PI: Berrien Moore @ OU (Leadership, science analysis) Partner Institutions: Lockheed-Martin (instrument) CSU (Algorithms) NASA Ames (Validation) GeoCarb A NASA Earth-Ventures mission, awarded in Dec 2016, cost $160M, expected launch 2021. The Geostationary Carbon Observatory Chris O Dell & Andrew Schuh CIRA, Colorado State University
Where Does CO 2 End Up? (2000-2009) 1.1±0.7 PgC y -1 4.1±0.1 PgC y -1 47% + 2.4 PgC y -1 7.7±0.5 PgC y -1 27% 26% 2.3±0.4 PgC y -1 Average of 5 models
Keeling Curve is the Fundamental Carbon Cycle Measurement Seasonal Cycle of Biosphere Upward trend Anthropogenic Forcing Inter-annual Variability Growth rate (time rate of change of this curve) = fossil source (land + ocean) Atmospheric Growth Rate is about half of global fossil fuel emissions highly variable from year to year, but Models tell us the ocean inter-annual flux variability is tiny land must be the cause
Science Questions What are the regional scale processes that drive the variability of the land sink? How long will the 50% discount continue? Feedbacks between the carbon cycle and the climate system? On long time horizons? On short time horizons? Surface observations are sparse in exactly the locations (oceans, high latitudes, tropics) that need to be observed in order to answer these questions!
Space-based Measurements Can Fill the Gaps Target Mode - Dryden Target Mode - Caltech
Motivation for a Geostationary Orbit GOSAT & OCO-2 successes Unprecedented coverage Instrument precision Significant engineering hurdles overcome!...and challenges Long revisit cycle and narrow swath: source attribution challenging at regional and urban scales Validation with limited number of samples of opportunity
The GeoCarb Mission: Measuring Carbon Trace Gases and Vegetation Health from Space Principal Investigator Technology Development Host Spacecraft & Mission Ops Berrien Moore, University of Oklahoma Lockheed Martin Advanced Technology Center SSE Government Solutions Instrument Single slit, 4-Channel IR Scanning Littrow Spectrometer Bands 0.76m, 1.61m, 2.06m and 2.32m Measurements Mass Dimensions Power Data Rate Daily Soundings O 2, CO 2, CO, CH 4 & Solar Induced Fluorescence 138 kg (CBE) 1.3 m x 1.14 m x 1.3 m 128W (CBE) 10 Mbps ~10,000,000 soundings per day 3km x 6km footprint at nadir
GeoCarb will be hosted on the nadir deck of an SES Government Solutions communications satellite
3T 2T T 0 secs Slit Projection 3072 km 1024 Px OCO-2 Sampling 10 km 0.7s 2km ½ Px Step per T GeoCarb uses a step and stare approach to provide mapping-like coverage with high signal to noise ratios over terrestrial landmasses in the western hemisphere
GeoCarb s Observing Strategy is Flexible Start of the Day End of the Day Rectangular box ~30 minutes of scanning time.
Validation through TCCON Remote sensors must be calibrated, and the resulting retrievals must be validated against independent data and/or models to remove bias. GeoCarb, like OCO-2/3 and GOSAT, will be validated against TCCON, which is in turn validated against in situ observations. TCCON Site in Lamont, OK at the Southern Great Plains Research Facility
The Goal: Top Down Constraint on Surface Fluxes from Local to National Scales Application: Power Plant Monitoring Courtesy: Peter Rayner Fluxes Uncertainty Reduction (kgc/m 2 /y) (%)
Solar Induced Fluorescence (SIF)
Chlorophyll Fluorescence: A probe of photosynthesis in vivo Absorbed Light Chlorophyll Fluorescence A distinct glow specific to green plants Heat / Non-Photochemical Quenching (NPQ) Direct information of plant functioning Structural Physiological 14
The emerging satellite capability for SIF observation is revolutionizing the monitoring of plant functioning Global satellite SIF RS (Available only in the last few years) GOSAT SIF Actual photosynthesis Functional proxy Early warning of stress Flux-based GPP (photosynthesis) (Frankenberg et al., 2011) Conventional reflectance -based RS Potential photosynthesis Empirical proxy Structural information: Chlorophyll content or LAI SIF and conventional remote sensing are complementary 15
Footprint of Existing Satellite SIF Products Data acquisition in August, 2015 in US Cornbelt OCO-2 (Nadir) GOSAT GOME-2 16
Spatial Coverage of Satellite SIF Products 17
Instantaneous Daily Average
Drought and early stress prediction Captures large scale droughts in 2011 and 2012 While greenness also likely captures this, SIF should theoretically allow improve short-term prediction skill in photosynthesis/gpp
GeoCarb: The Geostationary Carbon Observatory o With daily views of the land surface in the Americas, GeoCarb will o observe changes in CO 2, CO, CH 4 and SIF in near real time o connect concentrations to emissions with unprecedented spatial and temporal resolution o identify local emissions hot spots o enhance our understanding of ecosystem health and response to weather and climate patterns o work in concert with low earth orbiting satellites to quantify changes to the global carbon cycle
Drought Stress from 2016 El Niño seen in SIF
Solar Induced Fluorescence from OCO-2 Lake Superior (No SIF) Trees Solar Induced Fluorescence (SIF) Direct indicator of photosynthesis Responds quickly to environmental stressors (e.g. water limitation) Linked to ecosystem health Insensitive to thin clouds in the field of view Current space based SIF observations are from polar orbiting satellites with sparse coverage and/or long repeat cycles: OCO-2 GOME 2 GOSAT GeoCarb will provide daily maps of SIF that will give near real time ecosystem health information on the scale of a few tens of kilometers