Luncheon Seminar #149: Bridging the Gaps between Land and Oceans: A perspective from DLEM land-aquatic model

Abstract:

Riverine carbon (C) export and GHG (CO₂, CH₄and N₂O) emissions play important roles in the global GHG budgets, dynamics of continental shelf ecosystems and biosphere-climate feedback. Despite making up only 0.3% of the global area, rivers tightly connect two of the largest active C reservoirs on earth: terrestrial ecosystems and oceans. Natural and human-induced changes in the terrestrial C and nitrogen (N) cycles could greatly alter the magnitude and temporal patterns of terrestrial C and N exports to rivers, which would affect C and N dynamics of receiving freshwater and marine ecosystems, and exert a strong influence on the atmospheric radiation balance through the exchange of greenhouse gases. Therefore, it is essential to provide a robust estimate of riverine C fluxes and GHG emissions for a better understanding the global C and N cycles and the climate system. However, a reliable estimate of the riverine C and N exports and inland water GHG emissions is lacking. Process-based modeling of riverine C and N exports and GHG emission, which couples major biogeochemical and hydrological cycles, provides an alternative to empirical methods, that enables a more robust estimation of riverine GHG budgets and the response to changing climate and human disturbance. Here we used a process-based land-aquatic interface model, the Dynamic Land Ecosystem Model (DLEM), in conjunction with several sources of data, to quantify the magnitude and spatiotemporal patterns of riverine C export (DOC, TOC, DIC) from global land to coastal oceans and GHG emissions from global inland water systems.

Bio：

田汉勤博士, 美国奥本大学索伦·玛莎·狄克逊讲席教授, 国际气候与全球变化研究中心主任, 美国大学联盟海洋-大气-气候理事会成员，全球碳计划指导委员会委员, 全球碳计划和国际氮计划联合项目首席, 曾任美国生态学会亚洲分会主席。长期致力于全球变化生态学, 生物地球化学及生态水文的研究。 运用生态糸统过程模型和生态大数据方法, 并结合地面观测和卫星遥感技术, 理解和定量分析全球变化与生态系统的相互作用, 以及气候变化与粮食安全、水安全关系, 并取得系统性的创新成果。在Nature和Science等期刊发表论文300篇，被引用率万余次。承担主持了美国基金委等资助的30多项研究项目，累计获得科研经费超过3000多万美元, 其 研究成果成为IPCC及若干国家气候变化评估的重要科学依据。荣获首届叶笃正全球变化科学奖, 哈里·墨菲 (Harry Murphy)卓越研究奖, 美国奥本大学最高学术创新成就奖, 美国东南大学联盟学术成就奖, 安德鲁·卡耐基智慧奖。入选美国科学促进会会士(AAAS Fellow)。