Award: OPP-1443569

Award Title: Collaborative Research: Investigating the Role of Mesoscale Processes and Ice Dynamics in Carbon and Iron Fluxes in a Changing Amundsen Sea (INSPIRE)
Funding Source: NSF Office of Polar Programs (formerly NSF PLR) (NSF OPP)
Program Manager: Peter Milne

Outcomes Report

The INSPIRE project investigated a unique region of the coastal Antarctic (the Amundsen Sea Polynya, ASP) characterized by fast-melting glaciers and a very high production of microscopic algae during the summer season. It helped to undercover the inner workings of this region and to progressively reveal the secrets behind its unusually high productivity. One of the most important outcomes of INSPIRE relates to the circulation of the water in the region. The meltwater from the glaciers was found to act like warm air in a shower, rising toward the surface while pulling in water at the bottom. This 'meltwater pump' is amplified by the tremendously high glacier melt rates of the Amundsen Sea and influences the water circulation a hundred miles away from the glaciers. The key effect of this pump is that it pulls in bottom water that is rich in iron, transports it upward, and then releases it close to the surface. Computer simulations (akin to those used for weather forecasts) further revealed that the water that is pumped will accumulate over several years in the ASP. The accumulation of water that is rich in iron has important implications for marine life. Single-celled algae, the backbone of the marine food web, are often deficient in iron in this region of the World Ocean, which can limit their growth rate and therefore the annual 'yield' of the region. The meltwater pump partly alleviates this situation in the ASP and contributes to the region?s productivity. This productivity is eventually limited by another factor; the availability of light. Computer simulations revealed that the algae becomes sufficiently abundant in the ASP to partially block the incident sunlight. Ultimately, it is the limited availability of both light and iron that determines the decline of the algae production at the end of the summer season. With this additional insight on the productivity the ASP, the project investigated the fate of the tremendous amount of organic material produced during the summer bloom. This investigation was innovative because it used a state-of-the-art computer simulation representing simultaneously the melt of the glaciers, the circulation of the water and the biological interactions. The simulation revealed that organic matter is transported by the ocean circulation over a distance of a hundred miles before reaching the sea floor or being recycled. This result expands our understanding of the fate of organic matter in the ASP and represents valuable insight for future field efforts. The INSPIRE project had multiple beneficial impacts for society at large. The computer simulations developed during the course of INSPIRE are shared with other research groups, notably glaciologists studying the contribution of Antarctic glacial melting to global sea level rise. The latter process directly affects coastal communities throughout the world. Moreover, increasing atmospheric CO2 concentrations affect the environment through global warming and ocean acidification. INSPIRE contributed to our understanding of how the ocean, like forests on land, can potentially slow down the increase in atmospheric CO2 concentrations. The goals and outcomes of INSPIRE were communicated in a variety of formats including a magazine article targeting the general public, a website, and multiple publications and presentations for the scientific community. The results of INSPIRE were also integrated into educational activities by a STEM specialist. The activities introduced the students to important physical/biological concepts of marine life and to STEM-related careers in environmental sciences. Last Modified: 12/07/2018 Submitted by: Sharon E Stammerjohn

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Principal Investigator: Sharon E. Stammerjohn (University of Colorado at Boulder)