基于FSAM模型的城市碳通量观测贡献区研究

全球变化背景下，城市二氧化碳排放是全球大气二氧化碳的重要来源．以上海市奉贤区为研究对象，基于涡度相关观测系统所获得的通量观测数据，应用FSAM（theFlux—SourceAreaModel）模型，分析了不同大气条件、不同风向下通量贡献区的分布及时间动态．结果表明：大气稳定度会影响通量贡献区的范围，表现为不稳定大气条件下通量贡献区长度为66～491m，稳定条件下通量贡献区长度为94—1047m．风向对通量贡献区的影响表现为在主风风向90°-180°，稳定大气条件下（通量贡献P为0．9时）通量贡献区的范围为94～1047m，垂直于迎风方向的宽度为335in；其他风向的通量贡献区分布与主风风向各不相同，分别为103～1146，122—1337，110～1256m．通量贡献区具有明显的昼夜变化特征，表现为夜间通量区范围大于白天．

Research of flux footprint of city based on the FSAM model

The research of urban ecological system carbon plays a very important role in global climate change area. In this study, based on the eddy covariance system of Shanghai＇s peri - urban forest and FSAM model （the Flux - Source Area Model）, the distribution of footprint was analyzed in the different atmospheric conditions, wind directions, and the diurnal dynamics of footprint. Results showed that：The footprint in unstable atmospheric conditions was 66 -491 m, but in the stable atmospheric conditions was 94 - 1047 m. The wind directions influenced the footprint, the range of source areas was 94 - 1047 m in the prevailing wind direction （90~ -180~） ,while it was 335 m in the vertical upwind, and other wind directions of the flux source distributions were different from the above, the range of source areas were 103 - 1146,122 - 1337,110 - 1256 m, respectively. The diurnal variation of footprint appeared a rule that the footprint was larger in night than in the day.