The influence of multiple groups of biological ice nucleating particles on microphysical 1 properties of mixed-phase clouds observed during MC3E 2

: 31 A new empirical parameterization (EP) for multiple groups of primary biological aerosol 32 particles (PBAPs) is implemented in the aerosol-cloud model (AC) to investigate their roles 33 as ice-nucleating particles (INPs). The EP describes the heterogeneous ice nucleation by (1) 34 fungal spores, (2) bacteria, (3) pollen, (4) detritus of plants, animals, and viruses, and (5) 35 algae. Each group includes fragments from the originally emitted particles. A high-resolution 36 simulation of a midlatitude mesoscale squall line by AC is validated against airborne and 37 ground observations. 38 Sensitivity tests are carried out by varying the initial vertical profiles of the loadings 39 of individual PBAP groups. The resulting changes in warm and ice cloud microphysical 40 parameters are investigated. The changes in warm microphysical parameters including liquid 41 water content, and cloud droplet number concentration are minimal (< 10%). Overall, PBAPs 42 have little effect on ice number concentration (< 6%) in the convective region. In the 43 stratiform region, increasing the initial PBAP loadings by a factor of 1000 resulted in less 44 than 40% change in ice number concentrations. The total ice concentration is mostly 45 controlled by various mechanisms of secondary ice production (SIP). However, when SIP is 46 intentionally shut down in sensitivity tests, increasing the PBAP loading by a factor of 100 47 has less than a 3% effect on the ice phase. Further sensitivity tests revealed that PBAPs have 48 little effect on surface precipitation as well as on shortwave and longwave flux (< 4%) for 49 100-fold perturbation in PBAPs. 50

31 在气溶胶 - 云模式（AC）中实施了一种针对多组主要生物气溶胶32粒子（PBAPs）的新的经验参数化（EP），以研究它们作为冰核粒子（INPs）的作用。该经验参数化描述了以下几种情况的异质冰核形成：（1）34真菌孢子，（2）细菌，（3）花粉，（4）植物、动物和病毒的碎屑，以及（5）35藻类。每组都包括原始排放粒子的碎片。通过AC对中纬度中尺度飑线进行的高分辨率36模拟，依据空中和37地面观测进行了验证。 38 通过改变单个PBAP组的含量39的初始垂直廓线进行了敏感性试验。对暖云和冰云微物理40参数由此产生的变化进行了研究。暖云微物理参数的变化，包括液态41水含量和云滴数浓度是极小的（<10%）。总体而言，PBAPs 42对对流区域的冰粒子数浓度影响很小（<6%）。在43层状区域，将初始PBAP含量增加1000倍，导致冰粒子数浓度的变化小于40%。总冰浓度主要45由二次冰晶生成（SIP）的各种机制控制。然而，在敏感性试验中当有意关闭SIP时，将PBAP含量增加100 47倍对冰相的影响小于3%。进一步的敏感性试验表明，对于PBAPs的100倍扰动，PBAPs对地面降水以及短波和长波通量的影响也很小（<4%）。50