Clouds represent the largest uncertainty in the climate system and much greater understanding of cloud processes and cloud systems is essential if this uncertainty is to be reduced. The importance of describing and improving our scientific understanding of the climate system is to provide a 'healthier planet for tomorrow' by allowing government policy to be informed by accurate scientific assessments. In particular extra tropical oceanic storm-track cloud systems have been little studied yet represent a major component of the climate system.
The Fronts and Atlantic Storm Track Experiment (FASTEX) is taking place during January and February 1997 to provide a unique data-set in what is the largest international experiment of its type ever undertaken.
Funding for some of the observational facilities in FASTEX has been provided by the KU. The aim of FASTEX-CSS is to exploit the FASTEX data to describe, in as complete a way as possible, the cloud systems associated with the cyclones which are predominant in mid and high latitudes in producing cloud and precipitation. This will produce a comprehensive picture of the full life-cycle of FASTEX cyclone-cloud systems. This project has clear links with the GEWEX cloud system study in emphasizing the European regional aspects.
The specific objective is to produce a complete life-cycle description and understanding of the FASTEX cloud-cyclone system examining:
- initiation and evolution of the cloud-cyclone system in the Atlantic storm-track including the role of the synoptic environment in that development
- intercomparison of mesoscale numerical models of FASTEX cyclones, exploiting sophisticated cloud physics representations
- multiscale synthesis of the cloud-cyclone system enabling tuning of cloud parameterization and validation for climate models
The deliverables are:
- determination of the properties of extra-tropical cloud systems associated with oceanic cyclones from initiation to mature state including understanding the synoptic, mesoscale and cloud processes which lead to these systems.
- a set of reference cloud classifications during the life-cycle of frontal waves
- validation of regional and cloud-scale models of the cyclone/cloud system
- a set of reference FASTEX simulations suitable for parameterization tuning (cloud and marine boundary layer structure)
- improved cloud physics parameterisation schemes for such clouds for use in climate models.
Funding SchemeCSC - Cost-sharing contracts
78140 Velizy Villacoublay
RG6 6FN Reading