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The page will be updated as required. It was last changed on 1 March 12 May 2021.

For a record of changes made to this page please refer to Document versions .

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The planned timetable for the implementation of the cycle 47r2 is as follows:

The timetable represents current expectations and may change in light of actual progress made.

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The meteorological changes can be found on the ECMWF  IFS CY47R2 page.

The main change which impacts CAMS is the switch to running the forecasts (but not the analysis) using single-precision arithmetic for increased computational efficiency.

Atmospheric composition content of the new cycle

Assimilation

• None

Observations

• No other changes compared to 47R1

Observations

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• the observations used in 47r1.
  

Emissions

• Reduced volcanic outgassing of SO2 from certain volcanoes based on recent observations.
• Implemented cap on anthropogenic primary organic matter (OM) emissions to reduce excesses in highly polluted regions.
• Increased numerical precision in prescribed emission fields to remove artefacts.

Other model changes

• Numerical improvements to the aerosol and chemistry schemes to accommodate running the forecasts in single precision as noted above.

Impact of the new cycle

A comprehensive evaluation report of the 47r2 e-suite has been prepared documenting all the changes and their impact on the forecasts. The changes of this upgrade were evaluated with independent observations for Q1 and Q3 of 2020:

• strong improvements for PM2.5 over China and India in both bias and RMSE because of reduced PM2.5 (the overall bias is now slightly negative) 
• nearly neutral impact for PM2.5 and PM10 elsewhere. Where biases were increased, the RMSE was often improved
• small reduction in tropospheric and surface ozone, which is an improvement 
• neutral results for CO 

Technical details of the new cycle

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