SYNERGETIC USE OF RADAR AND OPTICAL SATELLITE IMAGES TO SUPPORT SEVERE STORM PREDICTION FOR OFFSHORE WIND FARMING

摘要

In this paper we show how satellite images taken byrnspace-borne radar sensors can be used to determinernmesoscale high resolution wind fields in synergy withrnoptical data. The aim of this study is to analyse severernweather systems, in particular to describe the spatialrnevolution of the atmospheric boundary layer processesrninvolved in cold air outbreaks. A severe weather eventrnhappened in early November 2006 over the North Searnand damaged the research platform FiNO 1. This casernof a particularly intense cold air outbreak over thernNorth Sea is investigated using satellite data.rnAtmospheric boundary layer rolls and open cellrnconvection were observed by the Advanced SyntheticrnAperture Radar (ASAR) and the Medium ResolutionrnImaging Spectrometer (MERIS) instrument, sensors onrnboard the ENVISAT satellite.rnCloud patterns parallel as well as perpendicular to thernmean wind direction showing a cell structure of aboutrn15 km diameter. Similar patterns were observed inrnSAR images. These are believed to be surface effectsrnof gust fronts induced by the mesoscale cellularrnconvection and enhanced by the overall northwesterlyrnflow. The phenomenon is explained by downwardrntransport of higher momentum in convective clouds.rnThe satellite data are used to validate numerical modelrnresults (LM, HIRLAM). The focus of this paper is onrnthe impact of high variability in wind speed ofrnmesoscale convective cloud patterns, which are notrnwell captured by these numerical models.