Effects of Ultraviolet Radiation on the Photosynthesis of Phytoplankton in the Antarctic Marginal Ice Zone

与南极臭氧空洞相关的中紫外线辐射增加已被证明会抑制浮游植物的光合作用，并已对结果进行外推，以估计臭氧耗竭对边缘冰带初级生产力的影响。本研究将通过详细说明波长依赖的生物加权函数来细化紫外线辐射对光合作用的抑制，并考虑垂直混合的缓解作用。将在受控条件下测量边缘冰带浮游植物的生物加权函数，并将其应用于一个新的光合作用模型中，以预测原位以及改变紫外线照射下的初级生产力。这些预测将与对水柱样品的观察结果以及在不同辐照度下孵育数小时期间的测量结果进行比较。这些比较的结果将用于测试模型和量化长期孵化的潜在工件。关于光抑制和恢复动力学的假设，对于模拟垂直混合的影响至关重要，将通过时间过程实验进行检验。结果将纳入水柱中的光合作用和光抑制模型，该模型将用于预测臭氧耗竭对海洋初级生产的影响，特别是在边缘区。

Increases in middle ultraviolet radiation associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, and results have been extrapolated to estimate the effect of ozone depletion on primary productivity in the marginal ice zone. This research will refine the assessment by specifying detailed wavelength-dependent biological weighting functions for the inhibition of photosynthesis by ultraviolet radiation, and by considering the mitigating effects of vertical mixing. Biological weighting functions of phytoplankton in the marginal ice zone will be measured under controlled conditions and applied in a new model of photosynthesis to predict primary productivity in situ, as well as under altered ultraviolet irradiance. These predictions will be compared with observations on samples from the water column and with measurements during incubations of several hours under different irradiance regimes. Results of these comparisons will be used to test the model and to quantify the potential artifact of long incubations. Assumptions about the kinetics of photoinhibition and recovery, critical to modeling the effects of vertical mixing, will be examined with time-course experiments. Results will be incorporated into a model of photosynthesis and photoinhibition in the water column that will be used to predict the influence of ozone depletion on marine primary production, particularly in the marginal zone.