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

该项目将继续进行并扩大在中纬度怀俄明州的拉勒米测量气溶胶大小和浓度的垂直剖面（从地面到33公里）。 扩展测量将增加直径在0.03至0.15微米之间的气溶胶的新的尺寸分辨浓度测量，以及来自巴西纳塔尔的热带测量。 气球上的测量将在五年内从拉勒米开始每两个月进行一次，从纳塔尔开始每年进行一次。 与剑桥大学的合作将允许结合一些气溶胶剖面对OCS（羰基硫）和SO 2（二氧化硫）进行探索性测量。 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门知识。 在拉勒米继续进行平流层气溶胶测量对于帮助明确确定火山静止“背景”时期平流层气溶胶水平至关重要。 维持背景气溶胶水平所需的硫源以及平流层气溶胶扰动的程度仍然不确定。 拉勒米的记录是平流层气溶胶存在的最长的持续记录，因此有利于解决这些问题。 对较小颗粒的新测量将解决在小颗粒控制表面积的背景期间卫星和现场估计的气溶胶表面积之间持续存在的差异。 如果发生大规模的热带火山爆发，测量重点将转移到新鲜的火山羽流。 每年的热带测量是探索性的，以解决几个问题，如如何以及中高纬度的大小分布特征的气溶胶在热带地区。 热带测量还将检验早期热带平流层新粒子形成和大粒子层的测量，以及模式是否正确地考虑了平流层气溶胶源气体OCS/SO2。平流层气溶胶对大气和社会具有广泛的影响。 全球平流层臭氧的建模需要精确估计气溶胶表面积。 重大火山爆发通过涉及氯的多相化学作用对臭氧产生直接影响，并对辐射产生直接影响，导致平流层升温和对流层降温。 对流层气溶胶对辐射的影响更为深远，既有直接的影响，也有对云的影响。 该项目将促进本科生和研究生的教学和培训。

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.