Category: Ocean and climate news

The strong "once-in-a-decade" typhoon Wipha hit the Japan on October 16th causing deaths and degradations. Saral and Jason-2 have flown over the typhoon path and have observed it.

Altimeters have been designed to observe the sea level variability. Although the probability to fly over such a phenomenon is low, the two satellites have observed strong winds and significant wave heights.

Path of typhoon Wipha with its intensity overlaid on the two passes of Saral and Jason-2: Saral overflew the typhoon on Oct 15 when the typhoon was in category 1 and jason-2 on Oct 14 when the typhoon was in category 3 (Credits CNES/CLS)

The Significant Wave Height measurements observed by Saral are displayed below. The peak value of 60.95 feet or 18.58 meters is impressive as well as the width of the seas in excess of 45 feet or 13.7m (a length of 370 km). Saral data have been fully integrated into warning and forecast operations at NOAA Ocean Prediction Center.  

Significant wave height seen by Saral on October 15 at 20:21 UTC. The wave heights are in feet and are color coded by the color scale in the upper right. The time stamp is in red and plotted every minute. (Credits Joe Sienkiewicz, NOAA Ocean Prediction Center).

	Wind Speed values measured by Saral altimeter reached values up to 28 m/s.
Wind Speed values seen by Saral and Jason-2 over Typhoon Wipha in m/s. (Credits CNES/CLS)

Further information:

• Applications: <link http: www.aviso.oceanobs.com en applications atmosphere-wind-and-waves hurricanes.html _blank external-link-new-window>Hurricanes
• Unisys weather Service: <link http: weather.unisys.com hurricane _blank external-link-new-window>weather.unisys.com/hurricane
• Nasa earth observatory: <link http: earthobservatory.nasa.gov naturalhazards _blank external-link-new-window>earthobservatory.nasa.gov/NaturalHazards
• <link http: www.mdpi.com _blank external-link-new-window>Carrère et al., 2009: "Observing and Studying Etreme Low Pressure Events with Altimetry"
• <link http: www.agu.org journals abs external-link-new-window>Quilfen, Y.; Tournadre, J.; Chapron, B. Altimeter dual-frequency observations of surface winds, waves and rain rate in tropical cyclone Isabel. J. Geophys. Res. 2006, 111, C01004.