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真光区紫外线辐射通量的增加。这种增加可能会导致水生生物的细胞损伤，从而导致光抑制和生产力下降。细胞损伤可以发生在细胞内，也可以发生在细胞表面的外部，这是由于与外部产生的反应性瞬变物种的生物分子反应造成的。细胞外的损害在很大程度上取决于细胞周围海水的光化学作用。到目前为止，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办法，以获得与紫外线辐射水平变化有关的南极洲水域真光带海洋光化学的基线信息。将现场测量一系列活性物种和溶解有机物降解产物的光化学产生速率和稳态浓度，以及下行紫外线辐射。此外，还将测定原位化学辐射测量的通量、各种活性物质和溶解有机物降解产物的光化学产物的作用光谱，以及溶解有机物的荧光和吸收特性。这些信息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海洋真光区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.