Antarctic ocean carbon absorption study reveals manganese mystery affecting climate predictions
Climate and Ecosystem Concerns: The Southern Ocean absorbs about 40% of human carbon dioxide emissions, aided by phytoplankton and krill. However, climate change threatens this process, with declining krill populations and uncertain phytoplankton growth challenging carbon absorption predictions.
IronMan Project Goals: Led by Alessandro Tagliabue, the £4m IronMan project aboard the RRS Sir David Attenborough aims to study the roles of iron and manganese in phytoplankton growth and carbon cycling – elements overlooked in climate models but potentially critical for global climate regulation.
Extreme Sampling Challenges: Researchers face harsh Antarctic conditions while measuring trace metals at concentrations as low as a teaspoon in the River Thames. They use specialized titanium equipment, clean labs, and advanced techniques to avoid contamination and gather over 1000 litres of seawater samples.
Broader Scientific Impact: The project combines chemical, biological, and genetic analyses to understand nutrient recycling, organism metabolism, and gene expression. Findings could reshape climate models and reveal how rapid sea ice loss and ecosystem changes affect global climate resilience.
Blue Whales and Krill: In the Southern Ocean near Antarctica, blue whales, the largest animals on Earth, have recovered since hunting reduced their numbers. BAS researchers measure whale numbers and krill consumption, with plans to study the impact of climate change on krill populations.
Climate Models and Nutrient Absorption: Climate models predict that phytoplankton should prosper with rising temperatures, acting as a brake on global heating. However, observations show the opposite, indicating that the Southern Ocean may absorb less of humanity's carbon emissions as the planet warms.
Manganese Mystery: Iron has been considered the key nutrient driving phytoplankton growth, but manganese could be equally critical in many parts of the ocean. Climate models overlook manganese's role, and its accurate representation is crucial for predicting future biodiversity, carbon cycling, and global climate.
Measuring Trace Metals: Researchers use specialized equipment, including a rosette with Niskin bottles, to measure trace metals in extreme conditions. They collect large volumes of seawater, filter out particles, and analyze samples in clean labs to understand nutrient recycling and organism metabolism.
Antarctic Unpredictability: The unpredictability of Antarctica's climate and sea ice poses challenges for the IronMan project. Researchers must prepare for various scenarios and adapt their plans, as the region's rapid changes in sea ice significantly impact global climate regulation and polar environment resilience.
