AGS-PRF: Photochemistry of Impurities in Nature-Identical Snow Crystals

GSTDTAP

项目编号	1524857
	AGS-PRF: Photochemistry of Impurities in Nature-Identical Snow Crystals
	Ted Hullar
主持机构	Hullar Ted
项目开始年	2015
	2015-10-01
项目结束日期	2017-09-30
资助机构	US-NSF
项目类别	Fellowship
项目经费	172000(USD)
国家	美国
语种	英语
英文摘要	This Postdoctoral Research Fellowship proposal focuses on characterizing photochemical reactions (caused by sunlight) on laboratory-generated snow crystals. The research will evaluate the impact of crystal type on photochemical reaction rates, and compare these findings to observations from previous work conducted in frozen solution and other natural snow analogs. Because many of the important reactions in snow are photochemically driven, the exact nature of the reaction environment must be well characterized in order to fully understand chemical reactions in snow. The proposed project has the following objectives: (1) develop and build a machine to make nature-identical snow and incorporate impurities into the synthetic snow; (2) determine the location of impurities in this nature-identical snow; (3) determine the relative actinic fluxes for various impurity locations and with various crystal habits; (4) for synthetic snow made in liquid nitrogen, a commonly used snow analog, determine the location of impurities and local actinic flux; and (5) compare photochemistry of polycyclic aromatic hydrocarbons (PAHs) in various compartments of nature-identical and liquid nitrogen synthetic snows. Identifying the locations of co-condensed impurities in nature-identical snow crystals will improve understanding of the possible suite of chemical transformations in the crystals and the eventual fate of their reaction products. Measurements of the sensitivity of photochemical parameters to crystal habit will provide information important for proper modeling of snow and ice photochemistry. By determining photolysis rates for several PAHs under varying snow crystal morphologies and impurity locations, this research will provide useful information about reaction rate constants under natural conditions, including sensitivity to impurity location or crystal habit. These data will help to resolve current discrepancies in measured photolysis rates. The proposed research will significantly advance the understanding of snow and ice photochemistry by providing both a refined tool to study the natural environment and substantial data to more accurately understand photochemical reactions in snow and ice.
来源学科分类	Geosciences - Atmospheric and Geospace Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68873
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Ted Hullar.AGS-PRF: Photochemistry of Impurities in Nature-Identical Snow Crystals.2015.