Studying dissolved organic carbon in tropical rivers of Malaysia using in-situ and satellite observations

气候与大气中温室气体二氧化碳（CO2）的浓度密切相关。因此，全球科学家的首要任务是量化地球系统内的碳通量，并了解人类如何改变这些通量。研究人员已经评估了陆地生物群落（即热带森林，温带森林和北方泥炭地）以及水生生态系统（即湖泊和海洋），但很少将两个生物群落连接起来或研究两者之间的路径，即河流。虽然泥炭地仅占地球陆地面积的3%，但它们储存了大量的碳，并在全球碳循环中发挥着重要作用。在热带地区，泥炭沼泽森林和下面的泥炭沉积物构成了最大的近地表有机碳库之一。东南亚泥炭含有约70 Gt C，主要在苏门答腊和婆罗洲。排放这些泥炭地的河流富含来自泥炭的DOC：印度尼西亚可能占全球DOC通量的10%，但这一估计仅基于两条河流的数据。在东南亚，陆地向海洋DOC通量也可能在最近泥炭地转为农业后显著增加，但由于缺乏数据，这尚未得到适当证实。在过去的4年里，这两位合作者都率先研究了婆罗洲泥炭排水河流释放的温室气体。拟议的项目将侧重于建立溶解有机碳的长期测量，以量化DOC运输的年度变化在一个地区，许多泥炭地正在转换为农业用地的代表性泥炭排水河流。作为对我们正在进行的工作的延伸和补充，我们将包括卫星遥感数据，以估计覆盖整个婆罗洲的较大沿海海洋中土壤来源的有机碳的浓度。拟议项目涉及A/P Müller对不莱梅大学的两次短期访问，以安装现场记录仪并分析2017年秋季收集的现场数据（WP 1），并将其与不莱梅大学的卫星数据（WP 2）进行比较。在第一次访问之后，将在马来西亚进行两次实地考察（在2018年10月和2019年3月的下一次东北季风前后），然后A/P Müller将对不莱梅大学进行第二次短暂访问，以整合收集的数据，完成出版手稿，并亲自讨论长期持续性（WP 3）。

Climate is intimately linked to the concentration of the greenhouse gas carbon dioxide (CO2) in the atmosphere. A priority amongst scientists worldwide is therefore to quantify fluxes of carbon within the Earth system, and to understand how mankind is altering these fluxes. Researchers have assessed terrestrial biomes (i.e. tropical forests, temperate forests, and boreal peatlands) as well as aquatic ecosystems (i.e. lakes and oceans), however very seldom connected both biomes or studied the pathway between the two, i.e. rivers. While peatlands only cover approximately 3% of Earth’s land area, they store a significant amount of carbon, and play an important role in the global carbon cycle. In the tropics, peat swamp forests and the underlying peat deposits constitute one of the largest near-surface reservoirs of organic carbon. South-East Asian peats contain ~70 Gt C, mostly on Sumatra and Borneo. The rivers draining these peatlands are very rich in DOC derived from peat: Indonesia alone may account for 10% of the global DOC flux, but this estimate is based on data from only two rivers. In South-East Asia, the land-to-ocean DOC flux may also have risen significantly following the recent conversion of peatlands for agriculture, but owing to the paucity of data here, this has not yet been properly confirmed. Both collaborators have pioneered studies on the release of greenhouse gases from peat-draining rivers in Borneo over the past 4 years. The proposed project will focus on establishing long-term measurements of dissolved organic carbon to quantify annual variations of DOC transport in a representative peat draining river in a region where many peatlands are being converted to agricultural lands. In an extension and complimentary to our ongoing work, we will include satellite remote sensing data to estimate the concentration of soil-derived organic carbon in larger coastal seas to cover the whole of Borneo. The proposed project involves two short visits by A/P Müller to the University of Bremen to install in-situ logger and analyse field data collected in autumn 2017 (WP1) and comparing it to satellite data at the University of Bremen (WP2). Following the first visit, two field expeditions will be conducted in Malaysia (before and after the next north-east monsoon in October 2018 and March 2019), followed by a second short visit by A/P Müller to the University of Bremen to consolidate collected data, finalise manuscript for publication, and discuss long-term continuation in person (WP3).