The Role of Dissolved Organic Matter Composition in Determining Photochemical Reactivity at the Molecular Level

2019 ◽  
Vol 53 (20) ◽  
pp. 11725-11734 ◽  
Author(s):  
Stephanie M. Berg ◽  
Quinn T. Whiting ◽  
Joseph A. Herrli ◽  
Ronan Winkels ◽  
Kristine H. Wammer ◽  
...  

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 128
Author(s):  
Dennis A. Hansell ◽  
Mónica V. Orellana

Marine dissolved organic matter (DOM) holds ~660 billion metric tons of carbon, making it one of Earth’s major carbon reservoirs that is exchangeable with the atmosphere on annual to millennial time scales. The global ocean scale dynamics of the pool have become better illuminated over the past few decades, and those are very briefly described here. What is still far from understood is the dynamical control on this pool at the molecular level; in the case of this Special Issue, the role of microgels is poorly known. This manuscript provides the global context of a large pool of marine DOM upon which those missing insights can be built.



2003 ◽  
Vol 37 (19) ◽  
pp. 4403-4409 ◽  
Author(s):  
Megan Gaberell ◽  
Yu-Ping Chin ◽  
Stephan J. Hug ◽  
Barbara Sulzberger


2019 ◽  
Vol 124 (10) ◽  
pp. 3125-3142 ◽  
Author(s):  
Jennifer L. Harfmann ◽  
François Guillemette ◽  
Karl Kaiser ◽  
Robert G. M. Spencer ◽  
Chia‐Ying Chuang ◽  
...  


2021 ◽  
Author(s):  
Hui Lin ◽  
Huacheng Xu ◽  
Yihua Cai ◽  
Claude Belzile ◽  
Robie W. Macdonald ◽  
...  


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brice K. Grunert ◽  
Maria Tzortziou ◽  
Patrick Neale ◽  
Alana Menendez ◽  
Peter Hernes

AbstractThe Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization.



2016 ◽  
Vol 3 ◽  
Author(s):  
Elizabeth B. Kujawinski ◽  
Krista Longnecker ◽  
Katie L. Barott ◽  
Ralf J. M. Weber ◽  
Melissa C. Kido Soule


Energy ◽  
2020 ◽  
Vol 213 ◽  
pp. 118818
Author(s):  
Li Zhang ◽  
Yongzhen Peng ◽  
Satoshi Soda ◽  
Xiaowu Huang ◽  
Yifei Wang ◽  
...  


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