Izbrane teme sodobne fizike in matematike
Nenadno segrevanje stratosfere sodi med najbolj dinamično aktivne procese, ki se dogajajo v tem delu ozračja. Pri tem nad polarnimi predeli v stratosferi temperatura bistveno naraste v relativno kratkem časovnem intervalu. Čeprav so ti dogodki opazovani že nekaj desetletij, pa je klasifikacija samega dogodka zaradi mnogih definicij in kriterijev neenotna, kar se odraža v različni pogostosti pojavljanja teh dogodkov. Članek obravnava obnašanje vertikalnega širjenja planetarnih valov, kar je dominanten razlog za nastanek nenadnega segrevanja stratosfere. Članek zajema tudi vpliv planetarnih valov na časovni razvoj tega dogodka. Za izračune so bili uporabljeni podatki reanalize ERA5 in sicer za leti 2009 in 2018.
One of the most dynamically active processes in the stratosphere results in abnormal warming in the region above the pole and it is called the sudden stratospheric warming (SSW). Although relatively precise monitoring of such events is done, there is still some confusion referring SSWs, because various different methods and criteria are being used to describe a SSW which leads to differences in the number of observed events. In this paper, the mechanisms, leading to the SSW are reviewed. In addition, by using ERA5 reanalysis data, it is illustrated, how the upward wave propagation interacts with the mean zonal flow and causes the SSW in winters 2009 and 2018.