FAQ - CT2011_oi
Q1: I'm a member of the press and would like more information, to whom do I turn?
Q2: Can I use whatever I find on these pages?
Q3: How do I cite or acknowledge CarbonTracker work?
Q4: What data are available beyond those currently offered through FTP, and how do I get it?
Q5: Why is CarbonTracker almost a year behind the current date?
Q6: How reliable are your products?
Q7: Where can I find more technical details on CarbonTracker?
Q8: I'm having trouble using the CarbonTracker results, where can I get help?
Q9: Are CarbonTracker results available for earlier releases?

Q1: I'm a member of the press and would like more information, to whom do I turn?
A1: Please contact Pieter Tans (NOAA ESRL Carbon Cycle Group Chief) to discuss CarbonTracker, get the latest carbon cycle insights, or obtain additional material.

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 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 efforts when you use them in your scientific endeavors.

Q3: How do I cite or acknowledge CarbonTracker work?
A3: We ask that scientific work that relies heavily on CarbonTracker 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 weekly global fluxes and North American mole fraction data, 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 time series of estimated fluxes for 50+ AmeriFlux eddy-covariance sites, optimized CO2 time series for 250+ locations worldwide, and routines to sample column CO2 abundances at other times of day to coincide with satellite overpasses of for instance AIRS or OCO. 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 almost a year behind the current date?
A5: CarbonTracker operates with a one-year delay. Our next release, scheduled for October, 2013, will update flux estimates through the end of 2012. There are several reasons for this delay, but the most important one is that there is a lag in our receiving air sample flasks from around the world, analyzing their contents, and performing the requisite quality control. This process involves many persons and many hours of meticulous work. As a result, the CO2 mole fraction data for 2011 won't be available for our CarbonTracker modeling efforts until mid-summer 2012. Preparing the CarbonTracker product itself requires another two months or so of modeling effort.

While CarbonTracker results are lagged by a year, 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 our interactive data visualization page at: http://www.esrl.noaa.gov/gmd/dv/iadv/.

Q6: How reliable are your products?
A6: The reliability of our products depends on the time and location for which they are assessed. 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 team. We welcome any help and assistance, or feedback you might have on this issue. The CarbonTracker team will generally quote conservative formal uncertainty estimates on all website products.

Q7: Where can I find more technical details on CarbonTracker?
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 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 results available for earlier releases?
A9: Yes. Previous versions of CarbonTracker have been archived and are available here.