Page History

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• Updates to photolysis quantum yields and cross sections for selected trace gases in troposphere  
• Tuning of ozone depletion modeling in the stratosphere
• dry deposition scheme to use IFS stomatal resistance 
• De-activation of dry deposition of CO
• Lopez-lightning emission parameterisation for Lightning NOx emissions  

Impact of the new cycle

A comprehensive evaluation report of the 49r1 e-suite, documenting all the changes and their impact on the forecasts will be provided ahead of the actual implementation. Initial testing results show improved aerosol forecasts, has now been provided and can be found here: Upgrade Verification Note. It summarizes the impact as follows: 

• Surface and free tropospheric ozone increase globally by about 5-10%, which leads to an increased overestimation in several regions.
• The coupling of stratospheric sulphate aerosol formation with BASCOE gas-phase chemistry improves the simulated stratospheric aerosol extinction significantly.
• The CO tropospheric profile improves considerably in the new control run; however, the e-suite and the o-suite are very similar (both of good quality) reflecting the strong impact of the CO satellite data in the analysis.
• The aerosol AOD, AE and PM comparisons show significant differences, but with both positive and negative changes of the scores.
• The Ångström exponent bias over the Middle East and temporal correlation over North America are improved.
• The aerosol optical depth improves in the new control run; however, the assimilation introduces a small positive bias globally.
• Both HCHO and NO2 show larger biases compared to TROPOMI satellite observations. An increased positive bias for NO2 is observed. For the Boreal fire regions, the NO2 comparison has improved.
• The evaluation of stratospheric gases shows differences, but a similar overall performance for e-suite and o-suite.

Image Added

Scorecard for the relative performance of the e-suite versus the performance of the o-suite for each of the observational datasets used. Meaning of the “relative score” symbols: (++) e-suite performs significantly better than the o-suite (+) e-suite shows small improvements, (n) (neutral) no significant difference between o-suite and e-suite, (-) score is somewhat degraded in the e-suite, (–) e-suite performs significantly worse than the o-suite. Remote: Remote Sensing from surface station, AOD: Aerosol Optical Depth at 550nm, Ångstrøm exponent between 440nm and 870nm, PM10: Particulate matter less than 10 microns, PM2.5: Particulate matter less than 2.5 microns.

Technical details of the new cycle

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