Matt McGrath Makes A Fool Of Himself–Part 94

By Paul Homewood

h/t Mr Grim

Climate Tales: Episode 94 – The BBC Discovers Weather

While high temperatures were critical to the melting seen in Greenland last year, scientists say that clear blue skies also played a key role.

In a study, they found that a record number of cloud free days saw more sunlight hit the surface while snowfall was also reduced.

These conditions were due to wobbles in the fast moving jet stream air current that also trapped heat over Europe.

As a result, Greenland’s ice sheet lost an estimated 600 billion tonnes.

Current climate models don’t include the impact of the wandering jet stream say the authors, and may be underestimating the impact of warming.

Researchers found that high pressure weather conditions prevailed over Greenland for record amounts of time.

They believe this is connected to what’s termed the "waviness" in the jet stream, the giant current of air that mostly flows from west to east around the globe.

As the current becomes more wobbly, it bends north, and high pressure systems that would normally move through in a few days become "blocked’ over Greenland.

These systems had different impacts depending on the part of Greenland you were in.

In the southern part of the island, the authors say, it caused clearer skies with more sunlight hitting the surface.

The cloud-free days brought less snow, which meant that 50 billion fewer tonnes were added to the ice sheet.

The absence of snow also exposed bare, dark ice in some place which absorbed more heat – contributing to the melt.

In other parts of Greenland, the changing atmospheric patterns had different but equally damaging impacts.

In northern and western region, the swirling but stuck high pressure systems pulled in warm air from southern latitudes.

Dr Tedesco explained that Greenland in 2019 experienced the largest drop in surface mass balance since records began in 1948.

The term surface mass balance describes the overall state of the ice sheet after accounting for gains from snowfall and losses from surface melt-water run-off.

The authors believe their study explains why, despite the fact that 2019 was not as warm as 2012, last year produced a record drop in surface mass balance.

The main message of the paper is that the very high melt was mostly driven by clear skies and direct melting rather than necessarily being attributable to unusually high temperatures over the ice sheet – a radiatively-driven, rather than thermally-driven, melt season as they put it," said Dr Ruth Mottram, a climate scientist at the Danish Meteorological Institute in Copenhagen.

https://www.bbc.co.uk/news/science-environment-52286165

At no point do any of these junk scientists prove that these sort of weather events are in any way unprecedented or unnatural.

Talking of junk science, the authors cannot even get their facts right. They claim that Greenland in 2019 experienced the largest drop in surface mass balance since records began in 1948. In reality much greater ice loss occurred in 2012.

http://polarportal.dk/en/greenland/surface-conditions/

Despite the wailing about “worse than we thought”, weather actually works both ways.

The summer of 2018 was particularly cold and wet, and the ice sheet added much more ice than average. The year before saw a snowy winter, with the same result, the SMB ended up well above average:

BTW – McGrath also highlights the fact that last December, researchers reported that the Greenland ice sheet was melting seven times faster than it had been during the 1990s.

Perhaps he should have had a word with his colleague Jonathan Amos, who laughingly calls himself the BBC Science Correspondent. Mr Amos might recall what he wrote in 2003!