基于热红外波段遥感观测的沙尘定量反演研究

项目名称： 基于热红外波段遥感观测的沙尘定量反演研究

项目编号： No.41301354

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 刘洋

作者单位： 北京师范大学

项目金额： 25万元

中文摘要： 沙尘是地球系统能量平衡、全球气候系统和生物地球化学循环的重要影响因子，并对空气质量和人类健康有着显著影响。卫星热红外波段观测可同时获得白天和夜间的沙尘信息。但是，热红外传感器所捕获的是地表及大气的混合信息，地表和大气状况对大气顶层亮温的影响非常复杂且相互叠加，导致从热红外波段定量提取沙尘信息变得很困难。本申请将提出一种独立于温度的热红外地表背景合成方法，并基于大气辐射传输模型，全面模拟在不同大气剖面、地表特性和卫星观测角度状况下，沙尘气溶胶光学厚度和热红外波段大气顶层亮温的关系，并进一步建立热红外地表背景参数、沙尘特性与卫星热红外波段观测值的定量关系。在此基础上，以MODIS数据为数据源，实现沙尘气溶胶光学厚度的定量反演，并利用OMI、MODIS气溶胶产品、CALIPSO激光雷达和地面观测对反演结果进行验证。

中文关键词： 沙尘；热红外遥感；亮温差；MODIS；夜间

英文摘要： Mineral dust is an important factor in earth system energy budget, global climate, and biogeochemical cycles. It also affects air quality and human health. Satellite radiometer measurements in thermal infrared channels are advantageous in monitoring the spatial and temporal variations of dust events during both the daytime and the nighttime. However, the satellite measurements provide the mixed signal of both the atmosphere and land surface. Since the properties of underlying surface and atmospheric profiles have complicated effects on the observed top of atmosphere (TOA) brightness temperature (BT), it is challenging to retrieval dust optical properties from satellite measurements. In this proposal, a novel method for compositing land surface references in thermal infrared channels is developed. The atmospheric transfer model is used to simulate the quantitative relationships between aerosol optical depth and TOA BTs in thermal infrared bands in various atmospheric profiles, underlying surface properties and viewing geometry. Based on these simulations, the relationships among land surface references, dust optical properties and satellite thermal infrared measurements are established and used to retrieve the dust optical properties from MODIS thermal infrared measurements. The results are evaluated by comparing

英文关键词： Dust；Thermal infrared remote sensing；Brightness temperature difference；MODIS；Nighttime