Hurricane Isabel
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Hurricane Isabel

January 19, 2006
These Medium Resolution Imaging Spectrometer (MERIS) images show the Hurricane Isabel located 2000 kilometers east of the Leeward Islands (Lesser Antilles) and moving west-northwest in the Atlantic Ocean at about 22.5 kilometers per hour. At the time the image was acquired the hurricane had strengthened into a Category 3 hurricane on the five-point Saffir-Simpson scale with winds estimated at 200 km per hour.

The left image, resulting from a color composite (R-865 nm, G-560 nm, B-412.5 nm), shows how the hurricane has a well-defined eye and the thick cloud structures associated with the convection within the eye wall -where the hurricane winds revolve at their fastest. The outer areas are made up of dense thunderstorm bands, which brought, ten days later than this image was acquired, intense rainfall and flooding to the North American coast.

The right image shows the cloud top pressure (CTP) defined as the atmospheric pressure at the altitude of the top of the cloud. As can be seen in the image, the CTP varies really largely, from 360 hPa (approximately 8 km) in the spiral arms down to lower than 800 hPa (approximately 2 km) in the center of the hurricane. This image demonstrates the great advantage of 2-level MERIS products to achieve information that cannot be derived today with any other spaceborne instrument.

Technical Information:
  • Satellite: Envisat
  • Instrument: MERIS
  • Acquisition: 08-Sep-2003
  • Orbit nr: 07965
  • Center coordinates: lat. 16.40, lon. -40.27

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