●前期科研成果

 本人专注从事近海河口碳循环研究，擅长运用碳酸盐系统和稳定同位素技术解析近海河口碳循环过程机制及其对富营养化、缺氧和酸化的响应。以第一作者在Nature Geoscience，Limnology and Oceanography，Biogeosciences等国际著名期刊发表SCI 论文5篇，此外在Annual Review of Earth and Planetary Sciences，Progress In Oceanography，Marine Chemistry等地学权威期刊合作发表SCI论文6篇。

（1）首次提出了切萨皮克湾碳酸盐矿物循环存在空间分离的特点以及由此产生的酸化缓冲机制。在夏天，位于切萨皮克湾北部和沿岸浅水区域的水草拥有高的光合速率，导致了高pH，高CaCO3饱和度以及TA的净吸收。在该环境下形成的碳酸钙（CaCO3）颗粒随后被传输至中部湾区次表层缺氧水体发生溶解，缓冲了由有氧呼吸和人为CO2引起的pH降低。该文章已经发表在Nature Geoscience期刊。

（2）作为Nature Geoscience文章的延续，通过解析溶解氧（DO）和碳酸盐系统的时空分布，结合历史监测数据，首次提出切萨皮克湾水体的DO和pH极低值存在时间和空间上的不耦合现象，而湾内CaCO3生成和溶解的季节变化是造成水体缺氧和酸化程度出现季节性不耦合的主要原因。该成果已经发表于Limnology and Oceanography期刊。

（3）运用端员混合模型，DIC及其碳稳定同位素的质量守恒，发现在珠江口下游有机物的有氧呼吸过程主导了DO的消耗，~65%的耗氧有机物来自海源浮游植物的初级生产，其余的35%来自陆源有机物的输入。2016年初夏在切萨皮克湾缺氧区耗氧有机物基本都来自于浮游植物的初级生产，而陆源有机物的贡献可以忽略不计。比较讨论了切萨皮克湾和珠江口缺氧区耗氧有机物来源存在差异的主要原因是二者拥有不同的水文、物理条件，有机物输入和生物活性。这两篇文章已经发表在Biogeosciences和Limnology and Oceanography期刊。

（4）搜集了1998年至今全球已报道的214处边缘海CO2通量数据，通过统一化气体传输速率（W14）和使用全球边缘海和流域分区（MARCATS），集成分析出7种不同类型的陆架边缘海拥有着不同的CO2源汇格局，全球陆架边缘海的通量更新为-0.25±0.05 Pg C yr-1。该第二作者文章已经发表在Annual Review of Earth and Planetary Sciences。

Research Projects

Su focuses on the study of carbon cycling in nearshore estuaries, and is skilled in using carbonate systems and stable isotope technology to analyze the mechanisms of carbon cycling processes in nearshore estuaries and their response to eutrophication, hypoxia, and acidification. As the first author, Su has published 5 SCI papers in international renowned journals such as Nature Geoscience, Limnology and Oceanography, and Biogeosciences. In addition, Su has collaborated to publish 6 SCI papers in authoritative journals in the field of geology, such as Annual Review of Earth and Planetary Sciences, Progress In Oceanography, and Marine Chemistry.

（1) Su first proposed the spatial separation of the Chesapeake Bay carbonate mineral cycle and the resulting acidification buffering mechanism. In the summer, the high photosynthetic rate of the seagrass in the northern and shallow coastal areas of the Chesapeake Bay leads to high pH, high CaCO3 saturation, and net absorption of TA. The formed calcium carbonate (CaCO3) particles in this environment are then transported to the suboxic water in the central bay area and dissolved, buffering the pH decrease caused by aerobic respiration and anthropogenic CO2. This paper has been published in Nature Geoscience.

（2）As a continuation of the Nature Geoscience paper, by analyzing the spatial and temporal distribution of dissolved oxygen (DO) and carbonate systems, combined with historical monitoring data, Su first proposed the uncoupling phenomenon of DO and pH extreme low values in time and space in Chesapeake Bay water. While the seasonal changes in CaCO3 generation and dissolution in the bay are the main reasons for the seasonal uncoupling of water hypoxia and acidification. This achievement has been published in Limnology and Oceanography.

(3) Using the end-member mixing model, DIC, and carbon stable isotopes mass balance, Su found that aerobic respiration of organic matter dominated DO consumption in the lower reaches of the Pearl River Estuary, with ~65% of oxygen-consuming organic matter coming from the primary production of marine phytoplankton and the remaining 35% from terrestrial organic matter input. In the Chesapeake Bay hypoxic zone in early summer 2016, oxygen-consuming organic matter was mainly derived from the primary production of phytoplankton, while the contribution of terrestrial organic matter could be neglected. The main reasons for the differences in the sources of oxygen-consuming organic matter in the hypoxic zones of the Chesapeake Bay and the Pearl River Estuary were compared and discussed, including hydrological, physical conditions, organic matter input, and biological activity. These two articles have been published in Biogeosciences and Limnology and Oceanography.

(4) Su collected 214 CO2 flux data from global marginal seas reported from 1998 to the present, and integrated analysis using standardized gas transfer velocity (W14) and global marginal seas and watershed partitioning (MARCATS) to identify seven different types of CO2 source-sink patterns in shelf-edge marginal seas. The updated flux of global shelf-edge marginal seas is -0.25±0.05 Pg C yr-1. The second author's article has been published in Annual Review of Earth and Planetary Sciences.