<
https://www.theguardian.com/environment/2023/aug/21/zero-degree-line-record-height-switzerland-heatwave-wildfire-europe>
"A Swiss weather balloon had to climb to an unprecedented 5,300 metres
(17,400ft) before the temperature fell to 0C (32F), meteorologists have said,
as a late summer heatwave and wildfires continue to pummel swaths of
continental Europe.
A man was found dead in a blaze raging north of Athens on Monday as the Greek
government warned of an extreme risk of fire across the country, while more
than half of mainland France was placed under an amber extreme heat alert and
local records tumbled in the south-east.
MétéoSuisse said the zero-degree line – the altitude at which the temperature
falls below freezing, considered a key meteorological marker particularly in
mountainous regions – was measured at 5,298 metres overnight.
The figure, which was registered by a weather balloon flown from Payerne in
western Switzerland, constituted “a record since monitoring began in 1954”, the
service said, and surpassed the previous high of 5,184 metres that was “only
set in July last year”.
The 0C line “affects vegetation, the snow line and the water cycle, so has a
considerable impact on the habitats of humans, animals and plants alike”,
MétéoSuisse said. It averaged 2,570 metres above sea level from 1991 and 2020,
fluctuating between 1,000 and 2,000 metres in winter, and 3,000 and 4,000
metres in summer.
In recent decades “anthropogenic climate change has caused the altitude of the
zero-degree line to rise significantly in every season”, the service said,
noting that successive records for the indicator had all been set in the past
10 years."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
