Hurricane Isaac, Mars Rover, and More

On the seventh anniversary of Hurricane Katrina, another hurricane is pounding the Gulf Coast. A tropical cyclone is a storm system characterized by a low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones strengthen when water evaporated from the ocean is released as the saturated air rises, resulting in condensation of water vapor contained in the moist air. They are fueled by a different heat mechanism than other cyclonic windstorms such as nor'easters, European windstorms, and polar lows. The characteristic that separates tropical cyclones from other cyclonic systems is that at any height in the atmosphere, the center of a tropical cyclone will be warmer than its surroundings; a phenomenon called "warm core" storm systems.

The term "tropical" refers both to the geographical origin of these systems, which usually form in tropical regions of the globe, and to their formation in maritime tropical air masses. The term "cyclone" refers to such storms' cyclonic nature, with counterclockwise wind flow in the Northern Hemisphere and clockwise wind flow in the Southern Hemisphere.

Here is a photo of Hurricane Isaac, which is spreading intense rain for over 1,200 miles.

I found this NASA photo of Hurricane Ivan, which occurred in 2004. I like the photo because you can see Michigan in the upper part of the picture.

Here are some hurricane records:

Fastest hurricane movement: 70 mph (110 km/h, Great New England Hurricane, 9/15/1938.

Fastest Intensification from a Tropical Storm to a Category 5 Hurricane: 16 hours - 70 mph to 155 mph - Hurricane Wilma 2005

Maximum pressure drop in 12 hours: 90+mb - Wilma 2005

Maximum pressure drop in 24 hours: 98mb - Wilma 2005 - 1200 UTC October 18 to October 19

Fastest Intensification from a Tropical Depression to a Hurricane: 12 hours - Lorenzo 2007

Fastest Intensification from a Depression to a Category Five Hurricane: 51 Hours - Felix 2007

Largest hurricane by gale diameter: Igor, 2010, 920 miles (1,480 km)

Longest duration hurricane: 28 days, Hurricane San Ciriaco, August 1899

Farthest Travel: 7500 miles, Hurricane Faith, 1966

Year with most hurricanes: 15 in 2005

Most tornadoes spawned: 117 during Hurricane Ivan in 2004

Costliest hurricanes:
$108.0 billion Hurricane Katrina 2005
$37.6 billion Hurricane Ike in 2008
$26.5 billion Hurricane Andrew in 1992

Here is a chart showing the number of storms per year from 1893 through 2010:

 

Good luck to everyone in the gulf coast region.

On a lighter note, here is the latest full resolution photo of Mount Sharp, taken by the Mars rover, Curiosity. This image taken by the Mast Camera (MastCam) on NASA's Curiosity rover highlights the interesting geology of Mount Sharp, a mountain inside Gale Crater, where the rover landed. Prior to the rover's landing on Mars, observations from orbiting satellites indicated that the lower reaches of Mount Sharp, below the line of white dots, are composed of relatively flat-lying strata that bear hydrated minerals. Those orbiter observations did not reveal hydrated minerals in the higher, overlying strata.

The MastCam data now reveal a strong discontinuity in the strata above and below the line of white dots, agreeing with the data from orbit. Strata overlying the line of white dots are highly inclined (dipping from left to right) relative to lower, underlying strata. The inclination of these strata above the line of white dots is not obvious from orbit. This provides independent evidence that the absence of hydrated minerals on the upper reaches of Mount Sharp may coincide with a very different formation environment than lower on the slopes. The train of white dots may represent an "unconformity," or an area where the process of sedimentation stopped.

We have no weather issues in the upper peninsula right now. Here are a couple of after glow photos of the sunset last night, taken form my front porch.