Three-Dimensional Simulations of Long-Range Pollutant Transport Using 222Rn and 210Ph as Tracers

这是一项为期两年的工作计划， 222 Rn和210 Pb在对流层中的分布， 三维模型 氡-222（半衰期3.8天） 由土壤释放到大气中;它衰变为210铅（一半- 寿命22.3年），可迅速融入气溶胶中 颗粒并通过沉积去除。 222 Rn/210 Pb系统 是一个很好的垂直混合，平流的示踪剂， 海洋和极地上空的大陆空气， 气溶胶的运输。 长期时间序列 可从大量地点获得浓度 世界各地 成功诠释了 三维模型的观测将大大提高我们的 了解污染物在海洋中的长程迁移 对流层 在这项研究中使用的三维模型已经 先前显示，提供了对 长线示踪剂（CFC的8.5Kr）的分布。第一 将努力模拟北美的222 Rn分布。 模型结果将通过与观测结果进行比较来评估 美国222 Rn浓度的时间序列 污染物从边界层向自由层的输送 对流层将进行调查。 222 Rn的全球模拟 将用于研究南方的远程传输 根据广泛的时间序列， 在亚南极点和南极点测量的浓度。 该项目的后半部分将涉及全球模拟 210 Pb，重点是解释观测结果， 北美、太平洋、北极和南极 210 Pb研究的结果将支持以下研究： 大陆气溶胶在海洋上空的远距离传输， 极地

This is a two-year program of work to simulate the global distributions of 222Rn and 210Pb in the troposphere, using a three-dimensional model. Radon-222 (half-life 3.8 days) is released to the atmosphere by soils; it decays to 210Pb (half- life 22.3 years), which is rapidly incorporated into aerosol particles and is removed by deposition. The 222Rn/210Pb system is an excellent tracer of vertical mixing, advection of continental air over oceans and polar regions, and long-rang transport of aerosols. Long-term time series of measured concentrations are available from a large number of sites around the world. Successful interpretation of the observations with a 3-d model will advance significantly our understanding of long-rang transport of pollutants in the troposphere. The 3-d model to be used in this study has been shown previously to provide excellent simulations of the distributions of long-lined tracers(CFC's 8.5Kr). The first effort will be to model 222Rn distributions over North America. Model results will be evaluated by comparison with observed time series of 222Rn concentrations in the United States. Transport of pollutants from the boundary layer to the free troposphere will be investigated. Global simulations of 222Rn will be used to study long-range transport in the southern hemisphere, on the basis of extensive time series of concentrations measured at subantarctic and antarctic sites. The latter part of the project will involve global simulations of 210Pb, with emphasis on interpreting observations over North America, the Pacific Ocean, the Arctic, and the Antarctic Results from the 210Pb study will support an investigation of long-range transport of continental aerosol over oceans and polar regions.