Archiv: jet stream


01.10.2018 - 18:50 [ Potsdam Institute / Youtube ]

Rossby waves and extreme weather

(15.4.2016) Learn how giant airstreams high in the sky get trapped sometimes – leading to devastating weather extremes on the ground. Copyright: Potsdam Institute for Climate Impact Research PIK and Climate Media Factory. This video was supported by the German Research Foundation (DFG) and the German Federal Ministry of Education and Research (BMBF). PIK research on the subject: – Evidence for wave resonance as a key mechanism for generating high-amplitude quasi-stationary waves in boreal Summer

19.08.2018 - 17:25 [ Potsdam Institute / Youtube ]

Rossby waves and extreme weather

(15.4.2016) Learn how giant airstreams high in the sky get trapped sometimes – leading to devastating weather extremes on the ground. Copyright: Potsdam Institute for Climate Impact Research PIK and Climate Media Factory. This video was supported by the German Research Foundation (DFG) and the German Federal Ministry of Education and Research (BMBF). PIK research on the subject: – Evidence for wave resonance as a key mechanism for generating high-amplitude quasi-stationary waves in boreal Summer

19.08.2018 - 17:09 [ National Center for Atmospheric Research, University Corporation for Atmospheric Research / ScienceDaily.com ]

Scientists link California droughts, floods to distinctive atmospheric waves

(6.4.2017) Wavenumber-5 consists of five pairs of alternating high- and low-pressure features that encircle the globe about six miles (10 kilometers) above the ground. It is a type of atmospheric phenomenon known as a Rossby wave, a very large-scale planetary wave that can have strong impacts on local weather systems by moving heat and moisture between the tropics and higher latitudes as well as between oceanic and inland areas and by influencing where storms occur.

The slow-moving Rossby waves at times become almost stationary. When they do, the result can be persistent weather patterns that often lead to droughts, floods, and heat waves.

19.08.2018 - 16:56 [ University Corporation for Atmospheric Research . ]

Planetary waves, first found on Earth, are discovered on Sun

(27.3.2017) for a brief period, from 2011 to 2014, scientists had the unprecedented opportunity to see the Sun’s entire atmosphere at once. During that time, observations from NASA’s Solar Dynamics Observatory (SDO), which sits between the Sun and Earth, were supplemented by measurements from NASA’s Solar TErrestrial RElations Observatory (STEREO) mission, which included two spacecraft orbiting the Sun. Collectively, the three observatories provided a 360-degree view of the Sun until contact was lost with one of the STEREO spacecraft in 2014. McIntosh and his co-authors mined the data collected during the window of full solar coverage to see if the large-scale wave patterns might emerge.

„By combining the data from all three satellites we can see the entire Sun, and that’s important for studies like this because you want the measurements to all be at the same time,“ said Dean Pesnell, SDO project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. „They’re pushing the boundary of how we use solar data to understand the interior of the Sun and where the magnetic field of the Sun comes from.“

19.08.2018 - 15:51 [ Massachusetts Insitute of Technology ]

Study: Hole in ionosphere is caused by sudden stratospheric warming

(6.8.2018) Geospace research has long established that certain changes in the atmosphere are caused by the sun’s radiation, through mechanisms including solar wind, geomagnetic storms, and solar flares. (…)

One of the more scientifically interesting large-scale atmospheric events is called a sudden stratospheric warming (SSW), in which enormous waves in the troposphere — the lowermost layer of the atmosphere in which we live — propagate upward into the stratosphere. These planetary waves are generated by air moving over geological structures such as large mountain ranges; once in the stratosphere, they interact with the polar jet streams.

19.08.2018 - 14:39 [ Wikipedia ]

Upper-atmospheric models: Planetary waves

According to a report in New Scientist[4] many researchers are in consensus that Rossby waves are acting against the jet stream’s usual pattern and holding it in place. Upper atmospheric studies using National Oceanic and Atmospheric Administration (NOAA) data indicates that during July 2010 these upper air stream patterns were most frequently observed in the Northern Hemisphere.[5] Examination of the climatology data over the same period of time indicates that these wild planetary wave meanderings[6] are not a normal aspect of our regional climate patterns. Meanwhile, ongoing research studies at the University of Reading show that unusual patterns in the polar jet stream are more common during a period of low activity in the solar cycle when the observed sun spot activity and their associated solar flares are at their minimum.