Particulate organic carbon exports from the terrestrial biosphere controlled by erosion

The transport of particulate organic carbon (POC) through rivers from land to sea affects the redistribution of global organic carbon. However, because of the limitation of the quantity and quality of monitoring data, the POC magnitude, scale and global distribution pattern of land-sea migration are still not well understood. Therefore, based on an updated GEMS-GLORI database and other reanalysis data, we use the soil erosion model (F-erosion), total suspended solids model (F-tss), and runoff model (F-runoff) to re-analyze and generate the POC flux of major rivers in the world dataset. The major results are as follows: the POC flux from global terrestrial biosphere rivers exports approximately 0.12-0.20 Pg C to oceans every year, including 0.20 Pg F-erosion, 0.17 Pg F-tss, and 0.12 Pg Frunoff. In contrast to earlier studies that the Pacific and Arctic Oceans are the main recipients of POC flux, we find that the Pacific and Atlantic received more POC flux and received 30.76%-62.51% and 26.77%-53.95%, respectively. This difference may be related to the combined effects of soil erosion, total suspended solids, and runoff. Asia exports more POC than other continents (60.50%-61.69%). The Amazon basin is the major contributor to the Atlantic POC, contributing 53.30%-58.68%. Furthermore, because of the intense human activities and the widespread distribution of many large watersheds in the highly eroded area, it was found that the POC flux has two key zones (25.75-41.5 degrees N and 4.50.N-13.50 degrees S) in the latitude zone. In summary, the above findings increase our understanding of the spatial redistribution of global organic carbon from land to sea.

Automated summary

This study reanalyzed and generated POC flux data of major rivers worldwide using updated databases and models. The results show that Asia exports the most POC, with the Amazon basin being a major contributor to the Atlantic POC. Additionally, there are two key zones of POC flux in the latitude belt.