Events

Professor Scot Miller, Johns Hopkins University, will discuss "A Tale of Two Satellites: Estimating carbon dioxide and methane fluxes from OCO-2 and GOSAT."

Satellite-based monitoring of greenhouse gases has expanded dramatically in the past decade, enabling new insight into greenhouse gas fluxes from regions of the world that were previously difficult to monitor. This talk will focus on insights from two satellites: carbon dioxide observations from NASA's OCO-2 satellite and methane observations from the Japanese GOSAT satellite. 

OCO-2 is NASA's first satellite dedicated to monitoring CO2 from space, and we evaluate the extent to which current OCO-2 observations can constrain monthly CO2 sources and sinks from the biosphere. Our goal is to guide top-down, inverse modeling studies and identify areas for future improvement. We find that a commonly-used version of the OCO-2 retrievals (ACOS version 7) has limited ability to detect or constrain regional carbon budgets, but recent advances in OCO-2 retrievals are are having a potentially transformative effect on the ability of satellite-based observations to constrain regional biospheric carbon balance.

In a separate study, we use GOSAT observations to examine recent trends in emissions of methane from the world's largest anthropogenic emitter of greenhouse gases — China. The largest fraction of China’s anthropogenic methane emissions is attributable to coal mining, but these emissions should be changing; China enacted a suite of regulations for coal mine methane (CMM) drainage and utilization that came into full effect in 2010. Here, we use methane observations from the GOSAT satellite to evaluate recent trends in Chinese emissions and the impact of China's ambitious CMM regulations. We further explore how China could use this CMM for electricity production or home heating and quantify the benefits of these different use cases for air quality and human health.