Size Distribution, Sources, and Seasonality of Suspended Particles in Southern California Marine Bathing Waters

详细信息    查看全文

• 作者：Jong Ho Ahn ; Stanley B. Grant
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：February 1, 2007
• 年：2007
• 卷：41
• 期：3
• 页码：695 - 702
• 全文大小：491K
• 年卷期：v.41,no.3(February 1, 2007)
• ISSN：1520-5851

文摘

In this paper we define seasonal and along-shorevariations in suspended particle size distributions (PSDs)at two marine bathing beaches in southern California, usinga low-angle light scattering instrument (LISST). EmpiricalOrthogonal Function (EOF) analysis of the LISST data set (n= 55 651) identified three particle size modes thatcollectively account for >90% of the variance in thede-meaned PSD data at six sites along the shoreline atHuntington Beach and Newport Beach: a dinoflagellatemode, a large particle mode, and a small particle mode.These three modes exhibit distinct seasonal patterns, andalong-shore distributions, reflecting both the sources ofparticles and environmental factors that trigger theiroccurrence. Comparison of volume-based PSDs generatedfrom the LISST and from image analysis of opticalmicrographs indicates that the LISST performs well whenmeasuring the size distribution of particles associatedwith dinoflagellate blooms. However, LISST measurementson stormwater-impacted samples consistently yield arising tail at small particle sizes that may be an artifactarising from the non-spherical nature of inorganic particlesin terrestrial runoff. The results presented here demonstratethat PSDs measured by light scattering instrumentssuch as the LISST represent a new data resource forassessing water quality, and managing human health risk,at marine bathing beaches.