Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B
Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B
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DOI：
10.5194/acp-8-6297-2008
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发表时间：
2008-10
影响因子：
6.3
通讯作者：
I. McKendry;A. Macdonald;W. Leaitch;A. Donkelaar;Qiang Zhang;T. Duck;R. Martin
中科院分区：
文献类型：
--
作者：
I. McKendry;A. Macdonald;W. Leaitch;A. Donkelaar;Qiang Zhang;T. Duck;R. Martin
描述了2006年春季影响加拿大西部的两个新的长距离沙尘输送案例的气溶胶的气象学和物理化学特征。每次事件都显示出硫酸盐气溶胶和亚洲起源的地壳物质的增强。然而，这些事件的性质完全不同，表明这些事件的性质变化很大。4月事件是一个显著的沙尘事件，细颗粒硫酸盐有相当大的增强，而5月事件是一个较弱的沙尘事件，也有显着的细颗粒硫酸盐增强。后一个事件值得注意，因为它持续时间很短，随后很可能是区域来源的有机物质大量增加。这两个事件与其他记录的情况下，延伸到1993年的比较表明，所有的尘埃事件同步增强硫酸盐和地壳气溶胶。然而，根据气溶胶增强的幅度及其硫酸盐与钙的比例，事件在很大程度上有所不同。在一个极端情况下，事件主要是由非常显着的地壳增强（如1998年和2001年的“灰尘”事件），而在另一个事件与一些尘埃运输，但硫酸盐增强是非常高的幅度（如1993年事件在火山口湖和2006年5月15日事件在惠斯勒）。其他事件代表了一种“混合”。这种变化可能是粉尘和人为SO 2源的相对强度、输送途径，特别是粉尘通过工业SO 2源输送的程度，以及气象和化学过程的函数。
The meteorology and physico-chemical characteristics of aerosol associated with two new cases of long range dust transport affecting western Canada during spring 2006 are described. Each event showed enhancements of both sulfate aerosol and crustal material of Asian origin. However, the events were of quite different character and demonstrate the highly variable nature of such events. The April event was a significant dust event with considerable enhancement of fine particle sulfate while the May event was a weaker dust event, also with significant fine particle sulfate enhancement. The latter event was notable in the sense that it was of short duration and was quickly followed by a large increase of organic material likely of regional origin. Comparison of these two events with other documented cases extending back to 1993, suggests that all dust events show coincident enhancements of sulfate and crustal aerosol. However, events vary across a wide continuum based on the magnitude of aerosol enhancements and their sulfate to calcium ratios. At one extreme, events are dominated by highly significant crustal enhancements (e.g. the well-documented 1998 and 2001 "dust" events) while at the other are events with some dust transport, but where sulfate enhancements are of very high magnitude (e.g. the 1993 event at Crater Lake and the 15 May 2006 event at Whistler). Other events represent a "mix". It is likely that this variability is a function of the comparative strengths of the dust and anthropogenic SO 2 sources, the transport pathway and in particular the extent to which dust is transported across industrial SO 2 sources, and finally, meteorological and chemical processes.