Geostationary Carbon Cycle Observatory (GeoCarb): Unraveling the Carbon-Weather-Climate System

Abstract:

The second NASA Earth Venture Mission, Geostationary Carbon Cycle Observatory (GeoCarb), will provide measurements of the concentration of atmospheric carbon dioxide (CO₂), methane (CH₄), carbon monoxide (CO), and solar-induced fluorescence (SIF) from Geostationary Orbit (GEO) at 103ºW. The GeoCarb mission will fly a 4-Channel scanning spectrometer as a hosted payload on a commercial communication satellite. GeoCarb will deliver daily maps of column concentrations of CO₂, CH₄, and CO over the observed landmasses in the Americas between 50ºN and 50ºS at a spatial resolution of roughly 10 x 10 km.

Global trends in the atmospheric concentrations of CO₂ and CH₄ are well established. The basic causalities for the observed trends are known; however, the spatial and temporal pattern of these perturbations and the flux dependence on the underlying processes are not well known. The fundamental roadblock to advancing knowledge of the carbon cycle is uncertainty about land-atmosphere CO₂ and CH₄ fluxes, and how they vary in the carbon-weather-climate system. This uncertainty is important and challenging.

Observations from space are providing revealing dynamics and demonstrate great promise: The Japanese Greenhouse Gas Observing Satellite (GOSAT-1) launched into Low Earth Orbit (LEO) in 2009; the Orbiting Carbon Observatory-2 (OCO-2) launched in 2014 into LEO; the GOSAT-2 launched in November of 2018, and finally, OCO-3 was launched in May 2019 and is flying on the International Space Station (ISS), which allows it to capture aspects of the diurnal cycle. The GeoCarb Mission builds particularly upon OCO-2 and OCO-3 heritage.

GeoCarb is unique in flying in a geostationary orbit and providing persistent measurements of CO₂, CH₄, CO, and SIF. As such, GeoCarb will contribute to resolving actual atherogenic carbon emissions as well as illuminating biotic processes that control land-atmosphere CO₂ and CH₄ fluxes at regional to continental scales. This will provide the foundation for essential improvements in modeled biogeochemical processes in Earth System Models as well as monitor the response of the biosphere to disturbance. This is essential to improve understanding of the Carbon-Weather-Climate System.

This paper will provide an update on the GeoCarb Mission, which was confirmed on 28 December 2019 by NASA.