“Cold blob” behind Europe’s heatwave
The heatwave battering Europe may have been exacerbated by a “cold blob” of water in the North Atlantic, a warning that a slowdown in a vital ocean current could create more extreme hot and cold temperatures
ATLANTIC MERIDIONAL OVERTURNING CIRCULATION (AMOC)
Warm, less saline water flows north
Cold blob: Marked decrease in heat escaping to atmosphere – epecially in last 30 years – from upper 1,000m
Cools to form sea ice
Loses salinity, rises to surface
Cooler, denser water sinks
Heat supply from AMOC slowing, nearing tipping point
Atlantic Ocean
ANTARCTIC
ARCTIC
Takes around 1,000 years for water to complete cycle
Cold blob
Cooled by around 1˚C since 1870. Creates front that slows and guides jet stream around it
Jet stream
Bends northward around cold anomaly trapping high pressure anti-cyclone over region
Heat dome over Europe
Rising warm air trapped, hot air subsides
Sources: Science News, AFP
© GRAPHIC NEWS