Hurricane Katrina One Year Later
3-day average of actual sea surface temperatures
The 2005 hurricane season will long be remembered both for the record-breaking number of storms and a devastating hurricane named Katrina.
Several NASA satellites gave important details about Katrina's storm structure and strength throughout her life cycle, aiding forecasters and emergency managers. In the aftermath, data from satellites and instruments on NASA planes became useful in recovery efforts, damage assessments, and analysis of the storm's environmental impacts. Katrina left as a number of as 1,833 dead as per the National Hurricane Center, and over $80 billion in damage.
Katrina began as only a feeble storm being tracked by satellites and forecasters. On Aug. 23, Katrina was nothing but a mass of organized clouds over the Bahamas. But later that day, she quickly intensified and headed toward the U.S. coastline. Late on Aug. 25, she made her first landfall just south of Fort Lauderdale, Fla., as a Category 1 hurricane.
As Katrina moved into the Gulf of Mexico, atmospheric conditions were favorable for rapid development. Data from the Advanced Microwave Scanning Radiometer (AMSR-E) instrument on NASA's Aqua satellite showed uncommonly warm ocean temperatures in her path -- prime fuel for a hurricane.
By early in the morning of Aug. 28, Katrina's winds reached a remarkable 175 mph -- a category 5 storm -- with a central pressure of 902 millibars, the fourth lowest pressure ever recorded in the Atlantic. During this phase of rapid development, forecasters were aided by data from NASA's Multi-angle Imaging Spectroradiometer (MISR) instrument on the Terra satellite that supplied information on Katrina's cloud motion and height, improving the accuracy of forecasts and warnings.
Katrina's peak intensity was also captured by NASA's Tropical Rainfall Measuring Mission (TRMM) satellite that looked through the storm's clouds to reveal the underlying rain structure. Rain rates in the center of Katrina were gathered by the TRMM Precipitation Radar, the only radar capable of measuring precipitation from space. Details on rainfall intensity were also available from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite that can identify regions of greatest tropical moisture. The shear power of monster storms like Katrina makes accurate measurements of wind and rainfall more difficult. Scatterometers, like NASA's QuikSCAT, help overcome this problem. By sending energy through the atmosphere to the ocean surface and measuring the amount of energy that bounces back from the wind-roughened surface, meteorologists determine a storm's wind speed and direction. Eventhough tropical cyclones of category 5 strength are rarely sustained for long, Katrina only barely weakened and remained a strong category 4 storm for a number of hours, despite a run in with drier air (which tends to weaken hurricanes) and an opening of the eyewall before her second landfall early on Aug. 29. Wind speeds over 140 mph were observed in southeastern Louisiana with gusts over 100 mph just west of the eye in New Orleans.
Posted by: Tyler Source