NO such thing as Climate Change?, page-221

quick and dirty - read with a grain of salt

follow the refs - and the refs in the refs - there's usually some good stuff to be found in there ------------- don't trust the opinion though



Both the Northern and Southern Hemispheres can experience large blocking weather systems simultaneously, but such occurrences are relatively uncommon.
### Blocking Weather Systems Overview
Blocking refers to a persistent weather pattern where high-pressure systems become stationary, effectively "blocking" the usual west-to-east movement of weather systems. This can lead to prolonged periods of specific weather conditions in the affected areas, such as extended dry spells or persistent rain.
### Frequency of Simultaneous Blocking Events
1. **Northern Hemisphere**: Blocking events are more frequent and can occur in multiple locations, particularly in the Atlantic and Pacific regions. Their dynamics often lead to significant weather extremes, including heatwaves and cold spells, depending on the time of year and geographical context[1][4].
2. **Southern Hemisphere**: While blocking does occur, it is generally less frequent than in the Northern Hemisphere. The Southern Hemisphere's blocking events tend to be more localized, primarily around the Pacific region. Studies indicate that simultaneous blocking events in the Southern Hemisphere are observed only about 10 days (approximately 2.8%) of the year[2][6].
### Conclusion
In summary, while both hemispheres can have blocking systems at the same time, it is less common for the Southern Hemisphere to experience multiple simultaneous blocking events compared to the Northern Hemisphere. The overall dynamics and frequency of these events differ significantly between the two hemispheres due to variations in atmospheric circulation patterns and geographical features[2][3][6].
Citations:
[1] https://journals.ametsoc.org/view/journals/mwre/122/9/1520-0493_1994_122_1971_nashsv_2_0_co_2.xml
[2] http://weather.missouri.edu/gcc/Lupo-blockreview.pdf
[3] https://wcd.copernicus.org/articles/3/305/2022/
[4] https://www.carbonbrief.org/jet-stream-is-climate-change-causing-more-blocking-weather-events/
[5] https://en.wikipedia.org/wiki/Block_(meteorology)
[6] https://oxfordre.com/climatescience...0228620.001.0001/acrefore-9780190228620-e-611
[7] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL083264