The Data User Guide describes the data products for the Making Earth Science Data Records for Use in Research Environments project (MEaSUREs 2017: Records of Fused and Assimilated Satellite Carbon Dioxide Observations and Fluxes from Multiple Instruments). The focus of this user guide is to describe the format, resolution, and contents of the netcdf products. Readers who are interested in the theoretical basis for the product should check the Algorithm Theoretical Basis Document (ATBD).
File:
Data_User_Guide.pdf
For questions and details contact: hai.m.nguyen@jpl.nasa.gov
This Algorithm Theoretical Basis Document (ATBD) describes the theoretical basis of the algorithm used to generate the fused data products for the Making Earth Science Data Records for Use in Research Environments project (MEaSUREs 2017: Records of Fused and Assimilated Satellite Carbon Dioxide Observations and Fluxes from Multiple Instruments. The data fusion approach is based on kriging is well developed in the literature, specifically for Level 3 XCO2 generation (e.g. Nguyen et al., 2012). However, this approach was modified as this MEaSUREs project is specifically geared towards producing data that could be incorporated into flux inversion studies. The key difference between Level 3 XCO2 generation and flux inversion is the number of variables required for the outputs. Therefore the modified approach produces the following fields i.e., longitude, latitude, pressure levels (which varies at each footprint), pressure weighting functions, XCO2, time in UTC prior mean, and column averaging kernel as part of the fused output.
File:
MEASURES17_ATBD.pdf
For questions and details contact: hai.m.nguyen@jpl.nasa.gov
The OCO-2 Version 9 “Lite” files provide bias-corrected versions of the Level 2 raw XCO2 retrievals found in the Standard product. We condense these corrected XCO2 values into summary measurements, one every 10 seconds (or ∼67.5 km along-track), at a resolution more appropriate for the atmospheric transport models used in global-scale CO2 flux inversions, which run with grid boxes 100s of km wide. These summary measurements can then be used more efficiently in the inversions, reducing the computations and I/O required while still capturing the relevant information contained in the original individual retrievals. This document describes our approach to computing 10-second-averaged products.
File:
10-second-averaged Documentation
For questions and details contact: david.f.baker@noaa.gov
Carbon Dioxide flux maps generated by utilizing satellite observations from Orbiting Carbon Observatory-2 and Greenhouse Gases Observing Satellite (GOSAT) are subject to several sources of uncertainty, including observational errors, spatio-temporal representation uncertainty and model transport error.
Some flux solutions attempt to account for these sources of uncertainty in their representation of the posterior uncertainty, but these are not always available and a coherent probabilistic assessment becomes challenging in the presence of multiple flux estimates with varying assumptions. The statistical methodology being developed as part of this project (MEaSUREs 2017: Records of Fused and Assimilated Satellite Carbon Dioxide Observations and Fluxes from Multiple Instruments) provides a framework for this common situation.
The preliminary details regarding the methodology that would be used to detect differences in flux maps is described in the Algorithm Theoretical Basis Document version 1. This document is different from the ATBD document for MEaSUREs 2017 fused products.
File:
spatial_map_comparison_TBD.pdf
For questions and details contact: jhobbs@jpl.nasa.gov