焦炭/烟炱比值，一种新的气候变化指标？—来自燃烧实验及土壤的证据

项目名称： 焦炭/烟炱比值，一种新的气候变化指标？—来自燃烧实验及土壤的证据

项目编号： No.41473119

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 韩永明

作者单位： 中国科学院地球环境研究所

项目金额： 95万元

中文摘要： 焦炭和烟炱是两种类型黑碳，二者尽管都来源于生物质和化石燃料不完全燃烧，但形成方式不同。焦炭是燃烧残留物，低温裂解生成；而烟炱是燃烧形成的气态前体物经气-粒转化过程中形成，因此二者具不同气候环境意义。但当前研究将黑碳作为一个整体测量，缺少有关焦炭/烟炱比值与气候环境关系的分析。我们前期在沉积物研究中发现焦炭/烟炱比值与火事件和大气降水关系明显，高比值对应于湿润气候。我们期望这种关系能在实验室模拟、野外观测和土壤研究中得到证实。因此，本研究一方面通过大型燃烧模拟实验和野外生物质燃烧观测，探讨和建立焦炭/烟炱比值与燃料湿度关系。另一方面，通过我国不同气候带土壤焦炭/烟炱比值变化与当地气温、降水关系研究，从统计学方面进一步验证二者比值与气候环境因子关系。本研究不仅为古环境研究提供一种新的大气降水指标，并为理解不同气候带大气气溶胶中焦炭/烟炱的差异性提供理论依据，可为气候模拟提供支持。

中文关键词： 黑碳；烟炱；生物质燃烧；沉积物和土壤；气候环境变化

英文摘要： Black carbon is composed of char and soot. Although both char and soot originate from incomplete combustion of biomass and fossil fuels, they form in different mechanisms. Char is combustion residues formed through pyrolysis; whereas soot forms via gas-to-particle conversion at high temperature. Thus, char and soot have different implications in global environmental and climatic changes. However, current studies have not differentiated between char and soot, and thus the relationship between char/soot ratio and climate change is still unknown. This proposal is put forward based on our previous studies that investigated the relations among char and soot in sediments, wildfire history and climate change and we found that high char/soot ratio corresponds to wet climate. In this study we will build the relationship between char/soot ratios and fuel moisture under the condition of different combustion efficiency from combustion chamber and field biomass burning experiments. In addition, we will collect soil samples from different climatic zones throughout China and test relationship between char/soot ratios in soils with local precipitation. This study will, on the one hand, provide a new proxy for precipitation in paleoclimate studies and, on the other hand, will help us understand the char/soot variations from different climatic zones for aerosol studies.

英文关键词： black carbon;soot;biomass burning;sediments and soils;envrionmental and climate change