A Model Study of the Chemistry of Biomass Burning Smoke Plumes Constrained by Aircraft Data

生物质燃烧是大气中痕量气体和颗粒的主要来源，但目前的模型尚未捕捉到导致臭氧和二次有机气溶胶（SOA）的显着形成的过程，这通常是在排放后的最初几个小时内观察到的。该项目将开发一个新的最先进的建模框架，将最新的进展建模气体和气溶胶相光化学到一个高分辨率的拉格朗日色散模型。新的建模框架将根据两个北美烟羽的化学演变的详细测量进行评估。这将使以下科学问题得到解决：* 是什么原因导致在新鲜生物质烟羽中观察到的高臭氧和羟基自由基（OH）浓度？* 烟羽中SOA的来源是什么？* 烟雾气溶胶对烟雾羽流中的光解速率以及光化学有何影响？2006年墨西哥MILAGRO（Megacity Initiative Local and Global Research Observations）活动和2009年加州圣路易斯奥比斯波生物质燃烧（SLOBB）实验中的年轻生物质燃烧烟羽的飞机测量提供了全面的痕量气体和气溶胶演变数据，包括生物质燃烧烟羽中OH的首次原位观测，因此是评估模型开发的理想方法。这些羽流的化学演变将使用新版本的气溶胶模拟程序（ASP），将纳入半经验的二维挥发性基集（2D-VBS）计划，已成功地用于模拟SOA的形成在墨西哥城。ASP的这一更新版本将被纳入由天气研究和预报模型（WRF）的高分辨率输出驱动的混合单粒子拉格朗日综合轨迹（HYSPLIT）弥散模型的增强版本。结合模型，飞机和GOES卫星观测的约束，然后将被用来研究O3和SOA的形成内的烟雾plumes.This研究将导致更好地了解气候，空气质量和生物质燃烧对人类健康的影响的基本。在这项工作中使用WRF-HYSPLIT框架来模拟大气扩散将有助于将来将该模型纳入现有的预报系统模型。该项目将在一名专门测量生物质燃烧烟羽中痕量气体的学术科学家和两名私营部门科学家之间建立合作关系，其中一名专门研究烟羽中的大气化学建模，另一名专门研究大气烟羽的扩散建模。这项工作还将刺激和支持WRF和ASP模型的继续开发，这些模型是在以前的NSF支持下开发的。两名研究生将接受培训，使用开发的模型，这将使他们有机会在非学术环境中与科学家合作。

Biomass burning is a major source of trace gases and particles to the atmosphere, but current models have not yet captured the processes that lead to the significant formation of ozone and secondary organic aerosol (SOA) that is often observed in the first few hours after emission. This project will develop a new state-of-the-art modeling framework that incorporates recent advances in modeling gas- and aerosol-phase photochemistry into a high resolution Lagrangian dispersion model. The new modeling framework will be evaluated against detailed measurements of the chemical evolution of two North American smoke plumes. This will allow the following science questions to be addressed: * What causes the high ozone and hydroxyl radical (OH) concentrations observed in fresh biomass smoke plumes? * What are the sources of SOA within the smoke plumes? * What is the impact of smoke aerosols on photolysis rates, and hence photochemistry, within the smoke plumes?The aircraft measurements of young biomass burning smoke plumes from the 2006 MILAGRO (Megacity Initiative Local and Global Research Observations) campaign in Mexico and the 2009 San Luis Obispo Biomass Burning (SLOBB) experiment in California provide comprehensive trace gas and aerosol evolution data, including the first in situ observations of OH in biomass burning plumes, and are thus ideal to evaluate the model development. The chemical evolution of these plumes will be modeled using a new version of the Aerosol Simulation Program (ASP) that will incorporate the semi-empirical two-dimensional Volatility Basis Set (2D-VBS) scheme that has been used successfully to model SOA formation in Mexico City. This updated version of ASP will be incorporated into an enhanced version of the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) dispersion model driven by high-resolution output from the Weather Research and Forecasting (WRF) model. The combined models, constrained by aircraft and GOES satellite observations, will then be used to study the formation of O3 and SOA within the smoke plumes.This research will lead to a better fundamental understanding of the climate, air quality, and human health impacts of biomass burning. Use of the WRF-HYSPLIT framework for modeling atmospheric dispersion in this work will facilitate the future inclusion of the model into the existing forecasting system models. This project will establish collaboration between an academic scientist specializing in the measurement of trace gases in biomass burning smoke plumes and two private sector scientists, one specializing in the modeling of atmospheric chemistry within smoke plumes and one specializing in modeling the dispersion of atmospheric plumes. The work will also stimulate and support the continued development of the WRF and ASP models, which were developed with previous NSF support. Two graduate students will be trained to use the developed models, which will give them the opportunity to work with scientists in a non-academic environment.