MEaSUREs 2017: Records of Fused and Assimilated Satellite Carbon Dioxide Observations and Fluxes from Multiple Instruments is geared towards creating fused and gap-filled Earth System Data Records (ESDR) of CO2 concentrations by integrating observations from the Atmospheric CO2 Observations from Space (ACOS) retrievals from the Greenhouse Gases Observing Satellite (GOSAT), Orbiting Carbon Observatory-2 (OCO-2) and Atmospheric Infrared Sounder (AIRS).

Products to be delivered:

This MEaSUREs project would deliver:

1) A level-3 gap-filled product by fusing bias-corrected level-2 XCO2 retrievals from ACOS-GOSAT and OCO-2 and AIRS. AIRS would only be included if it leads to significant improvements in estimation of global CO2 fluxes.

2) Two separate level-3 gap filled products obtained from bias-corrected level-2 XCO2 retrievals from OCO-2 and ACOS-GOSAT.

3) Source code for Enhanced False Discovery Rate algorithm that can be utilized to assess spatio-temporal patterns in the fluxes produced by DA systems, by using proposed ESDRs and level-2 retrievals.

All gridded ESDR products include XCO2, time stamps, location information, averaging kernels, prior mean profiles, pressure levels, uncertainties, and error covariance matrices.

Validation

The validation of these ESDR’s is being performed by (1) comparing them against in-situ and aircraft observations, (2) comparing regional fluxes and uncertainties obtained by utilizing level-2 satellite retrievals, against the fluxes obtained by using gap-filled and/or fused ESDRs, within CO2 flux data assimilation frameworks, and (3) identifying spatio-temporal similarity and ‘dissimilarity’ between fluxes obtained by using level-2 retrievals and gap-filled or fused ESDRs.

Expected Significance

The fused data records that are being created as part of this work will relieve users of the need to process and understand the details of individual input data sources including instrument characteristics, differences in footprints, measurement errors, and processing algorithms. In addition, the fused data will provide a standard platform for comparative assessment of the estimated CO2 exchange obtained from multiple Data Assimilation systems through a flux assessment tool provided as part of this work. The gap-filled, instrument-specific products will provide points of comparison for understanding and quantifying benefits of the fused data set over and above separate incorporation of instrument-specific, gap-filled products.