Science Seminars

12/01/2016 – Steven Massie; Orbiting Carbon Observatory (OCO-2) Measurements of CO2

Speaker: Steven Massie (LASP)
Date: Tuesday, Dec 01, 2020
Time: 4:00 PM
Location: SPSC W120

Seminar Abstract:

The experimental goal of the Orbiting Carbon Observatory (OCO-2) is to measure CO2 on regional scales to 1 ppmv accuracy in order for the Carbon Cycle modeling community to obtain better understanding of the natural land and ocean sources and sinks of CO2. These measurements are difficult due to the fact that atmospheric CO2 is near 400 ppmv, requiring instrument and retrieval accuracy near 1/4 %. The fundamentals of CO2 observational trends and variations, the radiative impacts of CO2 on global warming, and Carbon Cycle processes are reviewed. Background information on the OCO-2 measurement technique and the operational CO2 retrieval is also discussed. The last third of the seminar discusses physics not included in the operational retrieval, yet is demonstrated to be of importance: the effects of 3 dimensional radiative transfer due to clouds outside of the OCO-2 field of view. OCO-2 CO2 and MODIS (Moderate Resolution Imaging Spectroradiometer) radiance (i.e. cloud field proxy) data are co-analyzed. As the cloud fields become more complex, the 3D cloud effect increases the variance in retrieved CO2 values beyond the 1 ppmv requirement in some of the OCO-2 observations.