Ash cloud’s silver lining: bluer skies
Posted by Xeno on April 21, 2010
As volcanic ash cast a shadow over millions of lives, Londoners and other city dwellers across Europe were treated to a rare spectacle of nature: Pristine, blue skies brighter than any in recent memory.
The remarkable sight happened in part because mass flight groundings prevented busy airspace from being crisscrossed with plumes of jet exhaust that create a semi-permanent haze — and other effects beyond the white contrails themselves.
Just as city lights make it necessary for us to go to the desert to appreciate the true glitter of stars, so has modern aviation dulled us to what the noontime sky can really look like — until the erupting volcano in Iceland offered a reminder.
Britain’s poet laureate, Carol Ann Duffy, was inspired to write verses about the unusually clear skies above London: “Five miles up the hush and shush of ash/Yet the sky is as clean as a white slate/I could write my childhood there.”
Scientists cast the phenomenon in more prosaic terms. Without aircraft contrails, “the skies have been particularly blue,” said meteorology professor Chris Merchant of the University of Edinburgh.
The clearer skies are primarily due to a high pressure system in the region, but Merchant said the blue tone has been deeper than normal because of the lack of vapor from aircraft engines. Depending on weather conditions, the vapor trials can expand into thin cirrus clouds.
It’s as if somebody suddenly ripped a veil away, exposing the true colors of the heavens.
We do influence this planet in a big way every day. Same thing happened when flights were grounded after the 9/11 attacks.
Good time for a reminder from California Skywatch:
The public health impacts from this type of jet air pollution and lingering jet contrails may include but are not limited to:
- Respiratory problems
- Flu-like symptoms
- Chronic sore or raspy throat
- Persistent coughing
- Eye and skin irritations
- Nose bleeds, and
- Breathing difficulties
…Jet Emission Pollutants:
- Ozone: Lung function impairment, effects on exercise performance, increased airway responsiveness, increased susceptibility to respiratory infection, increased hospital admissions and emergency room visits, pulmonary inflammation and lung structure damage. (Examples of these effects are chronic inflammation and structural damage to lung tissue as well as accelerated decline in baseline lung function).
- Carbon Monoxide: Cardiovascular effects, especially in those persons with heart conditions. Effects on animals are similar to humans.
- Nitrogen Oxides: Lung irritation and lower resistance to respiratory infections. Premature mortality, aggravation of respiratory and cardiovascular disease, changes in lung function and increased respiratory symptoms, changes to lung tissues and structure, and altered respiratory defense mechanisms. (Asthmatics are especially sensitive).
- Volatile Organic Compounds: Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment.