Emissions of terpenoids, benzenoids, and other biogenic gas-phase organic compounds from agricultural crops and their potential implications for air quality
Emissions of terpenoids, benzenoids, and other biogenic gas-phase organic compounds from agricultural crops and their potential implications for air quality
复制标题
DOI：
10.5194/acp-14-5393-2014
复制
发表时间：
2014-01-01
影响因子：
6.3
通讯作者：
Goldstein, A. H.
中科院分区：
文献类型：
--
作者：
Gentner, D. R.;Ormeno, E.;Goldstein, A. H.
在世界许多地区，农业占土地使用的比例很大，而且还在不断增加。农业植被和其他生物和人为来源的排放在大气中发生反应，产生臭氧和二次有机气溶胶，其中颗粒物(PM2.5)占相当大的比例。使用来自三个测量活动的数据，我们检查了农作物活性气相有机碳排放的大小和组成，以及它们相对于加利福尼亚州圣华金山谷机动车辆人为排放的潜在影响区域空气质量的潜力，该地区不符合对流层臭氧PM2.5的州和联邦标准。2008年，在温室中测量了一组萜类化合物的排放速率，这些作物来自加利福尼亚州的25种代表性作物。在2010年的两个季节：夏季和春季开花期间，在贝克斯菲尔德市区和圣华金河谷农村地区的橙园对挥发性和中等挥发性有机化合物范围内的萜类化合物和其他生物来源化合物进行了环境测量。我们将果园现场的测量结果与臭氧建模方法结合起来，评估橙树对区域臭氧的净影响。考虑到活性前体的排放和臭氧对果园的沉积，橙子树在开花期间的春季是臭氧的净来源，在夏季的大部分时间里相对中性，直到秋天成为臭氧的汇。开花是一个重大的排放事件，导致排放量大幅增加，其中包括一系列以前没有在大气中测量到的化合物。这类生物排放事件需要在模型中更好地参数化，因为它们有很大的潜力影响区域空气质量，因为排放量增加了几个因素，超过一个数量级。在圣华金河谷等地区，夏季农作物(未开花)的大量生物排放以及这些排放可能形成的臭氧和二次有机气溶胶与机动车辆的人为排放处于同一数量级，必须在空气质量模型和二次污染控制战略中加以考虑。
Agriculture comprises a substantial, and increasing, fraction of land use in many regions of the world. Emissions from agricultural vegetation and other biogenic and anthropogenic sources react in the atmosphere to produce ozone and secondary organic aerosol, which comprises a substantial fraction of particulate matter (PM2.5). Using data from three measurement campaigns, we examine the magnitude and composition of reactive gas-phase organic carbon emissions from agricultural crops and their potential to impact regional air quality relative to anthropogenic emissions from motor vehicles in California's San Joaquin Valley, which is out of compliance with state and federal standards for tropospheric ozone PM2.5. Emission rates for a suite of terpenoid compounds were measured in a greenhouse for 25 representative crops from California in 2008. Ambient measurements of terpenoids and other biogenic compounds in the volatile and intermediate-volatility organic compound ranges were made in the urban area of Bakersfield and over an orange orchard in a rural area of the San Joaquin Valley during two 2010 seasons: summer and spring flowering. We combined measurements from the orchard site with ozone modeling methods to assess the net effect of the orange trees on regional ozone. When accounting for both emissions of reactive precursors and the deposition of ozone to the orchard, the orange trees are a net source of ozone in the springtime during flowering, and relatively neutral for most of the summer until the fall, when it becomes a sink. Flowering was a major emission event and caused a large increase in emissions including a suite of compounds that had not been measured in the atmosphere before. Such biogenic emission events need to be better parameterized in models as they have significant potential to impact regional air quality since emissions increase by several factors to over an order of magnitude. In regions like the San Joaquin Valley, the mass of biogenic emissions from agricultural crops during the summer (without flowering) and the potential ozone and secondary organic aerosol formation from these emissions are on the same order as anthropogenic emissions from motor vehicles and must be considered in air quality models and secondary pollution control strategies.