Featured Images

Hurricane Season 2008: Tropical Storm Mekkhala (Pacific Ocean)
 
Oct. 02, 2008

Mekkhala Now Dissipated, Caused Damages in Vietnam

Former Typhoon Mekkhala caused a lot of damage when it came ashore this week, and by Oct. 2 it had dissipated. The Agence-France Presse reported on September 30 that Typhoon Mekkhala brought floods to central Vietnam as it made landfall and killed at least nine people. Up to 11 were still missing.

Thanhnien News reported damages in several provinces in north central Vietnam. In the Thanh Hoa Province, the search for missing fishermen from capsized ships continued, and initial reports estimated 1,450 hectares of rice paddies and more than 1,600 hectares of other crops were destroyed totaling losses of more than $1.2 million. Meanwhile the Ha Tinh Province reported 500 damaged homes, 3 dead and almost 4,000 hectares of rice damaged worth $1.8 million.

AIRS image of Mekkhala from Oct. 2, 2008
> Larger image
Credit: NASA JPL
Aqua Satellite Sees Mekkhala's Cold Cloud Temperatures

This infrared image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. It was taken on Sept. 30 at 2:47 a.m. EDT (6:47 UTC). The infrared image shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it. The image shows that Mekkhala's clouds are over Hanoi during the time of this image.

The AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters. Text credit: Rob Gutro (from Joint Typhoon Warning Center reports)/Goddard Space Flight Center


Sept. 30, 2008

Mekkhala Made Landfall in Vietnam, Fading Fast Over Laos

Satellite image of Mekkhala Credit: NASA/JPL
> Larger image
The Joint Typhoon Warning Center issued its final advisory on Tropical Storm Mekkhala, now that it has swept through Vietnam and into Laos where it is expected to dissipate on October 1.

As Mekkhala made landfall, it took three lives and left 10 others missing in central Vietnam, according to the Associated Press. Mekkhala also caused structural damage to homes and caused power outages.

On Sept. 30 at 9:00 Zulu Time (5:00 a.m. EDT) Mekkhala had maximum sustained winds near 45 knots (52 mph) with higher gusts. Mekkhala was located approximately 155 nautical miles east of Vientiane, Laos, near 18.3 degrees north latitude and 104.6 degrees east longitude. Mekkhala is moving west-northwestward near 16 knots (18 mph) and is expected to dissipate during the day on October 1.

Aqua Satellite Sees Mekkhala's Clouds Over Vietnam

The image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was taken on Sept 29 at 18:17 UTC (2:175 p.m. EDT). The infrared image shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it.

The AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center