Natural Background Visibility and Regional Haze Goals in the Southeastern United States
Natural Background Visibility and Regional Haze Goals in the Southeastern United States
复制标题
美国东南部自然背景能见度和区域霾目标
DOI：
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发表时间：
2005
影响因子：
2.7
通讯作者：
P. Brewer
中科院分区：
文献类型：
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作者：
I. Tombach;P. Brewer
摘要：美国区域霾减排计划的目标是到2064年在国家公园和荒野地区实现“自然条件”。对海盐和生物源有机物的背景浓度、偶发性的撒哈拉沙尘和亚洲沙尘以及自然火灾产生的碳的研究调查结果进行了综述，以便为对美国东南部自然条件下大气细颗粒物成分的浓度进行特定地点的估算提供基础。基于此综述，对这些气溶胶成分对自然背景能见度的潜在贡献进行了粗略估算。在一个内陆山区地点，天然有机颗粒物对达到自然条件所需的能见度改善速率起主导作用，而在沿海地点，有机颗粒物和海盐起主导作用。非洲沙尘也有较大的偶发性影响，但当前的监管方法并非旨在解决偶发性的背景变化。尽管全球空气污染模型提供了一些见解，且野火排放物在局部可能占主导地位，但没有足够的数据详细量化野火的贡献。对默认自然背景估算进行保守的区域细化，不会大幅改变实现区域霾计划第一阶段所需的区域范围内环境颗粒物浓度的降低速率。然而，在特定的一类地区进行细化可能会对确定当地减排努力的性质（规模以及时空分布）产生相当大的影响。
Abstract The goal of the regional haze mitigation program in the United States is to attain “natural conditions” in national parks and wilderness areas by 2064. Results of research investigations on background concentrations of sea salt and biogenic organic matter, of episodic Saharan and Asian dust, and of carbon from natural fires were reviewed to provide a basis for making site‐specific estimates of what the concentrations of atmospheric fine particulate matter components might be under natural conditions in the Southeastern United States. Based on this review, rough estimates were made of potential contributions of these aerosol components to natural background visibility. Natural organic particles were the dominant influence on the rate of visibility improvement required to reach natural conditions at an inland, mountainous location, and organic particles and sea salt were the dominant influences on the rate at a coastal location. African dust also had a large episodic effect, but the current regulatory approach is not designed to address episodic background variations. Insufficient data exist to quantify the contributions of wildfires with any detail, although global air pollution modeling provides insight, and their emissions can be locally dominant. Conservative regional refinements to the default natural background estimates do not greatly alter the region‐wide rates of reduction of ambient particulate matter concentrations that will be needed to accomplish the first phase of the regional haze program. However, refinements at specific Class I areas may have considerable influence on defining the nature (magnitude and spatial and temporal distribution) of local emission reduction efforts there.