
Omega blocking highs can remain in place for several days or even weeks [image credit: UK Met Office]
Atmospheric blocking is a well-known weather phenomenon. The report below says ‘In recent years, the scientists observed a clear increase of these patterns’. But scientists have also reported a 20 year decline in solar magnetic fields and solar wind micro-turbulence levels. Coincidence, or possibly not?
Record breaking heatwaves and droughts in North America and Western Europe, torrential rainfalls and floods in South-East Europe and Japan – the summer of 2018 brought a series of extreme weather events that occurred almost simultaneously around the Northern Hemisphere in June and July, says IOP Publishing.
These extremes had something in common, a new study published today in Environmental Research Letters by an international team of climate researchers now finds.
The events were connected by a newly-identified pattern of the jet stream encircling the Earth. The jet stream formed a stalled wave pattern in the atmosphere, which made weather conditions more persistent and thus extreme in the affected regions.
The same pattern also occurred during European heat waves in 2015, 2006 and 2003, which rank among the most extreme heatwaves ever recorded. In recent years, the scientists observed a clear increase of these patterns.