. | . |
Making Waves on the Sun by Susanna Kohler for AAS Nova Washington DC (SPX) Nov 19, 2020
Sinuous, undulating waves in the Earth's atmosphere play a large role in driving the weather patterns on our planet. A new study now describes how similar motion can govern the behavior of the Sun - and what we stand to learn from it. When you plan a sunny picnic outing for the weekend, you can thank Carl-Gustav Rossby for his role in enabling the weather forecasts you're now able to check. In 1939, Rossby first identified large-scale waves in the Earth's atmosphere. These slow meanders of high-altitude winds are visible as long, persistent undulations in the jet stream that carry cells of warmer or cooler air to different regions of the planet. Through this transport, Rossby waves are critical in driving the day-to-day weather patterns that we experience at middle and higher latitudes on our planet's surface. Our understanding of the hydrodynamics of Rossby waves is, consequently, one of the things that enables us to make (approximate) weather predictions on timescales of roughly 14 days.
Waves Far and Wide Are the motions of the Sun's atmosphere governed by these same waves? And if so, can we figure out how to model them similarly to how we model Rossby waves on Earth, thereby unlocking a key to making solar weather predictions on 14-rotation (that's around a year, given the Sun's rotation period!) timescales?
But What About Magnetic Fields? The answer to the second question, however, is less clear. Why? Because there's a complicating factor: unlike Earth's lower atmosphere, the Sun is strongly magnetized. A new study led by Mausumi Dikpati (National Center for Atmospheric Research) now walks us through the basic physics involved in Rossby wave development in the Sun, and discusses how the Sun's magnetic fields influence those waves.
Sketching a Wavy Picture The basic physics described here is a first step that now needs to be expanded to include more complex interactions. But this starting point demonstrates that Rossby waves likely play an important role in organizing the motions of the Sun's atmosphere. And once we've developed more detailed models of this process, perhaps we'll be able to check our phones for the solar weather forecast for the year! Check out this wildly awesome NASA-produced simulation showing the development of Rossby waves in the Earth's northern jet stream.
Research Report: "Physics of Magnetohydrodynamic Rossby Waves in the Sun"
Ripples in the pond of magnetic field reconnection Taoyuan City, Taiwan (SPX) Nov 05, 2020 The majority of the visible matter in the Universe consist of charged particles or plasmas which may develop the magnetic field reconnection (MR) at the places where the magnetic field direction exhibits abrupt change. Through the MR the magnetic field energy may effectively be transferred into the kinetic and thermal energies of plasmas, resulting in many explosive plasma phenomena occurring on the Sun, planetary and pulsar magnetospheres, even the blackhole, etc. The interface or magnetopa ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |