Photochemistry of Antarctic Waters in Repsonse to Changing Ultraviolet Radiation Fluxes

南极上空平流层臭氧的减少导致海洋光区的紫外线辐射通量增加。这种增加可能导致水生生物的细胞损伤，导致光抑制和生产力下降。细胞损伤既可以发生在细胞内，也可以发生在细胞表面，由生物分子与外部产生的反应性瞬态物质发生反应。细胞外损伤在很大程度上取决于细胞周围海水的光化学性质。迄今为止，人们对独特的南极水域的光化学知之甚少。该项目综合了实地和实验室方法，以获取有关南极水域光区的海洋光化学与紫外线辐射水平变化有关的基线资料。将测量一系列反应物质和溶解有机物降解产物的原位光化学生产速率和稳态浓度以及下行紫外线辐射。此外，通量通过原位化学放光测定法，光化学生产的各种反应物质和溶解的有机物降解产物的作用光谱，以及溶解的有机物的荧光和吸光度特性将被确定。这一资料将作为了解和预测紫外线辐射引起的海洋光化学过程对南极洋光区的生产力和生态的影响的基础。

Decreases in stratospheric ozone over the Antarctic result in an increase in the ultraviolet radiation flux in the euphotic zone of the ocean. This increase may lead to cellular damage in aquatic organisms resulting in photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transient species. Extracellular damage will depend to a large degree on the photochemistry of the seawater surrounding the cell. To date, little is known about the photochemistry of the unique Antarctic waters. This project integrates a field and laboratory approach to obtain baseline information regarding the marine photochemistry of the euphotic zone in Antarctica waters as related to changes in ultraviolet radiation levels. In situ photochemical production rates and steady state concentrations of a suite of reactive species and dissolved organic matter degradation products as well as downwelling ultraviolet radiation will be measured. Additionally, flux by in situ chemical actinometry, action spectra for photochemical production of various reactive species and dissolved organic matter degradation products, and fluorescence and absorbance properties of dissolved organic matter will be determined. This information will serve as a basis for understanding and predicting the effects of ultraviolet radiation-induced marine photochemical processes on the productivity and ecology in the euphotic zone of the Antarctic Ocean.