Le cyclone tropical

Le cyclone tropical "Gafilo" cause une catastrophe majeure à Madagascar le 6 Mars 2004.

The severe Tropical Cyclone Gafilo was one of several cyclones to affect Madagascar in the 2003-2004 season. With 1-minute averaged windspeeds of about 250 km/h and gusts of up to 330 km/h, this cyclone struck the northeast coast of Madagascar early on the morning of 7 March 2004, in particularly, the city of Antalaha. There was massive distruction and 85% of the city was destroyed). 237 lives were lost, with 181 missing persons and 879 injured (official figures as of 30 March 2004). Of the total of 237 fatalities, more than 110 persons were killed on the ferry "Le Samson" from the nearby Comoro Islands that was reported to have capsized in heavy seas. More than 304,000 people were left homeless by the storm and more than six thousand hectares of agricultural land were flooded, resulting in major crop losses. According to the Multi-Satellite Precipitation Analysis (MPA) product from the NASA Goddard Space Flight Center, total rainfall for the period 3-10 March 2004 reached values of up to 500 mm in an area from the central Mozambique Channel eastward along the northwest coastline of Madagascar.

The upper two Meteosat-8 images below show Tropical Cyclone Gafilo about 18 hours before it made landfall. These two images have been reprojected into Mercator projection, which provides a better presentation for images that are viewed at very large satellite viewing angles.

The lower two images are presented in the original satellite projection. The lower right Meteosat-8 image shows the Tropical Cyclone on 7 March 2004, after landfall and when it had already weakened somewhat.

The Meteosat-8 images from 6 March show the marked spiral structure of Gafilo and a relatively large eye, with the eyewall and the Central Dense Overcast (CDO) region. They also show areas of small ice particles/intense precipitation (in yellow colour on the RGB images) within the CDO region and the spiral bands. The Meteosat-8 visible and infrared images, however, do not reveal an eyewall replacement cycle, which could only be observed in microwave imagery (e.g. AMSU on NOAA, TMI on TRMM, AMSR on Acqua or SSMI on DMSP). The two examples from 6 March 20

04 that show the double eyewall structure are also presented below.

Met-8, 06 March 2004, 09:00 UTC Channel 12 (HRV) Full Resolution (345 KB) Met-8, 06 March 2004, 09:00 UTC RGB Composite NIR1.6, HRV, HRV Full Resolution(324 KB) Met-8, 06 March 2004, 09:00 UTC RGB Composite WV6.2-WV7.3, IR3.9-IR10.8, NIR1.6-VIS0.6 Full Resolution (125 KB) Met-8, 07 March 2004, 09:00 UTC RGB Composite WV6.2-WV7.3, IR3.9-IR10.8, NIR1.6-VIS0.6 Full Resolution (127 KB)

 

TMI on TRMM, 06 March 2004, 08:01 UTC 85 GHz Channel (HH) Full Resolution (339 KB) Source: Naval Research Laboratory, Monterey, CA AMSU-B on NOAA, 06 March 2004, 10:45 UTC RGB Composite  150GHz, 89 GHz, 89 GHz Full Resolution (213 KB) Source: Naval Research Laboratory, Monterey, CA