湖冰生物光学特征研究

The optical properties of lake ice are crucial for the physical,chemical and biological processes of both the ice and underlying water ecosystems. Thus, this research is focused on the optical properties of lake ice locating in northeast of China, and try to examine the factors that regulate lake ice apparent optical properties (e.g., reflectance, albedo, transmittance and attenuation coefficient) and inherent optical properties (e.g., absorption and scattering). To date, more efforts have been devoted to the optical properties of sea ice, however, the lake ice optical properties were less investigated. This project is proposed to investigate the typical lake ice optical properties from both fresh and brackish inland waters. Along with in situ ice coring and underlying water sampling, spectral reflectance, albedo, attenuation coefficient (Kd) and transmittance will be collected or calculated through radiometric measurements. Laboratory analysis will be conducted on ice melted water and underlying water samples to determine inherent optical properties, particularly particulate matter (PM) and colored dissolved organic matter (CDOM). Further, ice melted water and underlying water physical, chemical and biological parameters are to determined for analyzing the controlling factors affecting lake ice optical properties. Comparison will be conducted to examine the lake ice inherent optical properties for both fresh and brackish lakes. The contribution of PM and CDOM absorption on the total ice absorption and their effects on ice transmittance will be investigated. The optically active constituents in lake ice will be traced for their sources; the relationship of the physiochemical parameters between lake ice and underlying water will be examined. The relationship between apparent and inherent optical properties will be explored based on the bio-optical model. Finally, the impact of lake ice apparent and inherent optical properties on underlying water primary productivity will be analyzed. The implementation of the proposed project will promote our understanding and accumulate the knowledge of the lake ice optical properties and it controlling mechanism. The potential findings from this study could be beneficial to quantitative remote sensing of the lake ice monitoring, also it could provide scientific basis for lake ice growing-melting process assessment, ice monitoring and management in northeast of China.

深入探讨与分析湖冰光学特性，定量阐明影响湖冰生物光学特性的主要因子，对理解太阳辐射在内陆湖冰中的传输、湖冰消长及冰下水生生态过程都有重要意义。相对海冰而言，湖冰组分与光学特性更为复杂，但是针对湖冰生物光学特性研究较少，亟待深入开展系统研究。本项目选择东北典型淡水与咸水湖冰为研究对象，通过野外观测、室内控制实验与测试分析、生物光学特性解析等方法，研究湖冰（含积雪）反照率、衰减系数、透过率等表观光学特性的时空变化及其差异；分析湖冰中的光学活性物质（藻类与非藻类颗粒物、CDOM）对湖冰吸收的贡献率，并阐明对光透过率的影响；揭示湖冰中主要光学活性物质的来源，研究湖冰的理化性质与冰下水体的关系，并阐明环境要素对湖冰及其冰下水体藻类生物量的影响。本项目的实施有助于提升湖冰的光学特性及其机理的认识，可以为湖冰理化性质遥感研究提供科学依据；对湖冰消融过程、北方冰凌监测与冰情管理具有潜在的应用价值。

深入研究与分析湖冰光学特性，定量阐明影响湖冰生物光学特性的主要因子，对理解太阳辐射在内陆湖冰中的传输、湖冰消长及冰下生态与环境过程都有重要意义。湖冰组分与来源及其光学特性复杂，针对湖冰中的光学活性物质开展生物光学特性及其对辐射传输的影响研究较少，亟待深入开展系统研究。本项目以东北典型淡水与咸水湖冰为研究对象，通过野外观测、室内控制实验与测试分析、生物光学特性解析等方法，构建典型湖冰表观光学特征数据库，研究了湖冰遥感反射率、衰减系数、透过率等表观光学特性的时空变化及其差异；深入分析了湖冰中的光学活性物质（藻类与非藻类颗粒物、CDOM）对湖冰吸收的贡献率，揭示湖冰中的光学活性物质的吸收对湖冰消光系数的贡献率；系统研究了湖冰中主要光学活性物质的来源，并阐明了湖冰的理化性质与冰下水体的关系，及其环境要素对湖冰及其冰下水体藻类生物量的影响。并以湖冰生物光学特性为依据，通过MODIS遥感数据研究了东北大型湖泊与水库的湖冰物候特征及其时空差异，为全球变化背景下开展湖冰特性遥感反演及其影响因素分析提供了重要的技术支撑。在国家需求目标上，提升了我国在湖冰生物光学传输机理和湖冰生态学方面的认识水平，为进一步应对全球变化背景下高寒地区湖泊生态系统变化及遥感监测提供重要科学依据；对湖冰消融过程、北方冰凌监测与冰情管理具有潜在的应用价值。目前已经发表SCI论文16篇，CSCD论文7篇，申请发明专利5项，授权软件著作权6项，组织召开全国水环境大会2次，达到了计划书中的指标要求。