Collaborative Research: Physical and Chemical Impacts on the Ice Nucleating Properties of Atmospheric Particles in Springtime

目前对冰成核过程的物理和化学影响知之甚少，理解气溶胶粒子向冰的转化是大气科学领域的研究热点。这一合作项目建立在首席调查员以前工作的基础上--在这种情况下，将现场的气溶胶和冰核测量结合起来，以确定成核冰的气溶胶的化学成分，并表征从气溶胶颗粒到冰晶的转化。通过科罗拉多州立大学(CSU)、科罗拉多大学(CU)和一个政府实验室的合作，研究人员将使用多种方法相结合，包括CSU连续流动扩散室测量冰核数量密度，电子显微镜测量成核冰粒的大小和组成，以及NOAA空气动力学实验室的粒子分析激光质谱仪和CU气溶胶质谱仪，以连续实时分析新成核冰粒的尺寸分辨化学残留物。研究人员将比较作为冰核活动的颗粒与周围大气气溶胶的物理和化学特征，以确定哪些特征因素与在典型卷云温度和过饱和条件下形成冰晶的能力有关。这项研究的结果对于理解气溶胶在全球气候中的作用以及它们对其他物种化学的影响应该是重要的。这项研究的结果应该对气候和全球变化产生影响，涉及到人为对云和辐射强迫的影响--特别是关于卷云的形成。实验数据将为约束气候模型提供新的数据，并使参数化更稳健和更具代表性。该项目涉及两个大学团体和一个政府实验室之间的跨学科合作。对教育的贡献包括支持博士后研究人员和研究生获得专业研究经验。

The physical and chemical influences on ice nucleation processes are poorly understood at present, and understanding the transformations from aerosol particles to ice is of high interest in the field of atmospheric sciences. This collaborative project builds upon previous work by the lead investigator - in this case combining aerosol and ice nucleus measurements at a field site to determine the chemical composition of aerosols that nucleate ice as well as characterizing those transformations from aerosol particles to ice crystals. Through collaborations between Colorado State University (CSU), University of Colorado (CU) and a government laboratory the investigators will use a combination of methods, including the CSU continuous flow diffusion chamber for ice nuclei number density measurements, electron microscopy for size and composition of nucleated ice particles, and the NOAA Aeronomy Laboratory Particle Analysis by Laser Mass Spectrometry instrument and CU aerosol mass spectrometer to continuously analyze size-resolved chemical residuals of freshly nucleated ice particles in real time. The investigators will compare physical and chemical characteristics of particles active as ice nuclei with ambient atmospheric aerosol to determine which characteristic factors are associated with the ability to form ice crystals at typical cirrus temperatures and supersaturations. The results of this research should be important for understanding the role of aerosols in global climate as well as their impacts on the chemistry of other species. The results of the research should have an impact on climate and global change relative to issues related to anthropogenic influences on clouds and radiative forcing - particularly with respect to cirrus formation. Experimental data will provide new data to constrain climate models, and make parameterizations more robust and representative. The project involves interdisciplinary collaboration between two university groups and a government laboratory. Contributions to education include support for postdoctoral researchers and graduate students to gain professional research experience.