Evidence of minimal carbon sequestration in the productive Amundsen Sea polynya. Issue 15 (13th August 2017)

• Record Type: Journal Article
• Authors: Lee, SangHoon; Hwang, Jeomshik; Ducklow, Hugh W.; Hahm, Doshik; Lee, Sang H.; Kim, Dongseon; Hyun, Jung‐Ho; Park, Jisoo; Ha, Ho K.; Kim, Tae‐Wan; Yang, Eun J.; Shin, Hyoung C.
• Is Part Of: Geophysical research letters. Volume 44:Issue 15(2017)
• Page Start: 7892
• Page End: 7899
• Publication Date: 2017-08-13
• Subjects: biological pump -- Amundsen Sea -- polynya -- carbon sequestration -- sediment trap -- circumpolar deep water; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL074646
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The Amundsen Sea polynya (ASP) is reportedly the most productive among the coastal polynyas around Antarctica. However, observational constraints limit our understanding of the biological pump and carbon cycle in the ASP. We measured various carbon‐related parameters such as primary production, bacterial production, sinking flux of particulate organic carbon (POC), and accumulation of organic carbon in the sediment as well as hydrographic parameters during field observations and by instrument moorings. Over 95% of the photosynthetically produced POC was converted to suspended POC and/or dissolved carbon forms in the upper ~400 m layer. We postulate that most of the carbon transported to the water column by the biological pump in the ASP was flushed out of the shelf without being sequestered for long‐term storage in sediments. Lack of bottom water formation due to intrusion of Circumpolar Deep Water in the lower layer reduces carbon sequestration efficiency. Key Points: Less than 5% of the POC produced by primary production sank to the seafloor of the Amundsen Sea Most of the carbon drawn into the subsurface by the biological pump was transported off the shelf by northward currents The intrusion of Circumpolar Deep Water and the lack of bottom water formation reduce carbon sequestration efficiency