Atmospheric Carbon and Transport – AmericaA new NASA Earth Venture Suborbital mission dedicated to improving the accuracy, precision

and resolution of atmospheric inverse estimates of CO2 and CH4 sources and sinks Kenneth Davis1, David Baker2, John Barrick3, Joseph Berry4, Kevin Bowman5, Edward Browell3, Lori Bruhwiler6, Gao Chen3, George Collatz7, Robert Cook8, Scott Denning2, Jeremy Dobler9, Chris

Hostetler3, Syed Ismail3, Andrew Jacobson6, Anna Karion6, Klaus Keller1, Thomas Lauvaux5, Bing Lin3, Byron Meadows3, Anna Michalak4, Natasha Miles1, John Miller6, Berrien Moore10, Amin Nehrir3, Lesley Ott7, Michael Obland3, Christopher O’Dell2, Stephen Pawson7, Gabrielle Petron6, Scott Richardson1, Andrew Schuh2, Colm Sweeney6, Pieter Tans6, Yaxing Wei8, Melissa Yang3, and Fuqing Zhang1

1The Pennsylvania State University, 2Colorado State University, 3NASA Langley Research Center, 4Carnegie Institution of Stanford, 5NASA Jet Propulsion Lab, 6NOAA ESRL/University of Colorado, 7NASA Goddard Space Flight Center, 8Oak Ridge National Lab, 9Exelis, Inc., 10University of Oklahoma

This investigation is supported by NASA’s Earth System Science Pathfinder Program Office.

Motivation

Goals

Investigation concept

Investigation Implementation

Instruments, Models and Aircraft

Management and Science Teams

Image credit: Tim Marvel / NASA Langley

Our inability to quantify carbon fluxes with accuracy and precision across regional domains is a primary methodological challenge in carbon cycle science today. It hamstrings our ability to address all other terrestrial carbon cycle science questions.

Overarching goal: The Atmospheric Carbon and Transport-America (ACT-America) mission aims to enable and demonstrate a new generation of atmospheric inversion systems for quantifying CO2 and CH4 sources and sinks at regional scales. These inversion systems will be able to:

• Evaluate and improve terrestrial carbon cycle models, and

• Monitor carbon fluxes to support climate-change mitigation efforts.

1. Quantify and reduce atmospheric transport uncertainty,2. Improve regional, seasonal estimates of CO2 and CH4

fluxes, and3. Evaluate the sensitivity of Orbiting Carbon

Observatory-2 (OCO-2) column CO2 measurements to regional variability in tropospheric CO2.

The overarching goal will be addressed by three mission goals, each of which addresses one of the three primary limits on the accuracy and precision of atmospheric inversions; atmospheric transport error, prior flux estimate error, and limited atmospheric data density.

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Distance downwind within a source/sink region

Backgroundmole fraction(tower network)

Flight domain

Elevation of mole fraction above continental background

Mean wind

= airborne mole fraction observations

Pruned flux and transport ensemble members

Retained flux and transport ensemble members

Aspiration: New flux and atmospheric transport process understanding will be common across the mid-latitudes, and the OCO-2 evaluation will apply globally, thus the results of the study will improve atmospheric inverse flux estimates around the globe and over decades.

Fair-weather (flux-dominated) flight plan (goals 1 and 2)

• Measure winds, ABL depth, CO2, CH4 and tracers (CO, 14CO2, O3, COS) across 100’s of km.

• Solve for regional fluxes for the days of flights directly – prune prior flux estimates.

• Evaluate fair weather meteorology in atmospheric transport ensemble. Prune transport ensemble.

Stormy-weather (transport-dominated) flight plans (goal 1)

• Measure atmospheric state, CO2, CH4 and tracers (CO, 14CO2, O3, COS) across and around frontal systems.

• Evaluate atmospheric transport in our model ensemble. Prune transport ensemble.

OCO-2 under-flights (goal 3)

• Measure most of the atmospheric CO2 column with precision at 20km horizontal resolution across 100’s of km below OCO-2. Also measure aerosols and clouds.

• Compare spatial variability in airborne CO2 to OCO-2 CO2. Evaluate OCO-2 ability to capture tropospheric CO2 variability. Quantify OCO-2 high resolution data quality.

Need

North American terrestrial ecosystem CO2 fluxes estimated using atmospheric inversions. Figure shows mean values and published uncertainties.

Figure courtesy Martha Butler, Penn State

Vision of error reduction in regional flux inversions to be achieved via the ACT America mission.

Compare airborne CO2, CH4 and other atmospheric state data to a flux and transport model simulation of the flight region.

Opportunties for collaboration are abundant! Contact kjd10@psu.edu.

Prune the ensemble to eliminate unrealistic flux prior and transport models (see idealized example above).

Quantify OCO-2 high-resolution data quality and uncertainty.

Use the pruned ensemble and OCO-2 data quality characterization for more accurate and precise regional flux inversions using the long-term GHG observational network (towers, flasks, satellite, profiling aircraft).

Hypothesis: Mid-latitude atmospheric GHG transport is dominated by synoptic weather. Synoptic conditions can be divided roughly into high- and low-pressure conditions. We have structured our flight plans along these lines.

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Principal Investigator: Kenneth Davis, Penn StateProject Scientist: Bing Lin, NASA LaRCProject Manager: Michael Obland, NASA LaRCInstrument and Aircraft Logistics Manager: Byron Meadows, NASA LaRCInstrument Science Manager: Amin Nehrir, NASA LaRCDeputy PI for Goals 1 and 2: Thomas Lauvaux, NASA JPLDeputy PI for Goal 3: Christopher O’Dell, Colorado State

Science team categories: Instrument science; Aircraft observational studies; Regional atmospheric and inversion modeling; Global atmospheric and inversion modeling; Ecosystem carbon cycle modeling; Satellite CO2 data evaluation; Statistical and ensemble methods; Data and model management.

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Boxes show approximate locations of regional flights.

ScheduleYear 1 (2015): Instrument aircraft, integrate modeling systems, perform flight design simulations.Years 2-4 (2016-18): Five flight campaigns and analyses. Address goals 1-3.Year 5 (2019): Wrap up goals 1-3. Apply findings to a multi-year reanalysis of N. American C fluxes using long-term observational assets (i.e., demonstrate new atmospheric inversion system).

Field campaigns• Five, six-week flight campaigns. Sample each season,

with a repeat summer campaign.• 2 weeks in each region (NE, MW, SE).• 4 flights per region (both aircraft)• Roughly 3:1 ratio between weather vs. OCO-2 flights• Aim for at least one fair and stormy weather flight in each

region, for each campaign.

Wallops C-130 replaces the proposed P-3B, and carries remote and in situ instruments.

Langley UC-12 carries in situ instruments.

Conceptual map of model-data synthesis plans, including a list of the model components to be used to create flux-transport model ensembles.