Smith R C, Prézelin B B, Baker K S, Bidigare R R, Boucher N P, Coley T, Karentz D, MacIntyre S, Matlick H A, Menzies D
Department of Geography, University of California, Santa Barbara 93106.
Science. 1992 Feb 21;255(5047):952-9. doi: 10.1126/science.1546292.
The springtime stratospheric ozone (O3) layer over the Antarctic is thinning by as much as 50 percent, resulting in increased midultraviolet (UVB) radiation reaching the surface of the Southern Ocean. There is concern that phytoplankton communities confined to near-surface waters of the marginal ice zone will be harmed by increased UVB irradiance penetrating the ocean surface, thereby altering the dynamics of Antarctic marine ecosystems. Results from a 6-week cruise (Icecolors) in the marginal ice zone of the Bellingshausen Sea in austral spring of 1990 indicated that as the O3 layer thinned: (i) sea surface- and depth-dependent ratios of UVB irradiance (280 to 320 nanometers) to total irradiance (280 to 700 nanometers) increased and (ii) UVB inhibition of photosynthesis increased. These and other Icecolors findings suggest that O3-dependent shifts of in-water spectral irradiances alter the balance of spectrally dependent phytoplankton processes, including photoinhibition, photoreactivation, photoprotection, and photosynthesis. A minimum 6 to 12 percent reduction in primary production associated with O3 depletion was estimated for the duration of the cruise.
南极上空春季平流层臭氧（O₃）层正以高达50%的幅度变薄，导致到达南大洋表面的中紫外线（UVB）辐射增加。人们担心，局限于边缘冰区近表层水域的浮游植物群落会受到穿透海洋表面的UVB辐照度增加的伤害，从而改变南极海洋生态系统的动态。1990年南半球春季在别林斯高晋海边缘冰区进行的为期6周的航行（“冰色”号）结果表明，随着O₃层变薄：（i）UVB辐照度（280至320纳米）与总辐照度（280至700纳米）的海表面和深度依赖比率增加，以及（ii）UVB对光合作用的抑制作用增强。“冰色”号的这些及其他发现表明，水中光谱辐照度的O₃依赖型变化改变了光谱依赖型浮游植物过程的平衡，包括光抑制、光复活、光保护和光合作用。据估计，在航行期间，与O₃消耗相关的初级生产力至少降低了6%至12%。
