部分。这将使我们能够在两个地点测量气溶胶，并使用它们来测试模型中的冰核参数化，并与来自冰核计数器和云中冰晶浓度测量的数据进行验证。该模型将用于推导不同颗粒的富集因子。它还将使我们能够处理各种目标。数据分析和建模程序将受益于：1。NCAS仪器科学家在数据分析和数据产品推导方面的专业知识。PDRA: Christopher Dearden，他在使用中尺度模型和详细的bin微物理模型建模云微物理过程方面具有一系列专业知识。PDRA: Ian Crawford，他在微物理探测和解释的现场部署方面具有广泛的专业知识。在野外冰核和参数化方面与同事密切合作，以便将最新的发展纳入分析。我们认为，通过将世界领先的科学家聚集在一起，以相似但不同的目标开展同一领域的运动，有可能在这方面取得重大进展。

In this proposal we are seeking funds to take part in a field campaign that we have been invited to contribute to, which has international participants, is multidisciplinary, and will study aerosol-cloud interactions at the Jungfraujoch mountain site in the Swiss Alps in winter 2013.This is a cost effective and timely project, building on previous NERC investment. The Earth's radiation budget is very greatly affected by clouds, and human-induced changes to the particle loading affecting them, known as indirect effects, are large and highly uncertain. A large part of this uncertainty is the result of poor knowledge of the fundamental aerosol and cloud properties and processes, leading to their poor representation in the current state-of-the-science models. Indeed the IPCC did not have any assessment of the sign, let alone the uncertainty in radiative forcing, which was attributable to the effects of aerosols on ice clouds as they thought that the uncertainties were at present too large.Hypotheses:1. That the rapid transitions between ice and mixed phase / liquid clouds are due to aerosol-cloud interactions.2. That the number of ice crystals within the clouds observed at Jungfraujoch can be explained by the heterogeneous IN observed at a site upwind of the clouds3. That laboratory derived ice nucleation parameterisations, based on surrogates of atmospheric particles (e.g. dust, biological particles, soot) are adequate to explain primary ice formation rates within the clouds.4. That the ice-ice aggregation rates derived from the NERC SIMPLEX project (PI: Connolly) can be used to explain ice-ice aggregation in the real atmosphere. 5. That the secondary ice multiplication is a strong contributor to ice within these clouds.We propose to gain further insight into these problems and test these hypotheses by conducting a field campaign followed by extensive data analysis and modelling. The field campaign will have several novel facets:1. State-of-the-science cloud microphysics measurements, including, 2DS and CPI-3V.2. Novel measurements of biological, dust, black carbon, volatile and total aerosols as well as their enrichment within ice particles at the site.3. Measurements of ice nuclei using IN counters, both at the site (in-cloud) and at an upwind site.4. A proven collaboration with international partners, involving scientists from Switzerland and several institutes in Germany.5. Expertise from NCAS instrument scientists in the deployment of instruments into the field.6. Measurements of profiles of aerosols and turbulence using lidar at the upwind site.In order to interpret the measurements we will use a detailed aerosol-cloud and precipitation interactions model, developed at Manchester as part of the APPRAISE research programme by the PI: Connolly. This will enable us to take the aerosols measured at two sites and use them to test ice nucleation parameterisations in the model and verify them against data from ice nucleus counters and in-cloud measurements of ice crystal concentrations. The model will be used to derive enrichment factors for the different particles. It will also allow us to address the various objectives.The data analysis and modelling program will benefit from:1. Expertise from NCAS instrument scientists in the analysis of data and derivation of data products.2. PDRA: Christopher Dearden who has a range of expertise in modelling cloud microphysical processes using both mesoscale models and detailed bin microphysics models.3. PDRA: Ian Crawford who has a range of expertise in field deployment of microphysics probes and interpretation.4. Close collaboration with colleagues in the field ice nucleation and parameterisation so that the latest developments can be incorporated into the analysis.We feel that there is the potential to make large gains here by bringing together world leading scientists to the same field campaign with similar, but distinct aims.