Water Briefing: A new research study says that climate change and extreme weather – including unusually wet summers in the UK – are linked to high pressure weather systems over Greenland, one of the fastest-warming regions of the world.

A team of climate change experts at the University of Sheffield, led by Professor Edward Hanna from the University’s Department of Geography, has identified changes in weather systems over Greenland that have dragged unusually warm air up over the western flank of Greenland’s Ice Sheet.

Temperatures on the west coast of the island have risen by up to 10 degrees Celsius during the winter in two decades.

The weather systems are also linked to extreme weather patterns over northwest Europe, such as the unusually wet conditions in the UK in the summers of 2007 and 2012.

The study analysed changes in weather systems over Greenland since 1851, using a measure called the Greenland Blocking Index (GBI). The index measures the occurrence and strength of atmospheric high pressure systems, which tend to remain stationary when they occur, causing long runs of relatively stable and calm weather conditions. The high pressure also blocks storm systems from moving in on the region. The previous available version of the GBI only extended back to 1948.

Professor Hanna and his team have found an increase in the occurrence of atmospheric high pressure ‘blocking’ systems over Greenland since the 1980s throughout all seasons, which relates to a significantly strong warming of the Greenland and wider Arctic region compared with the rest of the world.

The Sheffield-led team also found an especially strong recent increase in the occurrence of Greenland ‘blocking’ weather systems in summer, which is linked to a more northward-meandering branch of the atmospheric jet stream. This has resulted in warmer air more often moving north into the region in recent years. Click here to read more.