What is a polar vortex, the weather event causing winter storms in the US?
Al Jazeera
The expanding of the polar vortex – an area of cold air around the Arctic – southwards is causing cold spells in the US.
The United States has been experiencing severe winter storms, which is likely to affect more than 60 million people in the country’s east. The ongoing cold spell, which may bring down the mercury to as low as -50C (-60F), is caused by the expansion of the polar vortex – an area of extremely cold, rotating air around the Arctic – southwards.
Sub-freezing temperatures can extend as far south as the Gulf Coast and Florida Peninsula in the US.
The polar vortex primarily affects countries situated in the Northern Hemisphere’s mid to high latitudes. These regions are particularly susceptible to extreme cold weather events.
The polar vortex spins anticlockwise around the North Pole with wind speeds of about 155mph (250km/h).
There are two types of polar vortexes – tropospheric and stratospheric.
Ukrainian soldiers say Russia is waging fierce battles in the east while they attempt a renewed offensive in Kursk.
South Africa’s military has enhanced border operations along the Limpopo River to halt smugglers and illegal crossings.
The White House is to send $95m to Lebanon, citing regional security, while eyeing human rights concerns in Egypt, Reuters reports.
OCHA chief says attacks by Israeli troops and Palestinian groups stifling bid to save lives in war-torn enclave.
Rescue efforts are under way after the earthquake hits Tibet, with tremors felt as far as Nepal, India and Bhutan.
Washington opens the way for transactions needed for humanitarian purposes, in a move seen as an ‘important step’ towards easing the West’s sanctions regime on the country.
Rescue operations still under way as nine others remain trapped in flooded Assam coal mine.
Indonesia joins Russia, China and others in the group, which is viewed as a counterweight to the West.
England’s cricket board proposes an ‘ICC-wide’ response against Afghanistan over the Taliban’s crackdown on women in response to the MPs’ letter.
New intermediate-range hypersonic missile made with lighter materials, making it more lethal at penetrating enemy defences, Pyongyang says.
Here are the key developments on the 1,048th day of Russia’s invasion of Ukraine.