Title:	Simultaneous atmospheric inverse modeling of CO2 and 14CO2
DNr:	NAISS 2023/22-581
Project Type:	NAISS Small Compute
Principal Investigator:	Carlos Gomez <carlos.gomez@nateko.lu.se>
Affiliation:	Lunds universitet
Duration:	2023-06-01 – 2024-06-01
Classification:	10508
Keywords:

Abstract

Radiocarbon (14CO2) has been used as a tracer to separate the natural and anthropogenic signals in CO2 atmospheric observations to quantify fossil fuel CO2 emissions. Due to its half-life time of ~5730 years, radiocarbon has already decayed in fossil fuels deposited millions of years ago as organic matter. Radiocarbon is naturally produced in the upper atmosphere. Still, it is a by-product of nuclear activities such as bomb tests and power generation, affecting its natural cycle and producing disequilibrium fluxes. In this work, we are using LUMIA, the Lund University Modular Inversion Algorithm, for performing a series of observation system simulation experiments (OSSEs) inverting simultaneously atmospheric CO2 and 14CO2 observations from the Integrated Carbon Observation System (ICOS) station network to solve for the natural fluxes, disequilibrium fluxes, and the anthropogenic fossil fuel emissions. The OSSEs apply an inverse model to simulated observations with assumed uncertainties to evaluate the impact of a potential observing system on the estimated target quantities here, the radiocarbon observations on fossil fuel emissions. The inversions are being performed on a spatial domain over Europe, solving with a variable spatial and temporal resolution for each flux and evaluating the impact of constraining/prescribing 14CO2 related fluxes. I previously used the budget of my supervisor's project, but now it is not enough for both.