ATMOCHEM - Biological aerosol particles in the atmosphere and their impact on clouds (BIOCLOUDS)

气溶胶粒子在大气科学和气候中发挥着关键作用，因为它们对云的形成至关重要。其中一个亚类是生物来源的气溶胶颗粒(ABO)，包括植物碎片、花粉或细菌、真菌和酵母菌等生物。Puy de Dome空间站最近的测量结果表明，云水中存在细菌、酵母菌和真菌。人们可以推测，在更温暖和更潮湿的气候中，会有更多的细菌在大气中找到生存条件，从而在气溶胶和云中变得更加丰富。以往的研究表明，这种ABO粒子有可能作为云凝结核(CCN)和冰核(IN)，从而影响云的形成和演变，特别是降水的开始。然而，需要进行新的实验室和云模型研究，以量化ABO在云中的微物理作用，从而也量化其对气候的间接影响。原始ABO和那些在大气中通过非均相化学和云过程老化的ABO的微物理性质都是重要的，需要量化，特别是那些在云、雪和降水中发现的ABO物种。拟议的BIOCLOUDS项目旨在调查和量化ABO粒子在对流层云中的作用。这是对征求建议书范围内的专题1“对流层气溶胶和云”、分专题2(生物气溶胶)和4(云处理)的贡献。四个项目伙伴和两个相关伙伴将结合他们在微生物学、气溶胶-云微物理学、气象学和云模拟方面的专门知识，以便(1)确定云和降水水中的相关物种，并比较云外气溶胶中的相关物种，(2)提取和培养用于实验室研究CCN和IN属性的相关样本，以及(3)利用新的实验结果作为云模式的输入，以便改进模式中ABO的微物理过程的表述，并更准确地评估这些过程对云演变的潜在重要性。对建议的项目感兴趣的物种是细菌、酵母、真菌、花粉和植物碎片。

Aerosol particles play a key role in atmospheric sciences and climate, as they are essential for cloud formation. A subgroup are aerosol particles of biological origin (ABO) which include plant debris, pollen or living organisms like bacteria, fungi and yeasts. Recent measurements on the Puy de Dome station have identified in cloud water the presence of bacteria, yeasts and fungi. One can speculate that, in a warmer and more humid climate, more bacteria will find viable conditions in the atmosphere and, thus, become even more abundant in aerosols and clouds.It is known from previous studies that such ABO particles have the potential to act as cloud condensation nuclei (CCN) and ice nuclei (IN) and thereby influence the formation and evolution of clouds, in particular the initiation of precipitation. However, new laboratory and cloud modelling studies are needed to quantify the microphysical role of ABO in clouds and thereby also their indirect effect on climate. The microphysical properties of both pristine ABO and those aged in the atmosphere by heterogeneous chemistry and cloud processes are important and need to be quantified, in particular for those ABO species found in clouds, snow, and precipitation water.The proposed project BIOCLOUDS aims at investigating and quantifying the role of ABO particles in tropospheric clouds. It is a contribution to topic area 1 “Tropospheric Aerosols and Clouds”, subtopics 2 (The biogenic aerosol) and 4 (Cloud processing) within the call for proposals. The four project partners and two associated partners will combine their expertise in microbiology, aerosol-cloud microphysics, meteorology, and cloud modelling in order to (1) identify relevant species in cloud and precipitation water and, for comparison, in the aerosol outside clouds, (2) extract and culture relevant samples for laboratory investigations of CCN and IN properties, and, (3) make use of the new experimental results as input to cloud models in order to improve the formulation of microphysical processes for ABO in models and to more accurately assess the potential importance of these processes for cloud evolution. Species of interest for the suggested project are bacteria, yeasts, fungi, pollen and plant debris.