What causes haze, and how is it predicted?

Stuart wrote:
What causes haze, and how is it predicted?


dust, water vapour, etc..




--
Gianna

http://www.buchan-meteo.org.uk
* * * * * * *

Gianna wrote:
Stuart wrote:
What causes haze, and how is it predicted?


dust, water vapour, etc..





It can be countered by adding a skylight filter.

--
Joe Egginton
Wolverhampton
~175m ASL

Joe Egginton wrote:
Gianna wrote:
Stuart wrote:
What causes haze, and how is it predicted?


dust, water vapour, etc..





It can be countered by adding a skylight filter.


Ah yes, I have a Hoya 1A somewhere ...
(last seen adorning my webcam since my 35mm kit is retired)

--
Gianna

http://www.buchan-meteo.org.uk
* * * * * * *

I understand that MO use (or used to use) a relative huidity of 95% as a
guide to the dividing line between between mist and haze.
Further distinction between mist and fog is an arbitrary one of visibility.
Fog when vis less than half a mile, greater then mist.
(Maybe it has changed to metric since my day!)
PeterJ

"Gianna" wrote in message
...
Joe Egginton wrote:
Gianna wrote:
Stuart wrote:
What causes haze, and how is it predicted?


dust, water vapour, etc..





It can be countered by adding a skylight filter.


Ah yes, I have a Hoya 1A somewhere ...
(last seen adorning my webcam since my 35mm kit is retired)

--
Gianna

http://www.buchan-meteo.org.uk
* * * * * * *

On Apr 16, 3:12 pm, "Stuart" wrote:
What causes haze, and how is it predicted?

Any solid particles in suspension. This in effect means
either dust or smoke. Water vapour cannot cause haze because it is
invisible.
Sometimes when the sun is seen through a thin high layer of
cloud this is referred to as hazy sunshine but this is incorrect. The
terms "watwery" or "milky" would be better. Met Office presenters
don't know what haze is, or at least are told not to know, just like
footballers with brains find life easier if they pretend they haven't
got them.

Tudor Hughes.

Tudor Hughes wrote:
On Apr 16, 3:12 pm, "Stuart" wrote:
What causes haze, and how is it predicted?

Any solid particles in suspension. This in effect means
either dust or smoke. Water vapour cannot cause haze because it is
invisible.


Most of the web definitions include either 'moisture' or 'water vapour', while
the OED has 'a thin mist caused by fine particles of dust, water vapour, etc."

Princeton Uni suggests "(n) haze: atmospheric moisture or dust or smoke that
causes reduced visibility"

In the interest of balance, the BBC suggests "Haze: Impaired visibility as a
result of smoke or dust."

Telemet suggests "Many haze formations are caused by the presence of an
abundance of condensation nuclei which may grow in size, due to a variety of
causes, and become mist, fog, or cloud."

Perhaps 'moisture' would be an acceptable term, or 'condensing water vapour'.

--
Gianna

http://www.buchan-meteo.org.uk
* * * * * * *

"Tudor Hughes" wrote in message
ups.com...
On Apr 16, 3:12 pm, "Stuart" wrote:
What causes haze, and how is it predicted?

Any solid particles in suspension. This in effect means
either dust or smoke. Water vapour cannot cause haze because it is
invisible.
Sometimes when the sun is seen through a thin high layer of
cloud this is referred to as hazy sunshine but this is incorrect. The
terms "watwery" or "milky" would be better. Met Office presenters
don't know what haze is, or at least are told not to know, just like
footballers with brains find life easier if they pretend they haven't
got them.

Tudor Hughes.

Thanks for that, so to sum up. If the particles in the air are dry then it
is Haze, If it is water then it is mist.

So how do forecasters forecast it ? Take last weekend, the weather models
were such that I would have expected perfect weather for the west highlands,
forecasters such as Geoff Monk warned of Haze, he was correct, lots of blue
sky but always hazey. How did he know, what prompted him to add the haze to
his forecast??