What causes haze?

[mike57]

We were out and about in the North York Moors today, and there was a noticable haze. What causes it, I understand how clouds form, is it similar? It seems to have much less structure than clouds with large areas covered with the same haze, I would estimate visibility was around 2-3 miles most of the time.

[Terminal Moraine]

 Haze is caused by very small particulates such as dust, pollen, smoke etc and tends to have a colour( other than white) which can be anything from blueish, through reddish to a dirty yellow depending on the cause of the haze. Unlike mist or fog there is no upper or lower limit to the visibility when haze is present

 Mist, which looks greyish or white,  is impaired visibility due to water droplets. The Met Office definition of mist is visibility more than 1000m with a relative humidity of 95% or more. If visibility falls below 1000m it then becomes fog.

[Jo Farrow]

Mist/fog and haze all lower the visibility. Mist and fog are caused by water droplets. Haze is due to tiny airbourne particles, like smoke or pollution, saharan dust, salt etc so dry bits in the atmosphere. When the UK is under an area of high pressure the slowly descending air begins to stagnate and so the tiny particles, often present in the air, build up. They aren't washed away by rain, or blown away by the wind. As the settled spell continues the whitish tinge can become more defined, as more particles remain

[mike57]

Thanks for the answers, so I wonder was it haze or mist Saturday, there was a definate blueish tinge, as evidenced by people who took pictures of the Flying Scotsman loco which is visiting the North York Moors Railway. It made photography difficult.

[Thundery wintry showers]

I think the recent haze was caused by a combination of high pressure, and an east to south-easterly flow bringing polluted air in from eastern Europe.  

The high pollution episode in the third week of April 2011 was caused by high pressure combined with continental air.  In the pollution episode of late-March/early April 2014, continental air combined with Saharan dust was the main cause.

[Snowyowl9]

Haze from the SE/ east has always been very common.

But haze from the westerly to NWly flow never use to happen and its getting worse,and its a different type of haze to the normal one.

A watery  milky haze which comes from the atlantic.

The SW is the clearest air just before a weather front comes in,North with cold very cold air is clear.

Edited March 23, 2016 by Snowyowl9