Particle Size Distributions within Arctic Polar Stratospheric Clouds to Complement Particle Composition and Scattering Measurements

北极极地平流层云内的颗粒尺寸分布，以补充颗粒成分和散射测量

• 批准号: 0095158
• 负责人: Terry Deshler
• 金额: $ 24.81万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-15 至 2005-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0095158&HistoricalAwards=false
• 关键词: Particle; Size; Distributions; within; Arctic

Deshler OPP-0095158A more complete quantitative understanding of polar stratospheric ozone loss requires further work in several areas. The microphysics of the nucleation, growth, composition, and sedimentation of particles in polar stratospheric clouds (PSCs) is one of these areas. PSC particles provide sites for the heterogeneous chemistry required to activate chlorine, which then destroys ozone. The pivotal role played by PSC particles is most evident in the Arctic where ozone loss is essentially modulated by temperature, a surrogate for PSCs, from year to year. The frequency, duration, and timing of PSC occurrence determines the extent of chlorine activation and denitrification in the stratospheric polar vortex, and thus the amount of ozone loss. Removing some of the present uncertainties concerning PSC formation temperatures, particle composition, and particle phase will permit more careful modeling of the amount of chlorine processed by PSCs and the extent of denitrification. The activation of chlorine and ultimately ozone loss is dependent on all of these factors.This work takes advantage of invitations from several European colleagues to collaborate on joint measurements of PSC particles during the winters of 2000/2001 and 2001/2002. The European institutions and their measurements are: Max-Planck-Institut fur Kernphysik - Heidelberg, particle composition CNRS-Laboratoire de Meteorologie Dynamique - Paris, gas phase water vapor concentration; CNR - Istituto di Fisica dell'Atmosfera - Rome, aerosol backscatter and depolarization; and Danish Meteorological Institute - Copenhagen, aerosol backscatter and microphysical/mesoscale modeling. Under previous support these four instruments, plus the particle counters used in this work, have been integrated onto one balloon gondola which will simultaneously measure, in situ, PSC particle composition, concentration, size, depolarization, backscattering, and gas phase concentrations of water. This gondola was flown for the first time in January 2000 in the Arctic.This grant will complete four more Arctic PSC measurements with this unique set of instruments. Two instruments will be used to measure the ambient concentration of condensation nuclei and of aerosol with radii =0.15 - 10.0 mm in 12 size classes. From these measurements size distributions can be estimated. To provide estimates of the volume of the condensed nitric acid and water in the PSCs, a second aerosol counter will be included to measure the background stratospheric aerosol. This instrument will be fitted with an inlet heater, thus sampling aerosol after they have been exposed to an inlet wall temperature of 250 K for ~ 0.1 s prior to sampling.In addition to providing aerosol size distributions and estimates of condensed volume for the joint measurements, the work will continue to focus on methods to infer particle index of refraction, which is a function of composition, through comparisons of our size distribution measurements with in situ optical scattering measurements at a number of wavelengths. Estimates of particle index of refraction which result from these comparisons will be used in the interpretation of particle composition measurements.These new joint measurements will follow the first successful set of measurements by this configuration of instruments in January 2000. The January 2000 measurements constituted the first direct measurements of single particle composition within a PSC, coincident with a characterization of aerosol size, concentration, phase, and optical properties. These measurements revealed a PSC composed of layers of liquid droplets interspersed with layers of nitric acid hydrates. The agreement amongst the various instruments in capturing the fine layered structure of the cloud was impressive. Many layers of the cloud fit well within our thermodynamic understanding of PSCs while some new HNO3 rich particle types were observed.

DESHLER OPP-0095158A对极地平流层臭氧损失的更完整的定量了解需要在几个地区进行进一步的工作。这些区域之一是极性平流层云（PSC）中颗粒的成核，生长，成分和沉积的微物理学。 PSC颗粒提供了激活氯所需的异质化学的位点，然后破坏臭氧。 PSC颗粒扮演的关键作用在北极最明显，在北极，臭氧损失基本上是由温度（每年）的替代体温度调节的。 PSC发生的频率，持续时间和时机决定了平流层极性涡流中氯激活和反硝化的程度，因此决定了臭氧损失的量。消除有关PSC形成温度，颗粒组成和颗粒相的一些目前的不确定性，将允许对PSC处理的氯含量和硝化程度进行更仔细的建模。氯的激活和臭氧损失的激活取决于所有这些因素。这项工作利用了来自欧洲几个同事的邀请，在2000/2001和2001/2002的冬季期间，在PSC颗粒的关节测量中进行了协作。欧洲机构及其测量值是：Max-Planck-Institut fur kernphysik-Heidelberg，粒子组成CNRS-Laboratoire de Meteorologie Dynamique-巴黎，巴黎，气相水蒸气浓度； CNR- iStituto di fisica dell'Atmosfera -Rome，气溶胶反向散射和去极化；和丹麦气象研究所 - 哥本哈根，气溶胶反向散射和微物理/中尺度建模。在先前的支持下，这四种仪器以及这项工作中使用的粒子计数器已集成到一个球囊吊船上，该吊船将同时测量原位，PSC粒子组成，浓度，大小，去极化，反向散射和气相的浓度。该吊船是2000年1月在北极首次飞行的。这笔拨款将使用这套独特的仪器完成四次北极PSC测量。将使用两种仪器来测量12个尺寸类别中半径= 0.15-10.0 mm的冷凝核和气溶胶的环境浓度。从这些测量值可以估计。为了估算PSC中冷凝的硝酸和水的体积，将包括第二个气溶胶计数器，以测量背景平流层气溶胶。该仪器将配备入口加热器，因此在抽样前将气溶胶暴露于入口壁温度250 k的入口壁温度左右约0.1 s。除了提供气溶胶尺寸分布以及对关节测量值的凝固量分布和估计值的估计值，该工作将继续集中在衡量粒子的方法上，该方法是通过分布的分布来衡量的。许多波长的散射测量。这些比较产生的粒子粒子指标的估计值将用于粒子组成测量的解释。这些新的联合测量将遵循2000年1月的仪器配置的第一项成功测量。2000年1月的2000年测量值构成了PSC中单个粒子组成的第一个直接测量，在PSC中，均具有相结合的属性，相结合了一个阶段的尺寸，均匀尺寸，浓度均匀尺寸，并构成了型号，并构成了型号，并构成了型号的特征，并构成了构图。这些测量结果表明，PSC由液滴层组成，这些液滴插入了硝酸水合物层。各种仪器之间在捕获云层的层状结构方面的协议令人印象深刻。云的许多层非常适合我们对PSC的热力学理解，同时观察到一些新的HNO3富粒子类型。