Lensing effect on underwater levels of UV radiation
Lensing effect on underwater levels of UV radiation
复制标题
透镜效应对水下紫外线辐射水平的影响
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
K. Michael
中科院分区：
文献类型：
--
作者：
R. Deckert;K. Michael
在南方春夏季，南极臭氧空洞可引起南大洋光区的UVB辐射事件增强。如果这些事件与边缘冰区丰富的浅水藻华同时发生，就会导致高死亡率。探讨了由准直太阳辐射被表面波聚焦而产生的UVB光对次表面辐射场的贡献。建立了具有循环边界的三维蒙特卡罗模型，研究了UVB光的闪烁强度和时间特性。该模型考虑了光子的反射、折射、吸收和散射，并基于280至700 nm的海洋光学特性数据集。该模型考虑了生物源颗粒和共变黄色物质的影响。在350和300 nm的准直光下进行模型运行。对平坦海面的运行表明，统计波动（噪声）随深度的增加而迅速增加。这种增加在300 nm处更为明显。使用正弦波的模型运行显示出明显的闪光，在350 nm处闪光更强，穿透更深。在300 nm处，闪光有25%的时间超过了表面辐照度的准直部分，但在深度大于3.7 m时可以忽略不计。较小的正弦波比相同陡度的较大正弦波在较浅的深度产生更强烈的聚焦。在更复杂的海洋表面上运行的模型不太有说服力，因为闪光被水面高度的变化掩盖了。
In the austral spring/summer the Antarctic ozone hole can cause enhanced UVB radiation events in the photic zone of the Southern Ocean. If these events coincide with rich shallow-water algal blooms in the marginal ice zone, a high mortality rate can result. The contribution to the sub-surface radiation field of UVB light flashes created through the focusing of collimated solar radiation by surface waves is sought. A three-dimensional Monte Carlo model with cyclic boundaries was developed to investigate the intensity and temporal characteristics of UVB light flashes. The model accounts for reflection, refraction, absorption and scattering of photons, and is based on a data set of ocean optical properties from 280 to 700 nm. The model includes the effect of biogenic particles and covarying yellow substance. Model runs were performed with collimated light for both 350 and 300 nm. Runs for a flat ocean surface revealed a rapid increase of statistical fluctuations (noise) with depth. This increase was more pronounced at 300 nm. Model runs with sinusoidal surface waves showed significant light flashes which were stronger and penetrated more deeply at 350 nm. At 300 nm, the flashes could exceed the collimated part of surface irradiance for 25% of the time, but were negligible at depths greater than 3.7 m. Small sinusoidal waves produced a more intense focus at a shallower depth than larger sinusoidal waves of the same steepness. Model runs with a more complex ocean surface were less conclusive, as the light flashes were disguised by variations in the water elevation.