Explained: Frequent and long heatwaves, heat domes, jet streams and more

Our planet is slowly burning as it suffers from the wrath of heatwaves and subsequent forest fires. Conditions have reached such extremes that NASA took to Twitter to release this map highlighting shocking ground temperatures. In fact, in 2020, the met office produced a hypothetical weather forecast for 23 July 2050 based on UK climate projections. On July 19, 2022, the forecast was shockingly almost identical for large parts of the UK, nearly 28 years early. One major factor behind this is the trapped greenhouse gases caused by human activities. It is turning our blue-green planet, RED!

What we are facing currently is a prolonged sequence of sweltering days or a heatwave. In fact, the heatwaves are getting hotter, and longer and impacting temperate zones as well.
The UK is making headlines by beating its previous records multiple times in various places. Before 19th July 2022, the UK had never witnessed temperatures above 40°C. The Met office also had its first Red Extreme Heat Warning indicating a risk to life, travel, energy supply, and infrastructure.

Other parts of Europe are also prey to this heat. Parts of France, Spain, Portugal, and Greece have crossed 40°C as well. Around 2,000 people died in Portugal and Spain from heat-related causes in July. Even places such as Tromsø and Mehamn above the Arctic circle touched 30°C by June end.

China’s infrastructure is also crumbling due to heat waves. Heatwaves began in June, broke previous temperature records, and are estimated to last till August this year. Channel News Asia also reported that Shanghai and many other cities saw buckling streets and roof tiles popping due to the heat.

Japan also recorded above 40°C for the first time ever in June this year. Around 5,000 people were hospitalized and millions were told to conserve power due to a surge in demand.
The US did not fare well either. The National Weather Service issued heat warnings and advisories for 28 states, mainly in the South, Midwest, and Northeast.
So, the Northern hemisphere in general is breaking previous heat records by considerable margins and in atypical months. Heatwaves have thus become a typical summer event, but climate change is making them globally fearsome and dangerous.

In fact, the World Meteorological Organization (WMO) has warned that heatwaves will occur more and more frequently, into the 2060s. The pattern is linked to the observed warming of the planet that can be attributed to human activity, raising serious concerns for the planet’s future, the UN weather agency said.

But why are these heatwaves occurring so frequently and all over the world?
Let's move to the continent of North America to analyze the direct effect - of heat dome
Scientists had previously established that the heatwave was due to a heat dome of high pressure prevailing over western North America.
A heat dome is a mountain of warm air pressing down across a huge area. As warm air tries to rise, this high-pressure system above pushes the warm air back down to the surface. It becomes denser and hotter as it gets compressed.
The researchers identified three atmospheric patterns associated with the heat dome: The North Pacific, Arctic-Pacific Canada, and North America.
Atmospheric circulation patterns describe how air flows and influences surface air temperatures around the planet. They are responsible for daily weather, as well as the long-term patterns.
The North Pacific pattern appears to have helped initialize and develop the heat dome. The Arctic-pacific-Canada pattern may have played a role in the development and mature phases, while the North American pattern is linked with the decay and eastward movement of the heat dome, the study stated.
What’s more, simulations also showed that extreme heatwave events would increase by more than 30 percent in the future, of which almost two-thirds could be due to greenhouse gases, according to their results.

Indirect effect in the North Atlantic - the jet stream
As climate change intensifies, disruptions to traditional global atmospheric circulation systems, such as the jet stream in the northern hemisphere, are expected across the planet, leading to more frequent and intense extreme climate events. In particular, smaller differences in temperature between the poles and the equator can slow the jet stream, leading to a buildup of high or low-pressure weather systems, resulting in more persistent hot-dry extremes in mid-latitudes. The current heat wave in Europe is linked to a slow-moving system in the North Atlantic that allowed hot air from the Sahara to move north. In Pakistan and northern India, the heatwave lasted longer than usual due to a delayed start to the seasonal monsoon. This may become more common in the future as a shifting seasonality of the monsoon is expected with climate change.

These are the main causes behind the frequent heatwaves in the northern temperate regions in the last few years.