Periodic Reporting for period 1 - BeCoM (Better Contrails Mitigation)
Reporting period: 2022-06-01 to 2023-11-30
Civil aviation contributes to ~4% of the total anthropogenic radiative forcing, including the effects from CO2, NOx, water vapor and persistent contrails/contrail cirrus. The climate impact of contrails is significant and large uncertainties exist due to sparse relative humidity measurements at cruise levels and modeling inadequacies. Furthermore, one most critical aspect, which limits the projections of aviation’s climate impact, is the vast weather-induced variability of the radiative effect of individual contrails. This is the quantity, BeCoM will predict better since the knowledge of the individual radiative forcing is the basis for avoiding just those contrails that dominant the overall climate impact. Once this is accurate, BeCoM will formulate adequate mitigation measures and develop policy-driven implementation schemes for non-CO2 emissions/climate effects. The goal of BeCoM is to largely reduce or eliminate the global mean contrail radiative forcing, hence a substantial reduction of aviation’s global warming effects to be achievable on a much shorter time horizon.
BeCoM comprises six specific objectives:
• Objective O1: enhance the routine measurements of atmospheric humidity at the cruise altitude.
• Objective O2: improve the treatment of ice supersaturation conditions in numerical weather prediction models.
• Objective O3: develop appropriate AI algorithms for data assimilation, contrail detection, contrails classification, and uncertainties of contrail prediction (WP3).
• Objective O4: minimize overall cost when implementing climate optimized trajectories.
• Objective O5: develop non-CO2-based measures to be applied for ATM strategies for climate impact mitigation.
BeCoM comprises six specific objectives:
• Objective O1: enhance the routine measurements of atmospheric humidity at the cruise altitude.
• Objective O2: improve the treatment of ice supersaturation conditions in numerical weather prediction models.
• Objective O3: develop appropriate AI algorithms for data assimilation, contrail detection, contrails classification, and uncertainties of contrail prediction (WP3).
• Objective O4: minimize overall cost when implementing climate optimized trajectories.
• Objective O5: develop non-CO2-based measures to be applied for ATM strategies for climate impact mitigation.
The work performance and main achievements are summarized as below corresponding to the project objectives described above:
1) Water vapor measurements:
• Lidar hardware at OHP is upgraded by implementing coaxial emission to allow retrieving water vapor accurately down to the ground.
• Collecting observations for lidar and meteorological sondes at available sites (within French observational network) has been routinely performed. Past full sky Camera at OHP have been archived.
• The meteorological radiosondes from Nimes (meteorological center close to OHP) have been analyzed to compare with the European meteorological analyses ECMWF. The preliminary finding is a systematic bias around 250 mbar (9 km). It appears that the difference between both data sets is not a mean difference but is due to different distributions from both data sets. Radiosondes seem to observe more wet situations while ECMWF reports more humid events.
2) Numerical weather prediction model improvements:
• Two one-month periods of IAGOS aircraft humidity data including all meta-data and quality control information were received and stored in the observation data base system of DWD. A first investigation of the data quality was started.
• A novel concept of ice cloud microphysics for NWP models has been formulated, coded, and tested. It retains much more ice-supersaturation than the traditional one-moment scheme.
3) Data collection for AI algorithm development:
• Several promising data sources including ground-based images, satellite and LIDAR have been identified to construct a collocated dataset for AI algorithm training.
• A catalogue of data sources and their associated metadata, containing: Data source, type and acquisition devices, size of data set, licence, file format(s) has been established.
4) Minimize cost impact when implementing climate optimized trajectories:
• The first set of traffic sample focusing on ECAC aera for trajectory optimization was identified and made available on the project internal shared point. Further analysis is being carried to investigate the variability of Ice supersaturation conditions with respect to locations and seasons. Accordingly, the traffic sample can be expanded.
• The air traffic simulation tool is being improved to allow a more realistic simulation of trajectory optimization.
5) Non-CO2 based market measures for flight optimization:
• Existing and discussed operational policy instruments for the consideration of non-CO2 effects have been reviewed in a structured way. The concept development (based on CO2e accounting) for algorithmic cost functions to identify cost-optimal solutions by accounting for climate effects was carried out.
1) Water vapor measurements:
• Lidar hardware at OHP is upgraded by implementing coaxial emission to allow retrieving water vapor accurately down to the ground.
• Collecting observations for lidar and meteorological sondes at available sites (within French observational network) has been routinely performed. Past full sky Camera at OHP have been archived.
• The meteorological radiosondes from Nimes (meteorological center close to OHP) have been analyzed to compare with the European meteorological analyses ECMWF. The preliminary finding is a systematic bias around 250 mbar (9 km). It appears that the difference between both data sets is not a mean difference but is due to different distributions from both data sets. Radiosondes seem to observe more wet situations while ECMWF reports more humid events.
2) Numerical weather prediction model improvements:
• Two one-month periods of IAGOS aircraft humidity data including all meta-data and quality control information were received and stored in the observation data base system of DWD. A first investigation of the data quality was started.
• A novel concept of ice cloud microphysics for NWP models has been formulated, coded, and tested. It retains much more ice-supersaturation than the traditional one-moment scheme.
3) Data collection for AI algorithm development:
• Several promising data sources including ground-based images, satellite and LIDAR have been identified to construct a collocated dataset for AI algorithm training.
• A catalogue of data sources and their associated metadata, containing: Data source, type and acquisition devices, size of data set, licence, file format(s) has been established.
4) Minimize cost impact when implementing climate optimized trajectories:
• The first set of traffic sample focusing on ECAC aera for trajectory optimization was identified and made available on the project internal shared point. Further analysis is being carried to investigate the variability of Ice supersaturation conditions with respect to locations and seasons. Accordingly, the traffic sample can be expanded.
• The air traffic simulation tool is being improved to allow a more realistic simulation of trajectory optimization.
5) Non-CO2 based market measures for flight optimization:
• Existing and discussed operational policy instruments for the consideration of non-CO2 effects have been reviewed in a structured way. The concept development (based on CO2e accounting) for algorithmic cost functions to identify cost-optimal solutions by accounting for climate effects was carried out.
• The exploration of assimilating different datasets, e.g. IAGOS humidity measurements or satellite images, will improve the predictivity of the humidity forecast at cruise altitude, which is critical to contrail formation condition.
• The new concept of a one-moment ice cloud scheme has a potential to improve the ice supersaturation forecast quality within numerical weather models with less expensive computational load compared to the two-moment scheme method.
• The constructed database from various identified sources focuses on open access so that it serves the scientific community to predict contrail formation.
• The newly developed CO2e accounting will allow cost optimized flight planning while reducing the climate impact.
• The new concept of a one-moment ice cloud scheme has a potential to improve the ice supersaturation forecast quality within numerical weather models with less expensive computational load compared to the two-moment scheme method.
• The constructed database from various identified sources focuses on open access so that it serves the scientific community to predict contrail formation.
• The newly developed CO2e accounting will allow cost optimized flight planning while reducing the climate impact.