CAMS produces global forecasts for the two main long-lived greenhouse gases once a day. This dataset consists of 5-day high-resolution forecasts of carbon dioxide (CO2) and methane (CH4). Additionally, carbon monoxide (CO) and meteorological parameters relevant to the CAMS greenhouse gas forecast are included.
The initial conditions of each forecast are obtained by combining a previous forecast with current satellite observations through a process called data assimilation. This best estimate of the state of the atmosphere at the initial forecast time step, called the analysis, provides a globally complete and consistent dataset allowing for estimates at locations where observation data coverage is low.
The analysis has a resolution of approximately 25km and it is produced 4 days behind real-time due to the current latency of satellite retrievals of CO2 and CH4. As this analysis of greenhouse gases is not available close to real time, it is not provided. Instead, the high-resolution forecast with a resolution of approximately 9km is run a few hours behind real time, with initial conditions based on a 4-day forecast of the analysis experiment. Additionally, because some meteorological fields in the forecast do not fall within the general CAMS data licence, they are only available with a delay of 5 days.
The forecast itself uses a model of the atmosphere based on the laws of physics and prescribed chemical loss rates or simplified chemistry to determine the evolution of the concentrations of all species over time for the next five days. Apart from the required initial state, it also uses inventory-based, observation-based and modelled emission estimates as a boundary condition at the surface.
The CAMS global forecasting system is upgraded about once a year resulting in technical and scientific changes. The horizontal or vertical resolution can change, new species can be added, and more generally the accuracy of the forecasts can be improved. Details of these system changes can be found in the documentation.
Users looking for a more consistent long term data set should consider using the CAMS greenhouse gas reanalysis instead, which is available through the Atmosphere Data Store (ADS) and spans the period from 2003 onwards, or the CAMS global inversion-optimised greenhouse gas fluxes and concentrations which provides a longer dataset that is suitable for trend analysis and also available through the ADS.
The initial conditions of each forecast are obtained by combining a previous forecast with current satellite observations through a process called data assimilation. This best estimate of the state of the atmosphere at the initial forecast time step, called the analysis, provides a globally complete and consistent dataset allowing for estimates at locations where observation data coverage is low.
The analysis has a resolution of approximately 25km and it is produced 4 days behind real-time due to the current latency of satellite retrievals of CO2 and CH4. As this analysis of greenhouse gases is not available close to real time, it is not provided. Instead, the high-resolution forecast with a resolution of approximately 9km is run a few hours behind real time, with initial conditions based on a 4-day forecast of the analysis experiment. Additionally, because some meteorological fields in the forecast do not fall within the general CAMS data licence, they are only available with a delay of 5 days.
The forecast itself uses a model of the atmosphere based on the laws of physics and prescribed chemical loss rates or simplified chemistry to determine the evolution of the concentrations of all species over time for the next five days. Apart from the required initial state, it also uses inventory-based, observation-based and modelled emission estimates as a boundary condition at the surface.
The CAMS global forecasting system is upgraded about once a year resulting in technical and scientific changes. The horizontal or vertical resolution can change, new species can be added, and more generally the accuracy of the forecasts can be improved. Details of these system changes can be found in the documentation.
Users looking for a more consistent long term data set should consider using the CAMS greenhouse gas reanalysis instead, which is available through the Atmosphere Data Store (ADS) and spans the period from 2003 onwards, or the CAMS global inversion-optimised greenhouse gas fluxes and concentrations which provides a longer dataset that is suitable for trend analysis and also available through the ADS.
Interval
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DOI
10.24381/93910310
Portal
Atmosphere Data Store
Product Family
Data
Product Type
Forecast
Spatial Coverage
Global
Temporal Coverage
Present
Future
Variable Domain
Atmosphere (composition)