Hurricane Simon appeared to be keeping a secret before it rapidly intensified on Oct. 4, but the Global Precipitation Measurement or GPM satellite was able uncover it.
On Oct. 4 at 0940 UTC (5:40 a.m. EDT) observations by the Ku-band radar on the GPM satellite suggested that the Eastern Pacific Ocean's Hurricane Simon was hiding a very compact eyewall hours before the National Hurricane Center detected rapid intensification of Simon's surface winds. The GPM satellite was launched in February of this year and is managed by both NASA and the Japan Aerospace Exploration Agency.
"This eyewall, a hollow ring of intense storms, had a diameter too small to be detected by other satellite instruments or with real time wind analyses that blend together such satellite observations," said Owen Kelley of NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Kelley analyzed the GPM data. "The intense convective cells (small, intense, short-lived rainstorms) that sometimes occur in compact eyewalls are known to be able to cause rapid intensification of hurricanes, but such small features are only easy to detect with radar." That basically means radar-equipped aircraft or the GPM satellite must fly over the storm.
The NOAA P-3 aircraft did fly through Hurricane Simon on Oct. 4, but only after the National Hurricane Center determined that rapid intensification had already occurred.
In the coming years, GPM will enable scientists to study such unusual meteorological situations and may improve our understanding of hurricanes and of other kinds of severe storms. The GPM satellite will collect observations from a vast, but intermittent, sample of interesting meteorological situations, such as Hurricane Simon.
The GPM satellite will collect observations from the Arctic to the Antarctic circles and everything in between over the next three years, and perhaps longer. GPM will see features of the world's weather that otherwise might remain undetected.
At 5 a.m. EDT (2 a.m. PDT) on Oct. 4 the National Hurricane Center reported that Hurricane Simon was unable to form an eyewall that completely circled the eye because of a gap on the northeast side. Operational wind analyses that may have guided this statement were done at 11 p.m. on Oct. 3 and 3 a.m. PDT on Oct. 4. Those analyses showed a radius of maximum wind that was moderately large, 47 to 52 km (29 to 43 miles).
At 2:40 a.m. PDT, the GPM satellite saw that Hurricane Simon had a very compact eyewall. The eyewall had a radius of merely 10 km (6.2 miles) and hid a powerful convective cell. "The convective rain cell contained a 45 dBZ radar-reflectivity signal that reached 6.4 km (3.9 miles) altitude which is unusually high for such a strong signal in a hurricane eyewall," Kelley said.
Compact eyewalls can increase the chance of rapid intensification because there is so little air trapped in the eye of the hurricane. The small volume of air in a small eye is easier to heat with the energy released when rain forms in the eyewall. Ultimately, this energy lowers the surface air pressure under the eye, and in response, the circling winds speed up at the ocean's surface.
At 8 a.m. PDT, the National Hurricane Center reported that rapid intensification had occurred and that a small eye was visible. At 10:20 a.m. PDT the NOAA P-3 aircraft flew through Hurricane Simon and reported that the maximum winds were 10 km away from the center of the eye, which suggests that the very compact eyewall that GPM had observed at 2:40 a.m. had persisted and may have been Hurricane Simon's primary eyewall (the region of maximum wind speed) throughout this period.
This aircraft overflight was the first time that the NOAA P-3 had flown through Hurricane Simon, making the GPM overflight earlier that day the only prior radar "fix" on Hurricane Simon's "heat engine," its eyewall and eye. A detailed analysis would be needed to figure out how all of these observations illuminate Hurricane Simon's rapid intensification.
GPM data courtesy of NASA and JAXA.
For more information, visit: www.nasa.gov/gpm
Rob Gutro | Eurek Alert!
GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center
Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy