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

与南极臭氧层空洞相关的中紫外线辐射的增加已被证明抑制了浮游植物的光合作用，并对结果进行了外推，以估计臭氧消耗对边缘冰区初级生产力的影响。这项研究将通过为紫外线辐射对光合作用的抑制指定详细的依赖于波长的生物加权函数，并通过考虑垂直混合的缓解效应来完善评估。将在受控条件下测量边缘冰带浮游植物的生物加权函数，并将其应用于新的光合作用模型，以预测原地初级生产力，以及在紫外光照射变化的情况下。这些预测将与对水柱样本的观察以及在不同辐射制度下几个小时的孵化期间的测量进行比较。这些比较的结果将被用来测试该模型，并量化长期孵化的潜在伪影。关于光抑制和恢复动力学的假设，对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。结果将被纳入水柱中光合作用和光抑制的模型，该模型将用于预测臭氧消耗对海洋初级生产力的影响，特别是在边缘地带。

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.