ABSTRACT

Fuel sulfur emissions control areas have been established in a few marine coastal regions to reduce environmental impacts from combustion of high sulfur residual fuel oil (RFO). For example, in August of 2012, the U.S. began enforcing fuel sulfur limits on certain large commercial marine vessels up to 200 nautical miles (nm) of its coasts as part of a North American Emissions Control Area (NA-ECA), and in January of 2014, the U.S. began enforcing fuel sulfur limits on these vessels within up to 50 nm of Puerto Rico and the U.S. Virgin Islands as part of the U.S. Caribbean Sea ECA (USCAR-ECA). This work evaluates ECA effectiveness at reducing PM_2.5 from combustion of RFO by using both spatial analysis, comparing PM_2.5 source apportionment at IMPROVE monitoring sites largely impacted by air from either inside or outside of an ECA, along with temporal analysis, comparing RFO combustion impacts pre and post ECA enforcement at sites largely impacted by air from inside an ECA. Source apportionment was performed using Positive Matrix Factorization (PMF) on chemically speciated PM_2.5 data from 2009 to 2018. Results for 7 coastal U.S. IMPROVE sites influenced by marine air masses within the NA-ECA showed an annual mean reduction of PM_2.5 from RFO combustion of 79.0% (range, 60.2% to 91.5%) when comparing impacts from the pre-ECA (RFO average 2.7% S) period of 2009–2011 to the ECA 0.1% fuel S period of 2015–2018. In contrast, the Virgin Islands, Big Bend, and Baengnyeong Island South Korea IMPROVE sites were impacted by RFO combustion and were largely or wholly influenced by air masses from outside of an emissions control area. These sites saw a statistically significant 14.0% increase, a 21.0% decrease, or no statistically significant change, respectively, when comparing time periods pre and post ECA enforcement.

Implications: This study performs source apportionment on PM_2.5 monitoring data to identify 10 sites impacted by residual fuel oil combustion, mainly from marine vessel fuel use. The paper then evaluates the effects of enforcement of marine vessel fuel sulfur emissions control areas at reducing ambient impacts of this source on PM_2.5. This study uses both temporal analysis of the source apportionment results, comparing source impacts before and after enforcement of marine vessel fuel sulfur emissions control areas, and spatial analysis, comparing source impacts between sites largely impacted or not impacted by airmasses originating inside of marine vessel fuel sulfur emissions control areas.

摘要

在一些沿海地区建立了燃料硫排放控制区，以减少燃烧高硫渣油（RFO）对环境的影响。例如，2012 年 8 月，作为北美排放控制区 (NA-ECA) 的一部分，美国开始对距离其海岸 200 海里 (nm) 以内的某些大型商业船舶实施燃料硫含量限制，并于 1 月2014 年，作为美国加勒比海 ECA (USCAR-ECA) 的一部分，美国开始在波多黎各和美属维尔京群岛 50 海里范围内对这些船舶实施燃料硫含量限制。这项工作通过使用空间分析和比较 PM _2.5来评估 ECA 在减少 RFO 燃烧中的 PM _{2.5方面的有效性}IMPROVE 监测站点的源分配，主要受来自 ECA 内部或外部的空气的影响，以及时间分析，比较 RFO 燃烧对 ECA 执行前后在主要受来自 ECA 内部的空气影响的站点的影响。使用正矩阵分解 (PMF) 对 2009 年至 2018 年的化学特定 PM _2.5数据进行源分配。受 NA-ECA 内海洋气团影响的 7 个美国沿海 IMPROVE 站点的结果显示 PM _{2.5年平均减少}将 2009-2011 年 ECA 前（RFO 平均 2.7% S）时期的影响与 2015-2018 年 ECA 0.1% 燃料 S 期的影响进行比较时，RFO 燃烧为 79.0%（范围为 60.2% 至 91.5%）。相比之下，维尔京群岛、大弯和 Baengnyeong 岛韩国 IMPROVE 站点受到 RFO 燃烧的影响，并且在很大程度上或完全受到来自排放控制区之外的气团的影响。在比较 ECA 执行前后的时间段时，这些站点分别出现了 14.0% 的统计显着增长、21.0% 的下降或没有统计显着变化。

影响：本研究对 PM _2.5监测数据进行源解析，以确定 10 个受残余燃料油燃烧影响的地点，主要来自船舶燃料的使用。然后，本文评估了执行船舶燃料硫排放控制区在减少该源对 PM _2.5的环境影响方面的效果。本研究使用源分配结果的时间分析，比较船舶燃料硫排放控制区实施前后的源影响，以及空间分析，比较受源自船舶燃料内部的气团影响较大或未受影响的地点之间的源影响硫排放控制区。