Q2: Can I use whatever I find on these pages?
A2: Yes, all our results are free to be used by the public, scientists, and others. This includes all figures, numbers, data files, and even the Fortran and python source code. We encourage you to contact us with questions to ensure proper representation of the results, and we welcome any feedback and possibility for cooperation. Please acknowledge the CarbonTracker Europe efforts when you use them in your scientific endeavors.

Q3: How do I cite or acknowledge CarbonTracker Europe work?
A3: We ask that scientific work that relies heavily on CarbonTracker Europe products is discussed with us before publication, to ensure proper representation of our work and a co-authorship if appropriate. For suggestions, go to citation.

Q4: What data are available beyond that currently offered through FTP, and how do I get it?
A4: In addition to the available monthly and yearly global fluxes and mole fraction time series, we can generate global 1x1 degree biological fluxes at 3-hourly resolution, as well as optimized mole fraction data for any other part of the world. We have optimized CO2 time series for 150+ locations worldwide, and routines to sample column CO2 abundances at other times of day to coincide with TCCON observations or satellite overpasses of for instance AIRS, OCO-2, or GoSAT. We also offer the full covariances of our estimated parameters to any interested parties. Please contact us to discuss the sharing of these results.

Q5: Why is CarbonTracker Europe so far behind the current date?
A5: CarbonTracker Europe operates with at least a one-year delay. There are several reasons for this delay, but the most important one is that there is a lag in our receiving observed mole fraction data from around the world, and performing the required quality control. This process involves many persons and many hours of meticulous work. As a result, the CO2 mole fraction data for 2015 won't be available for our CarbonTracker Europe modeling efforts until mid-2016. Preparing the CarbonTracker Europe product itself requires another two months or so of modeling effort. While CarbonTracker Europe results are lagged by a year, subsets of the raw flask and in-situ observations themselves are posted as soon as they are available, even as the quality-control efforts are underway. For the most up-to-date observational data, you can visit the interactive data visualization page of NOAA ESRL at: http://www.esrl.noaa.gov/gmdl/ccgg/iadv/.

Q6: How reliable are your products?
A6: The reliability of our products depends on the time and location for which they are assessed. European and North American results will generally be more reliable than those in other parts of the world due to the focus of CarbonTracker on this region. Also, results that are aggregated in space (e.g., whole continents) or time (e.g., monthly averages) will be more robust than local or instantaneous estimates. For the fluxes, formal uncertainty estimates on the biological fluxes (full covariance matrices are available upon request) give some indication of the random errors we expect. However, systematic errors (e.g., biases) might dominate these at specific times and locations. Calculated mole fraction data will generally be reliable to within the specified errors at each site, while mole fractions at other locations will be better constrained in the proximity of assimilated sites. Assessing our products against independent data and quantifying their reliability is an important and ongoing task for the CarbonTracker Europe team. We welcome any help and assistance, or feedback you might have on this issue. The CarbonTracker Europe team will generally quote conservative formal uncertainty estimates on all website products.

Q7: Where can I find more technical details on CarbonTracker Europe ?
A7: For technical details beyond the documentation pages, we suggest you read the literature, visit our Collaborators page, see our release notes, or contact us.

Q8: I'm having trouble using the CarbonTracker Europe results, where can I get help?
A8: Send us an email describing in detail what you are trying to do, and what problem you run into. We will make every attempt to help you along.

Q9: Are CarbonTracker Europe results available for earlier releases?
A9: Yes. Contact us for more information.

Q10: How does CarbonTracker Europe differ from CarbonTracker at NOAA ESRL?
A10: CarbonTracker North America and CarbonTracker Europe are made by two separate, but collaborating, teams of researchers in the United States and Europe. CarbonTracker North America was first released in 2007, while the first release of CarbonTracker Europe was in 2009. Since then, the two development branches have shared many innovations, but also have slowly diverged. More specific details can be found here.