The Environmental Statistics section of the Statistical Society of Australia proudly presents the Tjanpi Award seminar. Josh Jacobson is the winner of the 2025 Tjanpi Award for best student paper in environmental statistics, and in this talk he will outline the key results of his award-winning paper.
Date: Wednesday 10 June 2026
Time: 9:00am - 10:00am (AEST)
Format: Online via Zoom. Details provided upon registration
Abstract: A Bayesian Hierarchical Model for CO₂ Flux Estimation from Multiprocess Satellite Data
Quantifying the natural components of CO₂ surface flux is key to monitoring Earth's carbon dynamics. Existing inverse methods struggle to isolate the natural components, which cannot be individually constrained using atmospheric CO₂ concentrations alone. However, the advent of solar-induced fluorescence (SIF) satellite data provides an opportunity to improve identifiability by constraining the distribution of gross primary production (GPP), the photosynthetic component of flux. Here, we develop a spatio-temporal hierarchical model linking GPP to SIF and embed it within the WOMBAT v2.0 (WOllongong Methodology for Bayesian Assimilation of Trace-gases, version 2.0) statistical flux-inversion framework. We call the new framework WOMBAT v2.S, and we apply it to multiprocess data from NASA's OCO-2 satellite to estimate natural flux components over the globe during a six-year period. In a simulation experiment that mimics OCO-2's retrieval characteristics, the inclusion of SIF substantially improves posterior prediction accuracy and uncertainty quantification. Comparing real-data estimates from WOMBAT v2.S, v2.0, and an alternative method, we observe a reversal in the inferred trend of global CO₂ absorption.
Presenter Bio: Josh Jacobson
Josh is a statistician whose work sits at the intersection of Bayesian inference, climate science, and large-scale data analysis, with applications to understanding the global carbon cycle and environmental change. He completed his PhD in Statistics at the University of Wollongong late last year, supervised by Andrew Zammit-Mangion, Michael Bertolacci and Noel Cressie, and he is currently a Visiting Assistant Professor at the University of Colorado Boulder.
@StatSocAus
