Balloon-Borne In Situ Measurements of Aerosol Size and Concentration in the Mid Latitudes and Tropics

该项目将继续并扩展在怀俄明州拉勒米的垂直（地表至33公里）气溶胶大小和浓度测量剖面，这是一个中纬度地点。扩展的测量将增加新的大小分辨浓度测量，用于测量直径在0.03至0.15微米之间的气溶胶，以及从巴西纳塔尔进行的热带测量。气球运载的测量将在拉勒米每隔两个月进行一次，在纳塔尔每年进行一次，为期五年。与剑桥大学的合作将允许对OCS（羰基硫化物）和SO2（二氧化硫）进行探索性测量，并结合一些气溶胶剖面。与丹麦气象研究所的另一项合作将为热带工作增加后向散射测量和建模专业知识。在拉勒米继续进行平流层气溶胶测量，对于帮助明确地确定火山静止“背景”时期的平流层气溶胶水平至关重要。维持本底气溶胶水平所需的硫源，以及对平流层气溶胶的扰动程度，仍不确定。拉勒米记录是平流层气溶胶存在的最长持续记录，因此有利于解决这些问题。在小颗粒控制表面积的背景期间，对小颗粒的新测量将解决卫星和现场气溶胶表面积估计值之间持续存在的差异。在热带大型火山喷发的情况下，测量重点将转移到新鲜的火山柱上。每年的热带测量是探索性的，以解决几个问题，例如，在热带地区，中高纬度大小分布的气溶胶特征如何。热带测量还将测试早期对热带平流层新颗粒形成和大颗粒层的测量，以及模型是否正确地解释了平流层气溶胶源气体OCS/SO2。平流层气溶胶对大气和社会都有广泛的影响。全球平流层臭氧的模拟需要精确估计气溶胶表面积。大型火山爆发通过非均相化学（包括氯）对臭氧产生直接影响，并对辐射产生直接影响，导致平流层变暖和对流层变冷。对流层气溶胶直接或通过对云的影响对辐射产生更深远的影响。本项目将促进研究生和研究生的教学和培养。

This project will continue and extend vertical (surface to 33 km) profiles of aerosol size and concentration measurements at Laramie, Wyoming, a mid-latitude site. Extended measurements will add new size-resolved concentration measurements for aerosol between 0.03 and 0.15 micrometers in diameter, and tropical measurements from Natal, Brazil. The balloon-borne measurements will be conducted at bi-monthly intervals from Laramie and annually from Natal over five years. A collaboration with the University of Cambridge will permit exploratory measurements of OCS (carbonyl sulfide) and SO2 (sulfur dioxide) in conjunction with some aerosol profiles. An additional collaboration with the Danish Meteorological Institute will add backscattering measurements and modeling expertise to the tropical work. Continuing stratospheric aerosol measurements at Laramie is essential to help establish, unequivocally, stratospheric aerosol levels during volcanically-quiescent, "background," periods. The sulfur sources necessary to maintain background aerosol levels, and the extent of perturbations to stratospheric aerosol, are still uncertain. The Laramie record is the longest sustained record of stratospheric aerosol existent, and thus favorably positioned to address these questions. New measurements of smaller particles will address a persistent discrepancy between satellite and in situ estimates of aerosol surface area during background periods, when small particles control surface area. In the event of a large tropical volcanic eruption, the measurement focus will shift to the fresh volcanic plume. The annual tropical measurements are exploratory to address several questions, such as, how well do mid- and high latitude size distributions characterize aerosol in the tropics. The tropical measurements will also test earlier tropical stratospheric measurements of new particle formation and large particle layers, and whether models properly account for the stratospheric aerosol source gases OCS/SO2.Stratospheric aerosols have broad impacts on the atmosphere and thus on society. Modeling of global stratospheric ozone requires accurate estimates of aerosol surface area. Major volcanic eruptions produce direct impacts on ozone through heterogeneous chemistry, involving chlorine, and on radiation leading to stratospheric warming and tropospheric cooling. Tropospheric aerosols have even more far reaching impacts on radiation both directly and through their impact on clouds. This project will promote the teaching and training of graduate and postgraduate students.