Information on Fire and Haze
What is HAZE? HAZE consists of sufficient smoke, dust, moisture, and vapour suspended in air to impair visibility. HAZE pollution can be said to be “transboundary” if its density and extent is so great at source that it remains at measurable levels after crossing into another country’s air space.
How does HAZE impact VISIBILITY? HAZE is caused by particulate matter from many sources including smoke, road dust, and other particles emitted directly into the atmosphere, as well as particulate matter formed when gaseous pollutants react in the atmosphere. These particles often grow in size as humidity increases, further impairing VISIBILITY. Sources hundreds or even thousands of miles away can contribute to VISIBILITY problems at remote locations. VISIBILITY often is measured as the farthest distance from which a person can see a landscape feature.
How about HAZE resulted from LAND AND FOREST FIRES? HAZE originating from large-scale forest and land fires is characterised by a high concentration of particulate matter, which, among other effects, reduces visibility. Due to the specific emission characteristics of land and forest fires, HAZE is predominately made of very fine particles with a diameter of less than 10 mm. While coarse particles flush out of the atmosphere within several hours up to a day, fine particles have the longest residence time (up to weeks) in the atmosphere and travel extensive distances (hundreds to thousands of kilometres). Their elimination out of the atmosphere is mainly due to rain.