Predicting persistent contrails using the ECMWF integrated forecast system
Abstract
Persistent contrails and in particular extended cirrus clouds that originate from the spreading of linear contrails still present one of the largest uncertainties when estimating the impact of aviation on climate. We studied the capability of the ECMWF integrated forecast system (IFS) to predict correctly the occurrence of cold ice supersatured regions (ISSR) in the upper troposphere, which are a necessary condition for persistent contrails to exist. The ISSR predictions of forecasts from nine hours up to three days have been compared to visual observations in seven locations in the UK and Ireland over several months as well as to corrected radiosonde data from the same area. The latter also provides information about the height if the occurrence of ISSR's which was used for the first time to evaluate the performance of the ECMWF IFS in the vertical dimension. A good agreement between predictions and observations was found which allows us to use the ECMWF forecasts to predict the occurrence of ISSRs for the aircraft in situ measuring campaign COSIC. This campaign has the aim to firstly produce persistent contrails, then track their development and measure their properties by flying through them repeatedly.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A51C0120R
- Keywords:
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- 0320 ATMOSPHERIC COMPOSITION AND STRUCTURE / Cloud physics and chemistry