Detection of dissolved pyrogenic carbon export following the Southern California fires of 2017

GSTDTAP

项目编号	1824133
	Detection of dissolved pyrogenic carbon export following the Southern California fires of 2017
	Andrew Zimmerman
主持机构	University of Florida
项目开始年	2018
	2018-02-15
项目结束日期	2019-01-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	38651(USD)
国家	美国
语种	英语
英文摘要	Water from stream samples draining watersheds burned in the Thomas fire of December 2017 (Santa Barbara County, California) will be collected during the first rains following the fire, which are likely to occur in January-March, 2018. Total organic carbon and pyrogenic carbon (i.e. derived from burned biomass) will be measured in these samples and compared with quantities of these components in water of these streams prior to the fire, and in streams of adjoining watersheds not affected by the fire. The objective of these measurements is to determine the influence of fire on the supply and composition of dissolved organic matter to the ocean. In particular, the investigator wishes to know whether dissolved pyrogenic carbon will be exported to the ocean as this is a controversial scientific subject. If dissolved pyrogenic C is as abundant and mobile as recent studies suggest, it may have a strong impact on marine chemistry, long-term C cycling and associated climate changes and pollutant transport. On the other hand, if pyrogenic C is not detected in the creeks draining these burned watershed in amounts greater than that of the unburned watersheds, biogeochemists will have to question the methods currently used as markers for fire-produced organic matter. Another important impact of the project will be to provide the opportunity for a graduate student to add a field component to his dissertation research on dissolved pyrogenic carbon. While knowledge of the properties of pyrogenic solids has increased in recent years, there has been relatively little study of the properties and cycling of pyrogenic dissolved organic matter. The method most commonly used for pyrogenic dissolved organic carbon (pyDOC) analysis involves the oxidation of condensed aromatic constituents into smaller, quantifiable monomers (i.e., benzenepolycarboxylic acids or BPCAs). Using this method, it has been suggested that pyDOC represents a constant proportion of riverine DOC globally (~10% pyDOC/DOC). This conclusion is problematic since one would expect this ratio to vary with regional climate and burning regimes. It may be that all these previous measurements were made in fairly large rivers, i.e. large watersheds, so the effects of fire have been hidden by other variations in biomass growth, precipitation etc. Also, pyC may be continually released from charcoals made during past fires. The Thomas fire of December 2017 provides an ideal scenario for detecting and characterizing pyC export from terrestrial to marine systems. There are several short-run creeks draining coastal catchments along the Santa Barbara Channel that have small watershed completely within the burned area, and similar creeks in several adjoining watershed that saw no fire for the past 60 years due to fire suppression. The investigator also has access to water samples that have been in storage from these creeks taken prior to the Thomas fire. There is probably no better scenario for detecting indisputable evidence for, or against, the claim of significant export of pyrogenic C to the ocean, as well as quantifying that export flux if it exists.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/72289
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Andrew Zimmerman.Detection of dissolved pyrogenic carbon export following the Southern California fires of 2017.2018.