image source, Stephen Henderson
The fog was particularly noticeable as the bright yellow peaks of Samson and Goliath stuck out above the fog bank.
High and moderate levels of air pollution are expected in Northern Ireland until Friday due to cold, calm weather and expected increased use of domestic heating.
Temperatures are expected to drop below -5C on Sunday night, and then again on Monday night.
Cold conditions caused widespread frost and ice.
However, cold, mild weather is expected to inhibit the spread of emissions from home heating and transportation.
As a result, the Department of Agriculture, Environment and Rural Affairs (Daera) and the Ministry of Health have issued a “Severe Air Pollution Alert”.
Users of the Air Aware app received a text alert warning of “high air pollution potential in isolated areas.”
People with respiratory or heart conditions are advised to monitor their symptoms and seek medical attention if they notice any changes.
Around two-thirds of Northern Ireland uses oil to heat homes, which releases particles that can be inhaled.
In the UK, most air pollution information services use air quality indices and banding systems approved by the Air Pollution Medical Effects Commission.
Similar to the pollen index, it uses an index from 1 to 10 to convey information about air pollution levels in a simple way.
Air quality is based on five pollutants, including nitrogen dioxide, sulfur dioxide, and other particles.
On Monday, the Londonderry suburb of Strathfoyle recorded high levels of pollution, registering a 7 on a scale of 1 to 10.
A medium level of five was recorded in Belfast city centre, Rosemount in Derry and Newtownstewart.
lingering fog
Cold air caused chaos in some areas on Monday, with some roads icy.
A yellow weather warning for ice has been issued for large parts of Counties Armagh and Down.
Fog persisted throughout the day in parts of Northern Ireland on Sunday, following a period of low sunshine and mostly calm conditions in January.
image source, alistair hamill
This phenomenon sometimes occurs when weather conditions are favorable.
A permanent fog bank formed over Belfast Lake and was observed by many people walking in the surrounding hills.
It was especially noticeable because the bright yellow heads of Samson and Goliath stuck out from above the fog bank.
Harland and Wolff Cranes are approximately 100 meters high, and many of Belfast’s hills are above this height.
If you’re on top of Cave Hill, Mt Divis or Holywood Hill, you’ll be looking down on a bank of mist with blue skies overhead.
This phenomenon sometimes occurs when weather conditions are favorable.
temperature inversion
An area of high pressure should have cold air trapped beneath it, clear skies, and calm conditions prevailing.
This initially forms a fog, with the area of high pressure overhead acting like a lid and preventing the cold air below from escaping.
Cold air from the surrounding hills sinks to the bottom of the basin.
A temperature inversion forms, where the air above the fog layer becomes warmer than the air at the bottom.
The fog gets trapped because the January sun is too weak to burn it off from above, unless the wind changes direction, picks up, or brings in dry air from somewhere else. Because the fog has nowhere to go.
Temperature inversions also reduce the quality of the air around us by trapping pollutants closer to the ground and preventing them from mixing into the atmosphere.