DRIVERS WARNED AS POLLEN CLOUD MENACE HEADS FOR UK
A MENACING cloud of acidic birch pollen – which eats into the paintwork of cars – is blowing towards Britain from Europe.
Millions of cars could be affected at the end of the week when the pollen reaches the UK.
To compound the misery, hay fever sufferers are being warned of a “nightmare scenario” of the cloud arriving at the same time as pollen levels are rising in Britain.
The birch pollen cloud has already hit Germany, where authorities have warned motorists to immediately wash it off their cars – or risk damage that could result in owners having to fork out for a full respray.
However there are many reports of green clouds in large thunder storm systems where the green colouration is well defined, coming from specific areas of cloud, and in manner that it is unlikely caused by ground reflection.
Using this explanation green clouds are likely when thunderstorm with heavy rain are strongly illuminated from behind by reddish sunlight, such as at sunset. The high water content of the cloud absorbs red light, resulting in a green colouration. The studies model also predicts that the colour will be blue-green for larger rain drops, and yellow-green for smaller.
This explanation does not require hail in the cloud. However it does require a very high water content which may only occur in thunderstorms which are likely to also produce hail. Thus in SE Queensland it may be that storms that produce hail also appear to have green clouds, but the colour is coincidental and not due to the hail.
“Birch pollen is the first of the tree pollens released every year, so if you already have symptoms it means you are allergic to this pollen rather than grass pollen.
If you were a cloud and you sailed up there,
You sail on water as blue as air,
You'd see me here in the fields and say,
"Doesn't the sky look green today?"