Alenga had grown from a tropical storm to a cyclone by 0300 UTC on Dec. 8 (10 p.m. EST, Dec. 7) when its maximum sustained winds reached 90 knots (103 mph/166 kmh).
On Dec. 8 at 7:10 UTC (2:10 a.m. EST), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite captured a visible image of Cyclone Alenga when it passed overhead from space. Alenga appeared as a rounded area of compact clouds. Credit: NASA Goddard MODIS Rapid Response Team
On Dec. 8 at 7:10 UTC (2:10 a.m. EST), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite captured a visible image of Cyclone Alenga when it passed overhead from space. Alenga appeared as a rounded area of compact clouds. Although an eye was not apparent on visible imagery, it was seen in earlier infrared imagery. At that time, Alenga's winds had decreased as a result of wind shear.
By 1500 UTC (10 a.m. EST) on Dec. 8, Alenga's maximum sustained winds were down to 80 knots (92 mph/148 kmh). Cyclone-force winds extended 25 miles (40 km) out from the center of the storm, while tropical storm-force winds extended out to 110 miles (177 km), making the storm at least 220 miles (354 km) in diameter. Alenga was about 400 nautical miles (460 miles/740 km) south-southeast of the Cocos Islands, near 18.9 South latitude and 99.6 East longitude. It was speeding to the east-southeast near 22 knots (25 mph/40 kmh). Infrared imagery at 1500 UTC no longer showed an eye, further indication that the storm was weakening.
In addition to facing higher wind shear, a field of cold air stratocumulus clouds to the west is moving into the low level circulation of the center, and cold air also weakens tropical cyclones. Alenga is also being stretched out from the wind shear, and the strongest convection (rising air that forms the thunderstorms that make up the tropical cyclone) is now starting to stretch to the southeast of the storm's center. Alenga now faces even a third challenge: dry air. Dry air is also starting to affect the western side of the storm by absorbing moisture and eroding the band of thunderstorms.
The Joint Typhoon Warning Center expects Alenga to begin transitioning to an extra-tropical storm later today. As it begins that transition, however, the cold and dry air and the increased wind shear will work in tandem with the cooler sea surface temperatures that lay ahead in Alenga's path to cause the storm to weaken quickly.
Rob Gutro | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences