TIP: The above chart is interactable; click and drag to zoom in on a specfic region, and click on a trace in the legend to toggle its visiblity. Press the camera icon to save a PNG file.

Models: The ensemble mean of the OCO-2 retrevial models is plotted by default. The shown error represents one standard deviation of the model suite. Each of these OCO-2 retrevials may be plotted individually for comparison. The CarbonTracker releases may also be shown for inter-model comparison.

Traces: The traces in this figure represent carbon dioxide emissions for each month in PgC yr^-1 from the specified region. OCO-2 models simulated three types of surface-to-amosphere exchange of CO₂, each of which is shown in a different color: fossil fuel emissions (tan), terrestrial biosphere flux possibly including implicit fires (green), and air-sea gas exchange (blue). The CarbonTracker models also separately include fire (red), Net Ecosystem Exchange (NEE, green). Land is, by default, plotted as the sum of NEE and fires for CT models. The total sum net surface exchange (gray) and the sum of natural fluxes (i.e. no fossil fuels (purple) may also be plotted. Negative emissions indicate that the flux removes CO₂ from the atmosphere, and such sinks extend below zero.

Experiments: Diffrent experiments on the data may be selected. For the OCO-2 runs, you may select: Prior Prior emissions and their spread. IS Posterior emissions and their spread for the IS experiment (assimilating traditional in situ measurements) LNLG Posterior emissions and their spread for the LNLG experiment (assimilating OCO-2 retrievals in Land Nadir and Land Glint mode) LNLGIS: Posterior emissions and their spread for the LNLGIS experiment (assimilating traditional in situ measurements and OCO-2 retrievals in Land Nadir and Land Glint mode) LNLGOGIS Posterior emissions and their spread for the LNLGOGIS experiment (assimilating traditional in situ measurements and all OCO-2 retrievals in all modes) OG Posterior emissions and their spread for the OG experiment (assimilating OCO-2 retrievals in Ocean Glint mode)

Resolutions: Annual and monthly data are available for all models. The climatological flux is the monthly means over the full data period, and longterm fluxes are long-term averages.

Plotting: Either a line, stacked bar, or grouped stacked bar may be plotted. The grouped stacked bar groups by model, and stacks by traces. The title, subtitle, and trace titles may be individually set. Shaded error is not meaningful for either of the bar charts. Up to five models may be compared.

In the OCO-2 model intercomparison leading to this Level 4 product release, bottom-up estimates of fossil fuel were applied directly without optimization. Inverse modelers were asked to estimate optimal fluxes from the ocean and land biosphere. This optimization for each model generally starts with a first guess of the flux component and its uncertainty, shown as priors. The first-guess fluxes are subsequently evaluated against atmospheric CO₂ observations and/or retrievals. These fluxes are then modified to be consistent with those observational constraints. The optimized results (various experiments) have different mean fluxes and uncertainty ranges, indicating the influence of information brought by the observations.