Periodic Reporting for period 1 - OXYPRO (Global biological productivity during abrupt climate change)
Reporting period: 2021-09-01 to 2023-08-31
This project will alleviate both problems by measuring triple isotope composition of air oxygen (O2) from the ancient air trapped in polar ice cores. The triple isotopic composition of O2 is a unique tracer of global biosphere productivity, and the polar ice core is the unique archive that preserves the ancient atmosphere in air bubbles that allows to study directly the composition of past atmosphere over the last 800 000 years. In particular, OXYPRO project aims to reconstruct the variations of the triple isotopic composition of O2 with the highest temporal resolution over the abrupt climate change events occurred during the last glacial period. These events are accompanied by abrupt warming of up to more than 10 degrees within a few decades showing a drastic change in climate and environement at global scale, and hence these events provide an optimal natural experience to study the response of global biosphere productivity to upcoming abrupt climate change and hence its impact on global carbon cycle.
To achieve the goal, the objective of OXYPRO projet is twofold: (1) to reconstruct the high-resolution records of triple isotopic composition of O2 and carbonyl sulfide (COS) concentrations over the transitions of Heinrich Stadial (HS) to Dansgaard-Oeschger (DO) events from ice cores drilled in Greenland, and (2) to make quantitative interpretation of the new data by using Earth system model equipped with triple O2 isotopes.