Ultraviolet radiation and bio-optics in Crater Lake, Oregon
Ultraviolet radiation and bio-optics in Crater Lake, Oregon
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DOI：
10.1007/s10750-006-0348-0
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发表时间：
2006
期刊：
影响因子：
2.6
通讯作者：
B. R. Hargreaves;S. Girdner;M. Buktenica;R. W. Collier;E. Urbach;G. Larson
中科院分区：
文献类型：
--
作者：
B. R. Hargreaves;S. Girdner;M. Buktenica;R. W. Collier;E. Urbach;G. Larson
俄勒冈州的火山口湖是一个中纬度火山口湖，以其深度（594 米）和蓝色而闻名。最近对太阳辐射（300-800 nm）的水下光谱测量支持了早期对异常透明度的观察，并将其扩展到 UV-B 波长。新数据表明，太阳紫外线辐射进入火山口湖会对生态产生重大影响。证据包括自 1984 年以来水柱叶绿素-a 与平流层臭氧之间的相关性、上层水柱中生物的稀缺性以及浮游植物中随深度变化的明显紫外线屏蔽色素。最低的 UV-B 漫反射衰减系数 (Kd,320) 与其他地方最清澈的天然水域报告的相似，并且低于 1981 年发布的纯水估计值。UVR 衰减的光学代理与 1984 年至 2002 年典型干燥夏季月份中的叶绿素 a 浓度 (0–30 m) 相关。使用所有代理和测量的紫外线透明度、十年和更长的时间 自 1896 年第一次光学测量以来，周期很明显，但没有长期趋势。
Crater Lake, Oregon, is a mid-latitude caldera lake famous for its depth (594 m) and blue color. Recent underwater spectral measurements of solar radiation (300–800 nm) support earlier observations of unusual transparency and extend these to UV-B wavelengths. New data suggest that penetration of solar UVR into Crater Lake has a significant ecological impact. Evidence includes a correlation between water column chlorophyll-aand stratospheric ozone since 1984, the scarcity of organisms in the upper water column, and apparent UV screening pigments in phytoplankton that vary with depth. The lowest UV-B diffuse attenuation coefficients (Kd,320) were similar to those reported for the clearest natural waters elsewhere, and were lower than estimates for pure water published in 1981. Optical proxies for UVR attenuation were correlated with chlorophyll-a concentration (0–30 m) during typical dry summer months from 1984 to 2002. Using all proxies and measurements of UV transparency, decadal and longer cycles were apparent but no long-term trend since the first optical measurement in 1896.